# NASASpaceFlight.com Forum

## General Discussion => New Physics for Space Technology => Topic started by: Chris Bergin on 11/30/2016 05:25 pm

Title: EM Drive Developments - related to space flight applications - Thread 9
Post by: Chris Bergin on 11/30/2016 05:25 pm
This is a thread - Thread 9 in the series - focused on objective analysis of whether the EM Drive (a cavity resonating at microwave frequencies) reported "thrust force" is an experimental artifact or whether it is a real propulsion effect  that can be used for space applications, and if so, in discussing those possible space propulsion applications.

Objective skeptical inquiry is strongly welcome.   Disagreements should be expressed politely, concentrating on the technical, engineering and scientific aspects, instead of focusing on people.   As such, the use of experimental data, mathematics, physics, engineering, drawings, spreadsheets and computer simulations are strongly encouraged, while subjective wordy statements are discouraged. Peer-reviewed information from reputable journals is strongly encouraged.  Please acknowledge the authors and respect copyrights.

In order to minimize bandwidth and maximize information content, when quoting, one can use an ellipsis (...) to indicate the clipped material.

Only use the embed [img ]http://code when the image is small enough to fit within the page. Anything wider than the width of the page makes the page unreadable as it stretches it (we're working on auto reduction, but different browsers work different ways, etc.)

http://math.typeit.org/

enables typing of mathematical symbols, including differentiation and integration, Greek letters, etc.

--

http://forum.nasaspaceflight.com/index.php?topic=29276.0

http://forum.nasaspaceflight.com/index.php?topic=36313.0

http://forum.nasaspaceflight.com/index.php?topic=37642.0

http://forum.nasaspaceflight.com/index.php?topic=38203.0

http://forum.nasaspaceflight.com/index.php?topic=38577.0

http://forum.nasaspaceflight.com/index.php?topic=39004.0

http://forum.nasaspaceflight.com/index.php?topic=39772.0

http://forum.nasaspaceflight.com/index.php?topic=40959.0
--

http://forum.nasaspaceflight.com/index.php?topic=37438.0

Baseline NSF Article:
http://www.nasaspaceflight.com/2015/04/evaluating-nasas-futuristic-em-drive/

This is the link to the EM Drive wiki that users are encouraged to contribute to, edit for accuracy, and build as a knowledge resource for the EM Drive:

http://emdrive.wiki
http://rfdriven.com

Chris note: Please note all posts need to be useful and worthwhile or they will be removed via moderation. This subject has large interest, with over 4.2 million thread reads and 880,000 article reads. Most people are reading and not posting, so when you post it is in front of a very large audience.

Also, and it should go without saying, amateur experiments are discouraged unless you have gained educated and/or professional advice for safety reasons.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Chris Bergin on 11/30/2016 05:34 pm
Right, a note from me.

1) All posts need to be useful and constructive.
2) Anyone attacking any other member in any form will result in their post being removed, without warning, and banned from posting. The forum rules here apply to all threads. I know most of you on this thread only read this subject.
3) Anyone repeating their argument in an attempt to promote it (known as bumping) will have their posts removed.
4) Stupid MEMEs and random pictures of ponies laughing as some sort of "humorous response" will be removed (although I really like horses).
5) If there is a problem post, don't post "Wow, why won't the moderators remove that" if you've not REPORTED TO MODERATOR. Don't quote bad posts.

--

Think really carefully before posting on this thread. If you see a breach of the above, report to moderator, it's the tab in the bottom right of the post in question.

How this thread goes will decide if there will be a thread 10, or at least one that isn't view only bar the good regular posters.

You've been warned! ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Josave on 11/30/2016 06:06 pm
This interesting article summarizes Lev A. Rivlin works on photon inertial mass and its relation to waveguide cross-section variations:

http://www.mathnet.ru/php/archive.phtml?wshow=paper&jrnid=qe&paperid=2500&option_lang=eng

Some ideas he proposes could shed light in other theories (say MiHsC) that need a physical mass equivalence for the amount of radiation confined in a cavity.

Photon rest mass exists when they are confined, is non-zero, and is determined by the geometry of the waveguide, and this mass can vary with the diameter. "Photon rest mass is equal to the work performed by an external force against the mode field force during the waveguide formation when the radiation pressure is 'raked' from infinite space (originally zero frequency or infinite wavelength) into the limited volume of the waveguide"...

..."The proper photon mass in the waveguide, defined as the equivalent of the energy mentioned above, serves in different situations precisely as the inertial and gravitational mass in the standard meaning of these concepts."

This is really a good starting point to do some engineering playing with diameters, frequencies and accelerations (Shawyer is indicating us that for observing a measurable thrust, there is necessary some initial acceleration). The recipe, more or less, could be to generate "stopped light", by modifying confinement geometries/cavity accelerations, so the radiation could leave inertia at rest.

"Equations (6.4) and (6.13) explain the difference between longitudinal and transverse masses: while both being proportional to the proper photon mass M, ML and MT are manifestations of the photon inertia in different types of accelerated waveguide motion. The longitudinal accelerated photon motion constitutes simply wave propagation with changing frequency through the waveguide. The transverse photon motion consists in the acceleration of the wave together with the waveguide confining it, as a whole".

This can be the explanation of different inertia if the EmDrive is in an upright position or in a lateral position respect to the external acceleration (or respect to Earth gravity). Following Lev A. Rivlin schema, could be possible to interchange or convert longitudinal mass into transverse mass, so the inertia is reduced for motion in one preferred direction, and CoM is not broken.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: InterestedEngineer on 11/30/2016 06:14 pm
Quote from: CorvusCorax
Just hypothetically, what happens if everyone flies around in those? With thrust forces in the kilonewton range.

If the EM drive creates its acceleration by "pushing against the quantum vacuum", would that yield measurable residual effects for matter riding the wake of an em drive? Like thrust fluctuations in another EM drive flying directly behind a first one, or measurable forces on masses that are placed in the thrust vector? Or spacetime distortions and eddies, like some proposed warp drive designs would create?

Could the presence and operation of an EM drive be detected from a distance?

(I know I'm mixing a lot of concepts here that have nothing directly to do with each other. Just food for thoughts)

In the just previous thread, this topic came up but was not replied to.  The QV hypothesis proponents have talked about a wake in the QV caused by an active EmDrive.   What are the implications of such a wake?

Just exactly how would one DETECT the hypothesized wake in the QV caused by an active EmDrive?

The only thing I can think of is another EmDrive directly behind a first EmDrive, which would act in the same way as a boat behind another boat in water, if the hypothesis is correct.

What other ways would you detect a wake in the QV?

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: LowerAtmosphere on 11/30/2016 07:06 pm
I assume you refer to Dr. White's QVP propulsion theory as outlined in http://www.lpi.usra.edu/meetings/nets2012/pdf/3082.pdf

Whether perturbations truly affect the QV and spread as a wake effect (at the speed of light presumably) is a matter of interpretation. As far as most QED is concerned, the QV responds linearly to perturbation by E+M fields. That is to say a wake, such as can be seen trailing and spreading out behind a boat passing through a body of water, does not appear according to classical theory since there is no significant interaction. Each stimulated point instantaneously changes at the same speed as the EM fields perturbing it. What is worth considering is a thought experiment in which ultra-high neutron star level M fields are generated in two points orbiting each other at high speeds. The QV will be perturbed at both extrema, will the perturbation be toroidal at sufficient speed or still have two distinct extrema i.e. does information in the QV propagate at the speed of light or slower? Will one strong field 'soften up' the QV for a slightly longer time period than a weak field?

Edit: I suppose I should further elaborate. Spacetime has a fluctuating stiffness, does QV? My question is not whether the QV is immutable or degradable but rather whether  it has a memory of sorts. I.e. can the threshold energy for QV plasma generation be lowered temporarily after exposure to high EM fields and what determines local ZPE fields in an empty/E+M fieldless universe? Note again that this differs from a wake as a wake would be governed by magnetohydrodynamics not QV inherent properties.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: therealjjj77 on 11/30/2016 07:35 pm
Have been considering ways to test my theory here:

http://forum.nasaspaceflight.com/index.php?topic=40959.msg1613281#msg1613281

And also some other comments have been given that lend toward theorizing that EM Drive may be producing gravitational waves(or I would say anti-gravity/creation of space).

Testing for this may be critical to confirming whether the EM Drive is producing a "gravity-like" affect for the following reasons:

1. Such an affect could create the impression of thrust without actual thrust occurring. This is because such an affect would "pull" or "push" on the measuring device giving a slight reading in the same way that an increase or decrease in gravity would impact measurements. That is not to say, however, that thrust had not been achieved, but that other testing methods would need to be developed to isolate if thrust is occurring.

2. Discovery of such an affect would have a profound impact on our understanding of gravity. The applications for technology that can impact gravity would be far-reaching.

3. Assuming such an affect was occurring AND thrust, in fact, was being produced, further study into this affect on the impact of the EM Drive may help develop more accurate calculations down the road.

Without calling up LIGO or building a smaller version of it, the easiest way to test for gravitational waves would be to have a 2nd scale or pendulum of identical orientation but not connected to the EM Drive. If the 2nd scale/pendulum shows a reading also, then we will know that the impact is from a gravity-like affect being produced.

IF the second scale/pendulum shows a reading, we can then deduce the thrust by finding the difference between the two scales.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 11/30/2016 08:15 pm
This interesting article summarizes Liv A. Rivlin works on photon inertial mass and its relation to waveguide cross-section variations:

http://www.mathnet.ru/php/archive.phtml?wshow=paper&jrnid=qe&paperid=2500&option_lang=eng

Some ideas he proposes could shed light in other theories (say MiHsC) that need a physical mass equivalence for the amount of radiation confined in a cavity.

Photon rest mass exists when they are confined, is non-zero, and is determined by the geometry of the waveguide, and this mass can vary with the diameter. "Photon rest mass is equal to the work performed by an external force against the mode field force during the waveguide formation when the radiation pressure is 'raked' from infinite space (originally zero frequency or infinite wavelength) into the limited volume of the waveguide"...

..."The proper photon mass in the waveguide, defined as the equivalent of the energy mentioned above, serves in different situations precisely as the inertial and gravitational mass in the standard meaning of these concepts."

The variation of the inertial mass of photons travelling in a tapered cavity has been claimed all along by Roger Shawyer, Mike McCulloch and Todd Desiato (WarpTech) using different theories :)

But Yikes! The available paper is in entirely in Russian but the abstract :\
Kvantovaya Elektronika articles are also edited in the journal Quantum ELectronics, but the English version is behind a paywall:

Rivlin, Lev A. (2003). "Stopped light: Towards plane-wave-free electrodynamics" (http://iopscience.iop.org/article/10.1070/QE2003v033n09ABEH002500), Quantum Electronics 33(9).
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Rodal on 11/30/2016 10:03 pm
This interesting article summarizes Lev A. Rivlin works on photon inertial mass and its relation to waveguide cross-section variations:

http://www.mathnet.ru/php/archive.phtml?wshow=paper&jrnid=qe&paperid=2500&option_lang=eng

Some ideas he proposes could shed light in other theories (say MiHsC) that need a physical mass equivalence for the amount of radiation confined in a cavity.

Photon rest mass exists when they are confined, is non-zero, and is determined by the geometry of the waveguide, and this mass can vary with the diameter. "Photon rest mass is equal to the work performed by an external force against the mode field force during the waveguide formation when the radiation pressure is 'raked' from infinite space (originally zero frequency or infinite wavelength) into the limited volume of the waveguide"...

..."The proper photon mass in the waveguide, defined as the equivalent of the energy mentioned above, serves in different situations precisely as the inertial and gravitational mass in the standard meaning of these concepts."

This is really a good starting point to do some engineering playing with diameters, frequencies and accelerations (Shawyer is indicating us that for observing a measurable thrust, there is necessary some initial acceleration). The recipe, more or less, could be to generate "stopped light", by modifying confinement geometries/cavity accelerations, so the radiation could leave inertia at rest.

"Equations (6.4) and (6.13) explain the difference between longitudinal and transverse masses: while both being proportional to the proper photon mass M, ML and MT are manifestations of the photon inertia in different types of accelerated waveguide motion. The longitudinal accelerated photon motion constitutes simply wave propagation with changing frequency through the waveguide. The transverse photon motion consists in the acceleration of the wave together with the waveguide confining it, as a whole".

This can be the explanation of different inertia if the EmDrive is in an upright position or in a lateral position respect to the external acceleration (or respect to Earth gravity). Following Lev A. Rivlin schema, could be possible to interchange or convert longitudinal mass into transverse mass, so the inertia is reduced for motion in one preferred direction, and CoM is not broken.

These ideas to apportion mass from the field into particles go a long way back.  To the great physicist Leon Brillouin, for example.  The idea of an electromagnetic mass goes even further in time.

However, nowadays the prevailing mainstream viewpoint is that apportioning mass to particles is not the best way to go.  The mainstream viewpoint is that all fields carry mass.  It is not just due to energy, that there is a mass, but also due to stress.   It should all be contained in the stress-energy tensor that carries the field.

The fields carry mass because they carry momentum, therefore the field that carries electromagnetic pressure also carries a mass associated with the pressure.  And they also carry energy, since E=mc^2, therefore mass.

This is preferable to thinking of a magic mass associated with particles like photons that should not have any rest mass.

The very old (it goes back 100 years) viewpoint of apportioning mass from the field to particles (although still works if one includes all terms in the equations of motion) suffers from the arbitrariness of having to apportion somehow also the cross-contribution from several interacting particles, and it also suffers from the viewpoint that we know from Quantum Mechanics that particles (also photons) are both particle and wave, and not confined to a point in space.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: CorvusCorax on 11/30/2016 10:26 pm
As shown with the plate-gap experiment, the quantum vacuum can excert a pressure force on matter. This pressure force is normally uniform and undirected. If  an EM drive can however impart momentum to the quantum vacuum - similar to how a photon drive would impart momentum on spacetime - then it follows that the quantum vacuum could in turn impart momentum on matter - just like a lightsail would with electromagnetic momentum.

It would be very likely that general relativity applies and quantum vacuum fluctuation moment speed is limited by light speed.

If virtual particles had more than one interaction within their lifetime, this would be relatively easy to model. A virtual particle spawns, receives momentum from the EM drive, tranfers this momentum to a real particle, then recombines. As such the effect would be just like a real photon emmitted by a light-source and then bounced by a lightsail

It gets more complcated if the distance to the next real particle is longer than the lifetime of the virtual particle. To conserce the momentum, the virtual particle would at least have to pass on this property to another virtual particle - for example by recombining with its anti that travels the opposite way and as such still leaving a net momentum in the quantum vacuum.

If this is the case, then the EM drive would likely put unidirectional quantum pressure equal to its thrust force on the sum of all matter that happens to get into this virtual-particle-beam.  But depending on the average energy of these virtual photons, some matter might simply be translucent. Just like glass makes a bad light-sail material for visual light photons

We could make the bold assumption, that an EM drive would impart the most momentum on virtual particles with the same energy as its in-chamber photons. As such this "virtual ray" would have microwave wavelengths and should affect metal reflectors. While this might not necessarily hold, one could test this relatively easily

Mount a stationary EM "drive" (aka virtual ray generator) next to a frustum
Mount a microwave reflector on the frustum in such a way that a "real" photon source if it was in place of the EM drive would cause a force on it.

Measure if the EM drive can put an acceleration force on this free remote receiver

If this works, it would create alot of new cool applications for EM drives.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Josave on 11/30/2016 10:43 pm

The very old (it goes back 100 years) viewpoint of apportioning mass from the field to particles (although still works if one includes all terms in the equations of motion) suffers from the arbitrariness of having to apportion somehow also the cross-contribution from several interacting particles, and it also suffers from the viewpoint that we know from Quantum Mechanics that particles (also photons) are both particle and wave, and not confined to a point in space.

This is interesting. The generalization of the 2-particles mechanics to the n-particles is the Hamiltonian mechanics. Roughly said, in this mechanics the invariant is no longer Conservation of Momentum, but the quantity conserved is the observable G, a function not only of the mass of the n-particles, but also of the inter-distances of all the particles of the system.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: zellerium on 11/30/2016 10:50 pm
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Rodal on 11/30/2016 11:45 pm
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...
The conventional type of Finite Element Method formulation always converges from above, always stiffer than an exact solution .
If you are comparing with the experimental resonance frequency, it makes sense it would be 1.5% stiffer (higher frequency) because of the finite mesh.  It also depends on the order of the basis functions used in the finite elements.  Are you able to choose finite elements with higher order polynomial basis functions?

The fields on the small base look better defined than in the FEKO model shown in thread 8
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Bob Woods on 11/30/2016 11:54 pm
In regards to NASA's apparent lack of funding for more research and testing, is there any bureaucratic will to allow outside funding from GoFundMe or Kickstarter, administered through NASA?

While Dave and Shell and other DIY'ers have received some funding, with an imprimatur from NASA with plenty of caveats about experimental risks, I could see hundreds of thousands being raised without much trouble.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 12:14 am
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...

The results of the diagrams make sense according to my theory. The majority of energy is at the big end, and the majority of the losses are at the small end. So the gradient is from big to small and so the frustum moves the other way. Big end leading. No argument from me! Looks great!
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Stormbringer on 12/01/2016 12:21 am
In regards to NASA's apparent lack of funding for more research and testing, is there any bureaucratic will to allow outside funding from GoFundMe or Kickstarter, administered through NASA?

While Dave and Shell and other DIY'ers have received some funding, with an imprimatur from NASA with plenty of caveats about experimental risks, I could see hundreds of thousands being raised without much trouble.
I believe Paul has been asked that before. I think he said it was highly problematic if not impossible under current regulations or laws.  :(
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Donosauro on 12/01/2016 12:28 am
In regards to NASA's apparent lack of funding for more research and testing, is there any bureaucratic will to allow outside funding from GoFundMe or Kickstarter, administered through NASA?

While Dave and Shell and other DIY'ers have received some funding, with an imprimatur from NASA with plenty of caveats about experimental risks, I could see hundreds of thousands being raised without much trouble.

I have read that, while NASA can accept donations, the donor(s) cannot specify what the funds are to be used for. It would be just as if NASA's budget had been increased by the amount of the donation.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 01:09 am
Amazing what you can get from Amazon, cheap! The frequency of the small one is too high, but the bucket is almost perfect with a big adjustable end plate at the right spot. It's SS, so it needs to be a little more "round" and polished and plated before it's useful, but it's a lot easier than making one from scratch. I may yet go for a double-walled ice tub, so I can pump coolant around the outside and use it as a heatsink for the RF amplifier.

Data from @X_RaY.
epsilon res   1,0001
DS in mm   190,5
DB in mm   292,1
z in mm   266,7

Theta in °   10,7843

Solutions of equation system 2
Mode   f in GHz
TE011   1,590
TE012   1,912
TE013   2,279
TE014   2,711

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: rq3 on 12/01/2016 01:59 am
In regards to NASA's apparent lack of funding for more research and testing, is there any bureaucratic will to allow outside funding from GoFundMe or Kickstarter, administered through NASA?

While Dave and Shell and other DIY'ers have received some funding, with an imprimatur from NASA with plenty of caveats about experimental risks, I could see hundreds of thousands being raised without much trouble.

Give it a shot! The issue with sites like KickStarter is that the funders get something for their money. It may be a tee-shirt, or a 3 hour trip to Earth's moon. Just don't make promises that you cannot fulfill. In that case, at least under KickStarter terms, everyone gets nothing except a waste of time.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/01/2016 03:21 am
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...

Is there any force vector in there showing which way it is going?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/01/2016 03:31 am
There are many ways to light a fire, from sparks to blow torch. If we have no idea how the emdrive makes sparks, we have little chance to graduate from sparks to blow torch. The number of parameters involved makes the empirical exploration way too long. We need some theoretical idea of what we are trying to achieve, and this is the causal structure....

These em waves each carry a Planck quantum of action h. What is the Planck of action? Nobody really knows. Here, the Planck h quantum of action is assumed as a being a time rate differential of a specific amount. Furthermore, in the em wave, this differential is spread in half above and below the local rate of time; 1/2h above and 1/2h below.  This describes the em waves as travelling variations in the rate of time. (Which is what?)

Earlier, I presented the rate of time as “per second” or 1/T. We may retrieve this rate of time from simple laws of induction. For example,   E = dB/dT   or  E/dB = 1/dT. An increase of the denominator dT actually means a decrease of the rate of time 1/T. The delta may be applied to the whole fraction if it is taken as the rate of time. Then, E/dB = d 1/T, a variation in the rate of time. This describes an em wave as a travelling variation of the magnetic field  conjugated by a constant electric loop field. But, there is also B = dE/dT  which suggests another model, equally valid, where the electric field varies while its conjugation magnetic loop field remains constant. This somehow suggests the existence of two types of em waves; one as a variation of the electric field and the other as a variation of the magnetic field. It is possible that reflection of an em wave upon a metallic surface changes it by induction from an electric field variation to a magnetic field variation or vice versa?

Now, let’s talk about the actual structure of the em wave. We have a sine wave with higher and lower rates of time. Which one comes first? In a gravitational field, an object move (fall) spontaneously toward a lower rate of time. We will then place the lower half of the time rate h in the front portion of the sine wave so that it moves toward it. What about the higher half of the time rate? If an object moves spontaneously toward a relatively lower time rate, it is assumed that it would spontaneously move away from a relatively higher time rate. Therefore, the higher time rate will fit nicely at the back of the em sine wave. Now, the higher time rate provides a cause for moving away from a place while the lower time rate provides a cause for moving toward another place. This combination of higher and lower time rate I call a “causal structure”. This is what makes the em wave move away from one place but also makes it move toward another place. In other words, it makes the em wave move, and move in a straight line. So, the Planck value is not just a number; it is an actual time rate differential structure for the quantum of action or movement. Better, it is a self contained structure having the properties of a wave and the properties of a finite quantity (Quantum) or a particle, both leading to the concept of a soliton wave.

Now, to the emdrive.  Every em wave contains the Planck quantum of action, momentum or pilot wave; the causal structure for motion. While working with these em waves, we are trying to impart, somehow, the Planck structure of these em waves to the cavity. As such, it is not enough. The em drive experiment must create a larger causal structure from the power injected. It has to produce a causal structure for the whole drive, and more.

As discussed before, the spontaneous motion in a gravitational field is an entropic event. Objects falling into a gravitational field actually fall into larger “space”, which means a lower power. (Same energy, now into a larger space is the normal direction of entropy) Then, the causal structure could be in the form of a differential in energy or in the “space” container that holds it. Now, “space” is but a concept used to represent time following the ratio of “c”, the speed of light; “c” is but a conversion ratio from time to space, for our use, in our reality.
So, the emdrive is supposed to produce, among other thing, a differential in the time (length) container for the whole drive....

IMO, this requires the emdrive to produce an em wave in one direction, not a standing wave. I mean, all the power should go into a wave without return, not a standing wave. A kind of wave generated and captive from its center, not shot from one end of the cavity. In other words, we have to produce a wave from its center, not from one end. A sort of rectified dipole.  As such the “cavity” would not be required anymore.

How do we produce such unidirectional captive wave structure? (Reminds me of the Pares fractal antenna)  Any induction process would produce a free to move away em wave. So, we can’t build directly the unidirectional captive wave (cuws) by induction of a resonant circuit. The wave structure has to be built and maintained as two adjacent separate portions. We could think of two axial (wrt direction of motion) static electric fields in opposite directions and insulated from one another. For increased energy we might insert some dielectric material. Then, we would have formed two capacitors.(Woodward?)

I think that such a cuws appears or emerges as a non-steady, low level side effect in various experiments and configurations, including the emdrive. The idea now would be to produce it on purpose with the appropriate configuration. But, can we produce directly this cuws or do we have to resort to producing it as an optimized side effect of some more complex process (like in the emdrive)? Pares, using a radio wave generator, is possibly optimizing a cuws produced as a side effect of his special fractal antenna. Woodward, working with capacitors, could be directly forming a small cuws, but inefficiently.

Food for thought .....
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 04:04 am
...
IMO, this requires the emdrive to produce an em wave in one direction, not a standing wave. I mean, all the power should go into a wave without return, not a standing wave. A kind of wave generated and captive from its center, not shot from one end of the cavity. In other words, we have to produce a wave from its center, not from one end. A sort of rectified dipole.  As such the “cavity” would not be required anymore.

How do we produce such unidirectional captive wave structure? (Reminds me of the Pares fractal antenna)  Any induction process would produce a free to move away em wave. So, we can’t build directly the unidirectional captive wave (cuws) by induction of a resonant circuit. The wave structure has to be built and maintained as two adjacent separate portions. We could think of two axial (wrt direction of motion) static electric fields in opposite directions and insulated from one another. For increased energy we might insert some dielectric material. Then, we would have formed two capacitors.(Woodward?)

I think that such a cuws appears or emerges as a non-steady, low level side effect in various experiments and configurations, including the emdrive. The idea now would be to produce it on purpose with the appropriate configuration. But, can we produce directly this cuws or do we have to resort to producing it as an optimized side effect of some more complex process (like in the emdrive)? Pares, using a radio wave generator, is possibly optimizing a cuws produced as a side effect of his special fractal antenna. Woodward, working with capacitors, could be directly forming a small cuws, but inefficiently.

Food for thought .....

What you are describing here at the end, I interpret as nothing more than a photon rocket, using 1/4-wave phased array antennas. It has been discussed by @dustinthewind and I many times in previous threads. Without the resonant Q factor, it can never achieve a thrust greater than a photon rocket. The resonance is what allows it to store enough energy to push against and exchange momentum.

Also, Planck's constant of action is just the magnetic flux quanta I've been talking about in my theory. I suggest you review the Lorentz Gauge wave equations, where the wave equations are easily separated and much easier to follow, especially for an EmDrive. The conservation of energy and momentum, as well as general covariance is inherent in these equations. "IF" it can be explained in this way with the addition of a dissipation factor, there can be no argument. That's what I'm working on.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: therealjjj77 on 12/01/2016 04:32 am
In a gravitational field, an object move (fall) spontaneously toward a lower rate of time. We will then place the lower half of the time rate h in the front portion of the sine wave so that it moves toward it. What about the higher half of the time rate? If an object moves spontaneously toward a relatively lower time rate, it is assumed that it would spontaneously move away from a relatively higher time rate.
Though this observation("objects being attracted toward lower time rates") may be true, it might not be causative. Suppose we had 2 clocks. One clock was in space with no or little gravitational fields acting on it and of the same velocity of a particular planet. The second clock was in free fall toward the planet. Both clocks would experience time the same. The only situation where time gets slowed(relatively speaking) is if the 2nd clock were in the gravitational field but not in free fall. Therefore, it might not go to reason that time effects are causative of gravity but that they are a result of gravity.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Star-Drive on 12/01/2016 04:53 am
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...

The results of the diagrams make sense according to my theory. The majority of energy is at the big end, and the majority of the losses are at the small end. So the gradient is from big to small and so the frustum moves the other way. Big end leading. No argument from me! Looks great!

Todd:

"So the gradient is from big to small and so the frustum moves the other way. Big end leading."

The documented force vector for the EW copper frustum with 2-PE discs driving the TM212 mode is from the frustum's large OD to small OD, so the small end is leading.  Sorry...

Best, Paul M.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: nukus on 12/01/2016 04:53 am
I'm been thinking a bit recently about how the N/kw of the Emdrive compares to existing engines and what level would be required to match them in performance. In his Emdrive website, on the page for Second Generation Drives, Shawyer mentions drives at the kN/kW level, but this seems like more of an upper limit since that is the amount that would be required for flight/hover, but it doesn't require that much to make something that could fly with wings if we are talking about something much closer to the Wright Brothers than modern spacecraft. I seem to recall that some WWI and/or WWII planes basically used car engines to power them, so I'm wondering what N/kw would be required to match various engines. Seems like the Emdrive power-to-weight ratio may be useful here.

As for spaceflight applications, this seems useful to know as it seems like an Emdrive powered plane could serve as a launch platform for satellites and such, even if it say can't function in a vacuum well enough or is limited to being close to the Earth or are severely limited in how fast they can go (rapid dropoff in acceleration as they increase velocity) due to some quirk on how the drive functions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 05:41 am
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...

The results of the diagrams make sense according to my theory. The majority of energy is at the big end, and the majority of the losses are at the small end. So the gradient is from big to small and so the frustum moves the other way. Big end leading. No argument from me! Looks great!

Todd:

"So the gradient is from big to small and so the frustum moves the other way. Big end leading."

The documented force vector for the EW copper frustum with 2-PE discs driving the TM212 mode is from the frustum's large OD to small OD, so the small end is leading.  Sorry...

Best, Paul M.

It would seem then that the graphs of Surface Force density and Volume Loss Density provided by @zellerium are not an accurate representation of what is going on in the EW frustum. Just looking at these graphs, I think anyone would expect the frustum to go the other way.

I can understand it having the small end leading, because it is evident that the magnetic field is primarily heating the big end, so I would expect the higher losses to be at the big end as I've said before. However, the graphs show the higher Volume Loss Density at the small end and "nothing" at all at the big end. I think this should not be the case.

Perhaps the graphics need to show Surface loss not Volume loss to see this accurately?

Thanks!
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 06:35 am
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...

The results of the diagrams make sense according to my theory. The majority of energy is at the big end, and the majority of the losses are at the small end. So the gradient is from big to small and so the frustum moves the other way. Big end leading. No argument from me! Looks great!

According to radiation pressure theory,  the end plate with the shortest 1/2 wave has the highest momentum & radiation pressure.  So would expect static force direction, with the dielectric, to be big to small as Paul measured.

When the dielectric is removed, the wave patterns reverse, with the shortest 1/2 wave at the big end. Measured static force direction also reverses being small to big, as Paul, Roger and I measured.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: OnlyMe on 12/01/2016 08:04 am
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...

The results of the diagrams make sense according to my theory. The majority of energy is at the big end, and the majority of the losses are at the small end. So the gradient is from big to small and so the frustum moves the other way. Big end leading. No argument from me! Looks great!

According to radiation pressure theory,  the end plate with the shortest 1/2 wave has the highest momentum & radiation pressure.  So would expect static force direction, with the dielectric, to be big to small as Paul measured.

When the dielectric is removed, the wave patterns reverse, with the shortest 1/2 wave at the big end. Measured static force direction also reverses being small to big, as Paul, Roger and I measured.

Some how me thinks, it would be a good idea if you were to agree on a definition of force and thrust that at least seems consistent with. What the definitions that others in these discussions seem to use. Maybe I am just really tiered but it sounds like your expected direction of thrust is not consistent with what Star-Drive just posted a bit earlier.

Yes, there was some issue between what WarpTech's theory predicted (or so it seems) and Paul's clarification, but your post above just seems confusing.

Right now that may be all me, tired and ..... maybe it is just me but the way you describe whatever you are trying to say just seems confused or confusing.

I am sure the same applies to much of what I post, but at present for reasons that have nothing to do with the subject at hand, it is what it is and just remains a bit beyond my control.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 09:41 am
EW's TM212 Frustum, Cu walls (5.8E7 S/m) Polyethylene disc (eps_r = 2.25) using eigenmode solver
Frequency was 1.97 GHz, not 1.94 , maybe due to antenna, small distortions in copper walls etc ???

Interesting results...

The results of the diagrams make sense according to my theory. The majority of energy is at the big end, and the majority of the losses are at the small end. So the gradient is from big to small and so the frustum moves the other way. Big end leading. No argument from me! Looks great!

According to radiation pressure theory,  the end plate with the shortest 1/2 wave has the highest momentum & radiation pressure.  So would expect static force direction, with the dielectric, to be big to small as Paul measured.

When the dielectric is removed, the wave patterns reverse, with the shortest 1/2 wave at the big end. Measured static force direction also reverses being small to big, as Paul, Roger and I measured.

Some how me thinks, it would be a good idea if you were to agree on a definition of force and thrust that at least seems consistent with. What the definitions that others in these discussions seem to use. Maybe I am just really tiered but it sounds like your expected direction of thrust is not consistent with what Star-Drive just posted a bit earlier.

Yes, there was some issue between what WarpTech's theory predicted (or so it seems) and Paul's clarification, but your post above just seems confusing.

Right now that may be all me, tired and ..... maybe it is just me but the way you describe whatever you are trying to say just seems confused or confusing.

I am sure the same applies to much of what I post, but at present for reasons that have nothing to do with the subject at hand, it is what it is and just remains a bit beyond my control.

See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.

Paul, Roger and I, with non dielectric frustums, measured a static force  direction small to big or big end forward as per the left side images.

Paul, with a dielectric containing frustum,  measured a static force direction big to small or small end forward as per the right side images.

It should be noted that the small to big non dielectric force direction, left side images, was in the opposite direction to the Lorentz and CG heating generated forces, which says that while there were Lorentz and CG alerting heating forces present, they did not generate the small to big impulse force measured. That force was generated by the EmDrive WITHOUT a dielectruc.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 10:58 am
For those considering building a YBCO based frustum, as I am, here are 2 interesting graphs:

1st is 2015 data showing max H field vs temp vs various superconductors. From this data it would seem that YBCO is the champ material for dealing with high H field, which suggests it can handle very high Q frustum builds.

2nd is 2009 data from Roger Shawyer showing YBCO Rs vs various temperatures at 3.85GHz. Note that the ~78uOhm value in 2009 is now 3uOhm in 2016.

While LNe is somewhat expensive, it does appear to offer a 5x lower Rs (5x higher Q) and 2.5x higher max Hc so maybe worth giving it a shot?

For sure design for LN2 and if you need to go further maybe consider LNe instead of LH2 or LHe?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Willem Staal on 12/01/2016 11:27 am
For those considering building a YBCO based frustum, as I am, here are 2 interesting graphs:

1st is 2015 data showing max H field vs temp vs various superconductors. From this data it would seem that YBCO is the champ material for dealing with high H field, which suggests it can handle very high Q frustum builds.

2nd is 2009 data from Roger Shawyer showing YBCO Rs vs various temperatures at 3.85GHz. Note that the ~78uOhm value in 2009 is now 3uOhm in 2016.

While LNe is somewhat expensive, it does appear to offer a 5x lower Rs (5x higher Q) and 2.5x higher max Hc so maybe worth giving it a shot?

For sure design for LN2 and if you need to go further maybe consider LNe instead of LH2 or LHe?
YBCO is a ceramic compound. The gap to excitations that leads to superconductivity is a result of pairs of electrons (or other fermions) bound together at (very) low temperatures, and thats in the case of ceramic superconductors usualy a surface effect. If a magnetic field is close to  these type of  superconductors  the effect will be lost. (meissner ochsenfeld effect)  as the frustrum works with a crude coil as rf transmitter , so how does Shawyer prevent magnetic interference and loss of superconductivity?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/01/2016 11:31 am
See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.

TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.

Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.

Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 11:55 am
See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.

TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.

Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.

Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.

We only have data for TE012 for both dielectric and non dielectric forces and direction.

It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.

As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed.

Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.

I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.

Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.

The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.

Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/01/2016 12:07 pm
Fair enough, let's discuss your "shorter vs longer 1/2 wave" conjecture.
You're saying that as the EM wave travels towards a larger space (to the big end in a frustum without dielectric) its wavelength decreases and the carried momentum increases. Conversely when the EM wave travels towards small end, its wavelength increases and the carrier momentum decreases.
This is all swapped with the PE discs at small end in Eagleworks frustum, where wavelength becomes larger at big end and smaller at small end, hence thrust reverses.

This is measured along the axis of the frustum.

But have you considered that when the zenith component of the wavelength indeed increases as you claim, its radial component locally decreases accordingly (and the opposite at the other side) so the wavelength as a whole keeps the same value everywhere, as pointed out by WarpTech in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1612667#msg1612667):
Quote from: WarpTech
1. The radial wavelength is longer toward the small end and shorter toward the big end.
2. The zenith wavelength is longer toward the big end and shorter toward the small end.
3. The sum of the squares of the two frequencies at each end is the square of the resonant frequency, and supposedly constant.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 12:36 pm
Fair enough, let's discuss your "shorter vs longer 1/2 wave" conjecture.
You're saying that as the EM wave travels towards a larger space (to the big end in a frustum without dielectric) its wavelength decreases and the carried momentum increases. Conversely when the EM wave travels towards small end, its wavelength increases and the carrier momentum decreases.
This is all swapped with the PE discs at small end in Eagleworks frustum, where wavelength becomes larger at big end and smaller at small end, hence thrust reverses.

This is measured along the axis of the frustum.

But have you considered that when the zenith component of the wavelength indeed increases as you claim, its radial component locally decreases accordingly (and the opposite at the other side) so the wavelength as a whole keeps the same value everywhere, as pointed out by WarpTech in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1612667#msg1612667):
Quote from: WarpTech
1. The radial wavelength is longer toward the small end and shorter toward the big end.
2. The zenith wavelength is longer toward the big end and shorter toward the small end.
3. The sum of the squares of the two frequencies at each end is the square of the resonant frequency, and supposedly constant.

As guide wavelength increases, group velocity decreases and radiation pressure decreases.
As guide wavelength decreases, group velocity increases and radiation pressure increases.

This has been known since 1951 via the work of Cullen.

It seems that placing a non resonant dielectric at the small end of the frustum, reverses the normal non dielectric guide wavelength distribution and causes the static force direction to swap to follow the longest 1/2 guide wavelength end to the shortest 1/2 guide wavelength end.

BTW freq does not alter inside a resonant cavity. Only guide wavelength, group velocity and radiation pressure alter.

Please continue to explore theory options, just be sure they fit the observed and measured experimental data.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/01/2016 12:51 pm
increasing the "guide wavelength" somewhere doesn't mean the wavelength of the traveling EM waves increases in that particular location?

Wait… all this time thinking Shawyer was saying the EM wavelength was varying, but all is varying is the guide wavelength which has a purely geometrical definition and has nothing to do with the actual EM wavelength variation? ???
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 01:05 pm
increasing the "guide wavelength" somewhere doesn't mean the wavelength of the traveling EM waves increase in that particular location?

The displayed standing wave is just the superposition of the 2 travelling waves. It has no reality without the 2 travelling waves as attached. It is a GIF file so click it to see the waves move.

So if the standing wave shows longer 1/2 guide waves at one end versus the other, the travelling waves must be doing the same thing as the standing wave is just their reflection.

BTW here is the E and H field distribution in my spherical frustum. I have NO DOUBT when placed on a scale, that frustum will generate a static force with a direction small to big.

Paul observed this non dielectric force direction as did Roger and as did I.

As I said, please explore theory options as long as the predicted force direction matches the experimental data with a non resonant dielectric at the small end and without.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/01/2016 01:30 pm
So if the standing wave shows longer 1/2 guide waves at one end versus the other, the travelling waves must be doing the same thing as the standing wave is just their reflection.

This sentence sounds to me as a hint towards a local variation of the wavelength. If so how could the 1/2 wave become longer at one end and shorter at the other end? Please confirm or deny my statement.

BTW here is the E and H field distribution in my spherical frustum. I have NO DOUBT when placed on a scale, that frustum will generate a static force with a direction small to big.

But you'd also admit according to your sketch that your frustum, when free to move, will accelerate small end leading (Shawyer's reaction force). I emphasis on that since it confuses everyone.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/01/2016 01:38 pm
In a gravitational field, an object move (fall) spontaneously toward a lower rate of time. We will then place the lower half of the time rate h in the front portion of the sine wave so that it moves toward it. What about the higher half of the time rate? If an object moves spontaneously toward a relatively lower time rate, it is assumed that it would spontaneously move away from a relatively higher time rate.

Though this observation("objects being attracted toward lower time rates") may be true, it might not be causative. Suppose we had 2 clocks. One clock was in space with no or little gravitational fields acting on it and of the same velocity of a particular planet. The second clock was in free fall toward the planet. Both clocks would experience time the same. The only situation where time gets slowed(relatively speaking) is if the 2nd clock were in the gravitational field but not in free fall. Therefore, it might not go to reason that time effects are causative of gravity but that they are a result of gravity.

This is where I usually pull my Unruh quote:

‘ .. A more accurate way of summarizing the lessons of General Relativity is
that gravity does not cause time to run differently in different places (e.g., faster far from the earth than near it). Gravity is the unequable flow of time from place to place. It is not that there are two separate phenomena, namely gravity and time and that the one, gravity, affects the other. Rather the theory states that the phenomena we usually ascribe to gravity are actually caused by time’s flowing unequably from place to place...  “   arXiv:gr-qc/9312027v2 17 Dec 1993  (my bold)

People often offer some GR gedanken which I personally find hard to follow..

[ I met Bill Unruh in Montreal in 2004 (?) at a conference... Big lumberjack style of a man .. did not go for my approach which has a pilot wave flavor he did not go for. ... 2016: Pilot waves are back.... ]

https://www.wired.com/2014/06/the-new-quantum-reality/

... and a few more arxiv articles easy to find..
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 01:53 pm
So if the standing wave shows longer 1/2 guide waves at one end versus the other, the travelling waves must be doing the same thing as the standing wave is just their reflection.

This sentence sounds to me as a hint towards a local variation of the wavelength. If so how could the 1/2 wave become longer at one end and shorter at the other end? Please confirm or deny my statement.

BTW here is the E and H field distribution in my spherical frustum. I have NO DOUBT when placed on a scale, that frustum will generate a static force with a direction small to big.

But you'd also admit according to your sketch that your frustum, when free to move, will accelerate small end leading (Shawyer's reaction force). I emphasis on that since it confuses everyone.

According to radiation pressure theory, the big to small accelerative force is the equal but opposite Reaction force to the small to big static Thrust force.

Roger has told me you can't measure a static force from the Reaction force as it can only be measured during free acceleration via F = A * M.

What Paul, Roger, and myself measure on a virtually non moving ( OK a few um of movement ) static force test rig is the Thrust force generated as the result of the differential of the end plate radiation pressure, adjusted for side wall radiation pressure.

Roger has clearly shown these two force directions being generated as the test rig alters from static to dynamic as attached.

By end 1st qtr 2017 I hope to be able to duplicate both the static force measurements and the dynamic force measurements, plus measuring Q drop (photon momentum drop) as acceleration starts and the change in power supply load as the rotary test rig increases angular velocity from 0 RPM to 60 RPM over 40 minutes or so.

That data will be a biggie as it should experimentally answer a few questions such as CofM and CofE.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 02:10 pm
See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.

TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.

Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.

Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.

We only have data for TE012 for both dielectric and non dielectric forces and direction.

It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.

As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed.

Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.

I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.

Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.

The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.

Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.

TT,

For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 02:13 pm
Another article from Ethan Seigal on the Forbes website:

http://www.forbes.com/sites/startswithabang/2016/11/30/could-dark-matter-be-powering-the-emdrive/#25e019901e53

Interesting conjecture that instead of pushing against the QV (which Woodward tells us the EMDrive can't do), the drive is instead expelling dark matter like a normal rocket through photon-axion interaction.

"How would it work? At any point in time, there are dark matter particles passing through all regions of space, undeterred by the presence of matter or other Standard Model particles. Inside the electromagnetic cavity, photons of a particular frequency bounce around in all directions, conserving momentum and generating no thrust. But if photons moving in a particular direction — towards the ‘back’ of the cavity, for example — are likely to strike a dark matter particle, three things ensue:

1) The photon changes momentum, and moves “less backwards” and “more forwards” than before it struck the dark matter particle.
2) The photon strikes the inside wall of the cavity, reflecting off of it and imparting its momentum in the forward direction to the cavity itself.
3) The struck dark matter particle gains momentum as well in the opposite direction: backwards.

Momentum is conserved because the dark matter carries it away, equal and opposite in magnitude to what the cavity absorbs."

I think it is much more likely and practical, that momentum is carried into the copper and through it by magnetic flux, which pass through due to the voltage drop (losses) from resistance and current.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: OnlyMe on 12/01/2016 02:32 pm
For those considering building a YBCO based frustum, as I am, here are 2 interesting graphs:

1st is 2015 data showing max H field vs temp vs various superconductors. From this data it would seem that YBCO is the champ material for dealing with high H field, which suggests it can handle very high Q frustum builds.

2nd is 2009 data from Roger Shawyer showing YBCO Rs vs various temperatures at 3.85GHz. Note that the ~78uOhm value in 2009 is now 3uOhm in 2016.

While LNe is somewhat expensive, it does appear to offer a 5x lower Rs (5x higher Q) and 2.5x higher max Hc so maybe worth giving it a shot?

For sure design for LN2 and if you need to go further maybe consider LNe instead of LH2 or LHe?
YBCO is a ceramic compound. The gap to excitations that leads to superconductivity is a result of pairs of electrons (or other fermions) bound together at (very) low temperatures, and thats in the case of ceramic superconductors usualy a surface effect. If a magnetic field is close to  these type of  superconductors  the effect will be lost. (meissner ochsenfeld effect)  as the frustrum works with a crude coil as rf transmitter , so how does Shawyer prevent magnetic interference and loss of superconductivity?

Very good question(s). From what I have read in these discussions and the limited information available from a few of Shawyer's papers/patent, upscalling the frustum to a superconducting cryogenic design is based on an assumption that high Q is the dominant factor in developing high thrust. Without any published experimental data involving a superconducting EmDrive design, it appears to me to be a theoretical leap of faith.

So the short answer is there seems to be a race by some to try and be the first, which demands an almost blind faith in conclusions based on flawed or incomplete theoretical interpretations of .....

I do tend to run on and often present off the wall observations and interpretations of my own, so in the spirit of old maps, "be warned beyond here there be dragons!"

As a non-expert in any of the areas specific to the design and construction of a functional device, and based only on what understanding I have been able to tease out of these discussions, it would seem far more productive to refine a room temperature design which if which of what information that has been made available should be able to developed thrusts in the Newton/Kw range, before chasing what seems purely theoretical upscalling based on what at present is very limited published data from mostly 1st to perhaps 3rd generation engineering attempts to recreate poorly described devices claiming up to triple digit mN/Kw results.

Any device that could consistently produce triple digit mN/Kw thrusts at room temperatures, would provide a far better basis for exploring any functionally measurable design and/or materials based aspects contributing to those results.

Right now from a peanut gallery observer, without better design blueprints from previously successful experiments, chasing superconducting promises of multi ton thrusts, just seems foolish.

The EW paper seems to have provided the first reliable data demonstrating repeatable thrust, but unless I am mistaken the frustum design and TM mode, in those tests, do not represent the only or perhaps even best approach, for obtaining higher room temperature thrusts.

Also I believe in Shawyer's last partnership patent, only the large flat end plate was coated with a superconducting material.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 02:35 pm
Here is something to consider.

If we input 1kW of Rf, the radiated heat energy by the frustum side walls and end caps is max 1kW of heat energy, minus any other energy conversions that may occur.

So there should be NO significant effect on sidewall and end plate eddy currents and the resultant heating as cavity Q increases.

Phil
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 02:42 pm
For those considering building a YBCO based frustum, as I am, here are 2 interesting graphs:

1st is 2015 data showing max H field vs temp vs various superconductors. From this data it would seem that YBCO is the champ material for dealing with high H field, which suggests it can handle very high Q frustum builds.

2nd is 2009 data from Roger Shawyer showing YBCO Rs vs various temperatures at 3.85GHz. Note that the ~78uOhm value in 2009 is now 3uOhm in 2016.

While LNe is somewhat expensive, it does appear to offer a 5x lower Rs (5x higher Q) and 2.5x higher max Hc so maybe worth giving it a shot?

For sure design for LN2 and if you need to go further maybe consider LNe instead of LH2 or LHe?
YBCO is a ceramic compound. The gap to excitations that leads to superconductivity is a result of pairs of electrons (or other fermions) bound together at (very) low temperatures, and thats in the case of ceramic superconductors usualy a surface effect. If a magnetic field is close to  these type of  superconductors  the effect will be lost. (meissner ochsenfeld effect)  as the frustrum works with a crude coil as rf transmitter , so how does Shawyer prevent magnetic interference and loss of superconductivity?

Very good question(s). From what I have read in these discussions and the limited information available from a few of Shawyer's papers/patent, upscalling the frustum to a superconducting cryogenic design is based on an assumption that high Q is the dominant factor in developing high thrust. Without any published experimental data involving a superconducting EmDrive design, it appears to me to be a theoretical leap of faith.

So the short answer is there seems to be a race by some to try and be the first, which demands an almost blind faith in conclusions based on flawed or incomplete theoretical interpretations of .....

I do tend to run on and often present off the wall observations and interpretations of my own, so in the spirit of old maps, "be warned beyond here there be dragons!"

As a non-expert in any of the areas specific to the design and construction of a functional device, and based only on what understanding I have been able to tease out of these discussions, it would seem far more productive to refine a room temperature design which if which of what information that has been made available should be able to developed thrusts in the Newton/Kw range, before chasing what seems purely theoretical upscalling based on what at present is very limited published data from mostly 1st to perhaps 3rd generation engineering attempts to recreate poorly described devices claiming up to triple digit mN/Kw results.

Any device that could consistently produce triple digit mN/Kw thrusts at room temperatures, would provide a far better basis for exploring any functionally measurable design and/or materials based aspects contributing to those results.

Right now from a peanut gallery observer, without better design blueprints from previously successful experiments, chasing superconducting promises of multi ton thrusts, just seems foolish.

The EW paper seems to have provided the first reliable data demonstrating repeatable thrust, but unless I am mistaken the frustum design and TM mode, in those tests, do not represent the only or perhaps even best approach, for obtaining higher room temperature thrusts.

Also I believe in Shawyer's last partnership patent, only the large flat end plate was coated with a superconducting material.

YBCO seems to have the highest Hc of any superconductor as I posted shortly ago.
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=41732.0;attach=1391109;image

The 60T indicated at LN2 temp is ~4.77x10^7 A/m.

As cavity TE013 H fields are max in the centre of the cavity, the side wall and end plate H fields are very low.

Please check back a few posts for the images.

Spherical cavity E * H fields:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=41732.0;attach=1391125;image
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: zellerium on 12/01/2016 02:49 pm
See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.

TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.

Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.

Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.

We only have data for TE012 for both dielectric and non dielectric forces and direction.

It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.

As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed.

Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.

I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.

Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.

The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.

Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.

TT,

For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.

So one side has losses in the volume and the other has losses on the surface... But somehow the surface losses dissipate momentum differently than the volume losses?
If we wanted to optimize a cavity for thrust, would we want a balance between highest surface losses on one side, highest volume losses on the other side, and quality?

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/01/2016 03:08 pm
According to radiation pressure theory, the big to small accelerative force is the equal but opposite Reaction force to the small to big static Thrust force.
This is not "according to radiation pressure theory." This is from statements by Shawyer in a paper where he utterly fails at a Physics 101 force diagram.

I have asked you many, many times to answer simple questions about a simple mechanical setup (originally in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1598852#msg1598852)), which you have refused to do. These questions are important to clarify the definitions of terms that you are using. You are confusing everyone because you are using the word force in a way that contradicts the definition of a force.

I ask again since this is the beginning of a new thread, and it would be nice to have some rational discourse.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: OnlyMe on 12/01/2016 03:24 pm
For those considering building a YBCO based frustum, as I am, here are 2 interesting graphs:

1st is 2015 data showing max H field vs temp vs various superconductors. From this data it would seem that YBCO is the champ material for dealing with high H field, which suggests it can handle very high Q frustum builds.

2nd is 2009 data from Roger Shawyer showing YBCO Rs vs various temperatures at 3.85GHz. Note that the ~78uOhm value in 2009 is now 3uOhm in 2016.

While LNe is somewhat expensive, it does appear to offer a 5x lower Rs (5x higher Q) and 2.5x higher max Hc so maybe worth giving it a shot?

For sure design for LN2 and if you need to go further maybe consider LNe instead of LH2 or LHe?
YBCO is a ceramic compound. The gap to excitations that leads to superconductivity is a result of pairs of electrons (or other fermions) bound together at (very) low temperatures, and thats in the case of ceramic superconductors usualy a surface effect. If a magnetic field is close to  these type of  superconductors  the effect will be lost. (meissner ochsenfeld effect)  as the frustrum works with a crude coil as rf transmitter , so how does Shawyer prevent magnetic interference and loss of superconductivity?

Very good question(s). From what I have read in these discussions and the limited information available from a few of Shawyer's papers/patent, upscalling the frustum to a superconducting cryogenic design is based on an assumption that high Q is the dominant factor in developing high thrust. Without any published experimental data involving a superconducting EmDrive design, it appears to me to be a theoretical leap of faith.

So the short answer is there seems to be a race by some to try and be the first, which demands an almost blind faith in conclusions based on flawed or incomplete theoretical interpretations of .....

I do tend to run on and often present off the wall observations and interpretations of my own, so in the spirit of old maps, "be warned beyond here there be dragons!"

As a non-expert in any of the areas specific to the design and construction of a functional device, and based only on what understanding I have been able to tease out of these discussions, it would seem far more productive to refine a room temperature design which if which of what information that has been made available should be able to developed thrusts in the Newton/Kw range, before chasing what seems purely theoretical upscalling based on what at present is very limited published data from mostly 1st to perhaps 3rd generation engineering attempts to recreate poorly described devices claiming up to triple digit mN/Kw results.

Any device that could consistently produce triple digit mN/Kw thrusts at room temperatures, would provide a far better basis for exploring any functionally measurable design and/or materials based aspects contributing to those results.

Right now from a peanut gallery observer, without better design blueprints from previously successful experiments, chasing superconducting promises of multi ton thrusts, just seems foolish.

The EW paper seems to have provided the first reliable data demonstrating repeatable thrust, but unless I am mistaken the frustum design and TM mode, in those tests, do not represent the only or perhaps even best approach, for obtaining higher room temperature thrusts.

Also I believe in Shawyer's last partnership patent, only the large flat end plate was coated with a superconducting material.

YBCO seems to have the highest Hc of any superconductor as I posted shortly ago.

The 60T indicated at LN2 temp is ~4.77x10^7 A/m.

As cavity TE013 H fields are max in the centre of the cavity, the side wall and end plate H fields are very low.

Please check back a few posts for the images.

Spherical cavity E * H fields:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=41732.0;attach=1391125;image

YBCO Hc field sensitivity vs temp:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=41732.0;attach=1391109;image

You are missing the point that this is all a theoretical leap of faith, that assumes there is nothing other than Q that affects the resultant thrust. The EM field being introduced into the frustum interacts with the materials of the frustum walls in more ways than just the Q achieved by design and frequency match. There are other differences between copper and YBCO than just Q.

For that matter has anyone tested how silver plating a polished copper frustum changes the developed thrust? Or even how any coating applied to the copper with the intent of reducing degradation affects performance.

DIY budgets don't often have the financial flexibility to run these kinds of incremental comparison experiments. Especially when a great deal of the design budgets have been consumed in attempts to address a never ending list of potential testing equipment design errors.

I was never interested in lab work. That does not mean I cannot see when or where what should be obvious incremental steps are being skipped, solely based on theoretical projections that have not been proven... Or if they have been proven, the proof is hidden behind walls of secrecy.

From the information provided so far, which is limited for certain, it still suggests that an optimized design of a room temperature copper frustum and microwave source, should produce enough thrust to be useful for satellites and when stacked even potentially manned moon and interplanetary missions.

If that is not the case, it seems to me the constant dangling of superconductor designs, functions more as a snipe hunt to keep everyone guessing and running in circles.

Build and test that self contained battery operated room temperature copper frustum and prove it works!

So far only Yang's first paper which seems suspicious, though potentially significant, EWs recent paper, that documented repeatable results with a less than optimum design and TM mode and a few rumored yet unpublished DIY results, indicate any real latent potential. Jumping from those to superconducting flying cars.., as I said sounds like a snipe hunt, certainly not good methodical science.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 03:34 pm
According to radiation pressure theory, the big to small accelerative force is the equal but opposite Reaction force to the small to big static Thrust force.
This is not "according to radiation pressure theory." This is from statements by Shawyer in a paper where he utterly fails at a Physics 101 force diagram.

I have asked you many, many times to answer simple questions about a simple mechanical setup (originally in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1598852#msg1598852)), which you have refused to do. These questions are important to clarify the definitions of terms that you are using. You are confusing everyone because you are using the word force in a way that contradicts the definition of a force.

I ask again since this is the beginning of a new thread, and it would be nice to have some rational discourse.

Static force: Causes a scale or torsion pendulum to record a force acting against or with the scale or torsion pendulum. Equation F = (2 Qu Pwr Df) / c.

Dynamic force: Causes the free to accelerate acceleration of mass and is measured via F = A * M.

Can't measure both forces at the same time.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/01/2016 03:40 pm
According to radiation pressure theory, the big to small accelerative force is the equal but opposite Reaction force to the small to big static Thrust force.
This is not "according to radiation pressure theory." This is from statements by Shawyer in a paper where he utterly fails at a Physics 101 force diagram.

I have asked you many, many times to answer simple questions about a simple mechanical setup (originally in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1598852#msg1598852)), which you have refused to do. These questions are important to clarify the definitions of terms that you are using. You are confusing everyone because you are using the word force in a way that contradicts the definition of a force.

I ask again since this is the beginning of a new thread, and it would be nice to have some rational discourse.

I thought you'd know by now how TT will answer. The route this conversation takes goes as follows:

1) Statement that the theoretical explanations on offer are non-nonsensical
2) Contradictions are rebuffed by endorsing data above theory
3) Statements to the effect that all theories are flawed but the good ones still make physical sense
4) Appeal to the authority of Shawyer because he made EM Drive work
5) Go to 1
I know, I am just giving it one last shot in light of the new thread (and for casual readers who look through the first few pages of a thread), my response to #2 this time (unless TT changes his pattern, and actually answers my questions) is planned to be along the lines of "I am tired of this cycle but figured I would give it one last shot. Just know that in the future when no one counters your claims it is only because everyone has given up on you listening to reason."
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/01/2016 03:46 pm
According to radiation pressure theory, the big to small accelerative force is the equal but opposite Reaction force to the small to big static Thrust force.
This is not "according to radiation pressure theory." This is from statements by Shawyer in a paper where he utterly fails at a Physics 101 force diagram.

I have asked you many, many times to answer simple questions about a simple mechanical setup (originally in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1598852#msg1598852)), which you have refused to do. These questions are important to clarify the definitions of terms that you are using. You are confusing everyone because you are using the word force in a way that contradicts the definition of a force.

I ask again since this is the beginning of a new thread, and it would be nice to have some rational discourse.

Static force: Causes a scale or torsion pendulum to record a force acting against or with the scale or torsion pendulum. Equation F = (2 Qu Pwr Df) / c.

Dynamic force: Causes the free to accelerate acceleration of mass and is measured via F = A * M.

Can't measure both forces at the same time.
That is not an answer to the questions I asked. That is just providing the same contradictory definitions, because no force measurement is static, they all start with an acceleration, and the torsion  pendulum and scale measure how much force is required to hold back the acceleration. The only way I know how to explain this more clearly is by example, but you refuse to actually work through the example with me.

As I said in reply to RotoSequence:
I am tired of this cycle but figured I would give it one last shot. Just know that in the future when no one counters your claims it is only because everyone has given up on you listening to reason.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/01/2016 04:01 pm
I would like my simple question to be answered too:

What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 04:06 pm
According to radiation pressure theory, the big to small accelerative force is the equal but opposite Reaction force to the small to big static Thrust force.
This is not "according to radiation pressure theory." This is from statements by Shawyer in a paper where he utterly fails at a Physics 101 force diagram.

I have asked you many, many times to answer simple questions about a simple mechanical setup (originally in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1598852#msg1598852)), which you have refused to do. These questions are important to clarify the definitions of terms that you are using. You are confusing everyone because you are using the word force in a way that contradicts the definition of a force.

I ask again since this is the beginning of a new thread, and it would be nice to have some rational discourse.

Static force: Causes a scale or torsion pendulum to record a force acting against or with the scale or torsion pendulum. Equation F = (2 Qu Pwr Df) / c.

Dynamic force: Causes the free to accelerate acceleration of mass and is measured via F = A * M.

Can't measure both forces at the same time.
That is not an answer to the questions I asked. That is just providing the same contradictory definitions, because no force measurement is static, they all start with an acceleration, and the torsion  pendulum and scale measure how much force is required to hold back the acceleration. The only way I know how to explain this more clearly is by example, but you refuse to actually work through the example with me.

As I said in reply to RotoSequence:
I am tired of this cycle but figured I would give it one last shot. Just know that in the future when no one counters your claims it is only because everyone has given up on you listening to reason.

For sure there is movement.

In the EW torsion pendulum a few um.

On a scale a lot less movement as the mass is reacting against a strain gauge.

If you are asking me what is it pushing against to generate the force, well that is where we will probably never agree until you see an EmDrive levitate.

Nevertheless, the experimental data from EW and Roger are very clear as to the direction of the generated static force that acts on a scale or stiff torsion pendulum to record the level of the generated force.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 04:11 pm
I would like my simple question to be answered too:

What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength?

In a resonant frustum, guide wavelength increases as the tapered waveguide diameter decreases, the group velocity decreases as does the radiation pressure it can generate on a end plate.

This is all existing microwave engineering.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/01/2016 04:22 pm
You are missing the point that this is all a theoretical leap of faith, that assumes there is nothing other than Q that affects the resultant thrust. The EM field being introduced into the frustum interacts with the materials of the frustum walls in more ways than just the Q achieved by design and frequency match. There are other differences between copper and YBCO than just Q

For sure there are other factors. Like the Rs vs freq scaling factor and the Rs vs temp scaling factor. However as a general guide the measured Rs for room temp Cu is ~15,000uOhm and I have been offered YBCO with a 3uOhm at 3.85GHz and 77K, which is a drop of 5,000x.

So estimated Q should increase around 5,000x assuming the YBCO is being working well with-in it's temp and Hc limits.

Then there are Kilpatrick limits on the max E field before the air starts to break down from 100MV/m E fields. So there are engineering issues that need to be addressed but it is not like this is unknown territory.

The experimental data, adjusted for specific force, shows the force scales with Power and Q as attached. My own experimental data suggests the data is real.

Others may have their own opinion and ask for more data. I have no issue with that as I working to provide it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/01/2016 04:32 pm
I would like my simple question to be answered too:

What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength?
That I can help with. The guide wavelength in a waveguide is basically due to the waves bouncing back and forth between the walls rather than straight down the middle. The superposition hides the non-axial portion, so you just see an apparently stretched axial wavelength, while the actual travelling waves maintain their original wavelength. In a smaller waveguide the angle of the bounces is steeper (for the same frequency of radiation), so the apparent wavelength gets longer. What Cullen originally showed was simply that the steeper the bounces, the less of the wave's momentum is in the axial direction, which is a very sensible result.

Something similar happens in an emDrive cavity as waves reflecting off the side walls cause the angles to get steeper towards the small end. You can't easily define a guide wavelength though because at any point the suprimposed waves are not all moving in the same direction, and it is not clear what modes (if any) the apparent standing wave has any meaningful relation to the angles the travelling waves are travelling at. The issue with this description and how Shawyer abuses Cullen's results is that by conservation of momentum, it is obvious that any change in axial momentum due to reflections off the sidewalls transfers that momentum to the sidewalls to end up with no net motion.

(Note:This post used simplified descriptions, to give an intuitive sense of what is going on. Boundary conditions and the wave equation make this more complicated than presented here.)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Bob012345 on 12/01/2016 04:40 pm
Another article from Ethan Seigal on the Forbes website:

http://www.forbes.com/sites/startswithabang/2016/11/30/could-dark-matter-be-powering-the-emdrive/#25e019901e53

Interesting conjecture that instead of pushing against the QV (which Woodward tells us the EMDrive can't do), the drive is instead expelling dark matter like a normal rocket through photon-axion interaction.

"How would it work? At any point in time, there are dark matter particles passing through all regions of space, undeterred by the presence of matter or other Standard Model particles. Inside the electromagnetic cavity, photons of a particular frequency bounce around in all directions, conserving momentum and generating no thrust. But if photons moving in a particular direction — towards the ‘back’ of the cavity, for example — are likely to strike a dark matter particle, three things ensue:

1) The photon changes momentum, and moves “less backwards” and “more forwards” than before it struck the dark matter particle.
2) The photon strikes the inside wall of the cavity, reflecting off of it and imparting its momentum in the forward direction to the cavity itself.
3) The struck dark matter particle gains momentum as well in the opposite direction: backwards.

Momentum is conserved because the dark matter carries it away, equal and opposite in magnitude to what the cavity absorbs."

I think it is much more likely and practical, that momentum is carried into the copper and through it by magnetic flux, which pass through due to the voltage drop (losses) from resistance and current.

Interesting. In a relativistic photon rocket, the transfer of energy to momentum nears 100% efficiency as the rocket nears c. I've always wondered if the surface effects in a resonant cavity act like a highly relativistic photon rocket transferring photon energy to momentum of the surface plasmons  much higher than 1/c which then push the cavity as a whole. If that were the case, it would be a much simpler model and well within the mainstream of current physics.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Bob012345 on 12/01/2016 04:45 pm
According to radiation pressure theory, the big to small accelerative force is the equal but opposite Reaction force to the small to big static Thrust force.
This is not "according to radiation pressure theory." This is from statements by Shawyer in a paper where he utterly fails at a Physics 101 force diagram.

I have asked you many, many times to answer simple questions about a simple mechanical setup (originally in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1598852#msg1598852)), which you have refused to do. These questions are important to clarify the definitions of terms that you are using. You are confusing everyone because you are using the word force in a way that contradicts the definition of a force.

I ask again since this is the beginning of a new thread, and it would be nice to have some rational discourse.

I thought you'd know by now how TT will answer. The route this conversation takes goes as follows:

1) Statement that the theoretical explanations on offer are non-nonsensical
2) Contradictions are rebuffed by endorsing data above theory
3) Statements to the effect that all theories are flawed but the good ones still make physical sense
4) Appeal to the authority of Shawyer because he made EM Drive work
5) Go to 1
I know, I am just giving it one last shot in light of the new thread (and for casual readers who look through the first few pages of a thread), my response to #2 this time (unless TT changes his pattern, and actually answers my questions) is planned to be along the lines of "I am tired of this cycle but figured I would give it one last shot. Just know that in the future when no one counters your claims it is only because everyone has given up on you listening to reason."

Data is above theory. Throwing out solid data that doesn't 'fit' current theory is not good science. Of course the key is having good reliable data not just any data. That's what NASA tried to do.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Bob012345 on 12/01/2016 05:23 pm
According to radiation pressure theory, the big to small accelerative force is the equal but opposite Reaction force to the small to big static Thrust force.
This is not "according to radiation pressure theory." This is from statements by Shawyer in a paper where he utterly fails at a Physics 101 force diagram.

I have asked you many, many times to answer simple questions about a simple mechanical setup (originally in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1598852#msg1598852)), which you have refused to do. These questions are important to clarify the definitions of terms that you are using. You are confusing everyone because you are using the word force in a way that contradicts the definition of a force.

I ask again since this is the beginning of a new thread, and it would be nice to have some rational discourse.

Any closed mechanical system should not provide a means to generate net momentum yet an electromagnetic system might since it is related to relativity, quantum field theory and at least weakly to gravitation.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Notsosureofit on 12/01/2016 05:45 pm
FYI:
http://scitation.aip.org/content/aip/magazine/physicstoday/article/69/12/10.1063/PT.3.3397?
utm_source=Physics%20Today&utm_medium=email&utm_campaign=7773957_December%202016%20Table%2
0of%20Contents&utm_content=Feat5&dm_i=1Y69,4MMF9,E1MTSN,H8E4P,1
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: PotomacNeuron on 12/01/2016 05:53 pm
FYI:

I was surprised that I had never heard of this powerful accelerator. Then I realize I am not the only one who have not.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Monomorphic on 12/01/2016 05:59 pm

I was surprised that I had never heard of this powerful accelerator. Then I realize I am not the only one who have not.

http://scitation.aip.org/content/aip/magazine/physicstoday/article/69/12/10.1063/PT.3.3397
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: DusanC on 12/01/2016 06:09 pm

I was surprised that I had never heard of this powerful accelerator. Then I realize I am not the only one who have not.

http://scitation.aip.org/content/aip/magazine/physicstoday/article/69/12/10.1063/PT.3.3397

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 07:25 pm
See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.

TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.

Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.

Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.

We only have data for TE012 for both dielectric and non dielectric forces and direction.

It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.

As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed.

Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.

I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.

Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.

The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.

Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.

TT,

For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.

So one side has losses in the volume and the other has losses on the surface... But somehow the surface losses dissipate momentum differently than the volume losses?
If we wanted to optimize a cavity for thrust, would we want a balance between highest surface losses on one side, highest volume losses on the other side, and quality?

I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.

If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end.  The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Mark7777777 on 12/01/2016 08:12 pm
FWIW, emdrives.com currently redirects to whatever is the last post on the last page of this new thread 9.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/01/2016 08:23 pm

I was surprised that I had never heard of this powerful accelerator. Then I realize I am not the only one who have not.

http://scitation.aip.org/content/aip/magazine/physicstoday/article/69/12/10.1063/PT.3.3397

We? This is only your 2nd posting.  ???
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: MrFrankenverse on 12/01/2016 08:25 pm
From Einstein we understand that an observer on a photon would see other photons, no matter their position, whether inside objects or elsewhere, traveling at the speed of light (discounting refraction for the moment). From inference then one might expect that when photons interact they do so with less reference to any previous interaction and more to their own vectors; the photons move energetically, without pushing against anything, until they actually push against something. In the context of these frustums and from Newton one must surely argue that any interaction at one end be canceled at the other, however, as Shawer points out, there's a difference in group velocity; there's an energy difference in the two standing waves which manifests as a vector of acceleration on the waveguide.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: InterestedEngineer on 12/01/2016 08:29 pm

Static force: Causes a scale or torsion pendulum to record a force acting against or with the scale or torsion pendulum. Equation F = (2 Qu Pwr Df) / c.

Dynamic force: Causes the free to accelerate acceleration of mass and is measured via F = A * M.

Can't measure both forces at the same time.

If I have an EmDrive sitting on a surface with significant friction (e.g. 1000 grit sandpaper), what happens when static force overcomes static friction and the EmDrive starts to move?  I think you indicated the dynamic force is in the other direction in a prior post.  Does the EmDrive reverse direction and try move the other way as soon as there's motion?  If so wouldn't the EmDrive+surface system be put back into the static friction regime when velocity relative to the surface momentarily reaches zero?  Seems like the EmDrive would effectively get nowhere on such a surface.

If my description is wrong, please supply a description of EmDrive behavior on a surface with significant friction.  The dynamic/static friction behavior of the movement on the surface is going to interact with your conjecture of static versus dynamic force, possibly in an interesting manner.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: X_RaY on 12/01/2016 08:41 pm
Regarding discussion about wave vectors and wave numbers, these are complex numbers*:
http://www.ece.rutgers.edu/~orfanidi/ewa/ch07.pdf
k=sqrt(kx^2+ky^2+kz^2)   [in cartesian coordinates]

*The radiation pressure is also related to complex expressions. If one only picks the z-component it leads to the incomplete viewpoint that there is a different radiation preasure at both end pates ::) hence the rest puts at the side wall and can also be separated into a r- and a z-component [terms in cylindrical coordinates].
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/01/2016 08:55 pm
See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.

TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.

Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.

Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.

We only have data for TE012 for both dielectric and non dielectric forces and direction.

It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.

As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed.

Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.

I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.

Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.

The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.

Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.

TT,

For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.

So one side has losses in the volume and the other has losses on the surface... But somehow the surface losses dissipate momentum differently than the volume losses?
If we wanted to optimize a cavity for thrust, would we want a balance between highest surface losses on one side, highest volume losses on the other side, and quality?

I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.

If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end.  The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.

So,.... What?  An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work?  A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin  :)
That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense?

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 09:16 pm

I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.

If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end.  The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.

So,.... What?  An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work?  A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin  :)
That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense?

Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/01/2016 09:37 pm

I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.

If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end.  The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.

So,.... What?  An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work?  A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin  :)
That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense?

Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity.

? A voltage drop is how you lose energy; voltage drop -  eddy current - etc. This is what you want at one end (metallic) of the cavity. We do have a voltage drop across the dielectric coatingt; metal surface behind on one side and MW on the other side, causing minimal charge movement ... essentially a variable polarization of the dielectric,
i.e. much much less loss of energy.... Better than nickel  ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: rfmwguy on 12/01/2016 09:44 pm

I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.

If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end.  The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.

So,.... What?  An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work?  A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin  :)
That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense?

Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity.

? A voltage drop is how you lose energy; voltage drop -  eddy current - etc. This is what you want at one end (metallic) of the cavity. We do have a voltage drop across the dielectric coatingt; metal surface behind on one side and MW on the other side, causing minimal charge movement ... essentially a variable polarization of the dielectric,
i.e. much much less loss of energy.... Better than nickel  ?
You cannot use a dielectric insert without a trade-off. In this case, an insert will lower the Q of the cavity, effectively widening the 3dB BW of the return loss response. More testing will be required to determine if that tradeoff is worth it, or...someone will have to develop a bullet-proof theory that "inserts provide X so thrust can become Y".
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 10:01 pm

I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.

If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end.  The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.

So,.... What?  An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work?  A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin  :)
That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense?

Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity.

? A voltage drop is how you lose energy; voltage drop -  eddy current - etc. This is what you want at one end (metallic) of the cavity. We do have a voltage drop across the dielectric coatingt; metal surface behind on one side and MW on the other side, causing minimal charge movement ... essentially a variable polarization of the dielectric,
i.e. much much less loss of energy.... Better than nickel  ?

A voltage drop in the metal allows magnetic flux (and momentum) to escape the frustum. A dielectric inside does not. I realize that the voltage drop is a loss of power and will result in a lower Q, and there will be a compromise between higher Q vs higher divergence of the flux, but unless something is getting out, or at least out of the cavity and into the copper, it's not going to move. My theory is the only one here that is proposing something observable that can get out of the cavity.

PS: I expect the nickel to be the higher losses and the copper to be lower loss. My expectation is, if you want the small end leading, then the small end and side walls should be low loss and the big end plate should be higher loss material. But not a lot higher loss, just enough to cause a gradient. It still requires a large Q to create any thrust.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: rq3 on 12/01/2016 10:33 pm
See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.

TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.

From your description, I envision a superconducting plate at the big end, with the interior of the silver plated copper frustum containing a polyethylene or polytetrafluorethylene hollow cone "wall liner", with wall thickness tapering from zero at the big end to maximum (an internal point) at the small end.

Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.

Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.

We only have data for TE012 for both dielectric and non dielectric forces and direction.

It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.

As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed.

Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.

I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.

Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.

The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.

Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.

TT,

For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.

So one side has losses in the volume and the other has losses on the surface... But somehow the surface losses dissipate momentum differently than the volume losses?
If we wanted to optimize a cavity for thrust, would we want a balance between highest surface losses on one side, highest volume losses on the other side, and quality?

I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.

If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end.  The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/01/2016 10:40 pm

I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.

If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end.  The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.

So,.... What?  An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work?  A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin  :)
That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense?

Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity.

? A voltage drop is how you lose energy; voltage drop -  eddy current - etc. This is what you want at one end (metallic) of the cavity. We do have a voltage drop across the dielectric coatingt; metal surface behind on one side and MW on the other side, causing minimal charge movement ... essentially a variable polarization of the dielectric,
i.e. much much less loss of energy.... Better than nickel  ?

A voltage drop in the metal allows magnetic flux (and momentum) to escape the frustum. A dielectric inside does not. I realize that the voltage drop is a loss of power and will result in a lower Q, and there will be a compromise between higher Q vs higher divergence of the flux, but unless something is getting out, or at least out of the cavity and into the copper, it's not going to move. My theory is the only one here that is proposing something observable that can get out of the cavity.

PS: I expect the nickel to be the higher losses and the copper to be lower loss. My expectation is, if you want the small end leading, then the small end and side walls should be low loss and the big end plate should be higher loss material. But not a lot higher loss, just enough to cause a gradient. It still requires a large Q to create any thrust.

I was not talking about a dielectric insert but rather a dielectric coating for one of the reflective end walls of the cavity. in order to minimize losses... at one end. But, it appears that microwave dielectric manipulation is done using meta-materials with macroscopic dielectric resonators structures... New, probably hard to get ...

https://arxiv.org/pdf/1605.07487v1.pdf
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/01/2016 11:01 pm

A voltage drop in the metal allows magnetic flux (and momentum) to escape the frustum. A dielectric inside does not. I realize that the voltage drop is a loss of power and will result in a lower Q, and there will be a compromise between higher Q vs higher divergence of the flux, but unless something is getting out, or at least out of the cavity and into the copper, it's not going to move. My theory is the only one here that is proposing something observable that can get out of the cavity.

PS: I expect the nickel to be the higher losses and the copper to be lower loss. My expectation is, if you want the small end leading, then the small end and side walls should be low loss and the big end plate should be higher loss material. But not a lot higher loss, just enough to cause a gradient. It still requires a large Q to create any thrust.

I was not talking about a dielectric insert but rather a dielectric coating for one of the reflective end walls of the cavity. in order to minimize losses... at one end. But, it appears that microwave dielectric manipulation is done using meta-materials with macroscopic dielectric resonators structures... New, probably hard to get ...

https://arxiv.org/pdf/1605.07487v1.pdf

I think the dielectric insert in EW TM212 mode test is doing just that, but I also think a good copper conductor with cooling would work better. They used FR4 1oz copper board on both ends. a 1oz copper platting, per my own experience, is very lossy. It doesn't take heat well. The dielectric is keeping it cool.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: CraigPichach on 12/01/2016 11:21 pm
So.. my assumptions were incorrect.

Here is a public link to commercially available magnetrons; note that you have ranges of powers available at various frequencies. These are generally due to practical limitations.

http://www2.l-3com.com/edd/products/r_magnetrons_s-band.htm

Looking at this you end up with one major question - is it better to do a >MW test for microseconds vs. a 100kW test over seconds.

My initial thought is 100kW sustained is easier to measure; unsure which has the advantage on cooling (at MW that’s a lot of juice where you prob having a cooling system either way or can we make the test short enough that air cooling is satisfactory). I think best plan is thrusting down into a scale, just to work out the cooling that we aren’t worrying about evaporation. Would be nice if we generated enough thrust that it offset any of that.

Paul March's simulation results seemed to indicate that the thrust happens very fast that we can use a short pulse to generate thrust. On a fast time scale could pulse the magnetron at different repetition rates to try to separate out the thrust from other noise like average heating effects however long pulse should be easier to measure but need to worry about robust cooling system.

Thoughts??

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: R.W. Keyes on 12/02/2016 12:13 am
I recall this issue being raised before, but it was a while ago and the situation may have changed.  Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it.

I am not asking if the typical $800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense? The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: toloverufan on 12/02/2016 12:33 am I know there's been some talk about the drive pushing against some quantum vacuum, but maybe something like this (http://www.sciencealert.com/we-just-got-the-first-real-evidence-of-a-strange-quantum-distortion-in-empty-space) is what's happening? Not sure if it's some separate phenomenon, or just a bigger version of the same thing, but it seems like something to add. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/02/2016 12:52 am I recall this issue being raised before, but it was a while ago and the situation may have changed. Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it. I am not asking if the typical$800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense?

The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP.

I think the casting places typically have their own 3d printer. All you do is provide the CAD file for the part. They will update it to work with their type of casting, and the type of finish required, and give you a chance to approve it before the part is cast. It's not that expensive, nowhere near six figures!  :o
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: VAXHeadroom on 12/02/2016 02:26 am
I recall this issue being raised before, but it was a while ago and the situation may have changed.  Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it.

I am not asking if the typical $800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense? The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP. I think the casting places typically have their own 3d printer. All you do is provide the CAD file for the part. They will update it to work with their type of casting, and the type of finish required, and give you a chance to approve it before the part is cast. It's not that expensive, nowhere near six figures! :o But for a high Q you need a post-printing/casting step for polishing. 3D printing can give you a near-net-shape, but the surface finish is nowhere near good enough. A 3D metal printer big enough to build an aluminum EMDrive in the 2.4 GHz range is upwards of$1M.  We just priced them at work :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/02/2016 02:55 am
How the universe does maths...

Some simple mathematical operations are very useful in equations describing how the universe appears to work. It is then only normal to wonder how these operations are done in or by the universe itself.

Let’s start with the addition. There are two ways in which to use the addition. One way is the conceptual addition. For example, I have $5 in my pocket and$10 in the bank. Addition says I have $15 in all. Nothing has moved. The other way of adding is by literally getting things together, like pouring milk in your coffee. This is the method we learned in kinder garden where addition meant getting and moving beads or what not together in a pile. This is the “natural” way of adding and the way the universe uses. A planet does not compute what mass is floating around it. No, it gains or adds mass by literally sucking up mass closer and onto its surface. We see here that the natural addition has a geometric component i.e. adding means getting stuff closer. Secondly, this natural addition comes with the addition of the properties of that stuff. Whatever the stuff is, it has mass, so mass is the first property necessarily added. On top of that, other properties will add up. If this stuff is, say, emitting light, their addition will increase the intensity i.e. more light coming from a smaller volume. ( I won’t go here-now into adding charges or magnetic domains..) Now, a planet will gain or add mass spontaneously through gravity. So, for matter addition is a spontaneous process. But, subtracting mass by moving it away from the planet will require energy and is not a spontaneous process. Matter subtraction is not a spontaneous process. To division now. Cutting a pie in four pieces is a conceptual division. The “natural” division of the pie consists in taking the four pieces away from each other in a way as symmetric as possible. What does that mean for a planet? A sort of explosion where all the pieces move away from each other i.e. the same mass but in a larger volume. So, in some sense, the “natural” division is like an integrated subtraction over a spherical volume...(?) This division is not a spontaneous process in the first instance; a lot of energy must be supplied first in order to create a condition for it to happen, in second instance, spontaneously. The reverse is multiplication, where matter occupies a smaller volume as with interstellar dust gathering to form a star. Multiplication is a spontaneous process because of gravity. So, what kind of universe are we in? Matter in the universe undergoes spontaneous multiplication (aggregation), while the expanding universe is in ..... spontaneous division? How come the universe’s division is a spontaneous process, when it is not for matter? I believe that the universe is somehow spontaneously “falling” and moving into the lowest rate of time possible; nothingness.... So, beyond the geometry of it all, the same type of cause is behind both the spontaneous multiplication or aggregation of matter and the spontaneous division or expansion of the universe.... This is a “different way” (to say the least) in which to consider how the universe naturally effects simple mathematical operations. I will conclude by saying that, IMO, the word “spontaneous” is the most underused concept in physics. If we were to consider for a moment how things naturally evolve spontaneously out there, we would understand that most time reversal equations on paper do not really work “in reverse” by themselves. The observation of unidirectional processes should invite the concepts of spontaneous processes, causality, all under a single logical and fully entropic system. [ emDrive related? Sure! Just bringing home the causal structure....the scenic way] Food for thought .... Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: rfmwguy on 12/02/2016 04:01 am How the universe does maths... Some simple mathematical operations are very useful in equations describing how the universe appears to work. It is then only normal to wonder how these operations are done in or by the universe itself. Let’s start with the addition. There are two ways in which to use the addition. One way is the conceptual addition. For example, I have$5 in my pocket and $10 in the bank. Addition says I have$15 in all. Nothing has moved. The other way of adding is by literally getting things together, like pouring milk in your coffee. This is the method we learned in kinder garden where addition meant getting and moving beads or what not together in a pile. This is the “natural” way of adding and the way the universe uses. A planet does not compute what mass is floating around it. No, it gains or adds mass by literally sucking up mass closer and onto its surface. We see here that the natural addition has a geometric component i.e. adding means getting stuff closer. Secondly, this natural addition comes with the addition of the properties of that stuff. Whatever the stuff is, it has mass, so mass is the first property necessarily added. On top of that, other properties will add up. If this stuff is, say, emitting light, their addition will increase the intensity i.e. more light coming from a smaller volume. ( I won’t go here-now into adding charges or magnetic domains..)

Now, a planet will gain or add mass spontaneously through gravity. So, for matter addition is a spontaneous process. But, subtracting mass by moving it away from the planet will require energy and is not a spontaneous process. Matter subtraction is not a spontaneous process.

To division now. Cutting a pie in four pieces is a conceptual division. The “natural” division of the pie consists in taking the four pieces away from each other in a way as symmetric as possible.  What does that mean for a planet? A sort of explosion where all the pieces move away from each other i.e. the same mass but in a larger volume. So, in some sense, the “natural” division is like an integrated subtraction over a spherical volume...(?) This division is not a spontaneous process in the first instance; a lot of energy must be supplied first in order to create a condition for it to happen, in second instance, spontaneously. The reverse is multiplication, where matter occupies a smaller volume as with interstellar dust gathering to form a star. Multiplication is a spontaneous process because of gravity.

So, what kind of universe are we in? Matter in the universe undergoes spontaneous multiplication (aggregation), while the expanding universe is in ..... spontaneous division? How come the universe’s division is a spontaneous process, when it is not for matter?

I believe that the universe is somehow spontaneously “falling” and moving into the lowest rate of time possible; nothingness.... So, beyond the geometry of it all, the same type of cause is behind both the spontaneous multiplication or aggregation of matter and the spontaneous division or expansion of the universe.... This is a “different way” (to say the least) in which to consider how the universe naturally effects simple mathematical operations.

I will conclude by saying that, IMO, the word “spontaneous” is the most underused concept in physics. If we were to consider for a moment how things naturally evolve spontaneously out there, we would understand that most time reversal equations on paper do not really work “in reverse” by themselves. The observation of unidirectional processes should invite the concepts of spontaneous processes, causality, all under a single logical and fully entropic system.

[ emDrive related? Sure! Just bringing home the causal structure....the scenic way]

Food for thought ....
Spontaneous reactions might describe the observed result but not the cause. Once all the causes of these type reactions are identified, we'll better understand the universe. However, we cannot directly observe the bulk of the universe. EmDrive might allow us to take a step in that direction IF we can identify what is happening in this open system. To date, I believe we are observing a result, not the cause of the spontaneous reaction...a displacement force.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: therealjjj77 on 12/02/2016 04:10 am

Now, a planet will gain or add mass spontaneously through gravity. So, for matter addition is a spontaneous process. But, subtracting mass by moving it away from the planet will require energy and is not a spontaneous process. Matter subtraction is not a spontaneous process.

Although it is true that a planet will gain mass through its gravitation field pulling in other matter, it is also worth noting that nuclear processes within the planet or star will result in the planet/star giving off a significant amount of energy. This radiation/energy will escape the gravitation field excepting for black holes(in theory). So there is also a loss occurring simultaneously(though it may or may not be as large as the gains depending on many other factors.

I believe that the universe is somehow spontaneously “falling” and moving into the lowest rate of time possible; nothingness.... So, beyond the geometry of it all, the same type of cause is behind both the spontaneous multiplication or aggregation of matter and the spontaneous division or expansion of the universe.... This is a “different way” (to say the least) in which to consider how the universe naturally effects simple mathematical operations.

So if I understand the theory you are proposing could be succinctly stated as:
1. "All matter/energy is attracted toward the lowest rate of time possible."
2. "Since general relativity shows that higher gravitation fields experience slower time, matter is pulled into these fields which is what we see as gravity."

Does that summarize what you are saying? Would like to make sure I'm clear on your hypothesis.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: ARW on 12/02/2016 05:28 am
I recall this issue being raised before, but it was a while ago and the situation may have changed.  Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it.

I am not asking if the typical $800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense? The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP. I think the casting places typically have their own 3d printer. All you do is provide the CAD file for the part. They will update it to work with their type of casting, and the type of finish required, and give you a chance to approve it before the part is cast. It's not that expensive, nowhere near six figures! :o But for a high Q you need a post-printing/casting step for polishing. 3D printing can give you a near-net-shape, but the surface finish is nowhere near good enough. A 3D metal printer big enough to build an aluminum EMDrive in the 2.4 GHz range is upwards of$1M.  We just priced them at work :)

Or you could do old fashioned CNC/casting + polishing for a fraction of your suggested cost.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/02/2016 06:05 am
I know there's been some talk about the drive pushing against some quantum vacuum, but maybe something like this (http://www.sciencealert.com/we-just-got-the-first-real-evidence-of-a-strange-quantum-distortion-in-empty-space) is what's happening? Not sure if it's some separate phenomenon, or just a bigger version of the same thing, but it seems like something to add.

It has connotations  of something I have been suspecting for a bit now.  That light may be stimulation of the quantum vacuum, made up of what is primarily observed as electrons and positrons, but the positrons being positive electrons, being positive because they are running backwards in time while having negative mass.  Negative mass/time behaving like real mass/time till it encounters positive mass/time and becomes negative in mass again annihilating its positive mass/time counterpart.  It takes work to separate them so real energy and appears to create real mass.  In annihilation the electron overlaps with the positron and disturbs the others around it causing a wave, losing energy to light, or other less disturbed pairs.

Unless massive amounts of light are concentrated into a very small area, you likely can't spontaneously create the pairs.  However, the creation of mass from separation of the pairs represents the non-linear behavior.  If one can osculate the non-linear pairs in a resonant fashion I think it may be possible to induce matter/anti-matter pairs at much lower energy levels.  Some papers have indicated this.

The giant magnetic fields would have an effect on the pairs locally.  Light being their vibrations, causing them to move in a magnetic field.  acceleration of the pair along a B field line should not effect their propagation but perpendicular motion may cause deflection - enhancing polarization effects.

Something I was considering was if the EM drive can make light more massive at one end in a cavity that the light could lose energy to the cavity in the form of Doppler shifts.  Such Doppler shifts may directly represent some local acceleration of the pairs and hence some local acceleration of a frame of reference for light.

I'm still wondering if their polarization could induce a flow in time and hence gravity effects (anti-matter=negative mass-time)

Also with light losing energy to Doppler shifts indicates a change in frequency f_o=(f_i-df).  Low Q cavities possibly handling light changing in frequency over time better because of their larger frequency range.  It may be beneficial to have successive cavities ranging from small to large in daisy chain operation.  That is the smaller cavities operating at high frequency lower Q downshift light till it resonates in the next cavity.  Have their Q's overlap so that light can be passed from one cavity to the next as the light gets rejected from the cavity it was in.

Those 2nd cavities in the daisy chain lighting up would possibly be evidence of some direct energy drain on the light.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/02/2016 06:15 am
I thought you'd know by now how TT will answer. The route this conversation takes goes as follows:

1) Statement that the theoretical explanations on offer are non-nonsensical
2) Contradictions are rebuffed by endorsing data above theory
3) Statements to the effect that all theories are flawed but the good ones still make physical sense
4) Appeal to the authority of Shawyer because he made EM Drive work
5) Go to 1
I know, I am just giving it one last shot in light of the new thread (and for casual readers who look through the first few pages of a thread), my response to #2 this time (unless TT changes his pattern, and actually answers my questions) is planned to be along the lines of "I am tired of this cycle but figured I would give it one last shot. Just know that in the future when no one counters your claims it is only because everyone has given up on you listening to reason."

Data is above theory. Throwing out solid data that doesn't 'fit' current theory is not good science. Of course the key is having good reliable data not just any data. That's what NASA tried to do.
There is no data throwing out going on. My response to this is number 3 from RotoSequence's list, no data can save an inconsistent theory.

Any closed mechanical system should not provide a means to generate net momentum yet an electromagnetic system might since it is related to relativity, quantum field theory and at least weakly to gravitation.
"relativity, quantum field theory, and gravitation" does not magically make a closed system an open one. For a system to be open, it needs to interact with something else by some mechanism. Of what you listed only gravitation is a mechanism (for the purpose of the definition I just provided), the others in no way make a system open, they are just physics frameworks. Even for gravity, you did not state what it would be interacting with. Also an electromagnetic system should have smaller coupling to gravity than a purely mechanical one (as implied when you said "weakly"), so that doesn't make a strong argument.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: ARW on 12/02/2016 07:11 am
So I submitted a query to a local foundry to die cast aluminum frustum 40cm tall, 1.5cm wall thickness and 0.05mm surface tolerance. Since it's not a mass production unit, the prototype would cost about 600 EUR.

Is 0.05mm surface tolerance good enough to obtain high Q or should i look into options to smoothen it further.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Monomorphic on 12/02/2016 12:46 pm
So I submitted a query to a local foundry to die cast aluminum frustum 40cm tall, 1.5cm wall thickness and 0.05mm surface tolerance. Since it's not a mass production unit, the prototype would cost about 600 EUR.

Is 0.05mm surface tolerance good enough to obtain high Q or should i look into options to smoothen it further.

That would be the largest emdrive built to date. A 2.4Ghz TE013 emdrive is ~24cm in length with a major end-plate diameter ~32cm, minor end-plate diameter of ~16cm.

Also, 1.5cm wall thickness is way overkill. It may be difficult to see any resonance patterns through so much metal. I would say 5mm is plenty.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 12:53 pm
So I submitted a query to a local foundry to die cast aluminum frustum 40cm tall, 1.5cm wall thickness and 0.05mm surface tolerance. Since it's not a mass production unit, the prototype would cost about 600 EUR.

Is 0.05mm surface tolerance good enough to obtain high Q or should i look into options to smoothen it further.

0.05mm tolerance is fine.

Surface needs to be very smooth, polished to a mirror like finish. NO SCRATCHES.

5 to 6mm thick side walls and min 10mm thick spherical end plates are fine.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/02/2016 12:59 pm
So I submitted a query to a local foundry to die cast aluminum frustum 40cm tall, 1.5cm wall thickness and 0.05mm surface tolerance. Since it's not a mass production unit, the prototype would cost about 600 EUR.

Is 0.05mm surface tolerance good enough to obtain high Q or should i look into options to smoothen it further.

What is the diameter of small and big ends, so someone like Monomorphic can calculate frequency?
With such large size, the operational frequency will be lower than anything tested to date (very good point) and Q should be very high if the frustum is well polished (preferably silver-plated or even gold flash over silver plating) so what do you plan to use as an RF generator?
Do you plan to make the end plates flat or better spherical?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 01:18 pm
So I submitted a query to a local foundry to die cast aluminum frustum 40cm tall, 1.5cm wall thickness and 0.05mm surface tolerance. Since it's not a mass production unit, the prototype would cost about 600 EUR.

Is 0.05mm surface tolerance good enough to obtain high Q or should i look into options to smoothen it further.

What is the diameter of small and big ends, so someone like Monomorphic can calculate frequency?
With such large size, the operational frequency will be lower than anything tested to date (very good point) and Q should be very high if the frustum is well polished (preferably silver-plated or even gold flash over silver plating) so what do you plan to use as an RF generator?
Do you plan to make the end plates flat or spherical?

Assuming TE013 excitment and Df around 0.8, freq would be around 1.5GHz (middle of L band) as a VERY rough guess.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/02/2016 01:28 pm
Assuming TE013 excitment and Df around 0.8, freq would be around 1.5GHz (middle of L band) as a VERY rough guess.

In this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1612609#msg1612609) ARW wanted to go the high power route with an RF source in the kilowatt range.

What kind of narrow band source available on the market can output ~1 kWrf at ~1.5GHz besides klystrons?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: ARW on 12/02/2016 02:15 pm

0.05mm tolerance is fine.

Surface needs to be very smooth, polished to a mirror like finish. NO SCRATCHES.

5 to 6mm thick side walls and min 10mm thick spherical end plates are fine.

Inside will be gold plated. So far I haven't received a reply for my query but based on wheel rim prices it shouldn't be too expensive.

What is the diameter of small and big ends, so someone like Monomorphic can calculate frequency?
With such large size, the operational frequency will be lower than anything tested to date (very good point) and Q should be very high if the frustum is well polished (preferably silver-plated or even gold flash over silver plating) so what do you plan to use as an RF generator?
Do you plan to make the end plates flat or better spherical?

Exact dimensions of the frustum are still in the making. We just had rough idea of the size we wanted  because I had to make a query to get the price. The goal is to have EM drive to operate up to 10kw with spherical end plates.

Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university.

A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 03:21 pm

0.05mm tolerance is fine.

Surface needs to be very smooth, polished to a mirror like finish. NO SCRATCHES.

5 to 6mm thick side walls and min 10mm thick spherical end plates are fine.

Inside will be gold plated. So far I haven't received a reply for my query but based on wheel rim prices it shouldn't be too expensive.

What is the diameter of small and big ends, so someone like Monomorphic can calculate frequency?
With such large size, the operational frequency will be lower than anything tested to date (very good point) and Q should be very high if the frustum is well polished (preferably silver-plated or even gold flash over silver plating) so what do you plan to use as an RF generator?
Do you plan to make the end plates flat or better spherical?

Exact dimensions of the frustum are still in the making. We just had rough idea of the size we wanted  because I had to make a query to get the price. The goal is to have EM drive to operate up to 10kw with spherical end plates.

Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university.

A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected.

There is a lot more involved to get good force generation than just building a frustum and filling it with Rf.

Excitment should be in TE013 as it has low losses and shallow cone angle.  Design and build goal should be a min Qu of 100,000, which can be directly measured via the forward power rise time to 63,2% or 1 TC. 0.05mm build accuracy is OK. Multi layers are ok. Surface finish is of prime importance as it needs to be like optical quality and NO SCRATCHES.

TE013 is also important as in that mode there are no eddy currents that cross from end plate to side wall and the physical end plate to side wall joint will not experience arcing across the joint, which can occur in other modes. I think Dave has pictures of the joint arcs that occured in his frustum.

I DO NOT suggest you use a wide band source.  You need single freq excitment and that freq needs to be adjustable in +-1kHz steps to get the lowest reflected power. Then further tuned to get best static force generation or best dynamic accelerative force generation. Plus your coupler need to be optimised to work without external tuners. IE you may need to be able to move the coupler around and alter orientation.

All doable but not simple nor apparent until you have build a few EmDrives.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: CraigPichach on 12/02/2016 03:22 pm
So TE 013 mode; 914.85MHz using HFSS via Eigenmode solver Q of 118602 with an S11 of 15dB; resonance at 914.069MHz.  If anyone on here knows how the pattern of the resonance helps EM Drive/Q Thruster thrust - looking at it from the side, six green circles  in two rows tapered end to big end with the two tapered end circles extremely red, the large diameter end all green. I'd love for someone to explain to me what pattern you want to see for maximum thrust.

Anyone want to take a shot at doing better at 914.85MHz?

Also anyone opposed to copper cladded stainless steel - we are going to potentially pressurize the vessel with argon the headache being we will have a PSV.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 03:41 pm
So TE 013 mode; 914.85MHz using HFSS via Eigenmode solver Q of 118602 with an S11 of 15dB; resonance at 914.069MHz.  If anyone on here knows how the pattern of the resonance helps EM Drive/Q Thruster thrust - looking at it from the side, six green circles  in two rows tapered end to big end with the two tapered end circles extremely red, the large diameter end all green. I'd love for someone to explain to me what pattern you want to see for maximum thrust.

Anyone want to take a shot at doing better at 914.85MHz?

Also anyone opposed to copper cladded stainless steel - we are going to potentially pressurize the vessel with argon the headache being we will have a PSV.

Patterns sound right, Q is around what I would expect, maybe a bit low,  S11 rtn loss of 15dB is not good. Would expect to see 35dB or better.

Cu cladded SS should be OK at say 50um thickness but SS is bad for thermal management.

Why Argon? The max E field will be a long way below Kilpatrick Limit.

Please post a screen shot of the mode pattern.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/02/2016 03:46 pm

I DO NOT suggest you use a wide band source.  You need single freq excitment and that freq needs to be adjustable in +-1kHz steps to get the lowest reflected power.

The Windfreak SynthNV has 1 kHz stepsize. And it is rather wideband, I would say.
I have ordered one (https://windfreaktech.com/product/rf-signal-generator-and-power-detector/)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: zellerium on 12/02/2016 03:47 pm
So TE 013 mode; 914.85MHz using HFSS via Eigenmode solver Q of 118602 with an S11 of 15dB; resonance at 914.069MHz.  If anyone on here knows how the pattern of the resonance helps EM Drive/Q Thruster thrust - looking at it from the side, six green circles  in two rows tapered end to big end with the two tapered end circles extremely red, the large diameter end all green. I'd love for someone to explain to me what pattern you want to see for maximum thrust.

Anyone want to take a shot at doing better at 914.85MHz?

Also anyone opposed to copper cladded stainless steel - we are going to potentially pressurize the vessel with argon the headache being we will have a PSV.

What kind of coupler did you use to get that S11?

I don't think anyone can answer which mode is best yet, the TE01X have a relatively high quality which is why Shawyer suggests TE013. But who knows, maybe there is a mode shape in which the dissipation (or whatever the thrust mechanism is) overrides the importance of quality.

What do you mean by "better at 915 MHz"? better quality?
Why 915 MHz? Considering using a magnetron?
Copper cladded shouldn't make a difference as long as its thicker than the skin depth.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: ARW on 12/02/2016 03:50 pm

0.05mm tolerance is fine.

Surface needs to be very smooth, polished to a mirror like finish. NO SCRATCHES.

5 to 6mm thick side walls and min 10mm thick spherical end plates are fine.

Inside will be gold plated. So far I haven't received a reply for my query but based on wheel rim prices it shouldn't be too expensive.

What is the diameter of small and big ends, so someone like Monomorphic can calculate frequency?
With such large size, the operational frequency will be lower than anything tested to date (very good point) and Q should be very high if the frustum is well polished (preferably silver-plated or even gold flash over silver plating) so what do you plan to use as an RF generator?
Do you plan to make the end plates flat or better spherical?

Exact dimensions of the frustum are still in the making. We just had rough idea of the size we wanted  because I had to make a query to get the price. The goal is to have EM drive to operate up to 10kw with spherical end plates.

Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university.

A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected.

There is a lot more involved to get good force generation than just building a frustum and filling it with Rf.

Excitment should be in TE013 as it has low losses and shallow cone angle.  Design and build goal should be a min Qu of 100,000, which can be directly measured via the forward power rise time to 63,2% or 1 TC. 0.05mm build accuracy is OK. Multi layers are ok. Surface finish is of prime importance as it needs to be like optical quality and NO SCRATCHES.

TE013 is also important as in that mode there are no eddy currents that cross from end plate to side wall and the physical end plate to side wall joint will not experience arcing across the joint, which can occur in other modes. I think Dave has pictures of the joint arcs that occured in his frustum.

I DO NOT suggest you use a wide band source.  You need single freq excitment and that freq needs to be adjustable in +-1kHz steps to get the lowest reflected power. Then further tuned to get best static force generation or best dynamic accelerative force generation. Plus your coupler need to be optimised to work without external tuners. IE you may need to be able to move the coupler around and alter orientation.

All doable but not simple nor apparent until you have build a few EmDrives.

Thank you for your feedback. Over the weekend we will be having few meetings to discuss and finalize all the details so I could start working on getting necessary equipment. Feel free to add any other remarks.

Another question I have is how to proceed with end plates, is there a need for any kind of seal or simply bolt 2 pieces together?

Also could you recommend RF generator to match my design vision of up to 10kw.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/02/2016 03:56 pm
Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university.

A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected.

So there are universities involved in this research. Good. I thought Martin Tajmar at Dresden was the only (official) university researcher in this field.
You should also publish if you do not detect thrust (at least at ArXiv).

How do you plan to measure the force? There is a lot of attention for the microwave part at this forum. I have the impression the other necessary part of the game, the force/thrust measurement, is a little bit neglected.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: zellerium on 12/02/2016 04:17 pm

I DO NOT suggest you use a wide band source.  You need single freq excitment and that freq needs to be adjustable in +-1kHz steps to get the lowest reflected power.

The Windfreak SynthNV has 1 kHz stepsize. And it is rather wideband, I would say.
I have ordered one (https://windfreaktech.com/product/rf-signal-generator-and-power-detector/)

Looks like it has great frequency characteristics, but +19 dBm (80 mW) seems pretty small. Even at 4 mN/kW you'd only get 0.32 uN.

Are you going to use more than one amp in series?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: ARW on 12/02/2016 04:29 pm
Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university.

A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected.

So there are universities involved in this research. Good. I thought Martin Tajmar at Dresden was the only (official) university researcher in this field.
You should also publish if you do not detect thrust (at least at ArXiv).

How do you plan to measure the force? There is a lot of attention for the microwave part at this forum. I have the impression the other necessary part of the game, the force/thrust measurement, is a little bit neglected.

My self, I'm a business man with deep passion for science and a dream to fly to space one day. However I do have lots of friends in university as they helped me immensely to start my business a decade ago.

This week I've signed a contract with university for a privately funded research project by my initiative. They like the idea of this kind of research but they wouldn't put their money into it.

Data will be published whether it's successful or not and the measurement methods will have to be worked out by people doing the science. I have masters in engineering and I know a thing or two but we will be discussing details this weekend/month. Official starting date is set in February when university returns to it's normal operation after holiday season, till than we have to finalize the build and start getting necessary equipment.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 04:32 pm

I DO NOT suggest you use a wide band source.  You need single freq excitment and that freq needs to be adjustable in +-1kHz steps to get the lowest reflected power.

The Windfreak SynthNV has 1 kHz stepsize. And it is rather wideband, I would say.
I have ordered one (https://windfreaktech.com/product/rf-signal-generator-and-power-detector/)

Wide band = magnetron freq splatter.

Did say single freq excitment.

Apologies for any confusion.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: CraigPichach on 12/02/2016 04:41 pm

Patterns sound right, Q is around what I would expect, maybe a bit low,  S11 rtn loss of 15dB is not good. Would expect to see 35dB or better.

Cu cladded SS should be OK at say 50um thickness but SS is bad for thermal management.

Why Argon? The max E field will be a long way below Kilpatrick Limit.

Please post a screen shot of the mode pattern.

Awesome feedback.. and thanks for pointing out the thermal management issue. It's going to be a real effort to keep this unit cool.

Argon would be to avoid plasma ignition if that is a real concern. There is a recommendation that this be pressurized with a PSV; what gas would you recommend?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: CraigPichach on 12/02/2016 04:46 pm

What kind of coupler did you use to get that S11?

I don't think anyone can answer which mode is best yet, the TE01X have a relatively high quality which is why Shawyer suggests TE013. But who knows, maybe there is a mode shape in which the dissipation (or whatever the thrust mechanism is) overrides the importance of quality.

What do you mean by "better at 915 MHz"? better quality?
Why 915 MHz? Considering using a magnetron?
Copper cladded shouldn't make a difference as long as its thicker than the skin depth.

Just to be clear I did not do the design but am getting review documents and am trying to be as helpful as possible...  The proposed frustrum is a loop coupled design for ease of build, cost and stress concerns.

By "better at 915MHz" (ok, 914.85MHz) I mean, what would generate more thrust (to get data that would show this is for real above background measurement uncertainties). I know that's a loaded question.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 04:47 pm

0.05mm tolerance is fine.

Surface needs to be very smooth, polished to a mirror like finish. NO SCRATCHES.

5 to 6mm thick side walls and min 10mm thick spherical end plates are fine.

Inside will be gold plated. So far I haven't received a reply for my query but based on wheel rim prices it shouldn't be too expensive.

What is the diameter of small and big ends, so someone like Monomorphic can calculate frequency?
With such large size, the operational frequency will be lower than anything tested to date (very good point) and Q should be very high if the frustum is well polished (preferably silver-plated or even gold flash over silver plating) so what do you plan to use as an RF generator?
Do you plan to make the end plates flat or better spherical?

Exact dimensions of the frustum are still in the making. We just had rough idea of the size we wanted  because I had to make a query to get the price. The goal is to have EM drive to operate up to 10kw with spherical end plates.

Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university.

A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected.

There is a lot more involved to get good force generation than just building a frustum and filling it with Rf.

Excitment should be in TE013 as it has low losses and shallow cone angle.  Design and build goal should be a min Qu of 100,000, which can be directly measured via the forward power rise time to 63,2% or 1 TC. 0.05mm build accuracy is OK. Multi layers are ok. Surface finish is of prime importance as it needs to be like optical quality and NO SCRATCHES.

TE013 is also important as in that mode there are no eddy currents that cross from end plate to side wall and the physical end plate to side wall joint will not experience arcing across the joint, which can occur in other modes. I think Dave has pictures of the joint arcs that occured in his frustum.

I DO NOT suggest you use a wide band source.  You need single freq excitment and that freq needs to be adjustable in +-1kHz steps to get the lowest reflected power. Then further tuned to get best static force generation or best dynamic accelerative force generation. Plus your coupler need to be optimised to work without external tuners. IE you may need to be able to move the coupler around and alter orientation.

All doable but not simple nor apparent until you have build a few EmDrives.

Thank you for your feedback. Over the weekend we will be having few meetings to discuss and finalize all the details so I could start working on getting necessary equipment. Feel free to add any other remarks.

Another question I have is how to proceed with end plates, is there a need for any kind of seal or simply bolt 2 pieces together?

Also could you recommend RF generator to match my design vision of up to 10kw.

Assuming you are using TE013, have flanges on the side wall section,  everything is flat to +-0.025mm, then the end plates should bolt to the side wall flanges with almost no gap. Suggest at least 12 bolts through the min 10mm thick end plate flange  and into the min 10mm thick side wall flange.

While I'm sure there are 10kW solid state Rf amps, I really suggest that 100W is more than enough to generate easily measurable static force using a simple scale based test setup. Would suggest 60mN or 6g of force should be doable with 100W.

Please read Roger's 2 detailed enginerring reports, which explain how he measured the forces his EmDrives generated.

I hate reinventing the wheel and will ak5ways try to 1st go with what has been shown to work
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 04:50 pm

What kind of coupler did you use to get that S11?

I don't think anyone can answer which mode is best yet, the TE01X have a relatively high quality which is why Shawyer suggests TE013. But who knows, maybe there is a mode shape in which the dissipation (or whatever the thrust mechanism is) overrides the importance of quality.

What do you mean by "better at 915 MHz"? better quality?
Why 915 MHz? Considering using a magnetron?
Copper cladded shouldn't make a difference as long as its thicker than the skin depth.

Just to be clear I did not do the design but am getting review documents and am trying to be as helpful as possible...  The proposed frustrum is a loop coupled design for ease of build, cost and stress concerns.

By "better at 915MHz" (ok, 914.85MHz) I mean, what would generate more thrust (to get data that would show this is for real above background measurement uncertainties). I know that's a loaded question.

Would suggest a side wall mounted 1/2 circle current loop is good.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/02/2016 04:50 pm

What kind of coupler did you use to get that S11?

I don't think anyone can answer which mode is best yet, the TE01X have a relatively high quality which is why Shawyer suggests TE013. But who knows, maybe there is a mode shape in which the dissipation (or whatever the thrust mechanism is) overrides the importance of quality.

What do you mean by "better at 915 MHz"? better quality?
Why 915 MHz? Considering using a magnetron?
Copper cladded shouldn't make a difference as long as its thicker than the skin depth.

Just to be clear I did not do the design but am getting review documents and am trying to be as helpful as possible...  The proposed frustrum is a loop coupled design for ease of build, cost and stress concerns.

By "better at 915MHz" (ok, 914.85MHz) I mean, what would generate more thrust (to get data that would show this is for real above background measurement uncertainties). I know that's a loaded question.

In my theory as well as @Notsosureofit's theory, "for a given set of dimensions" the thrust is inversely proportional to the frequency. However, if you scale up the dimensions to get a lower frequency, the expected thrust remains unchanged for the same value of Q. Primarily, thrust will depend on the internal pressure due to a high Q, and the amount of leakage through voltage drop and power dissipation that is asymmetrical on the surface of the cavity. So one end runs cool, the other end runs hot.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 05:01 pm

Patterns sound right, Q is around what I would expect, maybe a bit low,  S11 rtn loss of 15dB is not good. Would expect to see 35dB or better.

Cu cladded SS should be OK at say 50um thickness but SS is bad for thermal management.

Why Argon? The max E field will be a long way below Kilpatrick Limit.

Please post a screen shot of the mode pattern.

Awesome feedback.. and thanks for pointing out the thermal management issue. It's going to be a real effort to keep this unit cool.

Argon would be to avoid plasma ignition if that is a real concern. There is a recommendation that this be pressurized with a PSV; what gas would you recommend?

I doubt that your cavity will have E field above 50Mv/m. More likely a lot lower. Max E field increases as the sqrt of the incressed power. So increase pwr 9x, E field increases 3x and H field increases 3x.

Why do you want to use 10kW? 100W should be fine. Please don't take the NASA 1.2mN/kW as being representative. SPR'S Flight Thruster at 326mN/kW is closer to reality and that was with spherical end plates and a Q of 60,000.
http://www.emdrive.com/flightprogramme.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: CraigPichach on 12/02/2016 05:01 pm

Would suggest a side wall mounted 1/2 circle current loop is good.

What's your take on reaction time? You think if we put in a MW you would see something in a microsecond shot on a digitally recorded scale? Paul March had a simulation at 100kW that had a quick time response.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 05:25 pm

Would suggest a side wall mounted 1/2 circle current loop is good.

What's your take on reaction time? You think if we put in a MW you would see something in a microsecond shot on a digitally recorded scale? Paul March had a simulation at 100kW that had a quick time response.

Tuning is much more critical than most realise.  When I measured the thrust bandwidth it was very much narrower than the S11 rtn loss bandwidth. And best thrust freq was NOT the lowest reflected power freq but it was close.

When I had tuned for best thrust freq, force generation was instant with Rf power on. Remember my frustum sat on top of my scale, so there was already force on the strain gauges and mechanics of the scale.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: InterestedEngineer on 12/02/2016 05:29 pm

Why do you want to use 10kW? 100W should be fine. Please don't take the NASA 1.2mN/kW as being representative. SPR'S Flight Thruster at 326mN/kW is closer to reality and that was with spherical end plates and a Q of 60,000.
http://www.emdrive.com/flightprogramme.html

The lower the input power, the lower the measurement error due to thermal effects and Lorentz forces.  Another reason to go with 100W.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: PotomacNeuron on 12/02/2016 05:53 pm
ARW, you have gotten many suggestions from the supporters. Here are suggestion from a skeptic. Many of them may have already been suggested.

1. Do not go with 10KW. Stick to 100W or 50W, so that you can use a Cavendish balance with on-board battery power supply. Those are light, capable of tens of Ampares for an hour or more.
2. Use an RF or light controlled power switch. I have a tested non-magnetic switch design that you can obtain with 0 cost.
3. Use the NASA EW style signal chain with PLL.
4. Monitor the reflected power and feed-forward power.
5. Cut all ground loops to contain Lorentz force (this was missed by the EW team)
6. Do a cylinder control test
7. Do a DC control test (short the amp, feed the same amount of DC current, use lower supply voltage, of course) to detect Lorentz force. I have a tested non-magnetic current source design you can obtain with 0 cost.
8. Or do 7 with a properly sized resistor at the place of the amplifier.
9. Rotate your test apparatus to test 8 different directions to assess the earth magnetic field influence (again Lorentz force)
10. Or, use Helmholtz coils for 9
11. If you do the test in vacuum, do it under 1 air pressure, 0.1, 0.01, 0.001, 0.0001,... to assess the Crookes effect.
12. Think of other ways to control for thermal displacement (for example, test when you use wires with different sizes to hang the balance)
13. Use thermal camera to confirm the oscillation pattern of your cavity
14. Do thermal control tests, such as that in 8.
15+. Any important things I have missed.

Better come here often so we can criticize your design.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Bob012345 on 12/02/2016 06:01 pm
I thought you'd know by now how TT will answer. The route this conversation takes goes as follows:

1) Statement that the theoretical explanations on offer are non-nonsensical
2) Contradictions are rebuffed by endorsing data above theory
3) Statements to the effect that all theories are flawed but the good ones still make physical sense
4) Appeal to the authority of Shawyer because he made EM Drive work
5) Go to 1
I know, I am just giving it one last shot in light of the new thread (and for casual readers who look through the first few pages of a thread), my response to #2 this time (unless TT changes his pattern, and actually answers my questions) is planned to be along the lines of "I am tired of this cycle but figured I would give it one last shot. Just know that in the future when no one counters your claims it is only because everyone has given up on you listening to reason."

Data is above theory. Throwing out solid data that doesn't 'fit' current theory is not good science. Of course the key is having good reliable data not just any data. That's what NASA tried to do.
There is no data throwing out going on. My response to this is number 3 from RotoSequence's list, no data can save an inconsistent theory.

Any closed mechanical system should not provide a means to generate net momentum yet an electromagnetic system might since it is related to relativity, quantum field theory and at least weakly to gravitation.
"relativity, quantum field theory, and gravitation" does not magically make a closed system an open one. For a system to be open, it needs to interact with something else by some mechanism. Of what you listed only gravitation is a mechanism (for the purpose of the definition I just provided), the others in no way make a system open, they are just physics frameworks. Even for gravity, you did not state what it would be interacting with. Also an electromagnetic system should have smaller coupling to gravity than a purely mechanical one (as implied when you said "weakly"), so that doesn't make a strong argument.

There you go again. :) I actually don't have to state what it is. I stated it as places people are looking. And they are. I never said anything was magic. The point is I'm not confident that these fields are 100% able to make absolute statements on the EmDrive without further thought and lots of it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: zellerium on 12/02/2016 06:02 pm

Would suggest a side wall mounted 1/2 circle current loop is good.

What's your take on reaction time? You think if we put in a MW you would see something in a microsecond shot on a digitally recorded scale? Paul March had a simulation at 100kW that had a quick time response.

Tuning is much more critical than most realise.  When I measured the thrust bandwidth it was very much narrower than the S11 rtn loss bandwidth. And best thrust freq was NOT the lowest reflected power freq but it was close.

...

Does anyone have a theory for why the thrust bandwidth is narrower than the return loss bandwidth? And why optimum thrust occurs is NOT at the lowest reflection?
Assuming these are both true and not due to measurement error, it strikes me as odd.
TT could you put some estimated numbers to it? For example, did the optimum thrust occur at an S11 of -20 dB  rather than the minimum of -50 dB?
What is the difference between a signal injected into a cavity at -20 and -50?
Besides the obvious change in phase and magnitude of reflected power...

I wonder if there is an ideal phase of the reflection coefficient, TT did you ever plot your return loss on a Smith Chart?
What do you think the ideal magnitude of the reflection coefficient would be?

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/02/2016 06:16 pm

Now, a planet will gain or add mass spontaneously through gravity. So, for matter addition is a spontaneous process. But, subtracting mass by moving it away from the planet will require energy and is not a spontaneous process. Matter subtraction is not a spontaneous process.

Although it is true that a planet will gain mass through its gravitation field pulling in other matter, it is also worth noting that nuclear processes within the planet or star will result in the planet/star giving off a significant amount of energy. This radiation/energy will escape the gravitation field excepting for black holes(in theory). So there is also a loss occurring simultaneously(though it may or may not be as large as the gains depending on many other factors.

I believe that the universe is somehow spontaneously “falling” and moving into the lowest rate of time possible; nothingness.... So, beyond the geometry of it all, the same type of cause is behind both the spontaneous multiplication or aggregation of matter and the spontaneous division or expansion of the universe.... This is a “different way” (to say the least) in which to consider how the universe naturally effects simple mathematical operations.

So if I understand the theory you are proposing could be succinctly stated as:
1. "All matter/energy is attracted toward the lowest rate of time possible."
2. "Since general relativity shows that higher gravitation fields experience slower time, matter is pulled into these fields which is what we see as gravity."

Does that summarize what you are saying? Would like to make sure I'm clear on your hypothesis.

1. and 2. are not my theory but essentially the lesson of GR as described in Unruh's quote. "My" theory is much wider and as simple. Much of it appears in the essay associated with my poster presentation at the Science of Time 2016. I call it an "essay" instead of a "paper" since it was not accepted for publication in the proceedings of the conference; deemed off topic. (Essay attached; reposted)

http://sot2016.cfa.harvard.edu/SoT2016/cgi-bin/TXT/Poster/Oral_LeBelMarcelMarie.txt_N.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/02/2016 06:19 pm

Would suggest a side wall mounted 1/2 circle current loop is good.

What's your take on reaction time? You think if we put in a MW you would see something in a microsecond shot on a digitally recorded scale? Paul March had a simulation at 100kW that had a quick time response.

Tuning is much more critical than most realise.  When I measured the thrust bandwidth it was very much narrower than the S11 rtn loss bandwidth. And best thrust freq was NOT the lowest reflected power freq but it was close.

...

Does anyone have a theory for why the thrust bandwidth is narrower than the return loss bandwidth? And why optimum thrust occurs is NOT at the lowest reflection?
Assuming these are both true and not due to measurement error, it strikes me as odd.
TT could you put some estimated numbers to it? For example, did the optimum thrust occur at an S11 of -20 dB  rather than the minimum of -50 dB?
What is the difference between a signal injected into a cavity at -20 and -50?
Besides the obvious change in phase and magnitude of reflected power...

I wonder if there is an ideal phase of the reflection coefficient, TT did you ever plot your return loss on a Smith Chart?
What do you think the ideal magnitude of the reflection coefficient would be?

Paul March and I once discussed it as he found the same thing. Roger explained to us why the thrust bandwidth is narrower than the rtn loss bandwidth. Which is because both Q and forward power drop together as the freq moves off lowest reflected power / best rtn loss and force is based on (2 Qu Pwr Df) / c.

I believe that lowest reflected power to the Rf amp is not the lowest phase distortion in the internal standing wave and going slightly off freq injects a phase distortion that compensates for the internal phase distortion, which improves force generation.

Maybe Paul can comment?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/02/2016 07:02 pm

I DO NOT suggest you use a wide band source.  You need single freq excitment and that freq needs to be adjustable in +-1kHz steps to get the lowest reflected power.

The Windfreak SynthNV has 1 kHz stepsize. And it is rather wideband, I would say.
I have ordered one (https://windfreaktech.com/product/rf-signal-generator-and-power-detector/)

Looks like it has great frequency characteristics, but +19 dBm (80 mW) seems pretty small. Even at 4 mN/kW you'd only get 0.32 uN.

Are you going to use more than one amp in series?

Indeed, I am going to use an amp to get into the range 4-10 W.
0.3 uN will not be enough, indeed. That is close to the threshold level of my torsion balance.
But Eagleworks reached 55 uN with 2.6 W of input in the TE012 mode [Brady et al, 2014].
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/02/2016 07:07 pm
I know there's been some talk about the drive pushing against some quantum vacuum, but maybe something like this (http://www.sciencealert.com/we-just-got-the-first-real-evidence-of-a-strange-quantum-distortion-in-empty-space) is what's happening? Not sure if it's some separate phenomenon, or just a bigger version of the same thing, but it seems like something to add.

To put it clearly, this new cosmological observation shows a known consequence of electron-positron pair production, where those particles pop into existence from the quantum vacuum and become real for a very short instant (less then 3.2×10-22 s).

Dr White at Eagleworks thinks those ephemeral charged particles can be treated as a virtual plasma which can be pushed on with Lorentz E×B forces like a magnetohydrodynamic drive does with salt sea water or a ionized gas. The thruster then reacts forward against this "virtual wake". It is White's Quantum Vacuum Fluctuation (QVF) conjecture that supports his concept of quantum vacuum plasma thruster, or Q-thruster.

Several remarks from Jim Woodward and Heidi Fearn criticizing White's QVF conjecture:

1. The quantum vacuum would need to be degradable, but most scientists think the quantum vacuum is immutable.

2. Momentum would be conserved as the drive reacts against an ep wake, but what happens to the conservation of momentum when the ep pairs pop out of existence once they have been pushed on?

3. According to quantum theory and observations, in order for those electron-positron pairs to appear, tremendous magnetic or electric fields are needed at the Schwinger limit (the critical QED vacuum breakdown magnetic field strength is 1010 Tesla, and the critical QED vacuum breakdown electric field strength is about 1018 V/m) way beyond what occurs in an EmDrive, and still one or two orders of magnitude away from the most powerful laser available.

4. Notwithstanding if the ep pairs could still be produced in the EmDrive, as pointed out by WarpTech (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1612837#msg1612837), the temperature at which electron and positron annihilate each other is in excess of 108 Kelvin. If ep pairs in the frustum had a density ~1×1012 kg/m3, and a life time of ~10-22 s, the frustum would be vaporized from the heat, faster than dropping it onto the surface of the sun.

5. MHD interaction length is way too short with ep pairs lasting 3×10-22 s, before they pop out of existence. Thanks to Eagleworks COMSOL data we know E = 3780 V/m and cavity Q = 7000. Starting from rest, the electron would reach a velocity of 2.1×10-7m/s during its lifetime. But let's be generous and assume the velocity of the charged particles is 1 m/s, and they travel at that velocity for their entire lifetime (instead of accelerating to this velocity from zero). Then, even with this very optimistic velocity, the longest distance they can travel before annihilation is 3×10-22 m. Hydrodynamics is the appropriate effective theory for describing any fluid medium at sufficiently long length scales. Considering the diameter of an average atomic nucleus is 10-15 m, hydrodynamics laws and by extension magnetohydrodynamics cannot apply to the quantum vacuum plasma.

6. To account for the anomalous force observed with Eagleworks frustum, an enormous quantity of ep pairs generously accelerated up to 1 m/s is needed as a reaction mass: 1.5×1031 kg (the mass of the Sun is 2×1030 kg…)! Even considering the extreme unlikely case where those charged particles could accelerate near the speed of light, the total required mass would be no less than 5.5×105 kg, still disproportionate. Such wake if present would not stay unnoticed.

7. Jim Woodward and Heidi Fearn set up a dedicated experiment last year at their LetsHopeItWorks lab to detect pair production in a vacuum and such "quantum wake" with a Q-thruster. Over 200 runs, no ep pair have been detected.

Those issues have been detailed by Woodward and Fearn in their recent JBIS paper* where they squarely conclude the quantum vacuum plasma does not exist.

Paul March has answered the critics of point (4) above in this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1612848#msg1612848):
Quote from: Star-Drive
"My conclusion has been that, the temperature at which electron-positron pairs annihilate each other is in excess of 108 Kelvin."

Again you are making the assumption that the e/p pairs are fully fleshed out in our universe, which does require 0.511 MeV per particle and that would indeed melt the frustum if fully developed.  What Dr. White's QV conjecture posits is that these virtual force carriers can be expressed in our reality with a variable effective mass/energy density that goes from just barely here to fully here at the Schwinger limit energy densities. Of course the only way to prove this QV conjecture is to test a given frustum design over a broad input power range of four orders of magnitude or greater to see if it generates the COMSOL/QV Plasma code's EW copper frustum's TM010 thrust predictions I posted at NSF.com earlier, or not.

Best, Paul M.

OK, but if such "densification" mechanism indeed occurs allowing the ep pairs to really become "barely here" at considerably lower energies (vs "completely here" at the Schwinger limit which is beyond our reach) aren't their variable mass/energy density also "barely here" in this case? Thus an even much greater amount of those "almost-real" ep pairs would be needed to account for the total reaction mass calculated in point (6) which would become really unphysical.

* Fearn, H.; Woodward, J. F. (May 2016) "Breakthrough Propulsion I: The Quantum Vacuum" (http://www.bis-space.com/eshop/products-page-2/magazines/jbis/jbis-2016/jbis-vol-69-no-05-may-2016/), JBIS 59(5).
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Fan Boi on 12/02/2016 07:07 pm
I wanted to comment that if someone really wants to build the "perfect" cavity perhaps it should treated like an optical cavity and let a company that manufactures telescope lens/mirrors build the frustum. They should be able to get the surface as good as anyone can. Just a thought...
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Star-Drive on 12/02/2016 07:09 pm

Would suggest a side wall mounted 1/2 circle current loop is good.

What's your take on reaction time? You think if we put in a MW you would see something in a microsecond shot on a digitally recorded scale? Paul March had a simulation at 100kW that had a quick time response.

Tuning is much more critical than most realise.  When I measured the thrust bandwidth it was very much narrower than the S11 rtn loss bandwidth. And best thrust freq was NOT the lowest reflected power freq but it was close.

...

Does anyone have a theory for why the thrust bandwidth is narrower than the return loss bandwidth? And why optimum thrust occurs is NOT at the lowest reflection?
Assuming these are both true and not due to measurement error, it strikes me as odd.
TT could you put some estimated numbers to it? For example, did the optimum thrust occur at an S11 of -20 dB  rather than the minimum of -50 dB?
What is the difference between a signal injected into a cavity at -20 and -50?
Besides the obvious change in phase and magnitude of reflected power...

I wonder if there is an ideal phase of the reflection coefficient, TT did you ever plot your return loss on a Smith Chart?
What do you think the ideal magnitude of the reflection coefficient would be?

Paul March and I once discussed it as he found the same thing. Roger explained to us why the thrust bandwidth is narrower than the rtn loss bandwidth. Which is because both Q and forward power drop together as the freq moves off lowest reflected power / best rtn loss and force is based on (2 Qu Pwr Df) / c.

I believe that lowest reflected power to the Rf amp is not the lowest phase distortion in the internal standing wave and going slightly off freq injects a phase distortion that compensates for the internal phase distortion, which improves force generation.

Maybe Paul can comment?

Phil:

Until I have more data in hand Shawyer's explanation is as good as any for the difference in the S11 tracked minima frequency verses force output maximum frequency being different, but IMO all explanations of why this is so have to address the relative phase between the E&M fields in the frustum through all flight regimes.

BTW, in a private post Phil asked me to post my March 2014 TE012 Testing Clarification presentation for all to see.  Since it now appears unlikely that I will be able to get to add these observations as an addendum to the EW 2014 AIAA/JPP paper that covered those tests, I might as well post them here for the record.  I'm still chewing on what Dr. Woodward had to say about it though, so I have no grand observations about this experimental clarification at this time other than to say that the new way of looking at this data indicates that your argument over the direction of thrust for semi-static verses dynamic thrust vector directions for these frustum drives may be related the the induced Doppler shift of the accelerated copper frustum ions and internal E&M standing waves, but this surmise on my part is still very green in nature and it needs a lot of experimentation to validate or refute it.

BTW, for anyone who is considering performing a replication of these frustum thruster experiments, I recommend that you do NOT use a phased locked loop (PLL) resonant frequency tracking control, but instead use a digital S11 minima frequency tracking program with XXX degrees of phase offset vernier control using an RF bidirectional coupler for your controlling forward and reflected RF power signals to the S11 program and a separate phase detector between the E&B field at the frustum antenna port as your active inputs to the program.  You will get much more consistent thrust output results over extended run times than using the PLL frequency control approach.

Correction: The phase between the input E&B fields and the standing wave in the frustum cavity before and during acceleration of the frustum.

Best, Paul M.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Stormbringer on 12/02/2016 07:34 pm

Several remarks from Jim Woodward and Heidi Fearn criticizing White's QVF conjecture:

1. The quantum vacuum would need to be degradable, but most scientists think the quantum vacuum is immutable.

Comment from the back of the peanut gallery here:   It is my understanding of what is meant by quantum vacuum is seething ever changing froth of ghostly semi real stuff popping in and out of existence that is only immutable in the sense that violations of physical laws cannot exceed a threshold of duration that would make them permanent features of the normal universe. That said there are special circumstances where stuff from the quantum vacuum can be rendered a permanent feature. E.G; one virtual particle on one side of an event horizon and it's partner on the other side, or both on the outside of an event horizon side but one travels into the point of no return, or one is given energy by an outside source that is equal to the mass of one or both virtual particles...

Anyway the idea that the vacuum is immutable seems to be problematic in that if you temporarily emptied a volume of space of all virtual particles it would change but once you stopped preventing virtual particles from doing their thing the vacuum would return to it's original state in the area you had suppressed.

For example:  if you set up Casimir plates the volume between the plates would have less virtual particle creation. Once you separated the plates the virtual particle activity in the space that used to be constrained between the plates would return to normal.

Just speaking as a layman it seems really counter-intuitive to suggest the quantum vacuum is immutable since it seems to me it's primary trait is its chaotic ever changing elastic nature.

EDIT:  Add to that the idea of vacuum potential or false vacuum. Its' the notion that the present state of space time constants and the like do not represent the fabric of space time at it's lowest vacuum potential state and there is a finite but tiny chance that the universe and it's rules could collapse to a lower vacuum state which would be the end of everything in it.

If it were possible to depress or raise this vacuum potential temporarily without irreparably damaging it I imagine it springing back to normal as fast as it can once the deforming stress is removed.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/02/2016 08:41 pm

Several remarks from Jim Woodward and Heidi Fearn criticizing White's QVF conjecture:

1. The quantum vacuum would need to be degradable, but most scientists think the quantum vacuum is immutable.

Comment from the back of the peanut gallery here:   It is my understanding of what is meant by quantum vacuum is seething ever changing froth of ghostly semi real stuff popping in and out of existence that is only immutable in the sense that violations of physical laws cannot exceed a threshold of duration that would make them permanent features of the normal universe. That said there are special circumstances where stuff from the quantum vacuum can be rendered a permanent feature. E.G; one virtual particle on one side of an event horizon and it's partner on the other side, or both on the outside of an event horizon side but one travels into the point of no return, or one is given energy by an outside source that is equal to the mass of one or both virtual particles...

Anyway the idea that the vacuum is immutable seems to be problematic in that if you temporarily emptied a volume of space of all virtual particles it would change but once you stopped preventing virtual particles from doing their thing the vacuum would return to it's original state in the area you had suppressed.

For example:  if you set up Casimir plates the volume between the plates would have less virtual particle creation. Once you separated the plates the virtual particle activity in the space that used to be constrained between the plates would return to normal.

Just speaking as a layman it seems really counter-intuitive to suggest the quantum vacuum is immutable since it seems to me it's primary trait is its chaotic ever changing elastic nature.

EDIT:  Add to that the idea of vacuum potential or false vacuum. Its' the notion that the present state of space time constants and the like do not represent the fabric of space time at it's lowest vacuum potential state and there is a finite but tiny chance that the universe and it's rules could collapse to a lower vacuum state which would be the end of everything in it.

If it were possible to depress or raise this vacuum potential temporarily without irreparably damaging it I imagine it springing back to normal as fast as it can once the deforming stress is removed.

There are two very different interpretations of what we call the Quantum Vacuum.

1. The layman's interpretation, the one promoted most of the time is one where electron-positron pairs and other fermion pairs pop into, and out of existence randomly at time scales much less than the energy borrowed. This is all fine and dandy if your talking about the Dirac field. The field that governs the behavior of fermions.

2. There is also the Electromagnetic Quantum Vacuum, which is not fermions but rather bosons, photons. In this case, we treat space as a cavity resonator and we calculate the ground state of this cavity. Then we let the cavity expand to fill the entire universe. What remains is the Electromagnetic Zero-Point field. This is not something that pops into and out of existence. It is there, it is continuous. It is the ground state of the EM field and the field that sets the minimum ground state excitation of the Dirac field. The energy of the field cannot drop to zero, a state where the EM field vanishes completely. That is what is meant by immutable.

I happen to believe that the QV is degradable, but only in the sense that as energy is absorbed and dissipated by matter, the frequencies that make up the QV are being degraded to lower frequencies. i.e, Entropy.

IMO, is is the Electromagnetic Quantum Vacuum that we should focus on, not the Fermion field. I believe that the fermions do not pop into existence "unless" there is enough energy stored there in the EM field to allow for dielectric breakdown of the vacuum. Heisenberg's equation is simply saying, if the time or distance is so short that a full cycle of the wave cannot be measured before it is annihilated, then it isn't observable. "Therefore" it could be happening, but we don't know it. It does not say, nor could it say that these things MUST happen.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Stormbringer on 12/02/2016 09:06 pm
Will The Heisenberg cycle limit thing need to be adjusted now that it is technologically possible to observe objects far smaller than the wave length of light used to illuminate an object using light? I just read an article several day ago about such a breakthrough. It was not about non light based microscopy such as ion field probe, electron or the like.

It seems that if you can now resolve objects at  1/4 or less the length of one wave cycle now that it tightens  up ol' Heisenberg in that sense.

http://www.cantechletter.com/2016/11/worlds-smallest-magnifying-glass-amazing-things/

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/02/2016 09:38 pm
Will The Heisenberg cycle limit thing need to be adjusted now that it is technologically possible to observe objects far smaller than the wave length of light used to illuminate an object using light? I just read an article several day ago about such a breakthrough. It was not about non light based microscopy such as ion field probe, electron or the like.

It seems that if you can now resolve objects at  1/4 or less the length of one wave cycle now that it tightens  up ol' Heisenberg in that sense.

http://www.cantechletter.com/2016/11/worlds-smallest-magnifying-glass-amazing-things/

Nope, doesn't change anything. The observables are mutually exclusive. If we measure the wavelength at less than 1 wavelength, we still have no idea what the actual momentum is. And vise versa.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Stormbringer on 12/02/2016 10:37 pm

One last quibble... You can exclude photons or wavelengths from the space between Casimir plates or spheres too because of the discrete indivisible nature of quantum values for these things. I.E; you cannot have a fraction of a photon and so on. the photon or the wave simply does not fit.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Josave on 12/02/2016 11:15 pm
Assuming TE013 excitment and Df around 0.8, freq would be around 1.5GHz (middle of L band) as a VERY rough guess.

In this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1612609#msg1612609) ARW wanted to go the high power route with an RF source in the kilowatt range.

What kind of narrow band source available on the market can output ~1 kWrf at ~1.5GHz besides klystrons?

Actually the LDMOS and GaN technologies can reach 1.1 Kw up to frequencies of 1.2 GHz. There are transistors like the AFV121KH, BLA6H0912L or 1011GN-1200V. All of them for military applications, pulsed power or continuous wave.

A much cheaper option is to go for the MHT1004N LDMOS transistor that can deliver up to 300W of continuous wave at 2.45 GHz.

Another possibility proposed in a post by Mikegem is testing this RF heating device, that can save the time and money needed to develop a RF circuit board, and the best of all is that the lithium batteries are included:

Quote

Apologies if too far off topic. This is for all who are dealing with magnetrons and their idiosyncracies.

A small microwave oven/food heater based on LDMOS transistors is apparently being introduced. Power is 200 Watts, although it's not clear whether that refers to microwave power delivered to the load or power draw of the total device. Price will be US $199. If true, this is a very interesting development for any technology that needs appreciable microwave power at low cost. This may make it easier to build microwave power sources that are more stable and controllable than with magnetrons. Company's site is: http://www.wayvtech.com/#wayv I have no connection with the company at all, just thought it might be of interest to some here. https://vimeo.com/166847042 Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: dustinthewind on 12/03/2016 12:30 am Several remarks from Jim Woodward and Heidi Fearn criticizing White's QVF conjecture: 1. The quantum vacuum would need to be degradable, but most scientists think the quantum vacuum is immutable. Comment from the back of the peanut gallery here: It is my understanding of what is meant by quantum vacuum is seething ever changing froth of ghostly semi real stuff popping in and out of existence that is only immutable in the sense that violations of physical laws cannot exceed a threshold of duration that would make them permanent features of the normal universe. That said there are special circumstances where stuff from the quantum vacuum can be rendered a permanent feature. E.G; one virtual particle on one side of an event horizon and it's partner on the other side, or both on the outside of an event horizon side but one travels into the point of no return, or one is given energy by an outside source that is equal to the mass of one or both virtual particles... Anyway the idea that the vacuum is immutable seems to be problematic in that if you temporarily emptied a volume of space of all virtual particles it would change but once you stopped preventing virtual particles from doing their thing the vacuum would return to it's original state in the area you had suppressed. For example: if you set up Casimir plates the volume between the plates would have less virtual particle creation. Once you separated the plates the virtual particle activity in the space that used to be constrained between the plates would return to normal. Just speaking as a layman it seems really counter-intuitive to suggest the quantum vacuum is immutable since it seems to me it's primary trait is its chaotic ever changing elastic nature. EDIT: Add to that the idea of vacuum potential or false vacuum. Its' the notion that the present state of space time constants and the like do not represent the fabric of space time at it's lowest vacuum potential state and there is a finite but tiny chance that the universe and it's rules could collapse to a lower vacuum state which would be the end of everything in it. If it were possible to depress or raise this vacuum potential temporarily without irreparably damaging it I imagine it springing back to normal as fast as it can once the deforming stress is removed. There are two very different interpretations of what we call the Quantum Vacuum. 1. The layman's interpretation, the one promoted most of the time is one where electron-positron pairs and other fermion pairs pop into, and out of existence randomly at time scales much less than the energy borrowed. This is all fine and dandy if your talking about the Dirac field. The field that governs the behavior of fermions. 2. There is also the Electromagnetic Quantum Vacuum, which is not fermions but rather bosons, photons. In this case, we treat space as a cavity resonator and we calculate the ground state of this cavity. Then we let the cavity expand to fill the entire universe. What remains is the Electromagnetic Zero-Point field. This is not something that pops into and out of existence. It is there, it is continuous. It is the ground state of the EM field and the field that sets the minimum ground state excitation of the Dirac field. The energy of the field cannot drop to zero, a state where the EM field vanishes completely. That is what is meant by immutable. I happen to believe that the QV is degradable, but only in the sense that as energy is absorbed and dissipated by matter, the frequencies that make up the QV are being degraded to lower frequencies. i.e, Entropy. IMO, is is the Electromagnetic Quantum Vacuum that we should focus on, not the Fermion field. I believe that the fermions do not pop into existence "unless" there is enough energy stored there in the EM field to allow for dielectric breakdown of the vacuum. Heisenberg's equation is simply saying, if the time or distance is so short that a full cycle of the wave cannot be measured before it is annihilated, then it isn't observable. "Therefore" it could be happening, but we don't know it. It does not say, nor could it say that these things MUST happen. What if photons are electron-positron pairs such that when the pairs merge they appear to have zero rest mass. Photons being low level osculations of those pairs, hence the electro-magnetic fields (via their separation) and apparent zero rest mass but when separated a bit have effective mass. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/03/2016 12:34 am Assuming TE013 excitment and Df around 0.8, freq would be around 1.5GHz (middle of L band) as a VERY rough guess. In this post (http://forum.nasaspaceflight.com/index.php?topic=40959.msg1612609#msg1612609) ARW wanted to go the high power route with an RF source in the kilowatt range. What kind of narrow band source available on the market can output ~1 kWrf at ~1.5GHz besides klystrons? Actually the LDMOS and GaN technologies can reach 1.1 Kw up to frequencies of 1.2 GHz. There are transistors like the AFV121KH, BLA6H0912L or 1011GN-1200V. All of them for military applications, pulsed power or continuous wave. A much cheaper option is to go for the MHT1004N LDMOS transistor that can deliver up to 300W of continuous wave at 2.45 GHz. Another possibility proposed in a post by Mikegem is testing this RF heating device, that can save the time and money needed to develop a RF circuit board, and the best of all is that the lithium batteries are included: Quote Apologies if too far off topic. This is for all who are dealing with magnetrons and their idiosyncracies. A small microwave oven/food heater based on LDMOS transistors is apparently being introduced. Power is 200 Watts, although it's not clear whether that refers to microwave power delivered to the load or power draw of the total device. Price will be US$199.

If true, this is a very interesting development for any technology that needs appreciable microwave power at low cost. This may make it easier to build microwave power sources that are more stable and controllable than with magnetrons.

Company's site is: http://www.wayvtech.com/#wayv

I have no connection with the company at all, just thought it might be of interest to some here.

https://vimeo.com/166847042

That is a VERY interesting unit. Can't wait to hack it and design a frustum add-on. For sure there will be others. Curious what the cavity & antenna/coupler are like and the operating freq.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/03/2016 12:37 am

One last quibble... You can exclude photons or wavelengths from the space between Casimir plates or spheres too because of the discrete indivisible nature of quantum values for these things. I.E; you cannot have a fraction of a photon and so on. the photon or the wave simply does not fit.

The Casimir effect is just evidence of what I'm saying. No argument there, but it is a matter of information, or the lack thereof that is the problem. The philosophical look at it is simply that we can't know what we can't observe with suitable accuracy. An issue the readers of this thread are all too aware of.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/03/2016 12:55 am

That is a VERY interesting unit. Can't wait to hack it and design a frustum add-on. For sure there will be others. Curious what the cavity & antenna/coupler are like and the operating freq.

If it's meant to heat food and beverages, wouldn't you expect it to have a wide bandwidth with lots of splatter?

I would. It's cheaper.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Stormbringer on 12/03/2016 01:35 am

http://www.nextbigfuture.com/2016/12/cannae-will-try-to-prove-propellentless.html

the ambitious bit about deep space probes to .1 ly in 15 years travel time.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/03/2016 01:37 am
ARW, since you are new to posting in this forum, I do not know how much of the history of these threads you have gone through, but assuming it is not much there is some context you should be aware of. The Traveller has given you a lot of advice and much of it is good, but many of the things he says have nothing to back them up. For example, in the post quoted below he dismisses the actual, high quality experiments by EW as "not representative of reality". He instead quotes figures from Shawyer, when no other emDrive builder has gotten results close to Shawyer's, and Shawyers results are suspect due to insufficient data released for replication, known issues with the data that has been released, and the fact that Shawyer has demonstrated an inability to do a simple force balance.

Some of what TheTraveller posts is based on sound RF engineering, but other things are rules of thumb he got from Shawyer, when there is no evidence Shawyer has actually done the types of tests that would be required to determine them.

TT will inevitably respond to this saying to not listen to me, because I'm not a builder and therefore I don't know anything. My goal is just to give you context not advice. (If I did give advice it would largely mirror PotomacNeuron's advice above for minimizing error sources) As some additional context, TT's experience with building an emDrive is building a single one, which he has only provided hand sketches of and not a single picture. His explanation involves his RF equipment burning out during testing (a common occurrence here due to the nature of these experiments), but I still haven't figured out how that prevents him from taking a picture of the frustum. He supposedly is working on his second one now.

I doubt that your cavity will have E field above 50Mv/m. More likely a lot lower. Max E field increases as the sqrt of the incressed power. So increase pwr 9x, E field increases 3x and H field increases 3x.

Why do you want to use 10kW? 100W should be fine. Please don't take the NASA 1.2mN/kW as being representative. SPR'S Flight Thruster at 326mN/kW is closer to reality and that was with spherical end plates and a Q of 60,000.
http://www.emdrive.com/flightprogramme.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Nerm999 on 12/03/2016 03:07 am

0.05mm tolerance is fine.

Surface needs to be very smooth, polished to a mirror like finish. NO SCRATCHES.

5 to 6mm thick side walls and min 10mm thick spherical end plates are fine.

Inside will be gold plated. So far I haven't received a reply for my query but based on wheel rim prices it shouldn't be too expensive.

What is the diameter of small and big ends, so someone like Monomorphic can calculate frequency?
With such large size, the operational frequency will be lower than anything tested to date (very good point) and Q should be very high if the frustum is well polished (preferably silver-plated or even gold flash over silver plating) so what do you plan to use as an RF generator?
Do you plan to make the end plates flat or better spherical?

Exact dimensions of the frustum are still in the making. We just had rough idea of the size we wanted  because I had to make a query to get the price. The goal is to have EM drive to operate up to 10kw with spherical end plates.

Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university.

A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected.

There is a lot more involved to get good force generation than just building a frustum and filling it with Rf.

Excitment should be in TE013 as it has low losses and shallow cone angle.  Design and build goal should be a min Qu of 100,000, which can be directly measured via the forward power rise time to 63,2% or 1 TC. 0.05mm build accuracy is OK. Multi layers are ok. Surface finish is of prime importance as it needs to be like optical quality and NO SCRATCHES.

TE013 is also important as in that mode there are no eddy currents that cross from end plate to side wall and the physical end plate to side wall joint will not experience arcing across the joint, which can occur in other modes. I think Dave has pictures of the joint arcs that occured in his frustum.

I DO NOT suggest you use a wide band source.  You need single freq excitment and that freq needs to be adjustable in +-1kHz steps to get the lowest reflected power. Then further tuned to get best static force generation or best dynamic accelerative force generation. Plus your coupler need to be optimised to work without external tuners. IE you may need to be able to move the coupler around and alter orientation.

All doable but not simple nor apparent until you have build a few EmDrives.

Thank you for your feedback. Over the weekend we will be having few meetings to discuss and finalize all the details so I could start working on getting necessary equipment. Feel free to add any other remarks.

Another question I have is how to proceed with end plates, is there a need for any kind of seal or simply bolt 2 pieces together?

Also could you recommend RF generator to match my design vision of up to 10kw.

Dude has a vision and good money to spend to crank 10kw into a frustrum, and everyone is saying 100w is better. I for one really want to see what happens! Surely if that's a narrow band source then it's a very useful set of data? Especially if it's adjustable, so it can be measured at 100w, 1kw, 10kw. Maybe that's where the signal really leaves the noise.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/03/2016 03:13 am
ARW, since you are new to posting in this forum, I do not know how much of the history of these threads you have gone through, but assuming it is not much there is some context you should be aware of. The Traveller has given you a lot of advice and much of it is good, but many of the things he says have nothing to back them up. For example, in the post quoted below he dismisses the actual, high quality experiments by EW as "not representative of reality". He instead quotes figures from Shawyer, when no other emDrive builder has gotten results close to Shawyer's, and Shawyers results are suspect due to insufficient data released for replication, known issues with the data that has been released, and the fact that Shawyer has demonstrated an inability to do a simple force balance.

Some of what TheTraveller posts is based on sound RF engineering, but other things are rules of thumb he got from Shawyer, when there is no evidence Shawyer has actually done the types of tests that would be required to determine them.

TT will inevitably respond to this saying to not listen to me, because I'm not a builder and therefore I don't know anything. My goal is just to give you context not advice. (If I did give advice it would largely mirror PotomacNeuron's advice above for minimizing error sources) As some additional context, TT's experience with building an emDrive is building a single one, which he has only provided hand sketches of and not a single picture. His explanation involves his RF equipment burning out during testing (a common occurrence here due to the nature of these experiments), but I still haven't figured out how that prevents him from taking a picture of the frustum. He supposedly is working on his second one now.

I doubt that your cavity will have E field above 50Mv/m. More likely a lot lower. Max E field increases as the sqrt of the incressed power. So increase pwr 9x, E field increases 3x and H field increases 3x.

Why do you want to use 10kW? 100W should be fine. Please don't take the NASA 1.2mN/kW as being representative. SPR'S Flight Thruster at 326mN/kW is closer to reality and that was with spherical end plates and a Q of 60,000.
http://www.emdrive.com/flightprogramme.html

I don't currently have that frustum.  It was a quick build, was gravity stacked & didn't have flanges on the side wall. It was sent to my S band thruster fabricators to have flanges put on and to be machined so the end plates are parallel and orthanagal to the Z axis.

Plus I was very sick recovering from the after effects of 5 hours of cancerous prostate removal,  then 40 days of radiation treatment as attached. Dark area is cancerous tissue removed and the white line are where the radiation was applied. Plus several visits to hospital to deal with a superbug infection & cancer related bowel shortening.  Currently undergoing further cancer treatment with dual hormonal & chemo treatment as the cancer came back. The result of all that took many, many months in bed and not working in my workshop. This is not new to NSF. Have reported it before.

Do have 5 professionally fabricated thrusters and 4 Rf amps due to ship this month. $60k worth of gear. Have promised my wife & family to not engage with them until my current treatment is completed and New Year is well over. My next experimental programs will be extensively documented, with a YouTube channel any can watch. If I don't make it, all my frustums, test rigs, amps, freq trackers, etc go to Paul March. Is in my Will. BTW I've built several frustums. The Rf amp didn't burn out. The variable attenuator failed to deliver an output signal. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Bob Woods on 12/03/2016 03:18 am look at the latter half of this article: http://www.nextbigfuture.com/2016/12/cannae-will-try-to-prove-propellentless.html (http://www.nextbigfuture.com/2016/12/cannae-will-try-to-prove-propellentless.html) the ambitious bit about deep space probes to .1 ly in 15 years travel time. I hope Guido has the $$available. But I'll wait until it's packaged before I accept the proposal. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Choice777 on 12/03/2016 03:27 am What are these "modes" TE013, 012, etc? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: M.LeBel on 12/03/2016 03:31 am The uncertainty principle; revisited? First off, position and velocity (for momentum) are two contradictory aspects. Movement is a blur on position. But the problem is not there. Consider an oil tanker coming into harbor. We can determine its position by GPS to the centimeter precision. But, the oil tanker is 500 meters long and, it is “all tanker” from one end to the other. See me coming? The precision on the position of the oil tanker can NEVER be more precise than the actual size of the tanker! This is what you get when you work with “point” like particles without considering that things that exist must have an actual size. Furthermore, the wake, or the Broglie associated wave is an integral part of the moving particle making its operational size bigger than the actual particle. The moving particle is somewhere inside its associated wave... Associated wave ....Wass that? The particle replaces by logical substitution some of the local (explosive) time process, which creates a local explosive deficit of the time process, i.e. a slower time field a.k.a. its gravitational field. The gravitational field is the signature of the existence of the particle. What is existence? Anything that somehow-anyhow makes a difference... exists! So, the particle exists via this time process substitution, a difference. When the particle moves, the signature of its existence is distorted. How far the distortion goes (wavelength) depends on the velocity of the particle. (all absolute velocities wrt c). A slow particle allows more time (at c) for the change in signature to travel; equals a long De Broglie wavelength. A very fast particle gives little time for the change in signature to travel away; equal a short De Broglie wavelength. Very near c, no more change in signature may travel away and/and make a difference. Then, no more change in signature can happen as well. In summary, existence is about making a difference, somehow. Near c, no more change in signature difference may travel away. Therefore, no more change is possible. IMO, at this point, the time process substitution is maximum and so is its relative mass.... Now, because this existence is about replacing a dynamical process, “to exist” is also a dynamical process, not a steady state. In other words, how long an object stays in one place, the “time of residence”, determines how far away its gravitational signature will travel. The time of residence is inversely proportional to velocity.. This is also to be considered in macroscopic situations.... like planets. Consider the probability of finding a planet anywhere on its complete orbit around the Sun. (Assuming here a closed loop, not a slinky..) The integrated probability of finding a planet somewhere on its complete orbit within a complete period is equal to 1; it is there, somewhere. But, the “time of residence” is not the same in all parts of the orbit as the planet speeds up or slows down in various places of the orbit. From a large distance, the influence of its existence is blurred accordingly and would appear to be (averaged out) at the long foci. IMO, Keppler’s first law is about the computation of the relative existence (time of residence) of the celestial body along its orbit. Now, I believe, IMO, that one day we will teach in say, 7th grade, how logical and simple the universe DOES what it does by itself. If one want to DO something WITH the universe in our reality, he will get 12th grade physics and later, engineering. Sounds to me like, this emDrive adventure is like a 12th grade project without the 7th grade knowledge.... (headaches anyone ??? ) Food for thought Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Stormbringer on 12/03/2016 03:36 am The uncertainty principle; revisited? First off, position and velocity (for momentum) are two contradictory aspects. Movement is a blur on position. But the problem is not there. Consider an oil tanker coming into harbor. We can determine its position by GPS to the centimeter precision. But, the oil tanker is 500 meters long and, it is “all tanker” from one end to the other. See me coming? The precision on the position of the oil tanker can NEVER be more precise than the actual size of the tanker! This is what you get when you work with “point” like particles without considering that things that exist must have an actual size. Furthermore, the wake, or the Broglie associated wave is an integral part of the moving particle making its operational size bigger than the actual particle. The moving particle is somewhere inside its associated wave... Associated wave ....Wass that? The particle replaces by logical substitution some of the local (explosive) time process, which creates a local explosive deficit of the time process, i.e. a slower time field a.k.a. its gravitational field. The gravitational field is the signature of the existence of the particle. What is existence? Anything that somehow-anyhow makes a difference... exists! So, the particle exists via this time process substitution, a difference. When the particle moves, the signature of its existence is distorted. How far the distortion goes (wavelength) depends on the velocity of the particle. (all absolute velocities wrt c). A slow particle allows more time (at c) for the change in signature to travel; equals a long De Broglie wavelength. A very fast particle gives little time for the change in signature to travel away; equal a short De Broglie wavelength. Very near c, no more change in signature may travel away and/and make a difference. Then, no more change in signature can happen as well. In summary, existence is about making a difference, somehow. Near c, no more change in signature difference may travel away. Therefore, no more change is possible. IMO, at this point, the time process substitution is maximum and so is its relative mass.... Now, because this existence is about replacing a dynamical process, “to exist” is also a dynamical process, not a steady state. In other words, how long an object stays in one place, the “time of residence”, determines how far away its gravitational signature will travel. The time of residence is inversely proportional to velocity.. This is also to be considered in macroscopic situations.... like planets. Consider the probability of finding a planet anywhere on its complete orbit around the Sun. (Assuming here a closed loop, not a slinky..) The integrated probability of finding a planet somewhere on its complete orbit within a complete period is equal to 1; it is there, somewhere. But, the “time of residence” is not the same in all parts of the orbit as the planet speeds up or slows down in various places of the orbit. From a large distance, the influence of its existence is blurred accordingly and would appear to be (averaged out) at the long foci. IMO, Keppler’s first law is about the computation of the relative existence (time of residence) of the celestial body along its orbit. Now, I believe, IMO, that one day we will teach in say, 7th grade, how logical and simple the universe DOES what it does by itself. If one want to DO something WITH the universe in our reality, he will get 12th grade physics and later, engineering. Sounds to me like, this emDrive adventure is like a 12th grade project without the 7th grade knowledge.... (headaches anyone ??? ) Food for thought some of these things like the fact than an electron is not actually a point particle are only recently experimentally observed/verified. I digress... Most if not all of the EM drive DIYers *here* are certainly not lacking in education. :) Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: PotomacNeuron on 12/03/2016 04:10 am look at the latter half of this article: http://www.nextbigfuture.com/2016/12/cannae-will-try-to-prove-propellentless.html (http://www.nextbigfuture.com/2016/12/cannae-will-try-to-prove-propellentless.html) the ambitious bit about deep space probes to .1 ly in 15 years travel time. I hope Guido has the$$$ available. But I'll wait until it's packaged before I accept the proposal.

I hope Guido does not have the $$available. This is because those$$$, if exist, are not from his own pocket but from investors. The investors would have better ways to spend them, for example, to support DIYers here. Do not forget that Guido has not yet delivered his superconductor test results, which he carried out with the same or earlier investors. Updated for less misunderstanding. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/03/2016 04:44 am Went through my notes and created a spreadsheet of the result as attached. Was very careful to make each measurement sequence procedure as identical as the others. Did quite some practice to get the process to work well. I can't explain the difference between up and down weight changes. Roger also measured the same effect. Please note that each test run was hand tuned to the lowest reflected power. Test setup was very KISS as attached. I know all you guys are going to beat me up as no photos but I was in the heat of the measurements and I didn't have my phone handy. BTW my phone is a Samsung Note 10.1, so it doesn't fit in my pocket and I don't normally carry it with me. Then the Rf amp died and I was sucked back into hospital so it all stopped. Will not happen the next time. Will be heaps of videos and pics. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/03/2016 05:39 am Quote 'We will achieve extraordinary things and no doubt all the things we dream about, all the science fiction films, we all know it's going to come true at some point, so why not in my lifetime?' Gilo Cardozo, Gilo Industries Founder. Wonder what Gilo is referring to? https://www.facebook.com/eyalumninetwork/videos/1624069944563151/ Go Gilo. Go Roger. Go EmDrive development team. Make It So. ENGAGE! Another video is to be released in a few weeks. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: VAXHeadroom on 12/03/2016 06:29 am What are these "modes" TE013, 012, etc? If you don't know this - I didn't a year ago - you'll never be able to follow the discussions on this forum. I highly suggest watching this lecture series from MIT. It will take a while, there are 23 1-hour lectures, but will be very worthwhile. https://www.youtube.com/playlist?list=PLUdYlQf0_sSsdOhQ_8jfrAGzbGbJ7MXGe TE is a 'transverse electric' mode and the numbers refer to the number of standing waves in a resonant cavity in each direction. There's also a TM (magnetic) designation which favors the electric over the magnetic fields. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Mark7777777 on 12/03/2016 07:57 am Has Roger Sawyer given an ETA on a working superconducting version? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: RERT on 12/03/2016 08:30 am ARW - Great to hear about your project! The thing I didn't spot in flux capacitor's list of good suggestions for the experiment was any technique to remove the thermal signature (and apologies if I missed that). I think it's quite clear that just repeating the EW experiment but without the thermal noise would be extremely convincing. My suggestion for eliminating that signal is to bring the relevant parts to constant working temperature using active thermostatic heating before RF-on, and then during RF-on and after, keep the temperature at that level using thermostatic control. In other words, have the active heater turn down to compensate for the waste heat dissipated. You should then see a thrust signal with that source of noise removed, or at least reduced to second order effects (such as due to temperature distribution). I'm not any kind if experimentalist, so your guys may have better ideas on the thermal issue. But I think if you were laser-focussed on the single improvement which would make the EW test more convincing, then solving the thermal problem would be it. IMHO. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/03/2016 08:31 am Has Roger Sawyer given an ETA on a working superconducting version? Roger has publically stated to expect a demo of a wingless and propless drone in 2017. Gilo has recently talked about building noiseless VTVL aircraft that cost less than a helicopter, can get to places a helicopter can't and can be remotely controlled. Sure sounds like an EmDrive propless and wingless drone. BTW Universal Propulsions is the SPR (40%) and Gilo (60%) JV, which I believe will be doing the marketing. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: flux_capacitor on 12/03/2016 08:36 am I can't explain the difference between up and down weight changes. Roger also measured the same effect. Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird. Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/03/2016 08:56 am I can't explain the difference between up and down weight changes. Roger also measured the same effect. Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird. Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum. Did do a series of tests with the frustum horizontal but didn't see much. However as the end plates were held to the frustum by rubber bands, I don't consider that a good test. Used a double sided PCB as an EMI shield plus it was electrically insulated from the frustum and metal scale plate by thin sheets of paper. Each of the 2 Cu layers are more than thick enough to thermalise as eddy currents any 2.45GHz Rf that leaks out. Do plan on hacking the scale to get a real time weight feedback so had a look inside. There are 4 strain gauges, with wires tightly twisted and connected to a differential amp. So I expect the scale is fairly immune to EMI, well at least any 2.45GHz Rf that leaks and gets past the approx 1mm thick metal weight platform that is above the strain gauges. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/03/2016 09:27 am Went through my notes and created a spreadsheet of the result as attached. Was very careful to make each measurement sequence procedure as identical as the others. Did quite some practice to get the process to work well. I can't explain the difference between up and down weight changes. Roger also measured the same effect. Please note that each test run was hand tuned to the lowest reflected power. Test setup was very KISS as attached. I know all you guys are going to beat me up as no photos but I was in the heat of the measurements and I didn't have my phone handy. BTW my phone is a Samsung Note 10.1, so it doesn't fit in my pocket and I don't normally carry it with me. Then the Rf amp died and I was sucked back into hospital so it all stopped. Will not happen the next time. Will be heaps of videos and pics. That is quite a force you measure, Phil. Have you done tests to see what the influence of the RF cable to the frustum is? Too bad your amp died. [edit: I see you explained above] Are you planning to use a circulator or isolator for next setup? If you use a circulator, you also can use it to monitor the reflected power (a detector from Minicircuits [the ZX47-40+] costs little, ~$100). [I see your budget is an onder of magnitude bigger than mine. So stub tuners, dir couplers and circulators should not be a problem for you].
I wish you a lot of succes. And a better health!
Peter
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/03/2016 09:48 am
Went through my notes and created a spreadsheet of the result as attached. Was very careful to make each measurement sequence procedure as identical as the others. Did quite some practice to get the process to work well.

I can't explain the difference between up and down weight changes. Roger also measured the same effect.

Please note that each test run was hand tuned to the lowest reflected power. Test setup was very KISS as attached.

I know all you guys are going to beat me up as no photos but I was in the heat of the measurements and I didn't have my phone handy. BTW my phone is a Samsung Note 10.1, so it doesn't fit in my pocket and I don't normally carry it with me.

Then the Rf amp died and I was sucked back into hospital so it all stopped.

Will not happen the next time. Will be heaps of videos and pics.

That is quite a force you measure, Phil. Have you done tests to see what the influence of the RF cable to the frustum is?
Too bad your amp died. Are you planning to use a circulator or isolator for next setup? If you use a circulator, you also can use it to monitor the reflected power (a detector from Minicircuits [the ZX47-40+] costs little, ~100). Peter The Rf amp has inbuilt monitoring for forward and reflected power at 50mv / dBm. It can also handle VSWR 3:1 with inbuilt isolator. I did tests in 4 locations and rotated the thin & flexible 0.5m coax in different orientations to Earth's mag field. Even so no way can a 0.5m long coax with 100W of 2.45GHz can generate any significant Lorentz force to alter the frustums weight. Also consider that when the frustum was reversed on the scale and nothing else changed, other than the weigh gain changed to weight loss. Also the frustum was insulated from the scale by 2 pieces of paper and the fibreglass of the double sided pcb. Plus the scale was battery powered. So NO ground loops. No DC flowing over the coax shield. Rf amp was powered by a bank of sealed lead acid batteries. Laptop was running on batteries. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/03/2016 10:08 am I did tests in 4 locations and rotated the thin & flexible 0.5m coax in different orientations to Earth's mag field. Even so no way can a 0.5m long coax with 100W of 2.45GHz can generate any significant Lorentz force to alter the frustums weight. I was thinking more of mechanical forces. I guess the dielectric inside the cable heats up with supply of 100 W. Also consider that when the frustum was reversed on the scale and nothing else changed, other than the weigh gain changed to weight loss. That certainly is a good point. Well... the angle of the cable must have been changed (acc to your drawing). Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/03/2016 10:16 am Went through my notes and created a spreadsheet of the result as attached. Was very careful to make each measurement sequence procedure as identical as the others. Did quite some practice to get the process to work well. I can't explain the difference between up and down weight changes. Roger also measured the same effect. Please note that each test run was hand tuned to the lowest reflected power. Test setup was very KISS as attached. I know all you guys are going to beat me up as no photos but I was in the heat of the measurements and I didn't have my phone handy. BTW my phone is a Samsung Note 10.1, so it doesn't fit in my pocket and I don't normally carry it with me. Then the Rf amp died and I was sucked back into hospital so it all stopped. Will not happen the next time. Will be heaps of videos and pics. So you also mainly measure the "static force". And I see you measure a weight difference of ~0.7 gram, which corresponds to a force of 7 mN. This is about 100 times more than the Eagleworks guys have measured with the same power level. How come your frustum is much more efficient? (A difference is of course you measure forces in the vertical direction). Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Stormbringer on 12/03/2016 12:48 pm "4 meter long photons" ;D https://www.sciencedaily.com/releases/2016/12/161202074852.htm synopsis: the "shape" of a photon and the shape of the matter it interacts with determines whether it will be absorbed or not. Com'on; it's related to what we are discussing here... you know it is :) how photons interact with matter and that photons and their interactions can be even weirder than we knew. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/03/2016 01:37 pm I did tests in 4 locations and rotated the thin & flexible 0.5m coax in different orientations to Earth's mag field. Even so no way can a 0.5m long coax with 100W of 2.45GHz can generate any significant Lorentz force to alter the frustums weight. I was thinking more of mechanical forces. I guess the dielectric inside the cable heats up with supply of 100 W. Also consider that when the frustum was reversed on the scale and nothing else changed, other than the weigh gain changed to weight loss. That certainly is a good point. Well... the angle of the cable must have been changed (acc to your drawing). When the frustum was flipped / reversed / rotated 180 deg, the height and alignment of the Rf amp and frustum SMA connectors were adjusted so they were level, pointing at each other and the same distance apart. Which is what it says on the drawing. While the cable may stiffen, never noticed that happening, there is a 2cm dip in the centre of the cable. Any expansion of the cable is not going to at one time generate a 0.9g down force and then generate a 0.7g up force when the frustum is flipped. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/03/2016 01:55 pm Went through my notes and created a spreadsheet of the result as attached. Was very careful to make each measurement sequence procedure as identical as the others. Did quite some practice to get the process to work well. I can't explain the difference between up and down weight changes. Roger also measured the same effect. Please note that each test run was hand tuned to the lowest reflected power. Test setup was very KISS as attached. I know all you guys are going to beat me up as no photos but I was in the heat of the measurements and I didn't have my phone handy. BTW my phone is a Samsung Note 10.1, so it doesn't fit in my pocket and I don't normally carry it with me. Then the Rf amp died and I was sucked back into hospital so it all stopped. Will not happen the next time. Will be heaps of videos and pics. So you also mainly measure the "static force". And I see you measure a weight difference of ~0.7 gram, which corresponds to a force of 7 mN. This is about 100 times more than the Eagleworks guys have measured with the same power level. How come your frustum is much more efficient? (A difference is of course you measure forces in the vertical direction). From what I know, the EW frustum's antenna was designed to excite TM modes strongly. As such, I don't believe it is a good design to excite TE modes. My antenna is very different. Another difference is I manually tuned the EmDrive to lowset reflected power at each measurement, plus I didn't use an external tuner but instead adjusted the antenna side wall position, rotation, alignment to the side wall and 1/2 loop diameter to obtain a very low VSWR without needing an inline tuner to make the antenna look like it was an ideal load to the Rf amp, when it may have been a bad match. So lots if differences. I should point out that SPR's Flight Thruster, with a specific force of 326mN/kW and a max reported force of 175mN at 450W or 17g is way above by best result to date. My 8mN at 95W forward is a specific force of 84mN/kW, which is way below what Roger achieved in 2009. One test EW did was measured at 21.3mN/kW but that mode was too close to others for the PLL to handle so it was abandoned. As I know it, EW seemed to pick the most isolated mode to test and didn't bother that it was also one of the lowest force generating modes. Do trust that explains the differences. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: aero on 12/03/2016 03:29 pm As for why EW would do this, it is explained in their paper - EW was looking to verify that a thrust exists and so were satisfied with a mode that they could well control, while TheTraveler and SPR are beyond the point of existence and are looking for increased thrust. (correct me if I'm wrong, but I don't think so.) Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/03/2016 04:17 pm IAC, Adelaide, Australia, Sept, 2017 Hi Guys, I'm very seriously considering setting up an exhibit booth, so to demo my non cryo S band thruster happily spinning and accelerating on a rotary test rig during the conference. Will any of you guys be going and/or will any of you have a product in the market by then? All the best, Phil of course assuming my health will support that plan Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: flux_capacitor on 12/03/2016 04:30 pm As for why EW would do this, it is explained in their paper - EW was looking to verify that a thrust exists and so were satisfied with a mode that they could well control, while TheTraveler and SPR are beyond the point of existence and are looking for increased thrust. (correct me if I'm wrong, but I don't think so.) You're right, but strong critics of the Eagleworks peer-reviewed paper focus on the fact the very tiny anomalous force recorded is inferior to the thermal signature, which leads to a method trying to separate the real anomalous force from the normal thermal force. An anomalous force well above thermal would have not triggered such criticism. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Rodal on 12/03/2016 04:56 pm As for why EW would do this, it is explained in their paper - EW was looking to verify that a thrust exists and so were satisfied with a mode that they could well control, while TheTraveler and SPR are beyond the point of existence and are looking for increased thrust. (correct me if I'm wrong, but I don't think so.) You're right, but strong critics of the Eagleworks peer-reviewed paper focus on the fact the very tiny anomalous force recorded is inferior to the thermal signature, which leads to a method trying to separate the real anomalous force from the normal thermal force. An anomalous force well above thermal would have not triggered such criticism. Concerning your prior post http://forum.nasaspaceflight.com/index.php?topic=40959.msg1613822#msg1613822 I am periodically updating drafts of my article on Mach Effect Propulsion, a chapter in the proceedings of the 2016 Advanced Propulsion Workshop at Estes Park Colorado, to be published in the near future. If you like, you can download my report from here: https://www.researchgate.net/project/Mach-effect-propulsion Best regards Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Bob012345 on 12/03/2016 05:10 pm ARW, since you are new to posting in this forum, I do not know how much of the history of these threads you have gone through, but assuming it is not much there is some context you should be aware of. The Traveller has given you a lot of advice and much of it is good, but many of the things he says have nothing to back them up. For example, in the post quoted below he dismisses the actual, high quality experiments by EW as "not representative of reality". He instead quotes figures from Shawyer, when no other emDrive builder has gotten results close to Shawyer's, and Shawyers results are suspect due to insufficient data released for replication, known issues with the data that has been released, and the fact that Shawyer has demonstrated an inability to do a simple force balance. Some of what TheTraveller posts is based on sound RF engineering, but other things are rules of thumb he got from Shawyer, when there is no evidence Shawyer has actually done the types of tests that would be required to determine them. TT will inevitably respond to this saying to not listen to me, because I'm not a builder and therefore I don't know anything. My goal is just to give you context not advice. (If I did give advice it would largely mirror PotomacNeuron's advice above for minimizing error sources) As some additional context, TT's experience with building an emDrive is building a single one, which he has only provided hand sketches of and not a single picture. His explanation involves his RF equipment burning out during testing (a common occurrence here due to the nature of these experiments), but I still haven't figured out how that prevents him from taking a picture of the frustum. He supposedly is working on his second one now. Please review the attached document. I doubt that your cavity will have E field above 50Mv/m. More likely a lot lower. Max E field increases as the sqrt of the incressed power. So increase pwr 9x, E field increases 3x and H field increases 3x. Why do you want to use 10kW? 100W should be fine. Please don't take the NASA 1.2mN/kW as being representative. SPR'S Flight Thruster at 326mN/kW is closer to reality and that was with spherical end plates and a Q of 60,000. http://www.emdrive.com/flightprogramme.html I don't currently have that frustum. It was a quick build, was gravity stacked & didn't have flanges on the side wall. It was sent to my S band thruster fabricators to have flanges put on and to be machined so the end plates are parallel and orthanagal to the Z axis. Plus I was very sick recovering from the after effects of 5 hours of cancerous prostate removal, then 40 days of radiation treatment as attached. Dark area is cancerous tissue removed and the white line are where the radiation was applied. Plus several visits to hospital to deal with a superbug infection & cancer related bowel shortening. Currently undergoing further cancer treatment with dual hormonal & chemo treatment as the cancer came back. The result of all that took many, many months in bed and not working in my workshop. This is not new to NSF. Have reported it before. Do have 5 professionally fabricated thrusters and 4 Rf amps due to ship this month.60k worth of gear.

Have promised my wife & family to not engage with them until my current treatment is completed and New Year is well over.

My next experimental programs will be extensively documented,  with a YouTube channel any can watch.

If I don't make it, all my frustums, test rigs, amps, freq trackers,  etc go to Paul March. Is in my Will.

BTW I've built several frustums. The Rf amp didn't burn out. The variable attenuator failed to deliver an output signal.

We all want to see you do those tests yourself as soon as you are up to it!
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: mwvp on 12/03/2016 05:24 pm
"4 meter long photons"  ;D

https://www.sciencedaily.com/releases/2016/12/161202074852.htm

Really messes with your head, doesn't it? Tempts me to expound on dark solitons, vacuum energy, et.

You might enjoy Macken's book at: http://www.onlyspacetime.com/

I read it last month, and still chewing and digesting. Perhaps his property of "unity" and superluminal propagation of Plank-scale longitudinal waves could be accounted for by time symmetry mentioned in the spacedaily article; the Plank scale vacuum waves travel forward and reverse in time.

But the first chapter speaks on energy sloshing around in a waveguide accounting for particle motion.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/03/2016 05:53 pm
The uncertainty principle; revisited?

First off, position and velocity (for momentum) are two contradictory aspects. Movement is a blur on position. But the problem is not there.

Consider an oil tanker coming into harbor. We can determine its position by GPS to the centimeter precision. But, the oil tanker is 500 meters long and, it is “all tanker” from one end to the other. See me coming? The precision on the position of the oil tanker can NEVER be more precise than the actual size of the tanker! This is what you get when you work with “point” like particles without considering that things that exist must have an actual size. Furthermore, the wake, or the Broglie associated wave is an integral part of the moving particle making its operational size bigger than the actual particle. The moving particle is somewhere inside its associated wave...

Associated wave ....Wass that? The particle replaces by logical substitution some of the local (explosive) time process, which creates a local explosive deficit of the time process, i.e. a slower time field a.k.a. its gravitational field.  The gravitational field is the signature of the existence of the particle. What is existence? Anything that somehow-anyhow makes a difference... exists! So, the particle exists via this time process substitution, a difference. When the particle moves, the signature of its existence is distorted. How far the distortion goes (wavelength) depends on the velocity of the particle. (all absolute velocities wrt c). A slow particle allows more time (at c) for the change in signature to travel; equals a long De Broglie wavelength. A very fast particle gives little time for the change in signature to travel away; equal a short De Broglie wavelength. Very near c, no more change in signature may travel away and/and make a difference. Then, no more change in signature can happen as well. In summary, existence is about making a difference, somehow. Near c, no more change in signature difference may travel away. Therefore, no more change is possible. IMO, at this point, the time process substitution is maximum and so is its relative mass....

Now, because this existence is about replacing a dynamical process, “to exist” is also a dynamical process, not a steady state. In other words, how long an object stays in one place, the “time of residence”, determines how far away its gravitational signature will travel. The time of residence is inversely proportional to velocity.. This is also to be considered in macroscopic situations.... like planets.

Consider the probability of finding a planet anywhere on its complete orbit around the Sun. (Assuming here a closed loop, not a slinky..) The integrated probability of finding a planet somewhere on its complete orbit within a complete period is equal to 1; it is there, somewhere. But, the “time of residence” is not the same in all parts of the orbit as the planet speeds up or slows down in various places of the orbit. From a large distance, the influence of its existence is blurred accordingly and would appear to be (averaged out) at the long foci. IMO, Keppler’s first law is about the computation of the relative existence (time of residence) of the celestial body along its orbit.

Now, I believe, IMO, that one day we will teach in say, 7th grade, how logical and simple the universe DOES what it does by itself. If one want to DO something WITH the universe in our reality, he will get 12th grade physics and later, engineering. Sounds to me like, this emDrive adventure is like a 12th grade project without the 7th grade knowledge....

Food for thought
some of these things like the fact than an electron is not actually a point particle are only recently experimentally observed/verified. I digress...

Most if not all of the EM drive DIYers *here* are certainly not lacking in education. :)

... Education?.. No, of course not. But take PhD for example. Says “Doctor of Philosophy”. This last word is important. All the great scientists of the last century had some classical education including Greek philosophy, middle age and renaissance philosophies...  Philosophy is a system of opinion, not a truth system. Yet, forming proper opinions and questions is what gets us through all other truth systems. Theoretical physics requires more philosophy as forming and weighing assumptions, looking at the big picture etc. Engineering squeezes the equations and parameters to their limits to get results, here and now. The emDrive is an exploration both experimental and theoretical. But, IMO, there is nothing wrong about stepping  back, from time to time, and asking yourself; How does what I am doing compare to what I am trying to achieve?

Food for thought..
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: SeeShells on 12/03/2016 06:19 pm
As for why EW would do this, it is explained in their paper - EW was looking to verify that a thrust exists and so were satisfied with a mode that they could well control, while TheTraveler and SPR are beyond the point of existence and are looking for increased thrust. (correct me if I'm wrong, but I don't think so.)

You're right, but strong critics of the Eagleworks peer-reviewed paper focus on the fact the very tiny anomalous force recorded is inferior to the thermal signature, which leads to a method trying to separate the real anomalous force from the normal thermal force. An anomalous force well above thermal would have not triggered such criticism.

I am periodically updating drafts of my article on Mach Effect Propulsion, a chapter in the proceedings of the 2016 Advanced Propulsion Workshop at Estes Park Colorado, to be published in the near future.

https://www.researchgate.net/project/Mach-effect-propulsion

Best regards
Dr. Rodal,

Very well done. There is a tremendous amount of great information in this paper. It's going to take me several days to digest it.

Thank you for posting this.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/03/2016 06:39 pm

Thank you for your feedback. Over the weekend we will be having few meetings to discuss and finalize all the details so I could start working on getting necessary equipment. Feel free to add any other remarks.

Another question I have is how to proceed with end plates, is there a need for any kind of seal or simply bolt 2 pieces together?

Also could you recommend RF generator to match my design vision of up to 10kw.

Dude has a vision and good money to spend to crank 10kw into a frustrum, and everyone is saying 100w is better. I for one really want to see what happens! Surely if that's a narrow band source then it's a very useful set of data? Especially if it's adjustable, so it can be measured at 100w, 1kw, 10kw. Maybe that's where the signal really leaves the noise.

I think if you put 10kW RF into a frustum with no idea how much reflected power and power dissipation it will have, you're just asking for trouble. 10kW is a LOT of power to be dissipated by a thin walled copper can. It's going to need some serious mass and cooling. Not a quick or easy design. A lot of thought needs to be given to this.

I'm working on an experiment to try driving resonance with a spark gap. It's battery powered, only about 5W DC input at 12VDC, but it will provide an ~1 ns pulse at ~350kW, provided it works that is! It should have an adjustable repetition rate from low Hz to maybe 14kHz. I just ordered components to test it on one of my ice buckets. Now I just need to save up to buy a VNA, so I have something to measure with.

Note: I don't know how long the spark gap will last at this repetition rate, but they're dirt cheap and the system is easily scaleable to much higher pulsed power, or faster repetition rates by upgrading the power supply. This one was 14. Any thoughts or comments on this cheap experiment would be helpful. Thank you. (http://privat.bahnhof.se/wb907234/pics/sparktrans.gif) Edit: In this image, L and C2 are the frustum. The antenna is just a small loop of wire in series with the spark gap. It will provide an enormous H-field impulse through the loop. I'm assuming it can be tuned by the length of the antenna loop. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/03/2016 07:06 pm Went through my notes and created a spreadsheet of the result as attached. Was very careful to make each measurement sequence procedure as identical as the others. Did quite some practice to get the process to work well. I can't explain the difference between up and down weight changes. Roger also measured the same effect. Please note that each test run was hand tuned to the lowest reflected power. Test setup was very KISS as attached. I know all you guys are going to beat me up as no photos but I was in the heat of the measurements and I didn't have my phone handy. BTW my phone is a Samsung Note 10.1, so it doesn't fit in my pocket and I don't normally carry it with me. Then the Rf amp died and I was sucked back into hospital so it all stopped. Will not happen the next time. Will be heaps of videos and pics. What is the frequency for each run? What is the mode? What are the dimensions of the frustum? These should be added to this post and archived TT, as a vital part of the data. Thanks! Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/03/2016 07:27 pm I can't explain the difference between up and down weight changes. Roger also measured the same effect. Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird. Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum. Maybe not so weird. When the small end is down, it is resting on a copper clad PC board, which gives it a bit of a heat-sink effect that might reduce the losses at that end. This board might also be reflecting some of the escaping flux (momentum), that is not reflected when the small end is up. Thereby pushing the PC board down on the scale. TT also said there were no flanges, everything was held together by gravity, I assume he means at both ends. In which case there were plenty of leaks for hot air to escape. Maybe buoyancy in this case is negligible? Probably a good thing. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: meberbs on 12/03/2016 07:56 pm Any thoughts or comments on this cheap experiment would be helpful. Thank you. I think you have likened this previously to "ringing a bell," but there are some key differences, which is why I don't think this will work the way you are thinking. When you ring a bell, you transfer energy to it by hitting it, but then you pull the hammer back, so the energy is trapped in the bell. Also, generally the hit is much faster than the frequencies you are trying to excite. For your setup, a 1 ns pulse corresponds to a 1 GHz primary frequency, and some additional higher order frequencies depending on what actual rise/fall times you can achieve. Also, I would expect most of the energy to simply be reflected back due to mismatched frequency. I have some concerns about the potential to do bad things to the power supply when most of the energy feeds back into the battery, but I'll let someone with experience working with spark gaps determine if that is a real concern. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/03/2016 08:37 pm Any thoughts or comments on this cheap experiment would be helpful. Thank you. I think you have likened this previously to "ringing a bell," but there are some key differences, which is why I don't think this will work the way you are thinking. When you ring a bell, you transfer energy to it by hitting it, but then you pull the hammer back, so the energy is trapped in the bell. Also, generally the hit is much faster than the frequencies you are trying to excite. For your setup, a 1 ns pulse corresponds to a 1 GHz primary frequency, and some additional higher order frequencies depending on what actual rise/fall times you can achieve. Also, I would expect most of the energy to simply be reflected back due to mismatched frequency. I have some concerns about the potential to do bad things to the power supply when most of the energy feeds back into the battery, but I'll let someone with experience working with spark gaps determine if that is a real concern. Thank you. I have a lot of experience working with spark gaps for power protection circuits. I wish I had all the ancient test equipment I used to work with in the 80's. In this case, you are right. I'm not sure how fast a rise time I can get, but there are ways to increase it by overdriving a lower voltage spark gap with a higher voltage spark gap. It's a very inexpensive test, except for the VNA. As for feedback. The power supply is a DC/DC converter with an isolated 1.5kV output. The spark gap will close when the voltage across the gap exceeds 840V. The gap will open as soon as the current goes to zero, or typically within the first few cycles. This, and the fact there is a 1nf capacitor on the other side, makes sure that once that happens, the power supply is well decoupled from the ringing. (I hope.) Look at it this way. A 100W RF input is only going to provide 1.4A at 70V into 50 Ohms, or about 30 nV-s of magnetic flux per pulse. My spark gap should provide 840 nV-s of magnetic flux. If it can't cross back over the gap, it has to go somewhere, and dissipation is what makes it go. We shall see. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: InterestedEngineer on 12/03/2016 09:29 pm "4 meter long photons" ;D https://www.sciencedaily.com/releases/2016/12/161202074852.htm synopsis: the "shape" of a photon and the shape of the matter it interacts with determines whether it will be absorbed or not. Com'on; it's related to what we are discussing here... you know it is :) how photons interact with matter and that photons and their interactions can be even weirder than we knew. The researchers found that if the photon arrived dimly, from the atom's point of view, then ended brightly, the peak probability of excitation was just over 50% higher than when the photon arrived bright and had a long, fading tail. So there's an asymmetry in excitation. Is it possible to build a device where one side preferentially absorbs and another side preferentially reflects photons of a standing wave? You'd get a net thrust in the direction towards absorption. Until we can figure out the mechanism of the asymmetry, you'd have an apparent CoM violation.. but basically you are getting the difference between the force of absorption and reflection of a light sail, times Q. Alas, the article didn't detail the mechanism behind the asymmetry. Sounds kinda familiar. Add this one to the list of theories? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Stormbringer on 12/03/2016 09:37 pm "4 meter long photons" ;D https://www.sciencedaily.com/releases/2016/12/161202074852.htm synopsis: the "shape" of a photon and the shape of the matter it interacts with determines whether it will be absorbed or not. Com'on; it's related to what we are discussing here... you know it is :) how photons interact with matter and that photons and their interactions can be even weirder than we knew. The researchers found that if the photon arrived dimly, from the atom's point of view, then ended brightly, the peak probability of excitation was just over 50% higher than when the photon arrived bright and had a long, fading tail. So there's an asymmetry in excitation. Is it possible to build a device where one side preferentially absorbs and another side preferentially reflects photons of a standing wave? You'd get a net thrust in the direction towards absorption. Until we can figure out the mechanism of the asymmetry, you'd have an apparent CoM violation.. but basically you are getting the difference between the force of absorption and reflection of a light sail, times Q. Alas, the article didn't detail the mechanism behind the asymmetry. Sounds kinda familiar. Add this one to the list of theories? Only the guys and girls with the scientific experience could tell. I just brought it here because it looked like it might be of interest and might be helpful. The only 4 meter photons I am familiar with were the ones launched in the Star Trek reboot. :D Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/04/2016 12:10 am IAC, Adelaide, Australia, Sept, 2017 Hi Guys, I'm very seriously considering setting up an exhibit booth, so to demo my non cryo S band thruster happily spinning and accelerating on a rotary test rig during the conference. Will any of you guys be going and/or will any of you have a product in the market by then? All the best, Phil of course assuming my health will support that plan My intention from day one has been to manufacture and sell EmDrive based thrusters that are at least 5x more thrust efficient than the best Ion drives. Any reader here should know that. Believe my latest design will deliver on that goal with a min 600mn/kW rating. Intention in going to IAC 2017 will be to demo the thruster operating / accelerating on a rotary test rig and to fill my order book. It is my understanding that my potential clients will have little interest in CofM nor CofE discussions but instead their interest will be on how much energy X they need to supply the thruster to deliver a deltaV of Y to mass Z. The rotary test rig experiments I'll be doing are designed to provide that answer, ie what is the power supply load characterists during long term acceleration of mass X at acceleration Y? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/04/2016 12:16 am I can't explain the difference between up and down weight changes. Roger also measured the same effect. Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird. Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum. I expect the weight change difference may be hysteresis in the strain gauges. The scale is designed to be zeroed out and weight added. When the weight reduces, that may not be an optimised measurement situation. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Monomorphic on 12/04/2016 12:25 am Paul March was kind enough to invite me to tour the NASA Eagleworks lab as I was passing through Houston in September to visit family. I agreed at the time to delay posting about the tour until the AIAA paper had been released since I was given free reign to look around and take pictures. The visit to Eagleworks and touring the lab and meeting Paul was the highlight of my Texas trip. Thanks to Paul for taking three hours of his time and showing me around. ;D Here are a few of my favorite pictures. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: otlski on 12/04/2016 01:39 am Paul March was kind enough to invite me to tour the NASA Eagleworks lab as I was passing through Houston in September to visit family. I agreed at the time to delay posting about the tour until the AIAA paper had been released since I was given free reign to look around and take pictures. The visit to Eagleworks and touring the lab and meeting Paul was the highlight of my Texas trip. Thanks to Paul for taking three hours of his time and showing me around. ;D Here are a few of my favorite pictures. Very cool pictures. In the shot with the air bearing. The stator looks white in color. Is is made from Delrin or other plastic? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: M.LeBel on 12/04/2016 02:41 am "Potential Energy" ...: “energy” is a nice paper concept for sentient beings. Alone, it means nothing in this universe. Here is why, with an example. One tera-joule dissipated by a dripping faucet over eons will make a hole in the sink. The same tera-joule dissipated in a nanosecond ... and goodbye the sink and part of the neighborhood. Do you see a difference? I, for one, see a real difference. Real events out there happen in time and energy alone means nothing in the real world without time. In a universe with a background of running time, how quickly something happen does matter. The blue photon (short period) delivers its h content much faster than the red photon (long period). In a universe sizzling with time, power is the real money, not energy. We “collapse” the wave, which means forgetting about the delivery time and integrating the work done i.e. calling it energy. Was this written for a better understanding or for a better “doing?” The takeaway: “Think sink” "Negligible".... : The theoretical physicists (and the philosopher) trying to understand will be uncompromising on all aspects of his investigation. But, “physics”, for one, is demonstrated by physical experimental proof, in our reality. We notice then, that the discourse of the theorist will slowly shift from the will to understand.... to the need to prove. Leaving the absolutes of the theorist he engages now into the shaving off of those elements deemed “negligible” in preparation to present, not an understandable theory, but for a doable experiment. His final equation will not show necessarily that he understands, but rather that he can do. And doing something with the universe, controlling it, is how we define “understanding”. A doable experiment shows first hand the utility of the equation found and speeds up its technological extension. The equation does not describe our understanding of the universe but our ability to do something with it. So, do we understand the universe? Nope! We learn more and more how to do something with the universe. We don’t necessarily learn more about a) what the universe is made of or b) how it does what it does by itself. IMO, the need to prove physically some theory in our reality (conventional space and time) is a prejudice preventing physics answering these two questions. Food for thought... Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Bob Woods on 12/04/2016 04:38 am The visit to Eagleworks and touring the lab and meeting Paul was the highlight of my Texas trip. Thanks to Paul for taking three hours of his time and showing me around. ;D Here are a few of my favorite pictures. Jealous, Mono... VERY jealous. ;D Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: meberbs on 12/04/2016 06:03 am "Potential Energy" ...: “energy” is a nice paper concept for sentient beings. Alone, it means nothing in this universe. ... Your argument that energy doesn't really exist because power is a thing is completely wrong. It is like saying that water in a reservoir doesn't exist because it only matters when it is falling over a cliff in a waterfall. Remember that mass and energy are equivalent. If you want to see evidence that energy is a real thing, just try picking up (or pushing) a light and a heavy object. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/04/2016 09:55 am I did tests in 4 locations and rotated the thin & flexible 0.5m coax in different orientations to Earth's mag field. Even so no way can a 0.5m long coax with 100W of 2.45GHz can generate any significant Lorentz force to alter the frustums weight. I was thinking more of mechanical forces. I guess the dielectric inside the cable heats up with supply of 100 W. Also consider that when the frustum was reversed on the scale and nothing else changed, other than the weigh gain changed to weight loss. That certainly is a good point. Well... the angle of the cable must have been changed (acc to your drawing). When the frustum was flipped / reversed / rotated 180 deg, the height and alignment of the Rf amp and frustum SMA connectors were adjusted so they were level, pointing at each other and the same distance apart. Which is what it says on the drawing. While the cable may stiffen, never noticed that happening, there is a 2cm dip in the centre of the cable. Any expansion of the cable is not going to at one time generate a 0.9g down force and then generate a 0.7g up force when the frustum is flipped. In that case, I would say it is quite an interesting result. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/04/2016 09:59 am From what I know, the EW frustum's antenna was designed to excite TM modes strongly. As such, I don't believe it is a good design to excite TE modes. My antenna is very different. You mean TM modes in the last sentence? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/04/2016 12:55 pm From what I know, the EW frustum's antenna was designed to excite TM modes strongly. As such, I don't believe it is a good design to excite TE modes. My antenna is very different. You mean TM modes in the last sentence? Antenna / couplers used to excite TE or TM modes are different in design and are located at different locations. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/04/2016 01:07 pm From what I know, the EW frustum's antenna was designed to excite TM modes strongly. As such, I don't believe it is a good design to excite TE modes. My antenna is very different. You mean TM modes in the last sentence? Antenna / couplers used to excite TE or TM modes are different in design and are located at different locations. Yes, I'm aware of that. But since you advocate the use of TE modes (TE013 in particular, I believe), and Eagleworks lab, in their last publication, used only TM, it was not clear what you meant. You mean the Eagleworks lab design is not good for exciting TE modes? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: M.LeBel on 12/04/2016 01:43 pm "Potential Energy" ...: “energy” is a nice paper concept for sentient beings. Alone, it means nothing in this universe. ... Your argument that energy doesn't really exist because power is a thing is completely wrong. It is like saying that water in a reservoir doesn't exist because it only matters when it is falling over a cliff in a waterfall. Remember that mass and energy are equivalent. If you want to see evidence that energy is a real thing, just try picking up (or pushing) a light and a heavy object. The universe is happening... We freeze it on paper, throw away time, then try to figure out how it can possibly move... and happen! Yes, energy equals mass, right. Energy is measured in many forms, mechanical, chemical, nuclear etc, yet, .... :), YET nobody can say what energy really is! (REALLY) Mass, is considered everywhere in physics .... yet, we don’t even know what it really is to this day; what makes mass.... a soup a gravitons.. mixed with a few Higgs bosons ...? Equating two officially unknown quantities, the very basic ones, hardly explains anything! Food for thought... Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/04/2016 01:46 pm From what I know, the EW frustum's antenna was designed to excite TM modes strongly. As such, I don't believe it is a good design to excite TE modes. My antenna is very different. You mean TM modes in the last sentence? Antenna / couplers used to excite TE or TM modes are different in design and are located at different locations. Yes, I'm aware of that. But since you advocate the use of TE modes (TE013 in particular, I believe), and Eagleworks lab, in their last publication, used only TM, it was not clear what you meant. You mean the Eagleworks lab design is not good for exciting TE modes? As far as I understand the process, it was developed to excite TM modes as TM212 was their selected mode to do the testing in. As you have seen from other data, the mode patterns of the E and H fields are very different mode to mode. As such I believe doing optimal excitation for mode TX,xyz requires a coupler designed for that mode and placed where it can couple to and excite the desired field. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/04/2016 02:34 pm .... That would be the largest emdrive built to date. A 2.4Ghz TE013 emdrive is ~24cm in length with a major end-plate diameter ~32cm, minor end-plate diameter of ~16cm. Is there a geometry with ~ same TE013 frequency, but smaller major end-plate (28-30 cm diam) and bigger length? And maybe smaller minor end-plate (12 cm) as well. (and no degeneracy due to nearby other modes) Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: dustinthewind on 12/04/2016 03:11 pm "4 meter long photons" ;D https://www.sciencedaily.com/releases/2016/12/161202074852.htm synopsis: the "shape" of a photon and the shape of the matter it interacts with determines whether it will be absorbed or not. Com'on; it's related to what we are discussing here... you know it is :) how photons interact with matter and that photons and their interactions can be even weirder than we knew. The researchers found that if the photon arrived dimly, from the atom's point of view, then ended brightly, the peak probability of excitation was just over 50% higher than when the photon arrived bright and had a long, fading tail. So there's an asymmetry in excitation. Is it possible to build a device where one side preferentially absorbs and another side preferentially reflects photons of a standing wave? You'd get a net thrust in the direction towards absorption. Until we can figure out the mechanism of the asymmetry, you'd have an apparent CoM violation.. but basically you are getting the difference between the force of absorption and reflection of a light sail, times Q. Alas, the article didn't detail the mechanism behind the asymmetry. Sounds kinda familiar. Add this one to the list of theories? a photon will have a frequency attached to it, which gives it a wavelength. A perfect wavelength will have a sine wave shape. If you change the shape you get into fourier sums of frequencies where you can make any shape you want to. https://en.wikipedia.org/wiki/Fourier_series . Them talking about making the pulse at the front rather than the back sounds to me to be similar to the above mentioned. This introduces multiple frequencies which is odd because you would think it would mean multiple photons. Pre-separating the electron and proton due to an initial excitement (lower frequency) then introducing a higher frequency seems to me it may be changing the atomic oscillator initial conditions. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: dustinthewind on 12/04/2016 03:32 pm Thank you for your feedback. Over the weekend we will be having few meetings to discuss and finalize all the details so I could start working on getting necessary equipment. Feel free to add any other remarks. Another question I have is how to proceed with end plates, is there a need for any kind of seal or simply bolt 2 pieces together? Also could you recommend RF generator to match my design vision of up to 10kw. Dude has a vision and good money to spend to crank 10kw into a frustrum, and everyone is saying 100w is better. I for one really want to see what happens! Surely if that's a narrow band source then it's a very useful set of data? Especially if it's adjustable, so it can be measured at 100w, 1kw, 10kw. Maybe that's where the signal really leaves the noise. I think if you put 10kW RF into a frustum with no idea how much reflected power and power dissipation it will have, you're just asking for trouble. 10kW is a LOT of power to be dissipated by a thin walled copper can. It's going to need some serious mass and cooling. Not a quick or easy design. A lot of thought needs to be given to this. I'm working on an experiment to try driving resonance with a spark gap. It's battery powered, only about 5W DC input at 12VDC, but it will provide an ~1 ns pulse at ~350kW, provided it works that is! It should have an adjustable repetition rate from low Hz to maybe 14kHz. I just ordered components to test it on one of my ice buckets. Now I just need to save up to buy a VNA, so I have something to measure with. Note: I don't know how long the spark gap will last at this repetition rate, but they're dirt cheap and the system is easily scaleable to much higher pulsed power, or faster repetition rates by upgrading the power supply. This one was14.

Any thoughts or comments on this cheap experiment would be helpful. Thank you.

(http://privat.bahnhof.se/wb907234/pics/sparktrans.gif)

Edit: In this image, L and C2 are the frustum. The antenna is just a small loop of wire in series with the spark gap. It will provide an enormous H-field impulse through the loop. I'm assuming it can be tuned by the length of the antenna loop.
looking at your design made me think of the taser circuit designs that ramp to high voltage.  http://www.555-timer-circuits.com/stun-gun.html . (http://www.555-timer-circuits.com/images/StunGun.gif)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Star-Drive on 12/04/2016 03:34 pm

From what I know,  the EW frustum's antenna was designed to excite TM modes strongly.

As such, I don't believe it is a good design to excite TE modes. My antenna is very different.

You mean TM modes in the last sentence?

Antenna / couplers used to excite TE or TM modes are different in design and are located at different locations.

Yes, I'm aware of that. But since you advocate the use of TE modes (TE013 in particular, I believe), and Eagleworks lab, in their last publication, used only TM, it was not clear what you meant. You mean the Eagleworks lab design is not good for exciting TE modes?

As far as I understand the process, it was developed to excite TM modes as TM212 was their selected mode to do the testing in. As you have seen from other data, the mode patterns of the E and H fields are very different mode to mode. As such I believe doing optimal excitation for mode TX,xyz requires a coupler designed for that mode and placed where it can couple to and excite the desired field.

Phil & Peter:

You give me too much credit.  When building the EW copper frustum back in December 2013 I only had a vague notion where the TM010 mode B-fields were along with an even vaguer notion about where the TE012 mode B-fields were.  Thus when it came to drilling holes for the magnetic loop drive antenna, I made a semi-educated GUESS as to where to place the antenna on the side wall since that is where Shawyer placed his antenna ports.  After drilling two frustum side-wall, 0.250" OD SMA port holes, it turned out the antenna port at 15% above the BOD end of the frustum was usable for both the TE012, TM010 and the TM212 modes, but I had to change the diameter of the loop antenna and its angular orientation to get a good 50-ohm Smith Chart match for each mode in question.

Best, Paul M.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: R.W. Keyes on 12/04/2016 05:20 pm
I recall this issue being raised before, but it was a while ago and the situation may have changed.  Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it.

I am not asking if the typical $800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense? The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP. I think the casting places typically have their own 3d printer. All you do is provide the CAD file for the part. They will update it to work with their type of casting, and the type of finish required, and give you a chance to approve it before the part is cast. It's not that expensive, nowhere near six figures! :o But for a high Q you need a post-printing/casting step for polishing. 3D printing can give you a near-net-shape, but the surface finish is nowhere near good enough. A 3D metal printer big enough to build an aluminum EMDrive in the 2.4 GHz range is upwards of$1M.  We just priced them at work :)

Or you could do old fashioned CNC/casting + polishing for a fraction of your suggested cost.

This is all quite discouraging. I want to invest in equipment which will make it easier for designers to take the particular geometry they want to try, and get a quality finished cavity for not a lot of money.

Cost of 3D printer: As the build volume increases, so does the price. So the tiny, benchtop devices just don't have a good enough build area. I am looking at a Stratasys Fortus 400 with the optional larger 16" x 14" x 16" build size. This seems sufficient for at least some emdrive designs. What portion of designs will it be insufficient for?

Metal: I thought the above Fortus had an optional DMLS (metal) hot end but I may have misread.

In either case, it looks like I'd be getting into plating which involves dangerous chemicals, which I am not qualified to handle.

So, perhaps back to square one, and to ask the broader question: In what way can I quickly invest some capital in equipment and provide a useful service to emdrive developers?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/04/2016 05:22 pm
"Potential Energy" ...: “energy” is a nice paper concept for sentient beings. Alone, it means nothing in this universe. ...
Your argument that energy doesn't really exist because power is a thing is completely wrong. It is like saying that water in a reservoir doesn't exist because it only matters when it is falling over a cliff in a waterfall.

Remember that mass and energy are equivalent. If you want to see evidence that energy is a real thing, just try picking up (or pushing) a light and a heavy object.

The universe is happening... We freeze it on paper, throw away time, then try to figure out how it can possibly move... and happen!

Yes, energy equals mass, right. Energy is measured in many forms, mechanical, chemical, nuclear etc, yet, ....  :), YET nobody can say what energy really is! (REALLY)

Mass, is considered everywhere in physics ....  yet, we don’t even know what it really is to this day; what makes mass.... a soup a gravitons.. mixed with a few Higgs bosons ...?

Equating two officially unknown quantities, the very basic ones, hardly explains anything!

Food for thought...
Your description "We freeze it on paper, throw away time, then try..." does not describe physics at all, and indicates you do not understand how physicists describe the universe. The rest of your post confirms that you don't understand current physics, since energy and mass are not nearly as poorly understood as you make them out to be. All of those different types of energy are the same and all contribute to mass.

There are still some things we don't understand such as quantum gravity, but even then physicists understand how mass is generated through the Higg's Boson, now that it has been shown to exist. You seem to be trying to rewrite all of physics without first understanding what we currently know. This basically guarantees that whatever you come up with will not match some known results. I am not going to try to teach you all of the details you seem to be missing, both because it is off topic for this thread, and because there is too much to try to communicate through this medium. You will have to go learn things on your own. Also, don't start with the advanced topics until you understand the basic ones (I honestly can't tell what level you actually understand, so I don't know where you should begin.)

Quote from: Elon Musk
One bit of advice: it is important to view knowledge as sort of a semantic tree — make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/04/2016 05:38 pm
I can't explain the difference between up and down weight changes. Roger also measured the same effect.

Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird.

Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum.

I expect the weight change difference may be hysteresis in the strain gauges.

The scale is designed to be zeroed out and weight added. When the weight reduces, that may not be an optimised measurement situation.
No, digital scales should work just fine going negative. For any one I have worked with if I put something on, and then hit tare and take it off, the negative values always matches the positive value from before hitting tare.

What this does show is that you have at least 0.2 grams of uncharacterized error sources, and probably more, since as flux_capacitor pointed out, any rising hot air should have had the opposite effect. Considering the significant, but unknown error sources, and you having results significantly larger than basically all other experimenters, who did more careful experiments, generated less force, it is reasonable to conclude that if you generated any emDrive effect, it is too swamped by errors for your experiment to provide useful data.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/04/2016 05:46 pm
I recall this issue being raised before, but it was a while ago and the situation may have changed.  Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it.

I am not asking if the typical $800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense? The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP. I think the casting places typically have their own 3d printer. All you do is provide the CAD file for the part. They will update it to work with their type of casting, and the type of finish required, and give you a chance to approve it before the part is cast. It's not that expensive, nowhere near six figures! :o But for a high Q you need a post-printing/casting step for polishing. 3D printing can give you a near-net-shape, but the surface finish is nowhere near good enough. A 3D metal printer big enough to build an aluminum EMDrive in the 2.4 GHz range is upwards of$1M.  We just priced them at work :)

Or you could do old fashioned CNC/casting + polishing for a fraction of your suggested cost.

This is all quite discouraging. I want to invest in equipment which will make it easier for designers to take the particular geometry they want to try, and get a quality finished cavity for not a lot of money.

Cost of 3D printer: As the build volume increases, so does the price. So the tiny, benchtop devices just don't have a good enough build area. I am looking at a Stratasys Fortus 400 with the optional larger 16" x 14" x 16" build size. This seems sufficient for at least some emdrive designs. What portion of designs will it be insufficient for?

Metal: I thought the above Fortus had an optional DMLS (metal) hot end but I may have misread.

In either case, it looks like I'd be getting into plating which involves dangerous chemicals, which I am not qualified to handle.

So, perhaps back to square one, and to ask the broader question: In what way can I quickly invest some capital in equipment and provide a useful service to emdrive developers?

The biggest hurdle I am having is the cost of the test equipment. My 300MHz FFT oscilloscope is too slow for GHz frequencies, and a Pico 9000 scope is way out of my budget. The VNA has some low cost options but you get what you pay for. When you add up all the pieces to setup a lab it's very expensive, and all the DIY'ers are funding their now home based labs. I'm to the point of considering building a 250 MHz frustum to save the cost of equipment. I could monitor it with my existing scope and drive it with a cheap spark gap.

I think, setting up a lab with test equipment and a thrust balance, that could be "rented?" and used by other DIY'ers, so that we are all testing on the same test platform, might be a cost savings, even if testing required traveling and hotel accommodations. It would be cheap in comparison. You could get a business investment income (loss) from it as well. It all depends on how you look at providing a useful service.

Just my thoughts...
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/04/2016 05:53 pm
I can't explain the difference between up and down weight changes. Roger also measured the same effect.

Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird.

Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum.

I expect the weight change difference may be hysteresis in the strain gauges.

The scale is designed to be zeroed out and weight added. When the weight reduces, that may not be an optimised measurement situation.
No, digital scales should work just fine going negative. For any one I have worked with if I put something on, and then hit tare and take it off, the negative values always matches the positive value from before hitting tare.

What this does show is that you have at least 0.2 grams of uncharacterized error sources, and probably more, since as flux_capacitor pointed out, any rising hot air should have had the opposite effect. Considering the significant, but unknown error sources, and you having results significantly larger than basically all other experimenters, who did more careful experiments, generated less force, it is reasonable to conclude that if you generated any emDrive effect, it is too swamped by errors for your experiment to provide useful data.

I wouldn't be that harsh about it. It makes a lot of sense to me that when the small end was down, it was resting on a double sided copper plated board. Any thrust momentum coming out of the small end would be reflected from this board, and it would negate much of the thrust he was attempting to measure. Setting the frustum directly on copper confounded his data, but per my theory, what happened makes sense.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: R.W. Keyes on 12/04/2016 06:06 pm

This is all quite discouraging. I want to invest in equipment which will make it easier for designers to take the particular geometry they want to try, and get a quality finished cavity for not a lot of money.

Cost of 3D printer: As the build volume increases, so does the price. So the tiny, benchtop devices just don't have a good enough build area. I am looking at a Stratasys Fortus 400 with the optional larger 16" x 14" x 16" build size. This seems sufficient for at least some emdrive designs. What portion of designs will it be insufficient for?

Metal: I thought the above Fortus had an optional DMLS (metal) hot end but I may have misread.

In either case, it looks like I'd be getting into plating which involves dangerous chemicals, which I am not qualified to handle.

So, perhaps back to square one, and to ask the broader question: In what way can I quickly invest some capital in equipment and provide a useful service to emdrive developers?

The biggest hurdle I am having is the cost of the test equipment. My 300MHz FFT oscilloscope is too slow for GHz frequencies, and a Pico 9000 scope is way out of my budget. The VNA has some low cost options but you get what you pay for. When you add up all the pieces to setup a lab it's very expensive, and all the DIY'ers are funding their now home based labs. I'm to the point of considering building a 250 MHz frustum to save the cost of equipment. I could monitor it with my existing scope and drive it with a cheap spark gap.

I think, setting up a lab with test equipment and a thrust balance, that could be "rented?" and used by other DIY'ers, so that we are all testing on the same test platform, might be a cost savings, even if testing required traveling and hotel accommodations. It would be cheap in comparison. You could get a business investment income (loss) from it as well. It all depends on how you look at providing a useful service.

Just my thoughts...

This might be do-able. I see the Pico 9000 at around $10k? Thrust balance...any come to mind that you can give me an idea of the cost? What else would be needed? I'll have two LimeSDR units for signal generation by that time. I may need an amplifier. FYI I am located in Berkshire County, Massachusetts. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: aero on 12/04/2016 06:40 pm I can't explain the difference between up and down weight changes. Roger also measured the same effect. Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird. Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum. I expect the weight change difference may be hysteresis in the strain gauges. The scale is designed to be zeroed out and weight added. When the weight reduces, that may not be an optimised measurement situation. No, digital scales should work just fine going negative. For any one I have worked with if I put something on, and then hit tare and take it off, the negative values always matches the positive value from before hitting tare. What this does show is that you have at least 0.2 grams of uncharacterized error sources, and probably more, since as flux_capacitor pointed out, any rising hot air should have had the opposite effect. Considering the significant, but unknown error sources, and you having results significantly larger than basically all other experimenters, who did more careful experiments, generated less force, it is reasonable to conclude that if you generated any emDrive effect, it is too swamped by errors for your experiment to provide useful data. I wouldn't be that harsh about it. It makes a lot of sense to me that when the small end was down, it was resting on a double sided copper plated board. Any thrust momentum coming out of the small end would be reflected from this board, and it would negate much of the thrust he was attempting to measure. Setting the frustum directly on copper confounded his data, but per my theory, what happened makes sense. So would it work to put a stack of books on the scale, then the frustum, small end down? Or would a ring fitted around the small end then support that ring and frustum above the scale? Or maybe a copper ridge reflecting 90 degrees to each side to support the DUT? Or just an "X" support made of the material of choice? How far away from the scale is far enough? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/04/2016 07:04 pm I can't explain the difference between up and down weight changes. Roger also measured the same effect. Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird. Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum. I expect the weight change difference may be hysteresis in the strain gauges. The scale is designed to be zeroed out and weight added. When the weight reduces, that may not be an optimised measurement situation. No, digital scales should work just fine going negative. For any one I have worked with if I put something on, and then hit tare and take it off, the negative values always matches the positive value from before hitting tare. What this does show is that you have at least 0.2 grams of uncharacterized error sources, and probably more, since as flux_capacitor pointed out, any rising hot air should have had the opposite effect. Considering the significant, but unknown error sources, and you having results significantly larger than basically all other experimenters, who did more careful experiments, generated less force, it is reasonable to conclude that if you generated any emDrive effect, it is too swamped by errors for your experiment to provide useful data. I wouldn't be that harsh about it. It makes a lot of sense to me that when the small end was down, it was resting on a double sided copper plated board. Any thrust momentum coming out of the small end would be reflected from this board, and it would negate much of the thrust he was attempting to measure. Setting the frustum directly on copper confounded his data, but per my theory, what happened makes sense. So would it work to put a stack of books on the scale, then the frustum, small end down? Or would a ring fitted around the small end then support that ring and frustum above the scale? Or maybe a copper ridge reflecting 90 degrees to each side to support the DUT? Or just an "X" support made of the material of choice? How far away from the scale is far enough? Who knows? Do the test and find out. :) Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/04/2016 07:08 pm This is all quite discouraging. I want to invest in equipment which will make it easier for designers to take the particular geometry they want to try, and get a quality finished cavity for not a lot of money. Cost of 3D printer: As the build volume increases, so does the price. So the tiny, benchtop devices just don't have a good enough build area. I am looking at a Stratasys Fortus 400 with the optional larger 16" x 14" x 16" build size. This seems sufficient for at least some emdrive designs. What portion of designs will it be insufficient for? Metal: I thought the above Fortus had an optional DMLS (metal) hot end but I may have misread. In either case, it looks like I'd be getting into plating which involves dangerous chemicals, which I am not qualified to handle. So, perhaps back to square one, and to ask the broader question: In what way can I quickly invest some capital in equipment and provide a useful service to emdrive developers? The biggest hurdle I am having is the cost of the test equipment. My 300MHz FFT oscilloscope is too slow for GHz frequencies, and a Pico 9000 scope is way out of my budget. The VNA has some low cost options but you get what you pay for. When you add up all the pieces to setup a lab it's very expensive, and all the DIY'ers are funding their now home based labs. I'm to the point of considering building a 250 MHz frustum to save the cost of equipment. I could monitor it with my existing scope and drive it with a cheap spark gap. I think, setting up a lab with test equipment and a thrust balance, that could be "rented?" and used by other DIY'ers, so that we are all testing on the same test platform, might be a cost savings, even if testing required traveling and hotel accommodations. It would be cheap in comparison. You could get a business investment income (loss) from it as well. It all depends on how you look at providing a useful service. Just my thoughts... This might be do-able. I see the Pico 9000 at around$10k? Thrust balance...any come to mind that you can give me an idea of the cost? What else would be needed?

I'll have two LimeSDR units for signal generation by that time. I may need an amplifier.

FYI I am located in Berkshire County, Massachusetts.

The photos of the one from EW is what is needed. Shells might have a better design by now, but I do not think there is any "off-the-shelf" thrust balance you could just buy. It needs to be constructed for this purpose.

I might try floating it in an oil bath and measuring the relative change in depth. Or, packing the whole thing in a box and floating it, then see how well it moves. I suspect there is probably too much drag for that though. I haven't done the calculation.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: OnlyMe on 12/04/2016 07:17 pm
I recall this issue being raised before, but it was a while ago and the situation may have changed.  Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it.

I am not asking if the typical $800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense? The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP. I think the casting places typically have their own 3d printer. All you do is provide the CAD file for the part. They will update it to work with their type of casting, and the type of finish required, and give you a chance to approve it before the part is cast. It's not that expensive, nowhere near six figures! :o But for a high Q you need a post-printing/casting step for polishing. 3D printing can give you a near-net-shape, but the surface finish is nowhere near good enough. A 3D metal printer big enough to build an aluminum EMDrive in the 2.4 GHz range is upwards of$1M.  We just priced them at work :)

Or you could do old fashioned CNC/casting + polishing for a fraction of your suggested cost.

This is all quite discouraging. I want to invest in equipment which will make it easier for designers to take the particular geometry they want to try, and get a quality finished cavity for not a lot of money.

Cost of 3D printer: As the build volume increases, so does the price. So the tiny, benchtop devices just don't have a good enough build area. I am looking at a Stratasys Fortus 400 with the optional larger 16" x 14" x 16" build size. This seems sufficient for at least some emdrive designs. What portion of designs will it be insufficient for?

Metal: I thought the above Fortus had an optional DMLS (metal) hot end but I may have misread.

In either case, it looks like I'd be getting into plating which involves dangerous chemicals, which I am not qualified to handle.

So, perhaps back to square one, and to ask the broader question: In what way can I quickly invest some capital in equipment and provide a useful service to emdrive developers?

Perhaps a used vacuum chamber large enough to handle the design needs of a majority of the DIY builders. Maybe Paul March could provide some feedback on size and vacuum requirements, since he worked with the chamber at EW.

I am sure that a chamber and the vacuum equipment would meet or even exceed your $$needs, time deadlines for investment may be a more significant problem... Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Keith Ness on 12/04/2016 07:46 pm I recently came up with the following propellant recycling method which is a particle analogue of my explanation of the EmDrive results. The example below is intended to be very simple so that it shows the allocations of deflectiveness and momentum very clearly, but the general method is to cause a PARTIAL conversion of the rearward momentum of the propellant into change in its direction (or other energy which is not expressed fully in rearward momentum) so that the propellant eventually comes to move with the ship, but with the propellant (or something else moving with the ship) also still having momentum (or other energy) relative to the ship. I base the method on, among other things, the premise that an object can not have eliminated all its momentum relative to another object until the two objects are at rest relative to each other. Consider having your back up against the inside front wall of a spaceship in zero-g, placing a bowling ball under your feet with you directly between the ball and the wall behind you, and extending your whole body as hard as you can directly away from the wall to push the bowling ball directly towards the back wall of the ship, giving the ship a good amount of forward momentum, and the ball a good amount of rearward momentum. The bowling ball travels straight for a while down a tube, then comes to a gentle curve in the tube, gentle enough to change the direction of the bowling ball 90 degrees, heading towards the side wall of the ship, while reducing the momentum of the bowling ball relative to the ship by only half, and converting some of that loss of momentum into thrust into the ship’s rear wall, thus reducing but not eliminating the ship’s forward momentum. The bowling ball is then heading directly towards the side wall at half its former speed, and it passes through a gently springing gate which takes a little more momentum out of the ball to get out of the ball’s way and then shut behind the ball again. Then the bowling ball hits a big spring on the side wall, and bounces gently back towards the gate, which has a big spring on the side the ball is heading towards, and the gate does not swing in the direction the ball is now heading. The ball then dissipates its remaining momentum relative to the ship harmlessly in successive lateral bounces off the gate and side wall. When the ball comes to rest, an operator picks it up and throws it to you at any given speed. The more exactly you catch the ball in the reverse process of how it was thrown to you, then the more exactly the rearward momentum of the ship from the throw will be cancelled out and the forward momentum of the ship will be restored when you catch the ball. You are then free to repeat the process, this time with the ship moving forward faster relative to the last time you did it. Of course, in order that your ship does move straight forward in this example, you have another team doing the same thing at the same time in a bilaterally symmetrical chamber next to yours (for further stability, also assume the ship is considerably more massive than the ball, and at least as firm/sturdy as the ball where it counts, et c.). (http://gdurl.com/7cLa) Some points to consider: 1) The ball was at rest relative to the spaceship before being pushed in step 1, so the rearward momentum the ball got from the push is equal and opposite to the forward momentum the ship got from the push. Therefore, since the ball kept moving relative to the ship after changing direction, it can not possibly have put all its equal and opposite momentum into fully countering the forward momentum of the ship. If it were to still be moving relative to the ship after cancelling out the ship's forward momentum as such, then it would be in violation of conservation of energy, because one could not account for where it got that extra energy relative to the ship from. Consider a simpler transfer of momentum which does conform to the phrase "and opposite": you and a cube-shaped spaceship you are in are at rest relative to each other, then you push off the center of mass of one of the cube's walls and head directly towards the opposite wall's center of mass, and then come to rest on the opposite wall in the reverse process of how you pushed off the first wall. You and the ship would now be at rest relative to each other again, with the cube having moved a little and then come to rest again relative to its first resting position. If you try to go back to the first wall in the same manner, then you and the cube will be back at rest at the exact positions you were in before the first push. That's the equal and opposite Newton is talking about. However, thanks to change in direction and conversion into nonlinear momentum (e.g., scattering/shattering, and more or less static, omnidirectional momentum, e.g., vibrations, mechanical waves, thermal motion and EM radiation, et c.), the phrase "and opposite" apparently does not always apply. 2) As in Galileo's ship, where no experiment within the moving ship could tell you that the ship was moving, the bowling ball would indeed be moving parallel to the rear wall of the ship after changing direction 90 degrees, WITHOUT any further push from that wall on the ball. a) Neither ship nor ball is under acceleration from any additional input of energy during the period from the moment the push in step 1 ends to the moment the throw in step 4 begins. b) The observer's frame of reference is irrelevant; you could stabilize on the ball, the ship, or a point in space at rest relative to when the ball and ship were last at rest relative to each other, and the result would be the same, regardless... So it seems to me that the phrase "and opposite" in Newton's third law of motion is actually somewhat subordinate to the simple action of momentum-conversion. If I'm wrong, then please let me know how. Thanks. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: nacnud on 12/04/2016 07:59 pm That won't work. All you're doing is moving the centre of mass about. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: flux_capacitor on 12/04/2016 08:00 pm :-\ I would like my simple question to be answered too: What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength? That I can help with. The guide wavelength in a waveguide is basically due to the waves bouncing back and forth between the walls rather than straight down the middle. The superposition hides the non-axial portion, so you just see an apparently stretched axial wavelength, while the actual travelling waves maintain their original wavelength. In a smaller waveguide the angle of the bounces is steeper (for the same frequency of radiation), so the apparent wavelength gets longer. What Cullen originally showed was simply that the steeper the bounces, the less of the wave's momentum is in the axial direction, which is a very sensible result. Something similar happens in an emDrive cavity as waves reflecting off the side walls cause the angles to get steeper towards the small end. You can't easily define a guide wavelength though because at any point the suprimposed waves are not all moving in the same direction, and it is not clear what modes (if any) the apparent standing wave has any meaningful relation to the angles the travelling waves are travelling at. The issue with this description and how Shawyer abuses Cullen's results is that by conservation of momentum, it is obvious that any change in axial momentum due to reflections off the sidewalls transfers that momentum to the sidewalls to end up with no net motion. (Note:This post used simplified descriptions, to give an intuitive sense of what is going on. Boundary conditions and the wave equation make this more complicated than presented here.) Isn't it the opposite (emphasis mine)? A "steeper" angle means a more open angle, right? (English is not my primary language). Shawyer shows the sawtooth pattern gradually becomes sharper as the waveguide diameter becomes smaller, hence an apparent decreasing wavelength axially in the direction big to small in a frustum. Even if the EM frequency stays the same, the wavelength undergoes an apparent shrinking (in the axial direction) so the group velocity (which carries energy and information) decreases axially in an EM wave travelling big to small, as if the wave was undergoing an apparent blueshift in direction of the small end plate. [EDIT: wrong assumptions struck out, thanks to meberbs for his answer below. The bounce angles and the actual wave form are not the same, in fact quite the opposite, so the sharper the bounce angles, the longer the wave appears to be toward small end in the axial direction, and the shorter the wave appears toward big end.] Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: as58 on 12/04/2016 08:02 pm That won't work. All you're doing is moving the centre of mass about. Many would say the same about emdrive... edit: Moving the centre of mass would actually mean that the thing works. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/04/2016 08:04 pm Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university. A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected. So there are universities involved in this research. Good. I thought Martin Tajmar at Dresden was the only (official) university researcher in this field. You should also publish if you do not detect thrust (at least at ArXiv). How do you plan to measure the force? There is a lot of attention for the microwave part at this forum. I have the impression the other necessary part of the game, the force/thrust measurement, is a little bit neglected. My self, I'm a business man with deep passion for science and a dream to fly to space one day. However I do have lots of friends in university as they helped me immensely to start my business a decade ago. This week I've signed a contract with university for a privately funded research project by my initiative. They like the idea of this kind of research but they wouldn't put their money into it. Data will be published whether it's successful or not and the measurement methods will have to be worked out by people doing the science. I have masters in engineering and I know a thing or two but we will be discussing details this weekend/month. Official starting date is set in February when university returns to it's normal operation after holiday season, till than we have to finalize the build and start getting necessary equipment. Dear ARW, I noticed, your ideas about setting up the first measurements differ a lot from how I would do it/am going to do it. The people at the university who are going to work for you don't seem to have experience in this or a related field. I strongly recommend you to attract an advisory committee group, maybe some the more experienced people active at this forum am willing to participate in it (not me, I'm not experienced enough, yet). Best, Peter Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: nacnud on 12/04/2016 08:07 pm That won't work. All you're doing is moving the centre of mass about. Many would say the same about emdrive... Indeed, but in the case of the EM drive the maths is a lot more complex making casual observations much harder. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: X_RaY on 12/04/2016 08:22 pm :-\ I would like my simple question to be answered too: What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength? That I can help with. The guide wavelength in a waveguide is basically due to the waves bouncing back and forth between the walls rather than straight down the middle. The superposition hides the non-axial portion, so you just see an apparently stretched axial wavelength, while the actual travelling waves maintain their original wavelength. In a smaller waveguide the angle of the bounces is steeper (for the same frequency of radiation), so the apparent wavelength gets longer. What Cullen originally showed was simply that the steeper the bounces, the less of the wave's momentum is in the axial direction, which is a very sensible result. Something similar happens in an emDrive cavity as waves reflecting off the side walls cause the angles to get steeper towards the small end. You can't easily define a guide wavelength though because at any point the suprimposed waves are not all moving in the same direction, and it is not clear what modes (if any) the apparent standing wave has any meaningful relation to the angles the travelling waves are travelling at. The issue with this description and how Shawyer abuses Cullen's results is that by conservation of momentum, it is obvious that any change in axial momentum due to reflections off the sidewalls transfers that momentum to the sidewalls to end up with no net motion. (Note:This post used simplified descriptions, to give an intuitive sense of what is going on. Boundary conditions and the wave equation make this more complicated than presented here.) Isn't it the opposite (emphasis mine)? A "steeper" angle means a more open angle, right? (English is not my primary language). Shawyer shows the sawtooth pattern gradually becomes sharper as the waveguide diameter becomes smaller, hence an apparent decreasing wavelength axially in the direction big to small in a frustum. Even if the EM frequency stays the same, the wavelength undergoes an apparent shrinking (in the axial direction) so the group velocity (which carries energy and information) decreases axially in an EM wave travelling big to small, as if the wave was undergoing an apparent blueshift in direction of the small end plate. No it's the opposite. i.e. it depends on the component of ψ you are looking at. I think you are looking at the wavelength/better shell of constant phase right? Then the pic below shows whats happens. To quote TT (and I do this really not often ::) ) the "guide wavelength" will be longer, the smaller the diameter is. The wave is more stretched the smaller the diameter is. The point is this description is true regarding/whatever the terms he is using ωnmp=c*√(j(’)mn/a)²+(pπ/l)² decrease "a" you will see it using the equation for a cylindrical cavity. (frequency will be as higher as smaller "a" is) (https://upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Waveguide_wavelength.svg/330px-Waveguide_wavelength.svg.png)" Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: R.W. Keyes on 12/04/2016 08:33 pm I recall this issue being raised before, but it was a while ago and the situation may have changed. Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it. I am not asking if the typical 800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense? The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP. I think the casting places typically have their own 3d printer. All you do is provide the CAD file for the part. They will update it to work with their type of casting, and the type of finish required, and give you a chance to approve it before the part is cast. It's not that expensive, nowhere near six figures! :o But for a high Q you need a post-printing/casting step for polishing. 3D printing can give you a near-net-shape, but the surface finish is nowhere near good enough. A 3D metal printer big enough to build an aluminum EMDrive in the 2.4 GHz range is upwards of 1M. We just priced them at work :) Or you could do old fashioned CNC/casting + polishing for a fraction of your suggested cost. This is all quite discouraging. I want to invest in equipment which will make it easier for designers to take the particular geometry they want to try, and get a quality finished cavity for not a lot of money. Cost of 3D printer: As the build volume increases, so does the price. So the tiny, benchtop devices just don't have a good enough build area. I am looking at a Stratasys Fortus 400 with the optional larger 16" x 14" x 16" build size. This seems sufficient for at least some emdrive designs. What portion of designs will it be insufficient for? Metal: I thought the above Fortus had an optional DMLS (metal) hot end but I may have misread. In either case, it looks like I'd be getting into plating which involves dangerous chemicals, which I am not qualified to handle. So, perhaps back to square one, and to ask the broader question: In what way can I quickly invest some capital in equipment and provide a useful service to emdrive developers? Perhaps a used vacuum chamber large enough to handle the design needs of a majority of the DIY builders. Maybe Paul March could provide some feedback on size and vacuum requirements, since he worked with the chamber at EW. I am sure that a chamber and the vacuum equipment would meet or even exceed your$$ needs, time deadlines for investment may be a more significant problem...

Yes, vacuum chamber and torsion balance. along with miscellaneous other equipment and supplies. Thermal imager. voltage calibrator, VNA,  etc. Any help with the list of equipment, and its required specifications, would be helpful. I'd have to build the torsion balance, yes, so specs and plans could be useful.

I was also thinking of getting a COMSOL multiphysics license and then rent out use of the computer upon which it was installed (networked license, or not. With the non-network license, just transfer the data by USB stick from the non-networked computer to the networked one which clients would transfer data to/from).

The industrial space of have made inquiries about are variously located in Great Barrington, Pittsfield, and North Adams Massachusetts. These are approximately an hour's drive from the Albany airport.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/04/2016 08:57 pm
:-\
I would like my simple question to be answered too:

What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength?
That I can help with. The guide wavelength in a waveguide is basically due to the waves bouncing back and forth between the walls rather than straight down the middle. The superposition hides the non-axial portion, so you just see an apparently stretched axial wavelength, while the actual travelling waves maintain their original wavelength. In a smaller waveguide the angle of the bounces is steeper (for the same frequency of radiation), so the apparent wavelength gets longer. What Cullen originally showed was simply that the steeper the bounces, the less of the wave's momentum is in the axial direction, which is a very sensible result.

Something similar happens in an emDrive cavity as waves reflecting off the side walls cause the angles to get steeper towards the small end. You can't easily define a guide wavelength though because at any point the suprimposed waves are not all moving in the same direction, and it is not clear what modes (if any) the apparent standing wave has any meaningful relation to the angles the travelling waves are travelling at. The issue with this description and how Shawyer abuses Cullen's results is that by conservation of momentum, it is obvious that any change in axial momentum due to reflections off the sidewalls transfers that momentum to the sidewalls to end up with no net motion.

(Note:This post used simplified descriptions, to give an intuitive sense of what is going on. Boundary conditions and the wave equation make this more complicated than presented here.)

Isn't it the opposite (emphasis mine)? A "steeper" angle means a more open angle, right? (English is not my primary language). Shawyer shows the sawtooth pattern gradually becomes sharper as the waveguide diameter becomes smaller, hence an apparent decreasing wavelength axially in the direction big to small in a frustum.

Even if the EM frequency stays the same, the wavelength undergoes an apparent shrinking (in the axial direction) so the group velocity (which carries energy and information) decreases axially in an EM wave travelling big to small, as if the wave was undergoing an apparent blueshift in direction of the small end plate.
No its the opposite. i.e. it depends on the component of ψ you are looking at. I think you are looking at the wavelength/better shell of constant phase right? Then the pic below shows whats happens.

No, flux_capacitor's drawing was correct, yours clearly does not have equal incident and reflected angles.

Flux capacitor is wrong about the effect on wavelength his drawing implies though. (This is confusing, so these mistakes are understandable.)

While the bounces are getting more frequent, the wavelength actually gets longer, because projected distance between 2 constant phase surfaces gets larger. see attached for a picture. (Note that in reality there are constraints of the ratio of the wavelength and the angle of the bounces (depending on mode) I ignored these to make it easier to draw quickly)

The green lines are the direction of travel, the red lines are the wavefronts. If I drew it right, the distance between the red lines along the green lines should be the same for both (this is the free space wavelength). Due to superposition in a waveguide, what you see as the guide wavelength is the distance between where the red lines intersect the black lines (marked in grey), which gets larger as the direction of travel gets steeper.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: X_RaY on 12/04/2016 09:09 pm
:-\
I would like my simple question to be answered too:

What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength?
That I can help with. The guide wavelength in a waveguide is basically due to the waves bouncing back and forth between the walls rather than straight down the middle. The superposition hides the non-axial portion, so you just see an apparently stretched axial wavelength, while the actual travelling waves maintain their original wavelength. In a smaller waveguide the angle of the bounces is steeper (for the same frequency of radiation), so the apparent wavelength gets longer. What Cullen originally showed was simply that the steeper the bounces, the less of the wave's momentum is in the axial direction, which is a very sensible result.

Something similar happens in an emDrive cavity as waves reflecting off the side walls cause the angles to get steeper towards the small end. You can't easily define a guide wavelength though because at any point the suprimposed waves are not all moving in the same direction, and it is not clear what modes (if any) the apparent standing wave has any meaningful relation to the angles the travelling waves are travelling at. The issue with this description and how Shawyer abuses Cullen's results is that by conservation of momentum, it is obvious that any change in axial momentum due to reflections off the sidewalls transfers that momentum to the sidewalls to end up with no net motion.

(Note:This post used simplified descriptions, to give an intuitive sense of what is going on. Boundary conditions and the wave equation make this more complicated than presented here.)

Isn't it the opposite (emphasis mine)? A "steeper" angle means a more open angle, right? (English is not my primary language). Shawyer shows the sawtooth pattern gradually becomes sharper as the waveguide diameter becomes smaller, hence an apparent decreasing wavelength axially in the direction big to small in a frustum.

Even if the EM frequency stays the same, the wavelength undergoes an apparent shrinking (in the axial direction) so the group velocity (which carries energy and information) decreases axially in an EM wave travelling big to small, as if the wave was undergoing an apparent blueshift in direction of the small end plate.
No its the opposite. i.e. it depends on the component of ψ you are looking at. I think you are looking at the wavelength/better shell of constant phase right? Then the pic below shows whats happens.

No, flux_capacitor's drawing was correct, yours clearly does not have equal incident and reflected angles.

Flux capacitor is wrong about the effect on wavelength his drawing implies though. (This is confusing, so these mistakes are understandable.)

While the bounces are getting more frequent, the wavelength actually gets longer, because projected distance between 2 constant phase surfaces gets larger. see attached for a picture. (Note that in reality there are constraints of the ratio of the wavelength and the angle of the bounces (depending on mode) I ignored these to make it easier to draw quickly)

The green lines are the direction of travel, the red lines are the wavefronts. If I drew it right, the distance between the red lines along the green lines should be the same for both (this is the free space wavelength). Due to superposition in a waveguide, what you see as the guide wavelength is the distance between where the red lines intersect the black lines (marked in grey), which gets larger as the direction of travel gets steeper.
Please try to understand that the ray trajectory theory is not applicable 1 by 1 since the wavelength is of the same order as the structure of the cavity it self. We are talking about near field conditions.
The freespace wavelength is always smaller compared to the one in a waveguide with ε=1, μ=1 and  having conductive walls, if the diameter is in the order of the wavelength.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: demofsky on 12/04/2016 09:20 pm

Yes, vacuum chamber and torsion balance. along with miscellaneous other equipment and supplies. Thermal imager. voltage calibrator, VNA,  etc. Any help with the list of equipment, and its required specifications, would be helpful. I'd have to build the torsion balance, yes, so specs and plans could be useful.

I was also thinking of getting a COMSOL multiphysics license and then rent out use of the computer upon which it was installed (networked license, or not. With the non-network license, just transfer the data by USB stick from the non-networked computer to the networked one which clients would transfer data to/from).

The industrial space of have made inquiries about are variously located in Great Barrington, Pittsfield, and North Adams Massachusetts. These are approximately an hour's drive from the Albany airport.
The vacuum chamber should really be large enough to hold a rotational table/test rig.  Tiny vacuum chambers are the absolute bane of EM Drive research.  Rotational table/test rig is the recommended configuration for testing ion drives and the like.  The Cannae folks have this set up.

Another consideration is vacuum hardened electronics, particularly the RF drive section.  I recall Paul detailing the serious problems that EW had in this area.

Many folks have been getting good traction with Fekko.  Perhaps that should be given consideration over COMSOL?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/04/2016 09:53 pm
It might be oversimplified, but here is a rough draft on how modifying the mass of light in a cavity with regards to its wavelength might give it some push.  https://www.researchgate.net/profile/Dustin_Macdermott "Is the frustum EM Drive4 decelerating light for propellantless propulsion?"  It may still be flawed.  Will revise as I go.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: nacnud on 12/04/2016 09:58 pm
That won't work. All you're doing is moving the centre of mass about.

Many would say the same about emdrive...

edit: Moving the centre of mass would actually mean that the thing works.

Damn, yes. I edited my first post, should have just stuck to what I said initially. Anyway the thing won't work, it will vibrate a bit but not move anywhere. Back to lurking and waiting for more data.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/04/2016 10:03 pm
:-\
I would like my simple question to be answered too:

What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength?
That I can help with. The guide wavelength in a waveguide is basically due to the waves bouncing back and forth between the walls rather than straight down the middle. The superposition hides the non-axial portion, so you just see an apparently stretched axial wavelength, while the actual travelling waves maintain their original wavelength. In a smaller waveguide the angle of the bounces is steeper (for the same frequency of radiation), so the apparent wavelength gets longer. What Cullen originally showed was simply that the steeper the bounces, the less of the wave's momentum is in the axial direction, which is a very sensible result.

Something similar happens in an emDrive cavity as waves reflecting off the side walls cause the angles to get steeper towards the small end. You can't easily define a guide wavelength though because at any point the suprimposed waves are not all moving in the same direction, and it is not clear what modes (if any) the apparent standing wave has any meaningful relation to the angles the travelling waves are travelling at. The issue with this description and how Shawyer abuses Cullen's results is that by conservation of momentum, it is obvious that any change in axial momentum due to reflections off the sidewalls transfers that momentum to the sidewalls to end up with no net motion.

(Note:This post used simplified descriptions, to give an intuitive sense of what is going on. Boundary conditions and the wave equation make this more complicated than presented here.)

Isn't it the opposite (emphasis mine)? A "steeper" angle means a more open angle, right? (English is not my primary language). Shawyer shows the sawtooth pattern gradually becomes sharper as the waveguide diameter becomes smaller, hence an apparent decreasing wavelength axially in the direction big to small in a frustum.

Even if the EM frequency stays the same, the wavelength undergoes an apparent shrinking (in the axial direction) so the group velocity (which carries energy and information) decreases axially in an EM wave travelling big to small, as if the wave was undergoing an apparent blueshift in direction of the small end plate.
No its the opposite. i.e. it depends on the component of ψ you are looking at. I think you are looking at the wavelength/better shell of constant phase right? Then the pic below shows whats happens.

No, flux_capacitor's drawing was correct, yours clearly does not have equal incident and reflected angles.

Flux capacitor is wrong about the effect on wavelength his drawing implies though. (This is confusing, so these mistakes are understandable.)

While the bounces are getting more frequent, the wavelength actually gets longer, because projected distance between 2 constant phase surfaces gets larger. see attached for a picture. (Note that in reality there are constraints of the ratio of the wavelength and the angle of the bounces (depending on mode) I ignored these to make it easier to draw quickly)

The green lines are the direction of travel, the red lines are the wavefronts. If I drew it right, the distance between the red lines along the green lines should be the same for both (this is the free space wavelength). Due to superposition in a waveguide, what you see as the guide wavelength is the distance between where the red lines intersect the black lines (marked in grey), which gets larger as the direction of travel gets steeper.
Please try to understand that the ray trajectory theory is not applicable 1 by 1 since the wavelength is of the same order as the structure of the cavity it self. We are talking about near field conditions.
The freespace wavelength is always smaller compared to the one in a waveguide with ε=1, μ=1 and  having conductive walls, if the diameter is in the order of the wavelength.
Agreed, that is why I made a comment about ignoring the constraints of the specific angles it must propagate at, which is due to the near field nature of the propagation. This does correctly give the results for the relations between guide wavelength and propagation velocity. I want to say that you can produce the full near field result by summing superimposed plane waves, but it has been a while since I went through the full details, and I could be mis-remembering.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/04/2016 10:42 pm

Yes, vacuum chamber and torsion balance. along with miscellaneous other equipment and supplies. Thermal imager. voltage calibrator, VNA,  etc. Any help with the list of equipment, and its required specifications, would be helpful. I'd have to build the torsion balance, yes, so specs and plans could be useful.

I was also thinking of getting a COMSOL multiphysics license and then rent out use of the computer upon which it was installed (networked license, or not. With the non-network license, just transfer the data by USB stick from the non-networked computer to the networked one which clients would transfer data to/from).

The industrial space of have made inquiries about are variously located in Great Barrington, Pittsfield, and North Adams Massachusetts. These are approximately an hour's drive from the Albany airport.
The vacuum chamber should really be large enough to hold a rotational table/test rig.  Tiny vacuum chambers are the absolute bane of EM Drive research.  Rotational table/test rig is the recommended configuration for testing ion drives and the like.  The Cannae folks have this set up.

Another consideration is vacuum hardened electronics, particularly the RF drive section.  I recall Paul detailing the serious problems that EW had in this area.

Many folks have been getting good traction with Fekko.  Perhaps that should be given consideration over COMSOL?

FEKO is setup to do exactly that.

"FEKO is licensed under Altair’s HyperWorks Unit (HWU) Licensing system which is a token style licensing systems that draws a certain number of unit for the different software options available.

The minimum number of units required to run FEKO is 25 HWU and allows processing on up to 4 cores."

As I understand it, once you have the HWU, they can be shared amongst individuals in a group, but only one seat at a time can be active. The cost was $15k USD to me as a hobbiest. No way I can do it alone but if 10 or 20 people wanted to share the units, that would be almost affordable. Note: Training is EXTRA! Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: OnlyMe on 12/04/2016 11:06 pm Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university. A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected. So there are universities involved in this research. Good. I thought Martin Tajmar at Dresden was the only (official) university researcher in this field. You should also publish if you do not detect thrust (at least at ArXiv). How do you plan to measure the force? There is a lot of attention for the microwave part at this forum. I have the impression the other necessary part of the game, the force/thrust measurement, is a little bit neglected. My self, I'm a business man with deep passion for science and a dream to fly to space one day. However I do have lots of friends in university as they helped me immensely to start my business a decade ago. This week I've signed a contract with university for a privately funded research project by my initiative. They like the idea of this kind of research but they wouldn't put their money into it. Data will be published whether it's successful or not and the measurement methods will have to be worked out by people doing the science. I have masters in engineering and I know a thing or two but we will be discussing details this weekend/month. Official starting date is set in February when university returns to it's normal operation after holiday season, till than we have to finalize the build and start getting necessary equipment. Dear ARW, I noticed, your ideas about setting up the first measurements differ a lot from how I would do it/am going to do it. The people at the university who are going to work for you don't seem to have experience in this or a related field. I strongly recommend you to attract an advisory committee, maybe some the more experienced people active at this forum am willing to participate in it (not me, I'm not experienced enough, yet). Best, Peter ... A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. ... Even with the understanding that this is to be a project based at or associated witha University Physics Department, perhaps one of our builders with experience could repost the cautions and dangers involved. Most of what has been posted in these discussions has been working with DC voltages of 2 to 3 kv and raw microwave energies up to perhaps 1000watts. Both can be deadly if not handled carefully by experienced and qualified individuals. Once you start talking about 10kw of MW energies the danger increases more than 10 fold. Again maybe one of the DIY builders in these discussions with the experience I do not have can properly emphasize the need for caution and careful experienced handling of the DC and high frequency currents involved, even for a project being formulated at a university lab. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/04/2016 11:32 pm It might be oversimplified, but here is a rough draft on how modifying the mass of light in a cavity with regards to its wavelength might give it some push. https://www.researchgate.net/profile/Dustin_Macdermott "Is the frustum EM Drive4 decelerating light for propellantless propulsion?" It may still be flawed. Will revise as I go. Equations (5) and (6) seem to be contradictory. On the left they are equal, on the right they are not. I see what you're doing, but it's poorly expressed. Equations (19) and (20) where you derive K. I tried this. Did you notice that your K≤1, where K in the PV Model is always K≥1? In the PV Model, K≤1 is FTL, whereas in a waveguide v≤c. The logic doesn't fit the facts, at least not in a straight forward 1:1 comparison. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: demofsky on 12/04/2016 11:55 pm Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university. A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected. So there are universities involved in this research. Good. I thought Martin Tajmar at Dresden was the only (official) university researcher in this field. You should also publish if you do not detect thrust (at least at ArXiv). How do you plan to measure the force? There is a lot of attention for the microwave part at this forum. I have the impression the other necessary part of the game, the force/thrust measurement, is a little bit neglected. My self, I'm a business man with deep passion for science and a dream to fly to space one day. However I do have lots of friends in university as they helped me immensely to start my business a decade ago. This week I've signed a contract with university for a privately funded research project by my initiative. They like the idea of this kind of research but they wouldn't put their money into it. Data will be published whether it's successful or not and the measurement methods will have to be worked out by people doing the science. I have masters in engineering and I know a thing or two but we will be discussing details this weekend/month. Official starting date is set in February when university returns to it's normal operation after holiday season, till than we have to finalize the build and start getting necessary equipment. Dear ARW, I noticed, your ideas about setting up the first measurements differ a lot from how I would do it/am going to do it. The people at the university who are going to work for you don't seem to have experience in this or a related field. I strongly recommend you to attract an advisory committee, maybe some the more experienced people active at this forum am willing to participate in it (not me, I'm not experienced enough, yet). Best, Peter ... A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. ... Even with the understanding that this is to be a project based at or associated witha University Physics Department, perhaps one of our builders with experience could repost the cautions and dangers involved. Most of what has been posted in these discussions has been working with DC voltages of 2 to 3 kv and raw microwave energies up to perhaps 1000watts. Both can be deadly if not handled carefully by experienced and qualified individuals. Once you start talking about 10kw of MW energies the danger increases more than 10 fold. Again maybe one of the DIY builders in these discussions with the experience I do not have can properly emphasize the need for caution and careful experienced handling of the DC and high frequency currents involved, even for a project being formulated at a university lab. Can't emphasize the safety aspects enough. If you go the magnetron route there needs to be someone with experience in high voltage electronics and high energy microwaves or someone could be killed. Folks are converging on the idea that this is a highly narrowband phenomena and high energies may work against you unless you can keep the signal very narrow within the fustrum. A recent post by TheTraveller sums up for me a current state of the art approach: http://forum.nasaspaceflight.com/index.php?topic=41732.msg1615509#msg1615509 (http://forum.nasaspaceflight.com/index.php?topic=41732.msg1615509#msg1615509) Note that TT and others are planning to use 100W solid state rf sources that are highly tuneable (and reasonably inexpensive). The narrowband aspect of this phenomena may mean that there is a lot of benefit to actively tuning the frequency as it is expected to change as the frustum accelerates. A very interesting question is whether performance could be improved by anticipating where the frequency should be for a desired impulse and tuning accordingly. This would be a bit like feed forward signal conditioning. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/05/2016 12:57 am I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two. If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end. The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out. So,.... What? An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work? A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin :) That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense? Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity. ? A voltage drop is how you lose energy; voltage drop - eddy current - etc. This is what you want at one end (metallic) of the cavity. We do have a voltage drop across the dielectric coatingt; metal surface behind on one side and MW on the other side, causing minimal charge movement ... essentially a variable polarization of the dielectric, i.e. much much less loss of energy.... Better than nickel ? You cannot use a dielectric insert without a trade-off. In this case, an insert will lower the Q of the cavity, effectively widening the 3dB BW of the return loss response. More testing will be required to determine if that tradeoff is worth it, or...someone will have to develop a bullet-proof theory that "inserts provide X so thrust can become Y". Do you know of experiments done with a cylindrical cavity and dielectric inserts? I plan do these with shaped dielectrics (cones, to start with). Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: dustinthewind on 12/05/2016 12:58 am It might be oversimplified, but here is a rough draft on how modifying the mass of light in a cavity with regards to its wavelength might give it some push. https://www.researchgate.net/profile/Dustin_Macdermott "Is the frustum EM Drive4 decelerating light for propellantless propulsion?" It may still be flawed. Will revise as I go. Equations (5) and (6) seem to be contradictory. On the left they are equal, on the right they are not. I see what you're doing, but it's poorly expressed. Equations (19) and (20) where you derive K. I tried this. Did you notice that your K≤1, where K in the PV Model is always K≥1? In the PV Model, K≤1 is FTL, whereas in a waveguide v≤c. The logic doesn't fit the facts, at least not in a straight forward 1:1 comparison. I'll double check equations 5 and 6. Thanks. All equations 5 and 6 are stating is that both change in frames are equal after the impact. I'll make sure it is correct, but it should be. The 2nd solution for dv1 and dv2 is that the two colliding objects pass right through each other, so only the first solution makes sense. Regarding equations 19 and 20, K is supposed to be less than 1 at the narrow end. Supposedly the speed of light at that end becomes greater. This seems to go along with TT stating that they have measured a weaker impulse from photons at the narrow end but I don't know where he is getting this from. It also goes along with the wavelength growing larger and in the PV model the mass of the photon decreasing. Also with K dropping the energy should increase and generally where the wavelength appears to increase, the energy density of the radiation increases. That is consider http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html where he shows under, "Energy, pressure and forces" he shows the energy density and above that title, is how it effects the EM modes wavelength. You will also notice at this url I gave in the paper, "https://www.microwaves101.com/encyclopedias/waveguide-mathematics" they state, Quote "The guide wavelength in waveguide is longer than wavelength in free space. This isn't intuitive, it seems like the dielectric constant in waveguide must be less than unity for this to happen... don't think about this too hard you will get a headache". I always thought the phase velocity<c not the group velocity so I'll have to look a bit more into this. I could almost swear there were ways to make the group velocity faster than c. But here is another quote from: http://www.mathpages.com/home/kmath210/kmath210.htm Quote Hence, not only is the phase velocity generally greater than c, it approaches infinity as ω approaches the cutoff frequency ω0. This idea I am working with predicts, with the wavelength a force toward the big end unless a dielectric is introduced which changes the wavelength distribution. Similar to what TT has been saying. I appreciate your comments and I'll use it to help me refine and look for changes I should make. Both solutions for 5 and 6 from the energy equation appear to give the correct solution when substituted into the momentum equation 1 so it should be ok. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: rfmwguy on 12/05/2016 01:23 am Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university. A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. I may provide pictures of the build in 2017 as it progresses however testing data will be subject to NDA until paper is published/refused or experiment failed and no thrust was detected. So there are universities involved in this research. Good. I thought Martin Tajmar at Dresden was the only (official) university researcher in this field. You should also publish if you do not detect thrust (at least at ArXiv). How do you plan to measure the force? There is a lot of attention for the microwave part at this forum. I have the impression the other necessary part of the game, the force/thrust measurement, is a little bit neglected. My self, I'm a business man with deep passion for science and a dream to fly to space one day. However I do have lots of friends in university as they helped me immensely to start my business a decade ago. This week I've signed a contract with university for a privately funded research project by my initiative. They like the idea of this kind of research but they wouldn't put their money into it. Data will be published whether it's successful or not and the measurement methods will have to be worked out by people doing the science. I have masters in engineering and I know a thing or two but we will be discussing details this weekend/month. Official starting date is set in February when university returns to it's normal operation after holiday season, till than we have to finalize the build and start getting necessary equipment. Dear ARW, I noticed, your ideas about setting up the first measurements differ a lot from how I would do it/am going to do it. The people at the university who are going to work for you don't seem to have experience in this or a related field. I strongly recommend you to attract an advisory committee, maybe some the more experienced people active at this forum am willing to participate in it (not me, I'm not experienced enough, yet). Best, Peter ... A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. ... Even with the understanding that this is to be a project based at or associated witha University Physics Department, perhaps one of our builders with experience could repost the cautions and dangers involved. Most of what has been posted in these discussions has been working with DC voltages of 2 to 3 kv and raw microwave energies up to perhaps 1000watts. Both can be deadly if not handled carefully by experienced and qualified individuals. Once you start talking about 10kw of MW energies the danger increases more than 10 fold. Again maybe one of the DIY builders in these discussions with the experience I do not have can properly emphasize the need for caution and careful experienced handling of the DC and high frequency currents involved, even for a project being formulated at a university lab. I offer my advice for this. They can PM me here. I will soon be very busy with more project work however. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: M.LeBel on 12/05/2016 01:32 am It might be oversimplified, but here is a rough draft on how modifying the mass of light in a cavity with regards to its wavelength might give it some push. https://www.researchgate.net/profile/Dustin_Macdermott "Is the frustum EM Drive4 decelerating light for propellantless propulsion?" It may still be flawed. Will revise as I go. ... Was actually drawn by your Barnett type experiment thesis which I downloaded before realizing I already had your .pptx presentation of same. I researched this a bit for my own experiments.. What was Barnetts conjecture again about the magnetic field ... ? That it was some sort of emission? What are others conjectures about its dynamic nature? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: dustinthewind on 12/05/2016 01:59 am It might be oversimplified, but here is a rough draft on how modifying the mass of light in a cavity with regards to its wavelength might give it some push. https://www.researchgate.net/profile/Dustin_Macdermott "Is the frustum EM Drive4 decelerating light for propellantless propulsion?" It may still be flawed. Will revise as I go. ... Was actually drawn by your Barnett type experiment thesis which I downloaded before realizing I already had your .pptx presentation of same. I researched this a bit for my own experiments.. What was Barnetts conjecture again about the magnetic field ... ? That it was some sort of emission? What are others conjectures about its dynamic nature? Barnett's experiment that I cite in that thesis was to determine if the magnetic field could axially rotate. His experiment seemed to determine that that magnetic field did not rotate axially with an axially rotating solenoid. Imagine axial magnetic field lines rotating with an axially rotating solenoid. He created an open circuit capacitor to store charge, which he could close when the field lines should be rotating. The axial rotation of a magnetic field should give what might appear to be as a electric change in charge of the solenoid, except at the poles. I had serious doubts Barnett's experiment could detect this change in charge in the lab frame because he shielded his inner capacitor from the outer rotating solenoid. This rotating magnetic field in the lab frame would appear as an electric field in the lab frame. Any shielded with free electrons would react to that electric field and shield his detecting capacitor. The reason the magnetic field can pass through a shield is because the shield sees no electric field. I have to give him credit because Barnett and a friend came up with the idea to use a capacitor to detect the effect. I came to the conclusion the magnetic field can not rotate as did Barnett. I didn't detect such an electric field and my capacitor wasn't shielded. The other reason was because a magnetic field is what I show to be a dipole electric field, induced in a current loop by relativity. In fact the magnetic field wouldn't exist with out relativistic effects. It is one of the few everyday effects where we commonly observe relativity in action. If your moving with respect to a current loop your moving faster (with respect to) w.r.t. some charges than others (the current specifically) so by relativity charges bunch up where they are moving against your velocity. This is where the warped rotating wagon wheel image comes in. If you could rotate a current loop in the lab frame "axially" and observe charges in the far end of the current loop moving faster with respect to you than other charges in the current loop, while sitting still in the lab frame I would say we have some major problems with our understanding of physics. It seems impossible that the magnetic field can rotate axially because of this. I came to the conclusion that instead of rotating the magnetic field radiates, radially. After all, information generally travels radially from its source. This even seems to work with magnetic induction motors which supposedly generate rotating magnetic fields inside but have no rotating magnet. Hence the appearance of the rotating magnetic field is only a radiating magnetic field. Also pulsars being rotating magnetic stars send out pulses or radial emissions. The one exception to this is possibly if we start rotating space time (Lense–Thirring effect.) and then the magnetic field should rotate with it. Now were into messing with space time effects and "possibly" connected to the EM Drive "if it works". I'm also currently looking for a job. Left on good terms, wife wanted to move, contract was up, probably not the best choice I have made. If anyone knows some prospects I'm mobile and willing to move. Just shoot me a message. https://www.youtube.com/watch?v=8XF-11MQGQ0 Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: R.W. Keyes on 12/05/2016 02:04 am Yes, vacuum chamber and torsion balance. along with miscellaneous other equipment and supplies. Thermal imager. voltage calibrator, VNA, etc. Any help with the list of equipment, and its required specifications, would be helpful. I'd have to build the torsion balance, yes, so specs and plans could be useful. I was also thinking of getting a COMSOL multiphysics license and then rent out use of the computer upon which it was installed (networked license, or not. With the non-network license, just transfer the data by USB stick from the non-networked computer to the networked one which clients would transfer data to/from). The industrial space of have made inquiries about are variously located in Great Barrington, Pittsfield, and North Adams Massachusetts. These are approximately an hour's drive from the Albany airport. The vacuum chamber should really be large enough to hold a rotational table/test rig. Tiny vacuum chambers are the absolute bane of EM Drive research. Rotational table/test rig is the recommended configuration for testing ion drives and the like. The Cannae folks have this set up. Another consideration is vacuum hardened electronics, particularly the RF drive section. I recall Paul detailing the serious problems that EW had in this area. Many folks have been getting good traction with Fekko. Perhaps that should be given consideration over COMSOL? FEKO is setup to do exactly that. "FEKO is licensed under Altair’s HyperWorks Unit (HWU) Licensing system which is a token style licensing systems that draws a certain number of unit for the different software options available. The minimum number of units required to run FEKO is 25 HWU and allows processing on up to 4 cores." As I understand it, once you have the HWU, they can be shared amongst individuals in a group, but only one seat at a time can be active. The cost was$15k USD to me as a hobbiest. No way I can do it alone but if 10 or 20 people wanted to share the units, that would be almost affordable. Note: Training is EXTRA!

I have the capital to spring for that, but I'd want to have some risk reduction.  I am not sure of the license requirements and training costs. Can someone inform me? And help me balance this investment versus others. There is the possibility of making interested people minority investors, instead of clients, of my company - I have a wholly owned subsidiary which could hold the licenses and which could be carved up in proportion. I have the competence to buy a good s(Linux/Solaris) server and administer the same.  Ideas about structure of share versus time rental and combinations could be interesting to consider but I favor simplicity. Send me private messages if you want to talk specifics.

I am not a person who seeks out favor from governments, but the local economy has been losing, particularly in industry, for decades now and perhaps some grand could become available Thanks to being in the US, tax considerations are important, and quite honestly I'd rather suffer a loss for science than pay more money to the IRS. It's something for interested people to consider but remember that time is of the essence. If you are serious and want to come meet me and discuss this and get an opinion of my personal character, I am open to that, as long as you can convince me that you are serious and have some resources (but hey if you you want to come talk to me at the local pub I won't ask you for any references ahead of time). If you want to be a major partner (i.e. significant shareholding and an executive position) that's also possible but ability and resources must be shown.

I want to make maximal use of the equipment I'd be purchasing. I have some experience in antenna design, and would like to take advantage of my equipment to advance this, as well as provide services to non-Emdrive research.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: SeeShells on 12/05/2016 02:24 am
:-\
I would like my simple question to be answered too:

What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength?
That I can help with. The guide wavelength in a waveguide is basically due to the waves bouncing back and forth between the walls rather than straight down the middle. The superposition hides the non-axial portion, so you just see an apparently stretched axial wavelength, while the actual travelling waves maintain their original wavelength. In a smaller waveguide the angle of the bounces is steeper (for the same frequency of radiation), so the apparent wavelength gets longer. What Cullen originally showed was simply that the steeper the bounces, the less of the wave's momentum is in the axial direction, which is a very sensible result.

Something similar happens in an emDrive cavity as waves reflecting off the side walls cause the angles to get steeper towards the small end. You can't easily define a guide wavelength though because at any point the suprimposed waves are not all moving in the same direction, and it is not clear what modes (if any) the apparent standing wave has any meaningful relation to the angles the travelling waves are travelling at. The issue with this description and how Shawyer abuses Cullen's results is that by conservation of momentum, it is obvious that any change in axial momentum due to reflections off the sidewalls transfers that momentum to the sidewalls to end up with no net motion.

(Note:This post used simplified descriptions, to give an intuitive sense of what is going on. Boundary conditions and the wave equation make this more complicated than presented here.)

Isn't it the opposite (emphasis mine)? A "steeper" angle means a more open angle, right? (English is not my primary language). Shawyer shows the sawtooth pattern gradually becomes sharper as the waveguide diameter becomes smaller, hence an apparent decreasing wavelength axially in the direction big to small in a frustum.

Even if the EM frequency stays the same, the wavelength undergoes an apparent shrinking (in the axial direction) so the group velocity (which carries energy and information) decreases axially in an EM wave travelling big to small, as if the wave was undergoing an apparent blueshift in direction of the small end plate.
No its the opposite. i.e. it depends on the component of ψ you are looking at. I think you are looking at the wavelength/better shell of constant phase right? Then the pic below shows whats happens.

No, flux_capacitor's drawing was correct, yours clearly does not have equal incident and reflected angles.

Flux capacitor is wrong about the effect on wavelength his drawing implies though. (This is confusing, so these mistakes are understandable.)

While the bounces are getting more frequent, the wavelength actually gets longer, because projected distance between 2 constant phase surfaces gets larger. see attached for a picture. (Note that in reality there are constraints of the ratio of the wavelength and the angle of the bounces (depending on mode) I ignored these to make it easier to draw quickly)

The green lines are the direction of travel, the red lines are the wavefronts. If I drew it right, the distance between the red lines along the green lines should be the same for both (this is the free space wavelength). Due to superposition in a waveguide, what you see as the guide wavelength is the distance between where the red lines intersect the black lines (marked in grey), which gets larger as the direction of travel gets steeper.
Please try to understand that the ray trajectory theory is not applicable 1 by 1 since the wavelength is of the same order as the structure of the cavity it self. We are talking about near field conditions.
The freespace wavelength is always smaller compared to the one in a waveguide with ε=1, μ=1 and  having conductive walls, if the diameter is in the order of the wavelength.
Aero ran this sim in meep that shows the "stretching" of the mode in the small end. I added some additional drawing that doesn't mean anything in this disccussion but you can get the idea.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/05/2016 02:34 am
It might be oversimplified, but here is a rough draft on how modifying the mass of light in a cavity with regards to its wavelength might give it some push.  https://www.researchgate.net/profile/Dustin_Macdermott "Is the frustum EM Drive4 decelerating light for propellantless propulsion?"  It may still be flawed.  Will revise as I go.

Equations (5) and (6) seem to be contradictory. On the left they are equal, on the right they are not. I see what you're doing, but it's poorly expressed.

Equations (19) and (20) where you derive K. I tried this. Did you notice that your K≤1, where K in the PV Model is always K≥1?  In the PV Model, K≤1 is FTL, whereas in a waveguide v≤c. The logic doesn't fit the facts, at least not in a straight forward 1:1 comparison.

I'll double check equations 5 and 6.  Thanks.  All equations 5 and 6 are stating is that both change in frames are equal after the impact.  I'll make sure it is correct, but it should be.  The 2nd solution for dv1 and dv2 is that the two colliding objects pass right through each other, so only the first solution makes sense.  Regarding equations 19 and 20, K is supposed to be less than 1 at the narrow end.  Supposedly the speed of light at that end becomes greater.  This seems to go along with TT stating that they have measured a weaker impulse from photons at the narrow end but I don't know where he is getting this from.  It also goes along with the wavelength growing larger and in the PV model the mass of the photon decreasing.  Also with K dropping the energy should increase and generally where the wavelength appears to increase, the energy density of the radiation increases.  That is consider http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html where he shows under, "Energy, pressure and forces" he shows the energy density and above that title, is how it effects the EM modes wavelength.

You will also notice at this url I gave in the paper, "https://www.microwaves101.com/encyclopedias/waveguide-mathematics" they state,
Quote
"The guide wavelength in waveguide is longer than wavelength in free space. This isn't intuitive, it seems like the dielectric constant in waveguide must be less than unity for this to happen... don't think about this too hard you will get a headache".

I always thought the phase velocity<c not the group velocity so I'll have to look a bit more into this.  I could almost swear there were ways to make the group velocity faster than c.  But here is another quote from: http://www.mathpages.com/home/kmath210/kmath210.htm
Quote
Hence, not only is the phase velocity generally greater than c, it approaches infinity as ω approaches the cutoff frequency ω0.

This idea I am working with predicts, with the wavelength a force toward the big end unless a dielectric is introduced which changes the wavelength distribution.  Similar to what TT has been saying.

I appreciate your comments and I'll use it to help me refine and look for changes I should make.

Both solutions for 5 and 6 from the energy equation appear to give the correct solution when substituted into the momentum equation 1 so it should be ok.

1-  Not too sure I understand; in the text after equation 3 it says dv1=dv2. [ elastic collision... same masses ...] one decelerates as the other accelerates  i.e.  should it be  dv1 = - (minus) dv2 ??

2-   "The 2nd solution for dv1 and dv2 is that the two colliding objects pass right through each other, so only the first solution makes sense."      ;D Maybe, it is just ..... the momentum passing through....
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/05/2016 02:49 am

1-  Not too sure I understand; in the text after equation 3 it says dv1=dv2. [ elastic collision... same masses ...] one decelerates as the other accelerates  i.e.  should it be  dv1 = - (minus) dv2 ??

2-   "The 2nd solution for dv1 and dv2 is that the two colliding objects pass right through each other, so only the first solution makes sense."      ;D Maybe, it is just ..... the momentum passing through....

1. I didn't make any assumptions that dv1=dv2.  I left it to the math to prove they should be equal, and derive that.  Basically both objects undergo a change in frame.  The first solution of dv1(dv2) and dv2(dv1) are in terms of each other.  It is still a mystery if they are equal or not.  When they are substituted into the energy equation it becomes evident they are equal.  Try substituting equation 5 in equation 1 for both dv1 and dv2 and factoring the equation and you will see what I mean.  It comes out dv1*m1=dv1*m1.  You can substitute equation 5 into the energy equation 4 for both dv1 and dv2 and it comes out properly also.

2. Well yeah they retain their momentum so nothing happens.  They don't strike each other.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/05/2016 02:50 am
It might be oversimplified, but here is a rough draft on how modifying the mass of light in a cavity with regards to its wavelength might give it some push.  https://www.researchgate.net/profile/Dustin_Macdermott "Is the frustum EM Drive4 decelerating light for propellantless propulsion?"  It may still be flawed.  Will revise as I go.

... Was actually drawn by your Barnett type experiment thesis which I downloaded before realizing I already had your .pptx presentation of same.  I researched this a bit for my own experiments..  What was Barnetts conjecture again about the magnetic field ... ? That it was some sort of emission? What are others conjectures about its dynamic nature?
Barnett's experiment that I cite in that thesis was to determine if the magnetic field could axially rotate.  His experiment seemed to determine that that magnetic field did not rotate axially with an axially rotating solenoid.  Imagine axial magnetic field lines rota.....................  [/b]

Thanks for the reply ... and taking the time..  Radiating magnetic field......   :P
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Space Ghost 1962 on 12/05/2016 02:50 am
Btw just to clear things up, I'm not going to be the one building it. I've masters in biochemical engineering(far from expertise required). I will be providing financial support as well as building equipment as part of signed agreement between my company and university.

A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it.

So there are universities involved in this research. Good. I thought Martin Tajmar at Dresden was the only (official) university researcher in this field.
This week I've signed a contract with university for a privately funded research project by my initiative. They like the idea of this kind of research but they wouldn't put their money into it.
The people at the university who are going to work for you don't seem to have experience in this or a related field. I strongly recommend you to attract an advisory committee, maybe some the more experienced people active at this forum am willing to participate in it (not me, I'm not experienced enough, yet).

... A good friend of mine is head of physics department in a university. He and few phd students will be building and testing it. ...

Even with the understanding that this is to be a project based at or associated witha University Physics Department, perhaps one of our builders with experience could repost the cautions and dangers involved.

Would like to caution and assist interest here a bit first.

There are university physics and engineering departments involved with particle accelerators, plasma and fusion research programs ... that have the required safety and experience present to take on projects related to this form of propellent-less  propulsion. (If I were a EM Drive DIYer, these are the ones I'd want to deal with, because you can talk to the support staff about safety and apparatus and get confidence that the situation is well understood BEFORE committing to a relationship, as they've been down this route before.)

Since there is the peer reviewed and published Eagleworks paper, they can (and will) be attracted to applying effort and publishing follow-on papers to taking things further here. The hardest part is with the first paper, because the authors/reviewers take considerable flak for it being published in the first place.

The focus will be on finding/refuting the anomalous effect EW appears to have found - which is expected and reasonable for them to do, as most of them will be attempting to demonstrate there professional aptitude in doing so. There are few projects so easy as this one is to gain access/insight into for E/M and microwave grad students to "make a name" in a field by doing so. All of them will be even more critical of each other's efforts than those considered "outside" their professions, meaning that it will be hard for marginal work to qualify as a follow-on to the EW paper.

It will be the results of those papers that will set the grounds for any academic/institutional "follow on" funding in this area. A few of these might even jumpstart the next NASA funding for same.

Some in these potential researchers might be very appreciative of DIYers work, because that work saves them a ton of time in getting to the point of initial experimental apparatus, which is their "skin in the game".  They are also non-competitive with DIYers - they want to be acknowledged as to explaining the anomaly to own community, not actually "making things go", which is more what the DIYers want to own.

There are a lot of 2nd-3rd year grad students in these areas, who have safe access to means at the facilities, who have taken the advanced courses but lack laboratory projects to propose. A benefit of them doing something like this is that they gain the attention of research groups by doing so and demonstrating that they can be valuable research talent in a established lab by doing so. Far better than spending time as a teaching assistant.

And, if you are already at a university, outside of physics/engineering, and you are interested in this area, finding these grad students and becoming a part of said project, even if it starts "unofficially", is the safest/best way to explore the area by finding knowledgeable "allies" to pursue such.

FWIW.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/05/2016 03:18 am
...

I came to the conclusion that instead of rotating the magnetic field radiates, radially.  After all, information generally travels radially from its source.  This even seems to work with magnetic induction motors which supposedly generate rotating magnetic fields inside but have no rotating magnet.  Hence the appearance of the rotating magnetic field is only a radiating magnetic field.  Also pulsars being rotating magnetic stars send out pulses or radial emissions.  The one exception to this is possibly if we start rotating space time (Lense–Thirring effect.) and then the magnetic field should rotate with it.  Now were into messing with space time effects and "possibly" connected to the EM Drive "if it works".

I'm also currently looking for a job.  Left on good terms, wife wanted to move, contract was up, probably not the best choice I have made.  If anyone knows some prospects I'm mobile and willing to move.  Just shoot me a message.

Read up on the relativistic Homopolar Generator. An axially rotating magnet will produce a quasi-radial electric field provided the current density in the magnet is being length contracted by the relativistic speed. Becker gives a very good derivation of the effect, with experimental citations I think.

See: http://store.doverpublications.com/0486642909.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/05/2016 03:20 am
This is stepping back, asking questions, sorting out what we think we understand from what we think we know. This type of re-evaluation is always at the start of a new a direction of enquiry or exploration. We are stalling (now) when we think that knowing “A” means understanding “A”. Without realizing that you don’t actually understand, you ignore the existence of pending questions and you can’t even start looking for their answers.

In physics, we often start with “why” this and “why” that; these are valid “metaphysical” questions. And, accordingly, the system, the way it is built, always return the answer “how” things work... and always will.

The emDrive is radical in spirit, theory and technology. This requires radical thinking. (Thinking outside the cavity  :)  ) Although some of us think that this is business as usual, it is not. Looking for sparks with the usual approach will only give sparks. We are trying to work with the vacuum, which until recently was just that to us, empty. We know now that it is anything but empty.

Let’s think differently, for a second. A force field is an acceleration field, and acceleration is in m/s2. The “meter” part is for the observe onlyr. What is 1/s2?  It is 1/t (the rate of the time process) per unit time t   i.e. this is a gradient in the rate of the time process. (Remember Unruh’s; gravity is the unequable flow of time.) Is that surprising? We have to read the equations with that in mind. A clock is a device we use to do three things; a) detect time (it is ticking) b) measure the rate of time (how fast it is ticking) and c) integrate the rate of this ticking into graduations of seconds, hours,... The seconds are the integration of the rate of time. This clock “detector” detects the presence of some dynamic process with a local value....it is stuff! This time process is real. So, all our measurements of time refer to a real process, that is there, whether we measure it or not.

The rate of time is 1/T = E/dB  or B/dE ; photons as nice gliding em solitons with either E or B fixed.

With the emDrive, we try to produce this force or acceleration field. How do we get to this? IMO, we use the same equations (they work!) but flip them around (as above) in order to change “time” in them, from silent witness, to the active product we want to create; a force field = a gradient in the rate of the time process = the causal structure.

Food for thought
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/05/2016 03:25 am
Theory update. I put the damping in terms of Power in and Power lost. Hopefully, this makes it clearer what is going on?

This shows that thrust depends on the time rate of change in power, as it does for the MEGA thruster. I believe there is a connection there.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Stormbringer on 12/05/2016 03:38 am
...

I came to the conclusion that instead of rotating the magnetic field radiates, radially.  After all, information generally travels radially from its source.  This even seems to work with magnetic induction motors which supposedly generate rotating magnetic fields inside but have no rotating magnet.  Hence the appearance of the rotating magnetic field is only a radiating magnetic field.  Also pulsars being rotating magnetic stars send out pulses or radial emissions.  The one exception to this is possibly if we start rotating space time (Lense–Thirring effect.) and then the magnetic field should rotate with it.  Now were into messing with space time effects and "possibly" connected to the EM Drive "if it works".

I'm also currently looking for a job.  Left on good terms, wife wanted to move, contract was up, probably not the best choice I have made.  If anyone knows some prospects I'm mobile and willing to move.  Just shoot me a message.

Read up on the relativistic Homopolar Generator. An axially rotating magnet will produce a quasi-radial electric field provided the current density in the magnet is being length contracted by the relativistic speed. Becker gives a very good derivation of the effect, with experimental citations I think.

See: http://store.doverpublications.com/0486642909.html
If you need to check out high rpm anything you could use a dental drill for up to 400 thousand rpm or this...

for 600 million rpms.

And there are things along similar lines to the present topic that do need high rotation rates to rise above noise sigma .

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 04:50 am
I can't explain the difference between up and down weight changes. Roger also measured the same effect.

Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird.

Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum.

I expect the weight change difference may be hysteresis in the strain gauges.

The scale is designed to be zeroed out and weight added. When the weight reduces, that may not be an optimised measurement situation.
No, digital scales should work just fine going negative. For any one I have worked with if I put something on, and then hit tare and take it off, the negative values always matches the positive value from before hitting tare.

What this does show is that you have at least 0.2 grams of uncharacterized error sources, and probably more, since as flux_capacitor pointed out, any rising hot air should have had the opposite effect. Considering the significant, but unknown error sources, and you having results significantly larger than basically all other experimenters, who did more careful experiments, generated less force, it is reasonable to conclude that if you generated any emDrive effect, it is too swamped by errors for your experiment to provide useful data.

Actually it is +-0.1g of uncharacterised force. However it each test series of 50 measurements, the variance from the average was +-0.04g or around 4.4% for the big side down tests and 5.7% for the big side up tests.

Did just recheck the scale and good to report there is no observable hysteresis. So that is not what caused the orientation thruster orientation on the scale force variance.

Have attached a correct image of the test thruster and its dimensions. End plates were sized to the external diameter of the end of the frustum and gravity stacked, so any heated air during the 5 sec of 100W of Rf power application would be expelled at a right angle to the thruster Z axis.

While I didn't record frustum temperature, was going to do that later, there was very little observable heating. Probably as the 100W was only applied for 5 sec and any temp rise of the thruster side walls and end caps would be very small and slow to develop as the surface area was 0.264m^2 and had a mass of 1.9kg of Cu.

Please make suggestions as to where any errors are lurking so I can address them when I redo this test series.

The data and the static force direction was as real as was that of EW's  non dielectric Cu and Al thrusters and Roger's Experimental, Demonstrator and Flight Thruster thrusters.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/05/2016 05:01 am
...

I came to the conclusion that instead of rotating the magnetic field radiates, radially.  After all, information generally travels radially from its source.  This even seems to work with magnetic induction motors which supposedly generate rotating magnetic fields inside but have no rotating magnet.  Hence the appearance of the rotating magnetic field is only a radiating magnetic field.  Also pulsars being rotating magnetic stars send out pulses or radial emissions.  The one exception to this is possibly if we start rotating space time (Lense–Thirring effect.) and then the magnetic field should rotate with it.  Now were into messing with space time effects and "possibly" connected to the EM Drive "if it works".

I'm also currently looking for a job.  Left on good terms, wife wanted to move, contract was up, probably not the best choice I have made.  If anyone knows some prospects I'm mobile and willing to move.  Just shoot me a message.

Read up on the relativistic Homopolar Generator. An axially rotating magnet will produce a quasi-radial electric field provided the current density in the magnet is being length contracted by the relativistic speed. Becker gives a very good derivation of the effect, with experimental citations I think.

See: http://store.doverpublications.com/0486642909.html
That's the first thing we investigated.  At first I mounted a neodymium magnet on a dremel tool and spun it up to high rpm.  Calculated what I should have seen on the concentric circular capacitor and it wasn't there.

Something interesting to think about is imagine those axially rotated magnetic field lines rotating past you.  There relative velocity determines how much faster your moving with respect to some current in the current loop than the current moving in the other direction (as if you had velocity w.r.t. the current loop in the lab frame!).  Even though, all the current is doing is going around in a circle in front of you, so you shouldn't see any current moving faster with respect to other current in the loop.  This absurd difference in relative velocity (that corresponds to a rotating magnetic field) seems to be increasing with distance!  \omega x r x B = v x B.  Eventually they would appear to exceed the speed of light! It also seems to suggest information/light traveling in a circular path.

I can see it if your moving with respect to the magnet or your rotating around it but not if the magnet is rotating.  If the rotating magnet has metal on it, the metal will see an electric field because the metal is rotating.  I would be curious to see such experimental evidence of an axially rotating magnet giving off an electric field associated with its magnetic field though.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/05/2016 05:06 am
I can't explain the difference between up and down weight changes. Roger also measured the same effect.

Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird.

Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum.

I expect the weight change difference may be hysteresis in the strain gauges.

The scale is designed to be zeroed out and weight added. When the weight reduces, that may not be an optimised measurement situation.
No, digital scales should work just fine going negative. For any one I have worked with if I put something on, and then hit tare and take it off, the negative values always matches the positive value from before hitting tare.

What this does show is that you have at least 0.2 grams of uncharacterized error sources, and probably more, since as flux_capacitor pointed out, any rising hot air should have had the opposite effect. Considering the significant, but unknown error sources, and you having results significantly larger than basically all other experimenters, who did more careful experiments, generated less force, it is reasonable to conclude that if you generated any emDrive effect, it is too swamped by errors for your experiment to provide useful data.

Actually it is +-0.1g of uncharacterised force. However it each test series of 50 measurements, the variance from the average was +-0.04g or around 4.4% for the big side down tests and 5.7% for the big side up tests.

Did just recheck the scale and good to report there is no observable hysteresis. So that is not what caused the orientation thruster orientation on the scale force variance.

Have attached a correct image of the test thruster and its dimensions. End plates were sized to the external diameter of the end of the frustum and gravity stacked, so any heated air during the 5 sec of 100W of Rf power application would be expelled at a right angle to the thruster Z axis.

While I didn't record frustum temperature, was going to do that later, there was very little observable heating. Probably as the 100W was only applied for 5 sec and any temp rise of the thruster side walls and end caps would be very small and slow to develop as the surface area was 0.264m^2 and had a mass of 1.9kg of Cu.

Please make suggestions as to where any errors are lurking so I can address them when I redo this test series.

The data and the static force direction was as real as was that of EW's  non dielectric Cu and Al thrusters and Roger's Experimental, Demonstrator and Flight Thruster thrusters.

If each run was only 5 seconds, and you were adjusting the minimum VSWR for each run. Then what burned out your RF amplifier? That's the mistake I'm afraid of and would like to know how to avoid it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 06:41 am
If each run was only 5 seconds, and you were adjusting the minimum VSWR for each run. Then what burned out your RF amplifier? That's the mistake I'm afraid of and would like to know how to avoid it.

WT,

The Rf amp didn't burn out as such. I has a variable attenuator that can vary the output 0 - 31dBm in 1dBm steps. This circuit failed to produce an output and so there was no drive signal to the output stages.

BTW the amp is rated to be able to handle a full power VSWR of 3:1 without damage.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 06:46 am
Aero ran this sim in meep that shows the "stretching" of the mode in the small end. I added some additional drawing that doesn't mean anything in this discussion but you can get the idea.

Shell

Shell,

The "stretching" you mention is the result of the guide wavelength increasing as the diameter reduces.

FEKO and COMSOL show the same effect.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: RERT on 12/05/2016 06:53 am
Just wanted to register a gut reaction to the above post that a University Department test of the EM drive will be trying to show it fails.

Surely all of the community here knows that this work is hard enough to do that creating a failure isn't even a trick. Any team doing a replication attempt has to be fired up to try and make it work, not motivated by dogmatic scepticism. Which is not to say that such replicators don't need the highest standards of honesty, integrity, and sceptical enquiry, and willingness to report negative results. But they can't be content to just stop and report on the first failure.

The same thing happened with Fleischmann & Pons, where a hard experiment quickly generated nulls from folks with a vested interest in seeing one.

People need to be very careful that replication attempts don't turn into easy propaganda against the effect.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 07:40 am
It might be oversimplified, but here is a rough draft on how modifying the mass of light in a cavity with regards to its wavelength might give it some push.  https://www.researchgate.net/profile/Dustin_Macdermott "Is the frustum EM Drive4 decelerating light for propellantless propulsion?"  It may still be flawed.  Will revise as I go.

Equations (5) and (6) seem to be contradictory. On the left they are equal, on the right they are not. I see what you're doing, but it's poorly expressed.

Equations (19) and (20) where you derive K. I tried this. Did you notice that your K≤1, where K in the PV Model is always K≥1?  In the PV Model, K≤1 is FTL, whereas in a waveguide v≤c. The logic doesn't fit the facts, at least not in a straight forward 1:1 comparison.

WT,

Need to consider that as diameter drops and guide wavelength increases, group velocity drops. BTW group velocity inside a waveguide is always < c.

As Cullen has shown, the reduction in end plate radiation pressure is a function of external wavelength / internal guide wavelength or internal group velocity / c. As guide wavelength increases as diameter drops, thus end plate radiation pressure drops as diameter drops.

This is all predicted by existing microwave physics and has been known for 65 years, though Cullen's work is not largely known outside EmDrive groups. I expect very few physicists would know of it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 08:06 am
Just wanted to register a gut reaction to the above post that a University Department test of the EM drive will be trying to show it fails.

Surely all of the community here knows that this work is hard enough to do that creating a failure isn't even a trick. Any team doing a replication attempt has to be fired up to try and make it work, not motivated by dogmatic scepticism. Which is not to say that such replicators don't need the highest standards of honesty, integrity, and sceptical enquiry, and willingness to report negative results. But they can't be content to just stop and report on the first failure.

The same thing happened with Fleischmann & Pons, where a hard experiment quickly generated nulls from folks with a vested interest in seeing one.

People need to be very careful that replication attempts don't turn into easy propaganda against the effect.

Rert,

There are now enough experienced EmDrive builders who understand what needs to be done and what needs to NOT be done, that any negative result should be fairly easy to do analysis of and understand why it did not produce any results.

I'm still working on my $500 scale based EmDrive test kit, price includes everything needed, that will make replication fairly simple and sure. The thruster will be built like my Test Thruster and sit on a scale, with gravity stacked flat end plates and be driven by a 10W WiFi amp, USB freq gen and reflected power tuning device. KISS is the goal. See attached. I'm working to make this thruster and test rig real and to publish the full BOM (Bill Of Material) with measured data and video of the thruster construction and test phases. For$500, I expect to see many replications all around the planet. So unless EW, Universal Propulsion or someone else releases a commercial EmDrive, this replication should end the doubt.

Phil
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/05/2016 10:26 am
...
The thruster will be built like my Test Thruster and sit on a scale, with gravity stacked flat end plates and be driven by a 10W WiFi amp, USB freq gen and reflected power tuning device. KISS is the goal.
...

10 W? And in the above described exps you used 100 W.  ???
If that 10 W amp is cheap and usable, I'd be happy to know the brand and type.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/05/2016 12:25 pm
:-\
I would like my simple question to be answered too:

What is causing the 1/2 wave to lengthen on one side and shorten on the other side, but a local variation of the wavelength?
That I can help with. The guide wavelength in a waveguide is basically due to the waves bouncing back and forth between the walls rather than straight down the middle. The superposition hides the non-axial portion, so you just see an apparently stretched axial wavelength, while the actual travelling waves maintain their original wavelength. In a smaller waveguide the angle of the bounces is steeper (for the same frequency of radiation), so the apparent wavelength gets longer. What Cullen originally showed was simply that the steeper the bounces, the less of the wave's momentum is in the axial direction, which is a very sensible result.

Something similar happens in an emDrive cavity as waves reflecting off the side walls cause the angles to get steeper towards the small end. You can't easily define a guide wavelength though because at any point the suprimposed waves are not all moving in the same direction, and it is not clear what modes (if any) the apparent standing wave has any meaningful relation to the angles the travelling waves are travelling at. The issue with this description and how Shawyer abuses Cullen's results is that by conservation of momentum, it is obvious that any change in axial momentum due to reflections off the sidewalls transfers that momentum to the sidewalls to end up with no net motion.

(Note:This post used simplified descriptions, to give an intuitive sense of what is going on. Boundary conditions and the wave equation make this more complicated than presented here.)

Isn't it the opposite (emphasis mine)? A "steeper" angle means a more open angle, right? (English is not my primary language). Shawyer shows the sawtooth pattern gradually becomes sharper as the waveguide diameter becomes smaller, hence an apparent decreasing wavelength axially in the direction big to small in a frustum.

Even if the EM frequency stays the same, the wavelength undergoes an apparent shrinking (in the axial direction) so the group velocity (which carries energy and information) decreases axially in an EM wave travelling big to small, as if the wave was undergoing an apparent blueshift in direction of the small end plate.
No its the opposite. i.e. it depends on the component of ψ you are looking at. I think you are looking at the wavelength/better shell of constant phase right? Then the pic below shows whats happens.

No, flux_capacitor's drawing was correct, yours clearly does not have equal incident and reflected angles.

Flux capacitor is wrong about the effect on wavelength his drawing implies though. (This is confusing, so these mistakes are understandable.)

While the bounces are getting more frequent, the wavelength actually gets longer, because projected distance between 2 constant phase surfaces gets larger. see attached for a picture. (Note that in reality there are constraints of the ratio of the wavelength and the angle of the bounces (depending on mode) I ignored these to make it easier to draw quickly)

The green lines are the direction of travel, the red lines are the wavefronts. If I drew it right, the distance between the red lines along the green lines should be the same for both (this is the free space wavelength). Due to superposition in a waveguide, what you see as the guide wavelength is the distance between where the red lines intersect the black lines (marked in grey), which gets larger as the direction of travel gets steeper.
Please try to understand that the ray trajectory theory is not applicable 1 by 1 since the wavelength is of the same order as the structure of the cavity it self. We are talking about near field conditions.
The freespace wavelength is always smaller compared to the one in a waveguide with ε=1, μ=1 and  having conductive walls, if the diameter is in the order of the wavelength.
Aero ran this sim in meep that shows the "stretching" of the mode in the small end. I added some additional drawing that doesn't mean anything in this disccussion but you can get the idea.

Shell

So the EM frequency is supposed to be constant everywhere in the frustum, but the wave appears to be squeezed near big end and stretched near small end, at least in the axial direction, due to the tapered cross-section.

MEEP, FEKO and COMSOL all three show the axial wave being indeed modified especially for TE01 modes.

Most interesting, when a PE dielectric is present near small end, the pattern is reversed.

WarpTech supposes the waves are stretched and squeezed oppositely in the radial direction though (i.e. radially stretched and axially squeezed at big end; and radially squeezed and axially stretched at small end) with no dielectric.

The question is how to stretch a wave in a resonant cavity without touching its wavelength (the frequency)?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 12:51 pm
The question is how to stretch a wave in a resonant cavity without touching its wavelength (the frequency)?

FC,

When you "stretch" a wave, you make the wavelength longer, even though the frequency stays unaltered. This apparent magic happens inside waveguides and is called guide wavelength.

The smaller the diameter of the waveguide, the longer the guide wavelength becomes, until the diameter becomes too small, the wavelength becomes infinite, the waveguide is at cutoff and protons can no longer travel down the waveguide.

Check this out:
https://www.microwaves101.com/encyclopedias/waveguide-mathematics

Is why some call microwave physics "Black Magic".
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 12:56 pm
...
The thruster will be built like my Test Thruster and sit on a scale, with gravity stacked flat end plates and be driven by a 10W WiFi amp, USB freq gen and reflected power tuning device. KISS is the goal.
...

10 W? And in the above described exps you used 100 W.  ???
If that 10 W amp is cheap and usable, I'd be happy to know the brand and type.

Do expect to be able to generate enough force, around 0.1g, using the 10W Rf amp, to be able to see this force on a 0.01g resolution scale. Especially the weight increase and decrease as the gravity stacked thruster is reversed on the scale.

Of course a 100W Rf amp can be used but using it will increase the price to around $1,200. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: LowerAtmosphere on 12/05/2016 01:01 pm How to stretch a wave? Surely we are looking the answer in the face. The wavelength decreases as there are more reflections in the small end per unit time imparting more of the inertial mass of the photons on the cavity wall. It would be extremely illuminating if we could measure radiation pressure more accurately. And perhaps the tennis ball metaphors used earlier in the threads arent entirely wrong after all. Remember Bohmian mechanics has been receiving increasing experimental support recently. http://physicsworld.com/cws/article/news/2016/feb/26/surreal-behaviour-spotted-in-photon-experiment The microwave cavity and its effects on average wavelength along the length does not make sense if you refuse to consider it as filled with variably energetic photons. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Peter Lauwer on 12/05/2016 01:14 pm ... The thruster will be built like my Test Thruster and sit on a scale, with gravity stacked flat end plates and be driven by a 10W WiFi amp, USB freq gen and reflected power tuning device. KISS is the goal. ... 10 W? And in the above described exps you used 100 W. ??? If that 10 W amp is cheap and usable, I'd be happy to know the brand and type. Do expect to be able to generate enough force, around 0.1g, using the 10W Rf amp, to be able to see this force on a 0.01g resolution scale. Especially the weight increase and decrease as the gravity stacked thruster is reversed on the scale. Of course a 100W Rf amp can be used but using it will increase the price to around$1,200.

That doesn't sound so expensive. I am looking at amps from Kuhne Electronics [www.kuhne-electronic.de], like the rather broadband (2.0-2.7 GHz) and with good efficiency 4 W (€450) and 8 W (~€1000).
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 01:18 pm
How to stretch a wave? Surely we are looking the answer in the face. The wavelength decreases as there are more reflections in the small end per unit time imparting more of the inertial mass of the photons on the cavity wall.

Without a dielectric at the small diameter end, as the diameter decreases, the guide wavelength increases as shown by microwave physics, by FEKO and by COMSOL.

However yes, the radiation pressure at the small end plate is reduced from that external to the waveguide by the value of external wavelength / guide wavelength.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 01:29 pm
...
The thruster will be built like my Test Thruster and sit on a scale, with gravity stacked flat end plates and be driven by a 10W WiFi amp, USB freq gen and reflected power tuning device. KISS is the goal.
...

10 W? And in the above described exps you used 100 W.  ???
If that 10 W amp is cheap and usable, I'd be happy to know the brand and type.

Do expect to be able to generate enough force, around 0.1g, using the 10W Rf amp, to be able to see this force on a 0.01g resolution scale. Especially the weight increase and decrease as the gravity stacked thruster is reversed on the scale.

Of course a 100W Rf amp can be used but using it will increase the price to around $1,200. That doesn't sound so expensive. I am looking at amps from Kuhne Electronics [www.kuhne-electronic.de], like the rather broadband (2.0-2.7 GHz) and with good efficiency 4 W (€450) and 8 W (~€1000). For the higher power stuff try here: http://www.yonlit.com/ 100W, 2.4 to 2.5GHz, inbuilt programmable 31dBm attenuator, inbuilt forward and reflected power monitoring, ability to handle 3:1 VSWR at max power. Depending on what you select and quantity around$700.

For 8W WiFi amps use EBay as attached.

Working on a deal for a 10W amp that can be directly driven by the sig gen output. The 8W units will need to use 2 in series to overcome the lower 17dB transmit gain.

This is a very interesting Rf amp that is on my shopping list:
http://www.yonlit.com/ShowProducts.asp?Page=1&ID=33

2.5kW pulsed output.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/05/2016 01:52 pm

So the EM frequency is supposed to be constant everywhere in the frustum, but the wave appears to be squeezed near big end and stretched near small end, at least in the axial direction, due to the tapered cross-section.

MEEP, FEKO and COMSOL all three show the axial wave being indeed modified especially for TE01 modes.

Most interesting, when a PE dielectric is present near small end, the pattern is reversed.

WarpTech supposes the waves are stretched and squeezed oppositely in the radial direction though (i.e. radially stretched and axially squeezed at big end; and radially squeezed and axially stretched at small end) with no dielectric.

The question is how to stretch a wave in a resonant cavity without touching its wavelength (the frequency)?

Eliminate the taper and use a cylinder. The frequency doesn't change when the wavelength shifts. But the two orthogonal components of the frequency do change, in a way that keeps the frequency constant, despite the change in diameter.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/05/2016 02:10 pm

So the EM frequency is supposed to be constant everywhere in the frustum, but the wave appears to be squeezed near big end and stretched near small end, at least in the axial direction, due to the tapered cross-section.

MEEP, FEKO and COMSOL all three show the axial wave being indeed modified especially for TE01 modes.

Most interesting, when a PE dielectric is present near small end, the pattern is reversed.

WarpTech supposes the waves are stretched and squeezed oppositely in the radial direction though (i.e. radially stretched and axially squeezed at big end; and radially squeezed and axially stretched at small end) with no dielectric.

The question is how to stretch a wave in a resonant cavity without touching its wavelength (the frequency)?

Eliminate the taper and use a cylinder. The frequency doesn't change when the wavelength shifts. But the two orthogonal components of the frequency do change, in a way that keeps the frequency constant, despite the change in diameter.

You mean, a cylinder with a dielectric on one side? What "change in diameter" then? We don't expect any shift in wavelength in a hollow cylindrical cavity, only in a tapered one.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/05/2016 02:33 pm
...
The thruster will be built like my Test Thruster and sit on a scale, with gravity stacked flat end plates and be driven by a 10W WiFi amp, USB freq gen and reflected power tuning device. KISS is the goal.
...

10 W? And in the above described exps you used 100 W.  ???
If that 10 W amp is cheap and usable, I'd be happy to know the brand and type.

Do expect to be able to generate enough force, around 0.1g, using the 10W Rf amp, to be able to see this force on a 0.01g resolution scale. Especially the weight increase and decrease as the gravity stacked thruster is reversed on the scale.

Of course a 100W Rf amp can be used but using it will increase the price to around $1,200. That doesn't sound so expensive. I am looking at amps from Kuhne Electronics [www.kuhne-electronic.de], like the rather broadband (2.0-2.7 GHz) and with good efficiency 4 W (€450) and 8 W (~€1000). For the higher power stuff try here: http://www.yonlit.com/ 100W, 2.4 to 2.5GHz, inbuilt programmable 31dBm attenuator, inbuilt forward and reflected power monitoring, ability to handle 3:1 VSWR at max power. Depending on what you select and quantity around$700.

For 8W WiFi amps use EBay as attached.

Working on a deal for a 10W amp that can be directly driven by the sig gen output. The 8W units will need to use 2 in series to overcome the lower 17dB transmit gain.

This is a very interesting Rf amp that is on my shopping list:
http://www.yonlit.com/ShowProducts.asp?Page=1&ID=33

2.5kW pulsed output.

Interesting options. Thanks!
But the 100 MHz bandwidth of most models usually will allow the excitation of only one mode. 2-2.7 GHz will make it possible to switch remotely from one mode to another. (I have other research objectives than you do, I guess. But then again, I'm merely a starter in this field).
Cheers,
Peter
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 02:46 pm
But the 100 MHz bandwidth of most models usually will allow the excitation of only one mode. 2-2.7 GHz will make it possible to switch remotely from one mode to another.

Try this amp:
http://www.yonlit.com/ShowProducts.asp?Page=1&ID=18

Is 500 - 2,700MHz at 100W Rf wide enough for you?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 02:53 pm
Thought I would checkout what would be the max E field kV/m and max surface current kA/m at 2.5kW and YBCO in the spherical end plate thruster.

From the sim, the max E field is 7.5MV/m (so no Kilpatrick Effect) and the max surface current is 12.5kA/m, which is about 25% of the max the YBCO can handle.

Also shows the small end is where it will get hot and where the LN2 will need to be pumped fast enough to keep the YBCO superconducting.

Further work also calculated the room temp Cu Qu at around 120,000, which if increased 5,000x by the YBCO becomes Qu = 6x10^8 with a 5x TC of 260msec.

As for the force it becomes (2 * 8x10^8 * 2,500 * 0.8) / c = 10,678N/kW or 1,089kg/kW.

Can you guys please not dump on the force value as there is a LOT of work between here and there. Analysis was done to model the max limits that may occur inside a YBCO coated S band thruster.

OK hard for anyone to believe the force, including ME! But at least the cavity should not become filled with sparks nor should the YBCO stop being a superconductor. All engineering biggies!

Please consider the high Q does NOT increase the energy inside the cavity. Well it does increase the cavity energy a little bit as the low Rs of the YBCO reduces the loss per proton return trip from eddy current losses vs a room temp Cu thruster. So fixed input energy - lower eddy current loss = a little higher cavity energy but not a lot.

The higher Q just means the trapped photons will live 5,000 times longer, reflecting off each end plate 5,000 times more and transferring 5,000 times more of their lost momentum to the thruster as it accelerates.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/05/2016 02:55 pm
But the 100 MHz bandwidth of most models usually will allow the excitation of only one mode. 2-2.7 GHz will make it possible to switch remotely from one mode to another.

Try this amp:
http://www.yonlit.com/ShowProducts.asp?Page=1&ID=18

Is 500 - 2,700MHz at 100W Rf wide enough for you?

Yes, Phil. That starts to look like it. Thanks!  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/05/2016 04:26 pm
Thought I would checkout what would be the max E field kV/m and max surface current kA/m at 2.5kW and YBCO in the spherical end plate thruster.

From the sim, the max E field is 7.5MV/m (so no Kilpatrick Effect) and the max surface current is 12.5kA/m, which is about 25% of the max the YBCO can handle.

Also shows the small end is where it will get hot and where the LN2 will need to be pumped fast enough to keep the YBCO superconducting.

Further work also calculated the room temp Cu Qu at around 120,000, which if increased 5,000x by the YBCO becomes Qu = 6x10^8 with a 5x TC of 260msec.

As for the force it becomes (2 * 8x10^8 * 2,500 * 0.8) / c = 10,678N/kW or 1,089kg/kW.

Can you guys please not dump on the force value as there is a LOT of work between here and there. Analysis was done to model the max limits that may occur inside a YBCO coated S band thruster.

OK hard for anyone to believe the force, including ME! But at least the cavity should not become filled with sparks nor should the YBCO stop being a superconductor. All engineering biggies!

Please consider the high Q does NOT increase the energy inside the cavity. Well it does increase the cavity energy a little bit as the low Rs of the YBCO reduces the loss per proton return trip from eddy current losses vs a room temp Cu thruster. So fixed input energy - lower eddy current loss = a little higher cavity energy but not a lot.

The higher Q just means the trapped photons will live 5,000 times longer, reflecting off each end plate 5,000 times more and transferring 5,000 times more of their lost momentum to the thruster as it accelerates.

I would think you would reach some maximum quickly.  Specially with a superconductor.  I have heard before a superconductor Q cavity has a very narrow range of frequencies because of its large Q.  https://en.wikipedia.org/wiki/Q_factor  Copper or silver may be beneficial because of this and it may have something to do with what WarpTech has been going on about, thermal loss being beneficial.  If indeed there is some doppler-downshift in frequency the light will quickly become out of tune with the cavity and be rejected from the cavity.  I was thinking it may be beneficial to have a Q range over a range of frequencies with one cavity and map that Q frequency range.  Make another cavity that is coupled to that first cavity that resonates at a slightly lower frequency.  When the light in the first cavity starts becoming rejected because of its change in frequency it should be shunted to the other cavity which Doppler shifts it further.  "If it works", you could daisy chain the cavities one after the other till the light is fully depleted but the cavities would become unbearably large.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/05/2016 04:37 pm
...
The question is how to stretch a wave in a resonant cavity without touching its wavelength (the frequency)?

c/K=λ*f where f=frequency and λ=wavelength.  Supposedly at the narrow end many engineers claim the phase velocity increases as if K is decreasing.  This may change the wavelength with out changing the frequency.  However if the mass of the trapped light is modified by the change in wavelength by the PV equations a frequency change may result from Doppler shifting after many bounces.  That is light exchanging energy differently with one side of the cavity than the other.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 04:38 pm
Thought I would checkout what would be the max E field kV/m and max surface current kA/m at 2.5kW and YBCO in the spherical end plate thruster.

From the sim, the max E field is 7.5MV/m (so no Kilpatrick Effect) and the max surface current is 12.5kA/m, which is about 25% of the max the YBCO can handle.

Also shows the small end is where it will get hot and where the LN2 will need to be pumped fast enough to keep the YBCO superconducting.

Further work also calculated the room temp Cu Qu at around 120,000, which if increased 5,000x by the YBCO becomes Qu = 6x10^8 with a 5x TC of 260msec.

As for the force it becomes (2 * 8x10^8 * 2,500 * 0.8) / c = 10,678N/kW or 1,089kg/kW.

Can you guys please not dump on the force value as there is a LOT of work between here and there. Analysis was done to model the max limits that may occur inside a YBCO coated S band thruster.

OK hard for anyone to believe the force, including ME! But at least the cavity should not become filled with sparks nor should the YBCO stop being a superconductor. All engineering biggies!

Please consider the high Q does NOT increase the energy inside the cavity. Well it does increase the cavity energy a little bit as the low Rs of the YBCO reduces the loss per proton return trip from eddy current losses vs a room temp Cu thruster. So fixed input energy - lower eddy current loss = a little higher cavity energy but not a lot.

The higher Q just means the trapped photons will live 5,000 times longer, reflecting off each end plate 5,000 times more and transferring 5,000 times more of their lost momentum to the thruster as it accelerates.

I would think you would reach some maximum quickly.  Specially with a superconductor.  I have heard before a superconductor Q cavity has a very narrow range of frequencies because of its large Q.  https://en.wikipedia.org/wiki/Q_factor  Copper or silver may be beneficial because of this and it may have something to do with what WarpTech has been going on about, thermal loss being beneficial.  If indeed there is some doppler-downshift in frequency the light will quickly become out of tune with the cavity and be rejected from the cavity.  I was thinking it may be beneficial to have a Q range over a range of frequencies with one cavity and map that Q frequency range.  Make another cavity that is coupled to that first cavity that resonates at a slightly lower frequency.  When the light in the first cavity starts becoming rejected because of its change in frequency it should be shunted to the other cavity which Doppler shifts it further.  "If it works", you could daisy chain the cavities one after the other till the light is fully depleted but the cavities would become unbearably large.

Roger has already done the maths for room temp Flight Thruster with a Qu of 60,000 and various rates of acceleration as attached.

You are correct that the trapped photons red shift as they lose momentum to the accelerating mass, which is why Roger uses a piezo element to extend the length of the cavity so to keep the thruster in peak resonance during acceleration and photon momentum loss as attached.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 04:45 pm
If indeed there is some doppler-downshift in frequency the light will quickly become out of tune with the cavity and be rejected from the cavity.  I was thinking it may be beneficial to have a Q range over a range of frequencies with one cavity and map that Q frequency range.  Make another cavity that is coupled to that first cavity that resonates at a slightly lower frequency.  When the light in the first cavity starts becoming rejected because of its change in frequency it should be shunted to the other cavity which Doppler shifts it further.  "If it works", you could daisy chain the cavities one after the other till the light is fully depleted but the cavities would become unbearably large.

Or just send pulses of Rf into the cavity and extend the length as the photons lose momentum to the accelerating mass and red shift.

Note piezo cavity length increasing elements #13 that increase the thruster resonant cavity length, to track the continually red shifting trapped photons as attached.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/05/2016 05:25 pm
If indeed there is some doppler-downshift in frequency the light will quickly become out of tune with the cavity and be rejected from the cavity.  I was thinking it may be beneficial to have a Q range over a range of frequencies with one cavity and map that Q frequency range.  Make another cavity that is coupled to that first cavity that resonates at a slightly lower frequency.  When the light in the first cavity starts becoming rejected because of its change in frequency it should be shunted to the other cavity which Doppler shifts it further.  "If it works", you could daisy chain the cavities one after the other till the light is fully depleted but the cavities would become unbearably large.

Or just send pulses of Rf into the cavity and extend the length as the photons lose momentum to the accelerating mass and red shift.

Note piezo cavity length increasing elements #13 that increase the thruster resonant cavity length, to track the continually red shifting trapped photons as attached.
Can you confirm if it has been directly observed with instruments, if there is indeed some loss in the frequency of the trapped light inside?  It would go a long way in confirming if the hypothesis is correct or not.  Otherwise were just assuming it to be so.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: X_RaY on 12/05/2016 05:59 pm

So the EM frequency is supposed to be constant everywhere in the frustum, but the wave appears to be squeezed near big end and stretched near small end, at least in the axial direction, due to the tapered cross-section.

MEEP, FEKO and COMSOL all three show the axial wave being indeed modified especially for TE01 modes.

Most interesting, when a PE dielectric is present near small end, the pattern is reversed.

WarpTech supposes the waves are stretched and squeezed oppositely in the radial direction though (i.e. radially stretched and axially squeezed at big end; and radially squeezed and axially stretched at small end) with no dielectric.

The question is how to stretch a wave in a resonant cavity without touching its wavelength (the frequency)?

Eliminate the taper and use a cylinder. The frequency doesn't change when the wavelength shifts. But the two orthogonal components of the frequency do change, in a way that keeps the frequency constant, despite the change in diameter.

You mean, a cylinder with a dielectric on one side? What "change in diameter" then? We don't expect any shift in wavelength in a hollow cylindrical cavity, only in a tapered one.

Even in a cylindrical cavity, if there is a dielectric inside at on end the wavelength alters due to the different dielectric constants of air(or vacuum) and the dielectric media. In general the wavelength changes by a factor of √εr
but inside of a conductive cavity there are the boundery conditions of the conductive walls.
What happens exactly depends on the fieldpattern, the shape and position of the dielectric and the dielectric properties.  The effect is large at positions where the E-field is large and small where the H-field is large (when µr is~1).

The "change in diameter" in such a case is virtual from our perspective (because the diameter measured by a ruler doesn't change), for the photon the way looks longer by a factor of √εr. This is true for all vectors, therefore the space in the region with high dielectric constant seems larger (from the viewpoint of a photon) compared to the space where the dielectric constant is smaller.

Just another example: Construct a cylindrical cavity for a defined mode like TE012 for a specific frequency with air inside.
You know DIA and the Length. You will get the same mode shape and resonant frequency for a cavity filled with a specific dielectric when you choose the new cavity dimensions as
DIA/√εr
Length/√εr

-------------------
EDIT:
cylindrical cavity
mode is TE015
fH015res=2.57GHz

conductive cavity:
Length=300mm (225mm with εr=1)
DIA=200mm

dielectric section within the metallic cavity:
Length=75mm
DIA=200mm
εr=4
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/05/2016 06:04 pm
Can you confirm if it has been directly observed with instruments, if there is indeed some loss in the frequency of the trapped light inside?  It would go a long way in confirming if the hypothesis is correct or not.  Otherwise were just assuming it to be so.

Look at the dropping freq (lower portion of the freq plot) as the Demonstrator EmDrive accelerates a 100kg mass as attached.

The support electronics was always working to match freq to optimal.

Roger told me that prior to the use of the piezo adjusters that are needed with cryo thrusters, the freq was adjusted to stay in resonance during acceleration but that is not so doable as the Q and cavity TC increase. It was possible as the Demonstrator was excited by pulses of Rf from the freq splatter of the 1/2 wave driven magnetron.

Which is why SPR moved to pulsed excitation as there is NO WAY to track photons red shifting when there are new photons being emitted from the antenna as in CW excitation. So the cryo thrusters need to be operated in pulsed mode so the trapped red shifting photons can be kept in resonance via cavity length extension.

Roger did disclose they measured Q dropping as the Demonstrator accelerated but that data, there is an entire report on the Demonstrator EmDrive on the rotary test rig and the data collected, has not yet been made public due to NDA timeout. I have asked him to try to speed up the NDA timeout. He said he will see what can be done.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: zellerium on 12/05/2016 06:24 pm
Can you confirm if it has been directly observed with instruments, if there is indeed some loss in the frequency of the trapped light inside?  It would go a long way in confirming if the hypothesis is correct or not.  Otherwise were just assuming it to be so.

Look at the dropping freq (lower portion of the freq plot) as the Demonstrator EmDrive accelerates a 100kg mass as attached.

The support electronics was always working to match freq to optimal.

Roger told me that prior to the use of the piezo adjusters that are needed with cryo thrusters, the freq was adjusted to stay in resonance during acceleration but that is not so doable as the Q and cavity TC increase. It was possible as the Demonstrator was excited by pulses of Rf from the freq splatter of the 1/2 wave driven magnetron.

Which is why SPR moved to pulsed excitation as there is NO WAY to track photons red shifting when there are new photons being emitted from the antenna as in CW excitation. So the cryo thrusters need to be operated in pulsed mode so the trapped red shifting photons can be kept in resonance via cavity length extension.

Roger did disclose they measured Q dropping as the Demonstrator accelerated but that data, there is an entire report on the Demonstrator EmDrive on the rotary test rig and the data collected, has not yet been made public due to NDA timeout. I have asked him to try to speed up the NDA timeout. He said he will see what can be done.

I don't understand, how can the frequency of the light change inside a stationary cavity?
I understand that the wavelength and group velocity increase as the wave approaches the narrow end, but shouldn't the frequency remain constant unless the cavity were accelerating at a considerable rate?

Also, if I'm reading this plot correctly, there was a 7 MHz frequency shift all of the sudden at around 130 s which is when the drive began to accelerate AND the power was reduced, and then about 50 seconds later power is turned off and the cavity keeps accelerating for 50 seconds ???

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: X_RaY on 12/05/2016 07:03 pm
Can you confirm if it has been directly observed with instruments, if there is indeed some loss in the frequency of the trapped light inside?  It would go a long way in confirming if the hypothesis is correct or not.  Otherwise were just assuming it to be so.

Look at the dropping freq (lower portion of the freq plot) as the Demonstrator EmDrive accelerates a 100kg mass as attached.

The support electronics was always working to match freq to optimal.

Roger told me that prior to the use of the piezo adjusters that are needed with cryo thrusters, the freq was adjusted to stay in resonance during acceleration but that is not so doable as the Q and cavity TC increase. It was possible as the Demonstrator was excited by pulses of Rf from the freq splatter of the 1/2 wave driven magnetron.

Which is why SPR moved to pulsed excitation as there is NO WAY to track photons red shifting when there are new photons being emitted from the antenna as in CW excitation. So the cryo thrusters need to be operated in pulsed mode so the trapped red shifting photons can be kept in resonance via cavity length extension.

Roger did disclose they measured Q dropping as the Demonstrator accelerated but that data, there is an entire report on the Demonstrator EmDrive on the rotary test rig and the data collected, has not yet been made public due to NDA timeout. I have asked him to try to speed up the NDA timeout. He said he will see what can be done.

I don't understand, how can the frequency of the light change inside a stationary cavity?
I understand that the wavelength and group velocity increase as the wave approaches the narrow end, but shouldn't the frequency remain constant unless the cavity were accelerating at a considerable rate?

Also, if I'm reading this plot correctly, there was a 7 MHz frequency shift all of the sudden at around 130 s which is when the drive began to accelerate AND the power was reduced, and then about 50 seconds later power is turned off and the cavity keeps accelerating for 50 seconds ???

group velocity decrease  (vg=δω∕δk)
phase velocity increase  (vp=ω∕k=λf)
as the wave approaches the narrow end :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/05/2016 08:20 pm
I don't understand, how can the frequency of the light change inside a stationary cavity?

It doesn't. TT was speaking of an accelerating cavity, where the EM waves get redshifted due to Doppler shifts. I quote Roger Shawyer:

Quote from: Roger Shawyer
Assume the EM wavefront propagates initially from the large end plate towards the small end plate. At the end of this forward transit, the wavefront is reflected at the small end plate. At this time, due to cavity acceleration, the cavity velocity has increased to Vr whereas the wavefront has a constant guide velocity of Vg2. The relative addition of these velocities, gives the reflected wavefront a Doppler Shift, resulting in a reduced frequency Fr for the reverse transit.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: mwvp on 12/06/2016 12:53 am
Thought I would checkout what would be the max E field kV/m and max surface current kA/m at 2.5kW and YBCO in the spherical end plate thruster.

From the sim, the max E field is 7.5MV/m (so no Kilpatrick Effect) and the max surface current is 12.5kA/m, which is about 25% of the max the YBCO can handle.

What's the "Kilpatrick Effect"?

...
Further work also calculated the room temp Cu Qu at around 120,000, which if increased 5,000x by the YBCO becomes Qu = 6x10^8 with a 5x TC of 260msec.
...
Please consider the high Q does NOT increase the energy inside the cavity
....
The higher Q just means the trapped photons will live 5,000 times longer, reflecting off each end plate 5,000 times more and transferring 5,000 times more of their lost momentum to the thruster as it accelerates.

My understanding is, the "real" power from the RF amp into, and dissipated as heat and/or momentum-increase of the cavity is, say 1000 Watts, and if the cavity has a Q of 100,000,000 or 10^8, then you would have Q * input-power, or 10^11 watts of reactive or "imaginary" power in the cavity. The cavity dielectric and conductor would need to handle that much VAR - volts-amps reactive. Just as in an industrial lighting or motor system, the ballasts and motor-start caps need to be able to handle that energy. And when I say power, the power is only during the TC of the cavity, so the energy would be scaled with the frequency period.

As you've said yourself, energy put into the cavity will "ring" upwards. I don't mean to be a buzz-kill, but I do remember reading that state of the art accelerators are only approaching 10^9 watts of stored, resonant energy.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/06/2016 02:12 am
Thought I would checkout what would be the max E field kV/m and max surface current kA/m at 2.5kW and YBCO in the spherical end plate thruster.

From the sim, the max E field is 7.5MV/m (so no Kilpatrick Effect) and the max surface current is 12.5kA/m, which is about 25% of the max the YBCO can handle.

What's the "Kilpatrick Effect"?

...
Further work also calculated the room temp Cu Qu at around 120,000, which if increased 5,000x by the YBCO becomes Qu = 6x10^8 with a 5x TC of 260msec.
...
Please consider the high Q does NOT increase the energy inside the cavity
....
The higher Q just means the trapped photons will live 5,000 times longer, reflecting off each end plate 5,000 times more and transferring 5,000 times more of their lost momentum to the thruster as it accelerates.

My understanding is, the "real" power from the RF amp into, and dissipated as heat and/or momentum-increase of the cavity is, say 1000 Watts, and if the cavity has a Q of 100,000,000 or 10^8, then you would have Q * input-power, or 10^11 watts of reactive or "imaginary" power in the cavity. The cavity dielectric and conductor would need to handle that much VAR - volts-amps reactive. Just as in an industrial lighting or motor system, the ballasts and motor-start caps need to be able to handle that energy. And when I say power, the power is only during the TC of the cavity, so the energy would be scaled with the frequency period.

As you've said yourself, energy put into the cavity will "ring" upwards. I don't mean to be a buzz-kill, but I do remember reading that state of the art accelerators are only approaching 10^9 watts of stored, resonant energy.

Kilpatrick Limit as attached plus a few more microwave resonant cavity Black Arts. Dark Currents & Field Emissions are cool.

Resonant cavities don't multiple the input energy,  no matrer what the Q. kWh or J of input electrical energy will be converted into the same amount of kWh or J of thermal energy. Minus any used to do work on accelerating particles or accelerating mass.

What high Q does do is to allow the trapped photons to exist for a longer time. To do more transits between end plates, to do more end plate reflections,  to transfer and lose more momentum to mass, causing them to red shift more and more, until they are finally thermalised out of existence.

The internal E & H fields scale linear with power input but not with Q increase or Rs drop. Decreasing Rs (increasing Q) decreases the per return trip eddy current heat loss and thus the E & H fields are higher for higher Q but only higher by the amount of eddy current loss reduction. Any good simulator will confirm these relationships.

Stored cavity energy = J or kWh inputted.  Q doesn't multiply energy or thermal out + work done would be greater than input energy.

Max E & H fields do vary with geometry and scale linear with power. Higher Q doesn't scale E & H fields linear. Sure with higher Q, the fields do increase but only from the amount of eddy current loss reduction.

Ie for cavity input energy = 10,000 J.
At per cycle loss = 1 J, Cavity energy = 9,999 J, Q = 9,999
At per cycle loss = 0.1 J, Cavity energy = 9,999.9 J, Q = 99,999.9
At per cycle loss = 0.01 J, Cavity energy = 9,999.99 J, Q = 999,999
Etc.....
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/06/2016 05:26 am
Thought I would checkout what would be the max E field kV/m and max surface current kA/m at 2.5kW and YBCO in the spherical end plate thruster.

From the sim, the max E field is 7.5MV/m (so no Kilpatrick Effect) and the max surface current is 12.5kA/m, which is about 25% of the max the YBCO can handle.

What's the "Kilpatrick Effect"?

...
Further work also calculated the room temp Cu Qu at around 120,000, which if increased 5,000x by the YBCO becomes Qu = 6x10^8 with a 5x TC of 260msec.
...
Please consider the high Q does NOT increase the energy inside the cavity
....
The higher Q just means the trapped photons will live 5,000 times longer, reflecting off each end plate 5,000 times more and transferring 5,000 times more of their lost momentum to the thruster as it accelerates.

My understanding is, the "real" power from the RF amp into, and dissipated as heat and/or momentum-increase of the cavity is, say 1000 Watts, and if the cavity has a Q of 100,000,000 or 10^8, then you would have Q * input-power, or 10^11 watts of reactive or "imaginary" power in the cavity. The cavity dielectric and conductor would need to handle that much VAR - volts-amps reactive. Just as in an industrial lighting or motor system, the ballasts and motor-start caps need to be able to handle that energy. And when I say power, the power is only during the TC of the cavity, so the energy would be scaled with the frequency period.

As you've said yourself, energy put into the cavity will "ring" upwards. I don't mean to be a buzz-kill, but I do remember reading that state of the art accelerators are only approaching 10^9 watts of stored, resonant energy.

True, but I don't think you can get a Q that high without the losses going down. In a steady state situation, the maximum loss of power (dissipation) can be 1000W, the full "real" input power. At the same time, the amount of stored energy will depend on how many VARS the cavity can support. As losses go down, the VARS can go up until the Q is infinite. So as long as the cavity can dissipate 1000W continuously, it's all good.

FYI: I have not seen a build yet that could withstand that much power dissipation continuously. Solder joints would melt.  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/06/2016 05:43 am
Nice graphic from Paul that explains a lot as attached.

Note the force direction, dielectric or not, follows the end that has the shortest 1/2 wave (highest momentum and radiation pressure). It does NOT follow the end that has the highest E & H fields.

Also note force scaling with Q:

3.85uN/W at Q = 40,900 (TE012 mode without dielectric)
2.00uN/W at Q = 22,000 (TE012 mode with dielectric)
1.20uN/W at Q = 6,700 (TM212 mode with dielectric)

As Paul has stated, the PLL frequency control system used did not guarantee a good lowest reflected power freq lock, so the forces may be expected to vary a bit, especially as Q climbs and freq lock bandwidth drops. Which is why using a lowest reflected power freq tuner is the way to go.

What is clear from this data is:

1) Don't use a dielectric
2) Force scales with Q
3) Force direction follows the thruster end that has the shortest 1/2 guide wave.

And no the force generated is not Lorentz nor thermal CG shift as can be seen in the last 2 attachments.

Note on the non dielectric force image, the thermal CG shift after the long pulse is finished is very small and in the OPPOSITE direction to the thermal CG shift when the dielectric was fitted to the thruster. Which suggests the dielectric was really heating up the small end, as it would be expected to do as it was very lossy and dropped the dielectric Q a fair bit.

These 3 images are the smoking gun that shows the "Shawyer Effect" is real and is not the result of measurement error nor other suggested force generation sources.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/06/2016 06:39 am
True, but I don't think you can get a Q that high without the losses going down. In a steady state situation, the maximum loss of power (dissipation) can be 1000W, the full "real" input power. At the same time, the amount of stored energy will depend on how many VARS the cavity can support. As losses go down, the VARS can go up until the Q is infinite. So as long as the cavity can dissipate 1000W continuously, it's all good.

FYI: I have not seen a build yet that could withstand that much power dissipation continuously. Solder joints would melt.  8)

Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.

If you do a few sims and increase the conductivity of the Cu by say 9x (reducing Rs 9x) you will not see a 9X increase in the E & H fields. However increase the input power 9X and you will see the E fields increase 3x and the H fields increase 3x.

There is an effect from decreasing Rs 9x as the Q increases 9x but the E & H field energies do not each increase 3x.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Flyby on 12/06/2016 09:27 am
What I can make up from that data, is that forces do scale with increased Q, but not linear, as you first claimed...
I suspect we'll see a flattening logarithmic curve the higher the Q gets... 100times increase in Q will probably not result in a force x100 greater.
As we're still in the replication phase of the experiment (the number of announced experiments is suddenly booming, for sure...) it is hard to estimate to where the forces will top off.

But I remain highly skeptical on the flying car idea, as we have not seen any data yet on experiments with very high input power (100kW and more), nor any data with superconductors.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/06/2016 12:22 pm
What I can make up from that data, is that forces do scale with increased Q, but not linear, as you first claimed...
I suspect we'll see a flattening logarithmic curve the higher the Q gets... 100times increase in Q will probably not result in a force x100 greater.
As we're still in the replication phase of the experiment (the number of announced experiments is suddenly booming, for sure...) it is hard to estimate to where the forces will top off.

But I remain highly skeptical on the flying car idea, as we have not seen any data yet on experiments with very high input power (100kW and more), nor any data with superconductors.

Flyby,

You are assuming each test run was at optimal freq. As Paul has stated, with the PLL they had back then, that was not assured. He also has stated they tested in TM212 as it had very low Q and was therefore easier for the PLL to get somewhat close to an ideal freq.

We have seen the variance in force as the power was increased in the vac test data.  Note the wide variance,  which Paul has suggested may have been due to the PLL not finding the ideal freq.

When I did 100 tests, doing manual tuning to lowest reflected power for each test,   the variance was only 5%. Which suggests doing freq adjustment to lowest reflected power can achieve much better repeatability.

Had my amp not failed, had intended to do another series of tests at 80W, 40W, 20W and 10W. As the amp has a 31dBm attenuator in 1dBm steps, it is easy to reliably set the power to the desired level +-1dBm plus freq gen output level settings.

When I did my earlier tests, I failed to record the forward power at each of the 100 tests. So I can't calc the specific force for each test, which may have provided better data. Next time for sure.

I have found a 2.45GHz 2.5kW Rf amp, which I plan to purchase after the rotary test are completed. Also investigating various YBCO coating options for the S band thrusters. So maybe my mid year I have some YBCO data to compare against silver plated at room temp and at 77K.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Keith Ness on 12/06/2016 12:29 pm
Damn, yes. I edited my first post, should have just stuck to what I said initially. Anyway the thing won't work, it will vibrate a bit but not move anywhere. Back to lurking and waiting for more data.

I had thought, since the front received direct pressure but the rear received the same pressure at a 45 degree angle, that the rear would receive less pressure.  Based on nacnud's reaction (are you using a computer simulator, nacnud?), I thought about it, and now it seems to me that I'm probably just converting the forward momentum of the ship and rearward momentum of the balls to lateral momentum of all of them, with the ship expressing its lateral motion as vibration.

So here's an earlier and hopefully more robust example of my point:

(http://gdurl.com/g07N)

1.  Left operator throws cue ball right, causing X left momentum to ship, X right momentum to cue ball.
2.  Once momentum is established (acceleration stops), the other billiard balls are allowed to float freely (mechanical arms which were holding them release and retract :) ), moving with the ship.
3.  Cue ball hits billiard balls 1 and 2 simultaneously,  transferring some of its momentum (for the example's sake, let's say all of it, as in Newton's cradle, or the stop shot in billiards) to billiard balls 1 and 2, which then travel at 45 degree angles to right wall, and at a fraction of momentum X (X/2, for the example's sake).
4.  Billiard balls 1 and 2 each replicate what happened in step 3 with two more billiard balls each.  So billiard balls 1 and 2 stop relative to the ship, and two of the four billiard balls hit by billiard balls 1 and 2 in this step now travel directly towards the right wall at X/4 momentum each, and the other two billiard balls hit by billiard balls 1 and 2 in this step now travel parallel to the right wall.
5.  Operators on right, top, and bottom walls capture the balls moving towards them, transferring X/4 momentum to each of the top and bottom walls, and a total of X/2 to the right wall.  Left wall has momentum X leftward, right wall has momentum X/2 rightward, for a total of X/2 left.  Momentum on reset of the balls is deliberately not scattered, and thus cancels itself out, leaving ship ready to repeat, but moving left at X/2 relative to before the cue ball was thrown in step 1 the last time.

*edited a typo.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: JohnFornaro on 12/06/2016 01:15 pm
Momentum on reset of the balls is deliberately not scattered

All of the operators in your diagram must send the cue balls back to their original position.  Maybe you could provide a sketch showing how they do this while "deliberately not scattering" the momentum of the cue balls on the return trip.

I don't think it can be done.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/06/2016 01:26 pm
Nice graphic from Paul that explains a lot as attached.

Note the force direction, dielectric or not, follows the end that has the shortest 1/2 wave (highest momentum and radiation pressure). It does NOT follow the end that has the highest E & H fields.

[…]

There are two ways of seeing the thrust efficiency and the force vector swapping with or without the dielectric:

• The one that says (like TT): "the frustum with a dielectric provides an efficiency of 2 mN/kW and the no-dielectric frustum provides a better efficiency at 3.85 mN/kW", because the cavity Q drops due to the losses introduced by the dielectric."

• And the one that says:
Quote from: Jim Woodward
The effect with plastic is actually larger than without. The plastic result is +2 subtracted from -3, not from 0. If the plastic results were obtained without the cavity, the arithmetic you and others use would make sense. But the cavity is still there and responds to the field. So the plastic result must be subtracted from the empty cavity powered result, not the "null" position of the balance.

Seeing Eagleworks simulation showing the computed vacuum plasma wake with a dielectric at small end:

(http://2.bp.blogspot.com/-E-m3LYrZgNY/VSQS9Tg08yI/AAAAAAAA8yY/AJAUQR-9fnw/s1600/modelqvf.jpg)

It is clear White sees the EmDrive as a conventional rocket nozzle pushing on a reaction mass ejected backwards (even if the reaction mass is made of quantum virtual particles that may or may not have a "reality" in every sense of the word).

So the question is: Since the drive shows a thrust force vector towards big end without a dielectric, and a reversed thrust force vector towards small end with a dielectric, why not try to reinforce the big end force placing the dielectric at big end, instead of fighting against the big end force (and overcome it) placing the dielectric at small end?

Maybe Paul can comment on the PE discs placement near small end vs big end?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/06/2016 01:56 pm
Maybe Paul can comment on the PE discs placement near small end vs big end?

I would appear they did mount the dielectric disc to the big end and found the force direction was still big to small.

What is also interesting is that when they fitted ONE disc to the small end, the force vector was small to big. The single disc was fitted to the small end as there is no bolt hole in the big end plate to mount the dielectric disc.

Then fitting a 2nd to the small end (as was the final test configuration) reversed the force direction to big to small.

Maybe Paul can make further comment.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/06/2016 02:13 pm
Damn, yes. I edited my first post, should have just stuck to what I said initially. Anyway the thing won't work, it will vibrate a bit but not move anywhere. Back to lurking and waiting for more data.

I had thought, since the front received direct pressure but the rear received the same pressure at a 45 degree angle, that the rear would receive less pressure.  Based on nacnud's reaction (are you using a computer simulator, nacnud?), I thought about it, and now it seems to me that I'm probably just converting the forward momentum of the ship and rearward momentum of the balls to lateral momentum of all of them, with the ship expressing its lateral motion as vibration.

So here's an earlier and hopefully more robust example of my point:
...

Something you need to understand, is that the definition of conservation of momentum means that any time you get net motion through a setup like this, it means you made a mistake.

In this case, it seem that you don't understand that momentum is a vector quantity. When the ball with momentum X hits the 2 balls and send them off at 45 degree angles, each of the other 2 balls will have momentum X/sqrt(2), not X/2. This is because the horizontal component of momentum for each is X/2 in order to conserve momentum in that direction. Work this through to the end, and you'll see no pressure difference. (To determine the angles they will go at, you need to apply energy conservation, in this case with equal mass balls, opposing 45 degrees angles with the original ball coming to a complete stop is the right answer for a perfectly elastic collisionn.)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Star-Drive on 12/06/2016 03:35 pm
Maybe Paul can comment on the PE discs placement near small end vs big end?

I would appear they did mount the dielectric disc to the big end and found the force direction was still big to small.

What is also interesting is that when they fitted ONE disc to the small end, the force vector was small to big. The single disc was fitted to the small end as there is no bolt hole in the big end plate to mount the dielectric disc.

Then fitting a 2nd to the small end (as was the final test configuration) reversed the force direction to big to small.

Maybe Paul can make further comment.

Phil:

First off look at what the E&M field configuration is for the TM010 resonance in the EW frustum, see attached.  Note that the E&B fields are very weak at the small OD end of the frustum cavity for the TM010 mode resonance.  Also remember that the TM010 resonant frequency of the empty copper frustum was 957 MHz, whereas when the PE discs was mounted at the small OD end of the cavity, the resonant frequency only went down to 954 MHz which tells us that the dielectric disc was not interacting much with the E&B fields, and thus why the generate force direction was still from small OD to big OD as is was for the empty TM010 driven frustum.  However when I took out the PE discs at the small OD end of the TM010 driven frustum and replaced it with a Teflon disc at the large OD end of the frustum where the E&M fields were the strongest, the TM010 resonant frequency plunged down to 901 MHz due to the large interaction with the E&M fields, and the thrust vector reversed and became much larger than with the frustum cavity empty.  This TM010 data may support Jim Woodward interpretation that the dielectric discs can multiply the frustum thrust-effect in low Q-factor situations, but when the Q-factor becomes large enough, say over 30,000, another thrust generation mechanism may be taking over.  A thrust generation mechanism that is NOT dependent on the presence of the dielectric discs...

Best, Paul M.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/06/2016 04:56 pm
Any comments on the attached derivation would be appreciated. Good or bad.

https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0 (https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0)

Thanks!
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/06/2016 04:57 pm
True, but I don't think you can get a Q that high without the losses going down. In a steady state situation, the maximum loss of power (dissipation) can be 1000W, the full "real" input power. At the same time, the amount of stored energy will depend on how many VARS the cavity can support. As losses go down, the VARS can go up until the Q is infinite. So as long as the cavity can dissipate 1000W continuously, it's all good.

FYI: I have not seen a build yet that could withstand that much power dissipation continuously. Solder joints would melt.  8)

Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.

If you do a few sims and increase the conductivity of the Cu by say 9x (reducing Rs 9x) you will not see a 9X increase in the E & H fields. However increase the input power 9X and you will see the E fields increase 3x and the H fields increase 3x.

There is an effect from decreasing Rs 9x as the Q increases 9x but the E & H field energies do not each increase 3x.
Why not an increase in stored energy?  By the definition of Q factor, https://en.wikipedia.org/wiki/Q_factor (https://wikimedia.org/api/rest_v1/media/math/render/svg/f0661eedae5a3a141431125d7ff95d68a6b6bec1)
Power loss and omega remainig constant, [Q(w)*9]*power_loss/w=(9*Maximum_Energy_Stored).
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/06/2016 06:43 pm
This TM010 data may support Jim Woodward interpretation that the dielectric discs can multiply the frustum thrust-effect in low Q-factor situations, but when the Q-factor becomes large enough, say over 30,000, another thrust generation mechanism may be taking over.  A thrust generation mechanism that is NOT dependent on the presence of the dielectric discs...

Best, Paul M.

Without a dielectric and higher Q, wouldn't a skin effect in the copper walls take over and become the host of the Mach effect?
I quote Dr Rodal about Dr Montillet's work on that matter (message from Thread 8 (https://forum.nasaspaceflight.com/index.php?topic=40959.msg1588165#msg1588165)):

Quote from: Rodal
At the Estes Park Breakthrough Propulsion Workshop, Dr. Jean-Philippe Montillet of the École Polytechnique Fédérale de Lausanne, Switzerland, presented a paper titled "Model of the EM Drive with the EMG coupling" (that mathematically and physically) explains the EM Drive as a capacitor, where:

* Surface currents propagate inside the cavity on the conic wall (between the two end plates)
* electromagnetic resonant modes create electric charges on each end plate
* Mach/Woodward effect is triggered by Lorentz force from surface currents on the conic wall
* acceleration of RF cavity as due to the variation of Electro Magnetic density from evanescent waves inside the skin layer

A polymer insert placed asymmetrically in the cavity results in greater asymmetry, while decreasing Q. The cavity's acceleration is a function of all the above factors.  The model can explain acceleration with and without the polymer insert (to a more significant or less significant extent).

As the Mach/Woodward effect can be derived straight from the fully covariant nonlinear Hoyle Narlikar gravitational theory or it can also be obtained from linearized General Relativity it is really as much of a gravitational effect as gravity assist.  The difference being that gravity assist is something that people are now familiar with (since it was first used for interplanetary flight by the Mariner 10 in the mid-70's) and the Mach/Woodward effect is something that people are normally unfamiliar with (because time-dependent terms in General Relativity are usually ignored).

Gravity assist flight of a spacecraft is an open system where momentum is transferred by gravity to spaceship and so is the Mach/Woodward effect a gravitational effect.  Both of them are explained by General Relativity.  If somebody explains the acceleration of an EM Drive based on a gravitational effect (the Mach/Woodward effect), it would be incorrect to address conservation of momentum and energy solely based on the spaceship momentum while ignoring the effect of gravity.

Of course, nobody nowadays will write about "overunity" of gravity assist (as the spaceship involved in a sling shot maneuver apparently gains  velocity out of nothing, if one ignores gravity) because it is evident that gravity assist is ... gravity-assisted.   ;)

Similarly, the Mach/Woodward effect drive perhaps should be renamed "Mach Effect Gravity Assist" (MEGA) drive, to make it more obvious to the readers that the Mach Effect is a gravitational effect, and thus it would be completely incorrect to address conservation of momentum and energy without taking into account the gravitational effect.

The MEGA drive… As an European this name is very funny to me. The Mega Drive (https://en.wikipedia.org/wiki/Sega_Genesis) is the European name (among other countries, notably Japan: Mega Doraibu) of Sega's popular 16-bit home video game console known as the Genesis in the United States, that has been sold at 40 millions units in the 1990s. It was challenging the Nintendo Super NES before the advent of the Sony Playstation. Didn't know that console was propellantless ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: as58 on 12/06/2016 09:52 pm
Any comments on the attached derivation would be appreciated. Good or bad.

https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0 (https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0)

Thanks!

I have a hard time understanding anything. First of all, there are undefined symbols (what is £?). I have no idea what PV Lagrangian density means, so I'll skip straight to to the second paragraph.

- Where does the first equality under "Lorentz gauge electromagnetism" (btw, it should be Lorenz) come from?
- How does the wave equation for \Phi follow?
- Shouldn't \Phi  be a vector field, not scalar? But then you say it's obtained (why?) by integrating (wrt. to time) the electric potential, which is definitely a scalar field.
- The same questions apply largely for the "gravito-electromagnetism" equations. (It seems that for the first equality to hold, you have the assume that density is constant to get \rho outside the divergence.)

So in short, I don't get any idea of what's going on. Have I somehow completely misunderstood your notation?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/06/2016 11:06 pm
Any comments on the attached derivation would be appreciated. Good or bad.

https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0 (https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0)

Thanks!

I have a hard time understanding anything. First of all, there are undefined symbols (what is £?). I have no idea what PV Lagrangian density means, so I'll skip straight to to the second paragraph.

- Where does the first equality under "Lorentz gauge electromagnetism" (btw, it should be Lorenz) come from?
- How does the wave equation for \Phi follow?
- Shouldn't \Phi  be a vector field, not scalar? But then you say it's obtained (why?) by integrating (wrt. to time) the electric potential, which is definitely a scalar field.
- The same questions apply largely for the "gravito-electromagnetism" equations. (It seems that for the first equality to hold, you have the assume that density is constant to get \rho outside the divergence.)

So in short, I don't get any idea of what's going on. Have I somehow completely misunderstood your notation?

Thank you.

PV refers to Polarizable Vacuum, as in the Polarizable Vacuum Representation of General Relativity. The symbol "£" is just a typical way to express the Lagrangian Density. This part is not critical to the derivation. It's only a reference to where the solution for K comes from. Given that K is a solution to the £'s respective equations of motion, we can use it from there forward.

1. The first expression is the Lorenz gauge condition. (Spelling depends on your text book but you're correct.) Here's a good reference, I used the book; "Geometry, Particles and Fields" by Felsager.
https://www.phy.duke.edu/~rgb/Class/Electrodynamics/Electrodynamics/node31.html (https://www.phy.duke.edu/~rgb/Class/Electrodynamics/Electrodynamics/node31.html)

2. The "wave equation" is really a conservation equation for the magnetic flux /Phi, it comes from the fact that the vector potential "A", can be derived from the gradient of the scalar /Phi. It is an unusual interpretation, because typically "A" is rotational, it is not a gradient, but there is nothing that requires "A" to be rotational in this gauge, and the gradient does not change Maxwell's equations.

3. Magnetic flux is a scalar. The vector fields are "E, H and A". It is a measure of the "Volt-seconds" applied to the input terminals. The total flux inside is the integral of the Volts over time. This is pretty standard stuff. Review the workings of an inductor, or power transformer.

4. The intent is to show the parallels between the two sets of equations. "A" is the momentum per unit charge (coulomb). "v" is the momentum per unit mass (kg).  Volts => Velocity2 is the potential. /Phi => /Chi is the flux. The connection between magnetic flux and gravito-magnetic flux is just the charge to mass ratio. Probably sqrt(4piG*eps0)

You are correct that it is an "assumption" that the density is constant, in order to make the equations easier to understand, but it is assumed that the change in density is small compared to the change in momentum and can be neglected at this stage of the theory development.

Edit: Regarding proper spelling. I'm not the only one who makes that mistake. :-\

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Rodal on 12/07/2016 12:18 am
There is a formula that has both names: it is the formula for the mathematical relationship between the refractive index and the density of a medium that was published by Ludvig Lorenz in 1869 and by Hendrik Lorentz (who discovered it independently) in 1878 and is therefore called the Lorentz–Lorenz equation.

https://en.wikipedia.org/wiki/Ludvig_Lorenz
Danish physicist and mathematician
(January 18, 1829 – June 9, 1891)

https://en.wikipedia.org/wiki/Hendrik_Lorentz
Dutch physicist
(18 July 1853 – 4 February 1928)

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 12:42 am
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: masterharper1082 on 12/07/2016 01:07 am
Thought I would checkout what would be the max E field kV/m and max surface current kA/m at 2.5kW and YBCO in the spherical end plate thruster.

From the sim, the max E field is 7.5MV/m (so no Kilpatrick Effect) and the max surface current is 12.5kA/m, which is about 25% of the max the YBCO can handle.

What's the "Kilpatrick Effect"?

...
Further work also calculated the room temp Cu Qu at around 120,000, which if increased 5,000x by the YBCO becomes Qu = 6x10^8 with a 5x TC of 260msec.
...
Please consider the high Q does NOT increase the energy inside the cavity
....
The higher Q just means the trapped photons will live 5,000 times longer, reflecting off each end plate 5,000 times more and transferring 5,000 times more of their lost momentum to the thruster as it accelerates.

My understanding is, the "real" power from the RF amp into, and dissipated as heat and/or momentum-increase of the cavity is, say 1000 Watts, and if the cavity has a Q of 100,000,000 or 10^8, then you would have Q * input-power, or 10^11 watts of reactive or "imaginary" power in the cavity. The cavity dielectric and conductor would need to handle that much VAR - volts-amps reactive. Just as in an industrial lighting or motor system, the ballasts and motor-start caps need to be able to handle that energy. And when I say power, the power is only during the TC of the cavity, so the energy would be scaled with the frequency period.

As you've said yourself, energy put into the cavity will "ring" upwards. I don't mean to be a buzz-kill, but I do remember reading that state of the art accelerators are only approaching 10^9 watts of stored, resonant energy.

True, but I don't think you can get a Q that high without the losses going down. In a steady state situation, the maximum loss of power (dissipation) can be 1000W, the full "real" input power. At the same time, the amount of stored energy will depend on how many VARS the cavity can support. As losses go down, the VARS can go up until the Q is infinite. So as long as the cavity can dissipate 1000W continuously, it's all good.

FYI: I have not seen a build yet that could withstand that much power dissipation continuously. Solder joints would melt.  8)
That's because you haven't been using forced convection two-phase cooling with geometry enhancements for heat transfer (on the outside of the frustum). When the mN/kW get high enough that we're not worried about vibrations from a compressor or pump, that's how we can get the high heat transfer rates you need.

mh
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/07/2016 01:07 am
The electric and magnetic fields assume round and or bent shapes, curl etc. Yet, we keep using a frustum with sharp or right angles. These angles might adversely affect the overall efficiency of the process we intend to generate inside the cavity. The effects, forces etc. detected up to know are in the order of a side effect, not the actual process intended.

We might consider other types of cavity. (Remember, as usual, I dont really know what I am talking about  ) I was “thinking” along the lines of a shape like an amphora. Long tapered neck, shoulders and a concave bottom. It is rounded all over except in the neck where dissipation is expected.

Such a shape could allow a series of modes between the shoulder and the bottom. But these modes would not be parallel, but rather in cone shape. So, the conic shape is not that of the cavity itself but that of the modes inside. The long tapered neck would allow dissipation in the middle along the axis and punch a hole preventing the formation of any other modes but those between shoulder and concave bottom.

The question is; where do you inject MW from? Focus of concave bottom or end of tapered neck?

Food for thought...
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 01:55 am
True, but I don't think you can get a Q that high without the losses going down. In a steady state situation, the maximum loss of power (dissipation) can be 1000W, the full "real" input power. At the same time, the amount of stored energy will depend on how many VARS the cavity can support. As losses go down, the VARS can go up until the Q is infinite. So as long as the cavity can dissipate 1000W continuously, it's all good.

FYI: I have not seen a build yet that could withstand that much power dissipation continuously. Solder joints would melt.  8)

Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.

If you do a few sims and increase the conductivity of the Cu by say 9x (reducing Rs 9x) you will not see a 9X increase in the E & H fields. However increase the input power 9X and you will see the E fields increase 3x and the H fields increase 3x.

There is an effect from decreasing Rs 9x as the Q increases 9x but the E & H field energies do not each increase 3x.
Why not an increase in stored energy?  By the definition of Q factor, https://en.wikipedia.org/wiki/Q_factor (https://wikimedia.org/api/rest_v1/media/math/render/svg/f0661eedae5a3a141431125d7ff95d68a6b6bec1)
Power loss and omega remainig constant, [Q(w)*9]*power_loss/w=(9*Maximum_Energy_Stored).

Consider that reducing the per cycle energy loss 10x, will increase the Q 10x.

Now consider reducing the per cycle energy loss 5,000x by changing from room temp Cu with a Rs of 15,000uOhm to YBCO at 77k with a Rs of 3uOhm.

The Q will increase 5,000x.

Cavity E & H fields will increase a little due to less input energy being lost per cycle.  This effect is clearly shown by modeling the changes with any resonant cavity simulator thar allows the surface Rs to be varied.

The attached may help to explain.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 02:20 am
Maybe Paul can comment on the PE discs placement near small end vs big end?

I would appear they did mount the dielectric disc to the big end and found the force direction was still big to small.

What is also interesting is that when they fitted ONE disc to the small end, the force vector was small to big. The single disc was fitted to the small end as there is no bolt hole in the big end plate to mount the dielectric disc.

Then fitting a 2nd to the small end (as was the final test configuration) reversed the force direction to big to small.

Maybe Paul can make further comment.

Phil:

First off look at what the E&M field configuration is for the TM010 resonance in the EW frustum, see attached.  Note that the E&B fields are very weak at the small OD end of the frustum cavity for the TM010 mode resonance.  Also remember that the TM010 resonant frequency of the empty copper frustum was 957 MHz, whereas when the PE discs was mounted at the small OD end of the cavity, the resonant frequency only went down to 954 MHz which tells us that the dielectric disc was not interacting much with the E&B fields, and thus why the generate force direction was still from small OD to big OD as is was for the empty TM010 driven frustum.  However when I took out the PE discs at the small OD end of the TM010 driven frustum and replaced it with a Teflon disc at the large OD end of the frustum where the E&M fields were the strongest, the TM010 resonant frequency plunged down to 901 MHz due to the large interaction with the E&M fields, and the thrust vector reversed and became much larger than with the frustum cavity empty.  This TM010 data may support Jim Woodward interpretation that the dielectric discs can multiply the frustum thrust-effect in low Q-factor situations, but when the Q-factor becomes large enough, say over 30,000, another thrust generation mechanism may be taking over.  A thrust generation mechanism that is NOT dependent on the presence of the dielectric discs...

Best, Paul M.

From what I can see, the data shows:

1) Small to big static force vector with 1 disc at small end, none at big end
2) Big to small static force vector with 2 disc at small end, none at big end
3) Big to small static force vector with 1 disc at big end, none at small end
4) Small to big static force vector with no discs at either end

Is this correct? Are there more configurations?

If so do you have the mode maps & field intensity plots for each configuration?

Can you please supply Lorentz force & CG thermal shift adjusted impulse strength and direction for each configuration?

I believe that by comparing the force direction, adjusted force strength & mode map with field strength we may be able to get closer to understanding more about the measurable & calculable characterists that drive the direction and strength of the generated forces.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: ThinkerX on 12/07/2016 03:02 am
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.

But is this not yet another photon rocket equivalent, thrust wise?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: spupeng7 on 12/07/2016 03:49 am
This TM010 data may support Jim Woodward interpretation that the dielectric discs can multiply the frustum thrust-effect in low Q-factor situations, but when the Q-factor becomes large enough, say over 30,000, another thrust generation mechanism may be taking over.  A thrust generation mechanism that is NOT dependent on the presence of the dielectric discs...

Best, Paul M.

Without a dielectric and higher Q, wouldn't a skin effect in the copper walls take over and become the host of the Mach effect?
I quote Dr Rodal about Dr Montillet's work on that matter (message from Thread 8 (https://forum.nasaspaceflight.com/index.php?topic=40959.msg1588165#msg1588165)):

Quote from: Rodal
At the Estes Park Breakthrough Propulsion Workshop, Dr. Jean-Philippe Montillet of the École Polytechnique Fédérale de Lausanne, Switzerland, presented a paper titled "Model of the EM Drive with the EMG coupling" (that mathematically and physically) explains the EM Drive as a capacitor, where:

* Surface currents propagate inside the cavity on the conic wall (between the two end plates)
* electromagnetic resonant modes create electric charges on each end plate
* Mach/Woodward effect is triggered by Lorentz force from surface currents on the conic wall
* acceleration of RF cavity as due to the variation of Electro Magnetic density from evanescent waves inside the skin layer

A polymer insert placed asymmetrically in the cavity results in greater asymmetry, while decreasing Q. The cavity's acceleration is a function of all the above factors.  The model can explain acceleration with and without the polymer insert (to a more significant or less significant extent).

As the Mach/Woodward effect can be derived straight from the fully covariant nonlinear Hoyle Narlikar gravitational theory or it can also be obtained from linearized General Relativity it is really as much of a gravitational effect as gravity assist.  The difference being that gravity assist is something that people are now familiar with (since it was first used for interplanetary flight by the Mariner 10 in the mid-70's) and the Mach/Woodward effect is something that people are normally unfamiliar with (because time-dependent terms in General Relativity are usually ignored).

Gravity assist flight of a spacecraft is an open system where momentum is transferred by gravity to spaceship and so is the Mach/Woodward effect a gravitational effect.  Both of them are explained by General Relativity.  If somebody explains the acceleration of an EM Drive based on a gravitational effect (the Mach/Woodward effect), it would be incorrect to address conservation of momentum and energy solely based on the spaceship momentum while ignoring the effect of gravity.

Of course, nobody nowadays will write about "overunity" of gravity assist (as the spaceship involved in a sling shot maneuver apparently gains  velocity out of nothing, if one ignores gravity) because it is evident that gravity assist is ... gravity-assisted.   ;)

Similarly, the Mach/Woodward effect drive perhaps should be renamed "Mach Effect Gravity Assist" (MEGA) drive, to make it more obvious to the readers that the Mach Effect is a gravitational effect, and thus it would be completely incorrect to address conservation of momentum and energy without taking into account the gravitational effect.

The MEGA drive… As an European this name is very funny to me. The Mega Drive (https://en.wikipedia.org/wiki/Sega_Genesis) is the European name (among other countries, notably Japan: Mega Doraibu) of Sega's popular 16-bit home video game console known as the Genesis in the United States, that has been sold at 40 millions units in the 1990s. It was challenging the Nintendo Super NES before the advent of the Sony Playstation. Didn't know that console was propellantless ;)

Acronyms can be so confusing, especially in technical descriptions. But I really like that the Mach Effect is receiving consideration.

Surely an electromagnetic Mach Effect would be stronger than a gravitational Mach Effect by the same difference that exists between the strength of electromagnetic interactions in comparison to gravitational interactions. Could there be some insight to be gained from consideration of this comparison.

They are both inverse square interactions after all, and the separation between charges within the atom does leave room for question, does it not?

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 05:22 am
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.

But is this not yet another photon rocket equivalent, thrust wise?

A photon rocket is not a gradient in an effective potential energy per kg of field mass. So I'd have to say, no. Thrust in this theory depends on the field mass and the potential gradient it can fall through from one end to the other, and/or from one time to another.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/07/2016 12:47 pm
The Eagleworks torsion pendulum

Doing some calculations, I realised how little we know about the measurement device the Eagleworks team used. Below, I do some estimations and calculations.

What I should like to know, are: moment of inertia, resonant frequency, how much does the frustum moves at a given force, dynamic response.

Information we have: internal dimensions of the vacuum vessel (914 mm long) [Brady et al., 2014; White et al., 2016], mass of the complete frustum system (9.3 kg)  and figures from which we can estimate the frequency of the pendulum.

Calculation of the moment of inertia (MoI):
-   the pendulum arm, if symmetrical, can be at most ~ 900 mm long. But you have to subtract at least the radius of the frustum (including flange ~160 mm), so the centre-of-gravity of the frustum is then at 900-160)/2 = 370 mm mm from the centre of rotation.
-   The mass of the frustum and counterweight are given, e.g., in the attached figure [1]: 9.3 kg with a counterweight of 8 kg (OK, it is probably a bit asymmetrical, but we need only orders of magnitude).

⇨   I = 2 x (0.37^2 x 9.3) ≈ 2.5 kg m^2

the torsion pendulum beam and several parts will give a little contribution, maybe 0.1 kg m^2 in total, so say

I total = 2.6 kg m^2

In the first figure a number of calibration pulses are given [F1]. It can be seen that in this configuration the system is a little overdamped (bigger damping than critical, because it has no ‘overshoot’).
In some other figures overshoots after a stepfunction force can be seen. [F2] for instance, a measurement with a dummy load, shows some ringing which points to a slightly underdamped system. Probably this is because the MoI of the pendulum was less than in the configuration with the full frustum.
From this figure [2] a period of ~ 4 s can be estimated (neglecting the influence of damping).
However, in this configuration the frustum seems to be not present, only a big fat dummy load and a weight (1 kg?). So let’s suppose on both sides there is a mass of 3 kg (at distances of 0.4 m from the centre of rotation), this gives a MoI:

I = 2 x (0.37^2 x 3.0) = 0.8 N m rad^-1

Together with the calculated MoI above, the torsion constant can be calculated:
K = 2.0 N m rad^-1. From some other figures [e.g., F3], the pendulum frequency seems to be closer to 5 s, then I = 1.3 N m rad^-1, so let’s say

K (the torsion constant) = 1.7(3) N m rad^-1 .

This torsion constant corresponds to a steel wire of 5 mm diameter (k = πGd^4 / 32l [ref?]). Quite a thick ‘torsion wire’, but White et al. refer to it as a ‘flexure bearing’, which seems quite justified.

angle of rotation = force x arm length/K,   approx. angle = tan(angle) = displacement/arm length

⇨   displacement @ a force of 65 µN ≈ 5 µm

That aint much. I guess (from the figures) the optical displacement sensor has submicrometer resolution (but we don’t know the type).

Are these numbers approximately correct, Paul?

References
White et al., 2016.

Attached figures (I think they all come from Paul March / Star-Drive)
[F1] August 18, 2015_Copper Frustum Forward & Reverse Tests_9.3kg Integrated Copper Frustum Test Article with 8kg Counter Balance Force Calibrations.jpg
[F3] TE012NoDielectric.jpg
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Fan Boi on 12/07/2016 01:02 pm

http://phys.org/news/2016-12-mars-days-expert-discusses-nasa.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 01:09 pm
how much does the frustum moves at a given force, dynamic response.

Peter,

On the left side of each measurement image is the displacement scale in um.

There is more info on the torsion pendulum in the 1st paper as attached. Both papers should be read and considered as one paper.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/07/2016 01:30 pm
how much does the frustum moves at a given force, dynamic response.

Peter,

On the left side of each measurement image is the displacement scale in um.

There is more info on the torsion pendulum in the 1st paper as attached. Both papers should be read and considered as one paper.

A, yes, if you look carefully.

So my calculated numbers could be off by a factor of two. Well, at least I got my 'order of magnitude'.  :P

I can almost hear your sigh, Phil. But it is not unusual in a scientific paper to describe the measurement apparatus. That's not trivial.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 01:57 pm
how much does the frustum moves at a given force, dynamic response.

Peter,

On the left side of each measurement image is the displacement scale in um.

There is more info on the torsion pendulum in the 1st paper as attached. Both papers should be read and considered as one paper.

A, yes, if you look carefully.

So my calculated numbers could be off by a factor of two. Well, at least I got my 'order of magnitude'.  :P

I can almost hear your sigh, Phil. But it is not unusual in a scientific paper to describe the measurement apparatus. That's not trivial.

Peter,

No sigh. Been there, done that.

EmDrive are not straightforward nor are measuring the forces they generate.

The kit build I'm working on is to try to eliminate some of the learning curve effort and to hopefully eliminate almost all the errors and blind alleys that can entrap DIY builders.

Once many folks can easily build a thruster and test system from components they can buy from EBay and see it generates force, I expect the EmDrive industry will start to take off.

I've already been offered to work with a group who wish to put together a dedicated P-P (Propellant Less Propulsion) conference to help the P-P industry get moving. Of course working P-P thruster will be on display and operating.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: as58 on 12/07/2016 02:41 pm
PV refers to Polarizable Vacuum, as in the Polarizable Vacuum Representation of General Relativity. The symbol "£" is just a typical way to express the Lagrangian Density. This part is not critical to the derivation. It's only a reference to where the solution for K comes from. Given that K is a solution to the £'s respective equations of motion, we can use it from there forward.
Ah, ok. So it's meant to be \mathcal{L}.

Quote
1. The first expression is the Lorentz (Lorenz) gauge condition. (Spelling depends on your text book.) Here's a good reference, but I used the book; "Geometry, Particles and Fields" by Felsager.
https://www.phy.duke.edu/~rgb/Class/Electrodynamics/Electrodynamics/node31.html (https://www.phy.duke.edu/~rgb/Class/Electrodynamics/Electrodynamics/node31.html)

The first equality is what I was wondering about. The second is the Lorenz gauge condition.

Quote
2. The "wave equation" is really a conservation equation for the magnetic flux /Phi, it comes from the fact that the vector potential "A", can be derived from the gradient of the scalar /Phi. It is an unusual interpretation, because typically "A" is rotational, it is not a gradient, but there is nothing that requires "A" to be rotational in this gauge, and the gradient does not change Maxwell's equations.

How is A derived from \Phi? Why does \Phi satisfy the wave equation? (At least it has the form of a wave equation, so that's what I'll call it for now.)

Quote
3. Magnetic flux is a scalar. The vector fields are "E, H and A". It is a measure of the "Volt-seconds" applied to the input terminals. The total flux inside is the integral of the Volts over time. This is pretty standard stuff. Review the workings of an inductor, or power transformer.

Magnetic flux through a surface is scalar. But what is the surface here? Also, you say \Phi is angular momentum/coulomb, and angular momentum is definitely a (pseudo)vector.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/07/2016 03:06 pm
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.

But is this not yet another photon rocket equivalent, thrust wise?

A photon rocket is not a gradient in an effective potential energy per kg of field mass. So I'd have to say, no. Thrust in this theory depends on the field mass and the potential gradient it can fall through from one end to the other, and/or from one time to another.

May I risk an analogy for those who think the thrust of the EmDrive in your model is only due to the radiating thermal losses outside of the cavity: this is like saying an old locomotive is pushed on the railway by the reaction mass of the steam leaving the chimney. It's not. The steam is indeed at the source of propulsion, but it's not its mass or heat leaving the chimney that pushes on the train. Like in your PV model where the ohmic losses are there to trigger a much bigger effect in the cavity, on the EM momentum.

Yet I have a question about your model Todd. You're focusing on the momentum variation of trapped travelling photons in an asymmetric resonant cavity, and the continuous shifting of the inertial center of mass of the EM wave backwards, hence a reaction of the cavity forward. This is about the flowing electromagnetic energy, but what about the gravitational part of the theory: what about the fields and the spacetime itself? Does your PV model imply some spacetime warping and if so, does the PV model introduce a negative energy density somewhere in the metric tensor with the violation of the weak-energy condition provided by some scalar-tensor theories (https://arxiv.org/abs/1302.5690) with the help of a coupling scalar field? Or does it use plain vanilla GR with positive energy only (ok, with EM coupling) like Marco Frasca (StrongGR on NSF) did in his own paper (https://arxiv.org/abs/1505.06917)?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/07/2016 04:12 pm
True, but I don't think you can get a Q that high without the losses going down. In a steady state situation, the maximum loss of power (dissipation) can be 1000W, the full "real" input power. At the same time, the amount of stored energy will depend on how many VARS the cavity can support. As losses go down, the VARS can go up until the Q is infinite. So as long as the cavity can dissipate 1000W continuously, it's all good.

FYI: I have not seen a build yet that could withstand that much power dissipation continuously. Solder joints would melt.  8)

Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.

If you do a few sims and increase the conductivity of the Cu by say 9x (reducing Rs 9x) you will not see a 9X increase in the E & H fields. However increase the input power 9X and you will see the E fields increase 3x and the H fields increase 3x.

There is an effect from decreasing Rs 9x as the Q increases 9x but the E & H field energies do not each increase 3x.
Why not an increase in stored energy?  By the definition of Q factor, https://en.wikipedia.org/wiki/Q_factor (https://wikimedia.org/api/rest_v1/media/math/render/svg/f0661eedae5a3a141431125d7ff95d68a6b6bec1)
Power loss and omega remainig constant, [Q(w)*9]*power_loss/w=(9*Maximum_Energy_Stored).

Consider that reducing the per cycle energy loss 10x, will increase the Q 10x.

Now consider reducing the per cycle energy loss 5,000x by changing from room temp Cu with a Rs of 15,000uOhm to YBCO at 77k with a Rs of 3uOhm.

The Q will increase 5,000x.

Cavity E & H fields will increase a little due to less input energy being lost per cycle.  This effect is clearly shown by modeling the changes with any resonant cavity simulator thar allows the surface Rs to be varied.

The attached may help to explain.
Your not holding constant the power your feeding in which equals the losses.  I thought the point of using a superconducting cavity was to store more power for the same amount of power fed in.

If you change your input power when you change Q then your stored power may stay the same. Power loss=power supplied [Q(w)*9]*[power_supplied*(1/9)]/w=(Maximum_Energy_Stored)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/07/2016 04:18 pm
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.

Would this count as an experiment here: https://en.wikipedia.org/wiki/Pioneer_anomaly ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 04:22 pm
PV refers to Polarizable Vacuum, as in the Polarizable Vacuum Representation of General Relativity. The symbol "£" is just a typical way to express the Lagrangian Density. This part is not critical to the derivation. It's only a reference to where the solution for K comes from. Given that K is a solution to the £'s respective equations of motion, we can use it from there forward.
Ah, ok. So it's meant to be \mathcal{L}.

Quote
1. The first expression is the Lorentz (Lorenz) gauge condition. (Spelling depends on your text book.) Here's a good reference, but I used the book; "Geometry, Particles and Fields" by Felsager.
https://www.phy.duke.edu/~rgb/Class/Electrodynamics/Electrodynamics/node31.html (https://www.phy.duke.edu/~rgb/Class/Electrodynamics/Electrodynamics/node31.html)

The first equality is what I was wondering about. The second is the Lorenz gauge condition.

Quote
2. The "wave equation" is really a conservation equation for the magnetic flux /Phi, it comes from the fact that the vector potential "A", can be derived from the gradient of the scalar /Phi. It is an unusual interpretation, because typically "A" is rotational, it is not a gradient, but there is nothing that requires "A" to be rotational in this gauge, and the gradient does not change Maxwell's equations.

How is A derived from \Phi? Why does \Phi satisfy the wave equation? (At least it has the form of a wave equation, so that's what I'll call it for now.)

Quote
3. Magnetic flux is a scalar. The vector fields are "E, H and A". It is a measure of the "Volt-seconds" applied to the input terminals. The total flux inside is the integral of the Volts over time. This is pretty standard stuff. Review the workings of an inductor, or power transformer.

Magnetic flux through a surface is scalar. But what is the surface here? Also, you say \Phi is angular momentum/coulomb, and angular momentum is definitely a (pseudo)vector.

1b. The first term is simply saying momentum density is "charge density * A", or is "mass density * v". That's all. You're reading too much into it. It is just showing the relationship between these vector field quantities and momentum density. Nothing more.

2b. A = Grad(Phi).  We don't know what the Grad(Phi) is, inside the frustum as a function of time or position. I can't say it is a solution or not since I don't have a function for it, only that this is the type of solution we are looking for. I can assume that over a small enough region, it will hold but I don't have an exact solution. Only these general equations.

3b. The surface of the frustum. Ultimately, we are looking for the divergence of the momentum NOT equal to zero, when integrating over the entire surface of the frustum. Edit: Angular momentum is just one way to look at the units of measure. It can also be thought of as energy per frequency mode.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 04:51 pm
Your not holding constant the power your feeding in which equals the losses.  I thought the point of using a superconducting cavity was to store more power for the same amount of power fed in.

If you change your input power when you change Q then your stored power may stay the same. Power loss=power supplied [Q(w)*9]*[power_supplied*(1/9)]/w=(Maximum_Energy_Stored)

Dustin,

Cavities store energy and not power.

When you hold input power constant and reduce surface Rs, the Q increases linearly with Rs decrease. However the value of the max E & H fields only see a small increase, which is the reduced energy loss per cycle instead of being thermalised, being in the cavity E & H fields.

If the input power is held constant and cavity Q increases from lower Rs, what increases the generated force is the larger number of reflections the trapped photons will do, due to a longer 5x discharge TC which is due to reduced energy loss per cycle, as they give up some momentum on each reflection.

If you have access to a cavity simulator, you can verify this by keeping input power constant, noting max E & H field values and then reduce the Rs 5,000x. Q will increase 5,000x, as will 5x TC discharge time, but the E & H max fields will only increase a small value.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 05:05 pm
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.

But is this not yet another photon rocket equivalent, thrust wise?

A photon rocket is not a gradient in an effective potential energy per kg of field mass. So I'd have to say, no. Thrust in this theory depends on the field mass and the potential gradient it can fall through from one end to the other, and/or from one time to another.

May I risk an analogy for those who think the thrust of the EmDrive in your model is only due to the radiating thermal losses outside of the cavity: this is like saying an old locomotive is pushed on the railway by the reaction mass of the steam leaving the chimney. It's not. The steam is indeed at the source of propulsion, but it's not its mass or heat leaving the chimney that pushes on the train. Like in your PV model where the ohmic losses are there to trigger a much bigger effect in the cavity, on the EM momentum.

Yet I have a question about your model Todd. You're focusing on the momentum variation of trapped travelling photons in an asymmetric resonant cavity, and the continuous shifting of the inertial center of mass of the EM wave backwards, hence a reaction of the cavity forward. This is about the flowing electromagnetic energy, but what about the gravitational part of the theory: what about the fields and the spacetime itself? Does your PV model imply some spacetime warping and if so, does the PV model introduce a negative energy density somewhere in the metric tensor with the violation of the weak-energy condition provided by some scalar-tensor theories (https://arxiv.org/abs/1302.5690) with the help of a coupling scalar field? Or does it use plain vanilla GR with positive energy only (ok, with EM coupling) like Marco Frasca (StrongGR on NSF) did in his own paper (https://arxiv.org/abs/1505.06917)?

I think it is probably similar to Marco's solution, but his Tensor math is beyond my comprehension, so I can't answer that. We both come up with a charge to mass ratio coupling constant, sqrt(4pi*G*e0).

The energy density inside the frustum is not enough to actually bend/warp space-time. However, what it does create is a "potential energy per kg of mass", which is by definition, a gravito-electric field. In my notes I refer to this potential as an "effective potential", but that is what it is.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: as58 on 12/07/2016 05:08 pm
2b. A = Grad(Phi).  We don't know what the Grad(Phi) is, inside the frustum as a function of time or position. I can't say it is a solution or not since I don't have a function for it, only that this is the type of solution we are looking for. I can assume that over a small enough region, it will hold but I don't have an exact solution. Only these general equations.

Ok. And how is the magnetic field related to A?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/07/2016 05:31 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: HMXHMX on 12/07/2016 05:32 pm
As many of you know, SSI hosted the Estes Park Breakthrough Propulsion Workshop last September 20-22, 2016. At that time we said that videos and presentation materials would be available at the SSI site and on YouTube in early December.  Thanks to the efforts of our volunteer audio-visual team (Robert Smith, SSI Chief Archivist and Evangelist and Robin Snelson, SSI Executive Director), plus Drs. Heidi Fearn and Lance Williams, among others, we have met that self-imposed deadline.  Thanks to all concerned!

Videos will be posted in sequence over the next few days.  PDFs of papers and presentations will be available on the SSI site in a few weeks, and we should be able to generate hardcopy books of the proceedings by early next year for those who are interested.

Thanks again for your patience.  I hope Chris Bergin will forgive a minor plug for SSI donations, as well.  For those who are interested, go to our home page at www.ssi.org and select your favorite project from the sidebar.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 05:57 pm
2b. A = Grad(Phi).  We don't know what the Grad(Phi) is, inside the frustum as a function of time or position. I can't say it is a solution or not since I don't have a function for it, only that this is the type of solution we are looking for. I can assume that over a small enough region, it will hold but I don't have an exact solution. Only these general equations.

Ok. And how is the magnetic field related to A?

"A" can be a superposition of vector fields, both rotational and non-rotational. "B = curl(A)", "E = -dA/dt". "Phi = Integral(A)ds", where "s" is a closed path around the flux being measured. There are many ways the field "A" can be expressed. From the color plots produced by the modelers, we can estimate "A" from "E". That is the easiest way to visualize it for me.  In QM, the 4-vector field Au is the EM field, and Maxwell's equations are derived from it. In the Lorenz gauge, <|duAu|> = 0, is generally covariant.

I don't know your level of understanding of these things. Some of your statements imply you are well versed in Maxwell's equations, but others show you're not so familiar with the electrical engineering terms that I use. What is your level of EM Theory and QM comprehension? I do not consider myself an expert, but rather someone with a good intuition and knows just enough of the Math to be dangerous.  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 06:00 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: as58 on 12/07/2016 06:25 pm
2b. A = Grad(Phi).  We don't know what the Grad(Phi) is, inside the frustum as a function of time or position. I can't say it is a solution or not since I don't have a function for it, only that this is the type of solution we are looking for. I can assume that over a small enough region, it will hold but I don't have an exact solution. Only these general equations.

Ok. And how is the magnetic field related to A?

"A" can be a superposition of vector fields, both rotational and non-rotational. "B = curl(A)", "E = -dA/dt". "Phi = Integral(A)ds", where "s" is a closed path around the flux being measured. There are many ways the field "A" can be expressed. From the color plots produced by the modelers, we can estimate "A" from "E". That is the easiest way to visualize it for me.  In QM, the 4-vector field Au is the EM field, and Maxwell's equations are derived from it. In the Lorenz gauge, <|duAu|> = 0, is generally covariant.

I don't know your level of understanding of these things. Some of your statements imply you are well versed in Maxwell's equations, but others show you're not so familiar with the electrical engineering terms that I use. What is your level of EM Theory and QM comprehension? I do not consider myself an expert, but rather someone with a good intuition and knows just enough of the Math to be dangerous.  8)

If B=curl(A) and A=Grad(\Phi), then B=0 (this is just a vector calculus identity which holds for any twice differentiable scalar field \Phi).

I'm (astro)physicist so engineering terms and to some extent notation is unfamiliar to me.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 06:37 pm
2b. A = Grad(Phi).  We don't know what the Grad(Phi) is, inside the frustum as a function of time or position. I can't say it is a solution or not since I don't have a function for it, only that this is the type of solution we are looking for. I can assume that over a small enough region, it will hold but I don't have an exact solution. Only these general equations.

Ok. And how is the magnetic field related to A?

"A" can be a superposition of vector fields, both rotational and non-rotational. "B = curl(A)", "E = -dA/dt". "Phi = Integral(A)ds", where "s" is a closed path around the flux being measured. There are many ways the field "A" can be expressed. From the color plots produced by the modelers, we can estimate "A" from "E". That is the easiest way to visualize it for me.  In QM, the 4-vector field Au is the EM field, and Maxwell's equations are derived from it. In the Lorenz gauge, <|duAu|> = 0, is generally covariant.

I don't know your level of understanding of these things. Some of your statements imply you are well versed in Maxwell's equations, but others show you're not so familiar with the electrical engineering terms that I use. What is your level of EM Theory and QM comprehension? I do not consider myself an expert, but rather someone with a good intuition and knows just enough of the Math to be dangerous.  8)

If B=curl(A) and A=Grad(\Phi), then B=0 (this is just a vector calculus identity which holds for any twice differentiable scalar field \Phi).

I'm (astro)physicist so engineering terms and to some extent notation is unfamiliar to me.

Agreed B=0, but it would be more accurate to say that some components of "A" are rotational and some are not. There is definitely a non-zero "B" field, but there is also a gradient in the scalar flux. The two are not mutually exclusive, they are simply a linear superposition of fields. The gradient in the flux does not change the value of B for the rotational part of the field.

The scalar /Phi is mathematically a gauge transformation of the rotational field "A". It doesn't affect B, but does have other effects.

Another way I think of it, but I'm not sure it's accurate, is to think of the scalar not simply as magnetic flux, but as the Magnitude of the probability, "<|A*A|>". This is just the photon probability density of the EM field.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 06:49 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.

When a resonant cavity is excited at resonance, the energy is equally stored in the internal E and H fields. The resonant cavity Power Factor at resonance is 1. There is no "Reactive Power" at resonance. BTW as I'm an electronics engineer I do understand what VAR and Reactive Power are.

I really don't care what happens inside the cavity if the freq is a bit low or high but I do understand what happens.

I'm having a hard time understanding where you are going with this?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 07:03 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.

When a resonant cavity is excited at resonance, the energy is equally stored in the internal E and H fields. The resonant cavity Power Factor at resonance is 1. There is no "Reactive Power". BTW as I'm an electronics engineer I do understand what VAR and Reactive Power are.

I really don't care what happens inside the cavity if the freq is a bit low or high but I do understand what happens.

I'm having a hard time understanding where you are going with this?

In an LC oscillator, where R=0, Voltage and Current are always 90 deg. out of phase. Therefore, the power factor  is zero. If the power factor were 1, then a cavity would dissipate all the input power instantly and nothing would be stored. It would have a Q = 0. A perfectly conducting cavity has zero power loss, so it would have a power factor of 0 and an infinite Q.

You are thinking of the LC as being the termination of a network transmission line, but a resonant cavity is not a transmission line.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/07/2016 07:09 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.

When a resonant cavity is excited at resonance, the energy is equally stored in the internal E and H fields. The resonant cavity Power Factor at resonance is 1. There is no "Reactive Power" at resonance. BTW as I'm an electronics engineer I do understand what VAR and Reactive Power are.

I really don't care what happens inside the cavity if the freq is a bit low or high but I do understand what happens.

I'm having a hard time understanding where you are going with this?

In response to the field increasing only a small amount.  I think that's because it is the field squared that is the energy stored so the field should increase as sqrt(Energy).  Sounds about right.

I think where he is going is that you store a photon in the cavity and it osculates then dissipates mostly through the cavity large end.  Most of them (the stored energy)/h/f appear to be stored near the narrow end but then exit as heat through the large end.  There is this constant time flow of energy from the narrow end to the large end as we keep throwing more photons in to keep the stored energy constant.   It being an open system because of the flow from stored energy to the flow through the copper.  I get the impression it suggests optimal antenna injection near the narrow end where the electric field is maximum.

The E and B fields should stagger in time.  At one instant the energy is in the E field and thats all that exists in the cavity at that time.  At another time both E and B fields exist but are each weaker together.  At another time all the energy is in the B field.  But these are all superimposed counter-propagating light waves which is the time evolution of the system as old photons die out, new ones are introduced.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: mwvp on 12/07/2016 07:54 pm
Perhaps I can help resolve this?

...
Cavities store energy and not power.

While true, there is a power flux or flow, which is what I referred to a few posts back. So while it has a fixed energy storage capacity, as an inductor and capacitor or network equivalent circuit would, that energy is in flux, consequently a power flow.

...
When you hold input power constant and reduce surface Rs, the Q increases linearly with Rs decrease. However the value of the max E & H fields only see a small increase, which is the reduced energy loss per cycle instead of being thermalised, being in the cavity E & H fields.

If the input power is held constant and cavity Q increases from lower Rs, what increases the generated force is the larger number of reflections the trapped photons will do, due to a longer 5x discharge TC which is due to reduced energy loss per cycle, as they give up some momentum on each reflection.

If you have access to a cavity simulator, you can verify this by keeping input power constant, noting max E & H field values and then reduce the Rs 5,000x. Q will increase 5,000x, as will 5x TC discharge time, but the E & H max fields will only increase a small value.

I can see how you would produce that result using a simulator. You have a network with Qn, impedance Zn, and power Pin. It has a fixed coupling network. You Keep Pin constant, while you reduce the losses of the network, resulting in Qn and Zn increasing, but the energy in the network nearly the same.

If you don't modify your input coupling network to match the input power impedance to the new, increased network impedance. But you should vary the input matching network to match the new impedance.

So, why don't you have a look at your simulation, and see if you're still dissipating your, say 1kW of power after you change your Rs surface resistance?

The good news is as your Q increases, that bandwidth decreases, dispersion increases and there is better optomechanical transducer gain for realistic accelerations, that is efficiency - N/kW.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 08:04 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.

When a resonant cavity is excited at resonance, the energy is equally stored in the internal E and H fields. The resonant cavity Power Factor at resonance is 1. There is no "Reactive Power". BTW as I'm an electronics engineer I do understand what VAR and Reactive Power are.

I really don't care what happens inside the cavity if the freq is a bit low or high but I do understand what happens.

I'm having a hard time understanding where you are going with this?

In an LC oscillator, where R=0, Voltage and Current are always 90 deg. out of phase. Therefore, the power factor  is zero. If the power factor were 1, then a cavity would dissipate all the input power instantly and nothing would be stored. It would have a Q = 0. A perfectly conducting cavity has zero power loss, so it would have a power factor of 0 and an infinite Q.

You are thinking of the LC as being the termination of a network transmission line, but a resonant cavity is not a transmission line.

In a parallel LC circuit at resonance there is only resistance as voltage and current are in phase. Power factor is 1.

http://www.electronics-tutorials.ws/accircuits/parallel-resonance.html

Quote
So at the resonant frequency, ƒr the current drawn from the supply must be “in-phase” with the applied voltage as effectively there is only the resistance present in the parallel circuit, so the power factor becomes one or unity, ( θ = 0o ).
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 08:11 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.

When a resonant cavity is excited at resonance, the energy is equally stored in the internal E and H fields. The resonant cavity Power Factor at resonance is 1. There is no "Reactive Power" at resonance. BTW as I'm an electronics engineer I do understand what VAR and Reactive Power are.

I really don't care what happens inside the cavity if the freq is a bit low or high but I do understand what happens.

I'm having a hard time understanding where you are going with this?

In response to the field increasing only a small amount.  I think that's because it is the field squared that is the energy stored so the field should increase as sqrt(Energy).  Sounds about right.

I think where he is going is that you store a photon in the cavity and it osculates then dissipates mostly through the cavity large end.  Most of them (the stored energy)/h/f appear to be stored near the narrow end but then exit as heat through the large end.  There is this constant time flow of energy from the narrow end to the large end as we keep throwing more photons in to keep the stored energy constant.   It being an open system because of the flow from stored energy to the flow through the copper.  I get the impression it suggests optimal antenna injection near the narrow end where the electric field is maximum.

The E and B fields should stagger in time.  At one instant the energy is in the E field and thats all that exists in the cavity at that time.  At another time both E and B fields exist but are each weaker together.  At another time all the energy is in the B field.  But these are all superimposed counter-propagating light waves which is the time evolution of the system as old photons die out, new ones are introduced.

Yes you are correct, the cavity energy storage alternates between E and H fields.

Stopped using CW excitation quite a long time ago. Moved onto pulsing my thrusters for only a small portion of 1 TC to allow the trapped photons to totally die out and transfer max momentum.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 08:21 pm
Perhaps I can help resolve this?

...
Cavities store energy and not power.

While true, there is a power flux or flow, which is what I referred to a few posts back. So while it has a fixed energy storage capacity, as an inductor and capacitor or network equivalent circuit would, that energy is in flux, consequently a power flow.

...
When you hold input power constant and reduce surface Rs, the Q increases linearly with Rs decrease. However the value of the max E & H fields only see a small increase, which is the reduced energy loss per cycle instead of being thermalised, being in the cavity E & H fields.

If the input power is held constant and cavity Q increases from lower Rs, what increases the generated force is the larger number of reflections the trapped photons will do, due to a longer 5x discharge TC which is due to reduced energy loss per cycle, as they give up some momentum on each reflection.

If you have access to a cavity simulator, you can verify this by keeping input power constant, noting max E & H field values and then reduce the Rs 5,000x. Q will increase 5,000x, as will 5x TC discharge time, but the E & H max fields will only increase a small value.

I can see how you would produce that result using a simulator. You have a network with Qn, impedance Zn, and power Pin. It has a fixed coupling network. You Keep Pin constant, while you reduce the losses of the network, resulting in Qn and Zn increasing, but the energy in the network nearly the same.

If you don't modify your input coupling network to match the input power impedance to the new, increased network impedance. But you should vary the input matching network to match the new impedance.

So, why don't you have a look at your simulation, and see if you're still dissipating your, say 1kW of power after you change your Rs surface resistance?

The good news is as your Q increases, that bandwidth decreases, dispersion increases and there is better optomechanical transducer gain for realistic accelerations, that is efficiency - N/kW.

Not at my PC at the moment but I seem to remember that when I ran S parameters, the impedance was still around 50 ohm, that is if the excitation freq as at resonance.

For sure E & H max fields increase as the sqrt of the increased power, as they should. ie 9x increase in power = 3x increase in both max E and H field strength.

However drop Rs 9x and around 1.5x increase in E & H max field strength. Do another 9X drop in Rs and the E & H field increases are like 1.2x Another 9x drop in Rs and they increase like 1.1.

I do a few runs and post the data as input power and Rs are varied.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 08:27 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.

When a resonant cavity is excited at resonance, the energy is equally stored in the internal E and H fields. The resonant cavity Power Factor at resonance is 1. There is no "Reactive Power". BTW as I'm an electronics engineer I do understand what VAR and Reactive Power are.

I really don't care what happens inside the cavity if the freq is a bit low or high but I do understand what happens.

I'm having a hard time understanding where you are going with this?

In an LC oscillator, where R=0, Voltage and Current are always 90 deg. out of phase. Therefore, the power factor  is zero. If the power factor were 1, then a cavity would dissipate all the input power instantly and nothing would be stored. It would have a Q = 0. A perfectly conducting cavity has zero power loss, so it would have a power factor of 0 and an infinite Q.

You are thinking of the LC as being the termination of a network transmission line, but a resonant cavity is not a transmission line.

In a parallel LC circuit at resonance there is only resistance as voltage and current are in phase. Power factor is 1.

http://www.electronics-tutorials.ws/accircuits/parallel-resonance.html

Quote
So at the resonant frequency, ƒr the current drawn from the supply must be “in-phase” with the applied voltage as effectively there is only the resistance present in the parallel circuit, so the power factor becomes one or unity, ( θ = 0o ).

The voltage and current "from the supply" is NOT the voltage and current stored in the LC oscillator or inside the frustum. The Supply current is not the Circulating current, they are two different loops in the Mesh diagram. The LC oscillator is NOT a resistor. You are confusing the voltage and current "from the supply", with the voltage and current "inside the oscillator". Inside the oscillator, they are 90 deg out of phase if resistance losses are neglected.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 08:41 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.

When a resonant cavity is excited at resonance, the energy is equally stored in the internal E and H fields. The resonant cavity Power Factor at resonance is 1. There is no "Reactive Power". BTW as I'm an electronics engineer I do understand what VAR and Reactive Power are.

I really don't care what happens inside the cavity if the freq is a bit low or high but I do understand what happens.

I'm having a hard time understanding where you are going with this?

In an LC oscillator, where R=0, Voltage and Current are always 90 deg. out of phase. Therefore, the power factor  is zero. If the power factor were 1, then a cavity would dissipate all the input power instantly and nothing would be stored. It would have a Q = 0. A perfectly conducting cavity has zero power loss, so it would have a power factor of 0 and an infinite Q.

You are thinking of the LC as being the termination of a network transmission line, but a resonant cavity is not a transmission line.

In a parallel LC circuit at resonance there is only resistance as voltage and current are in phase. Power factor is 1.

http://www.electronics-tutorials.ws/accircuits/parallel-resonance.html

Quote
So at the resonant frequency, ƒr the current drawn from the supply must be “in-phase” with the applied voltage as effectively there is only the resistance present in the parallel circuit, so the power factor becomes one or unity, ( θ = 0o ).

The voltage and current "from the supply" is NOT the voltage and current stored in the LC oscillator or inside the frustum. The Supply current is not the Circulating current, they are two different loops in the Mesh diagram. The LC oscillator is NOT a resistor. You are confusing the voltage and current "from the supply", with the voltage and current "inside the oscillator". Inside the oscillator, they are 90 deg out of phase if resistance losses are neglected.

Power factor of 1 says the load took all the energy the generator sent it. This is what happens at resonance. There are no L or C phase shifting components to the load. If fact one way to detect resonance is when the reflected power phase shift hits zero as attached. The zero phase shift means there are no reactive components of the load at that freq. As you can see in the attached, that happens at resonance.

When you talk about Reactive Power and VARS INSIDE a cavity, can you please explain?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: TheTraveller on 12/07/2016 08:44 pm
“...Watt is not energy. kWh or J are energy. The cavity stores energy, not watts, and it can only output that amount of energy as either work accelerating mass or thermalised photons as heat.....”

The moment the concept of “energy” leaves the sheet of paper and, in the real world, is injected inside a cavity, it becomes “real”, bound in time, or space if you prefer. The energy trapped inside the cavity is in fact power, j/s ; seconds from Length/c or volume/c...

Food for thought...

Phil doesn't seem to understand the concept of VARS. The energy stored in the cavity is not "static", it is dynamic, time varying E and H fields. Therefore, the stored energy has a time derivative and as such is stored as "Reactive Power" in VARS.

When a resonant cavity is excited at resonance, the energy is equally stored in the internal E and H fields. The resonant cavity Power Factor at resonance is 1. There is no "Reactive Power". BTW as I'm an electronics engineer I do understand what VAR and Reactive Power are.

I really don't care what happens inside the cavity if the freq is a bit low or high but I do understand what happens.

I'm having a hard time understanding where you are going with this?

In an LC oscillator, where R=0, Voltage and Current are always 90 deg. out of phase. Therefore, the power factor  is zero. If the power factor were 1, then a cavity would dissipate all the input power instantly and nothing would be stored. It would have a Q = 0. A perfectly conducting cavity has zero power loss, so it would have a power factor of 0 and an infinite Q.

You are thinking of the LC as being the termination of a network transmission line, but a resonant cavity is not a transmission line.

In a parallel LC circuit at resonance there is only resistance as voltage and current are in phase. Power factor is 1.

http://www.electronics-tutorials.ws/accircuits/parallel-resonance.html

Quote
So at the resonant frequency, ƒr the current drawn from the supply must be “in-phase” with the applied voltage as effectively there is only the resistance present in the parallel circuit, so the power factor becomes one or unity, ( θ = 0o ).

The voltage and current "from the supply" is NOT the voltage and current stored in the LC oscillator or inside the frustum. The Supply current is not the Circulating current, they are two different loops in the Mesh diagram. The LC oscillator is NOT a resistor. You are confusing the voltage and current "from the supply", with the voltage and current "inside the oscillator". Inside the oscillator, they are 90 deg out of phase if resistance losses are neglected.

At resonance there are no external reactive components of the load and the LC circuit looks to the generator as a resistor.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: SeeShells on 12/07/2016 08:52 pm
As many of you know, SSI hosted the Estes Park Breakthrough Propulsion Workshop last September 20-22, 2016. At that time we said that videos and presentation materials would be available at the SSI site and on YouTube in early December.  Thanks to the efforts of our volunteer audio-visual team (Robert Smith, SSI Chief Archivist and Evangelist and Robin Snelson, SSI Executive Director), plus Drs. Heidi Fearn and Lance Williams, among others, we have met that self-imposed deadline.  Thanks to all concerned!

Videos will be posted in sequence over the next few days.  PDFs of papers and presentations will be available on the SSI site in a few weeks, and we should be able to generate hardcopy books of the proceedings by early next year for those who are interested.

Thanks again for your patience.  I hope Chris Bergin will forgive a minor plug for SSI donations, as well.  For those who are interested, go to our home page at www.ssi.org and select your favorite project from the sidebar.
Thank you for hosting the Advanced Propulsion workshop, Thank you for inviting me.

It took me a week,  to calm down and be able to sleep all night without waking up at 3AM and going, "OMG, it makes sense". Quite sure after refreshing and renewing my memory with your videos, I'll be in the same pattern for another week. Not complaining, but thanking you for being hosts for a fantastically brilliant group dedicated to the next giant leap for mankind.

My Very Best,
Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/07/2016 09:07 pm

The voltage and current "from the supply" is NOT the voltage and current stored in the LC oscillator or inside the frustum. The Supply current is not the Circulating current, they are two different loops in the Mesh diagram. The LC oscillator is NOT a resistor. You are confusing the voltage and current "from the supply", with the voltage and current "inside the oscillator". Inside the oscillator, they are 90 deg out of phase if resistance losses are neglected.

At resonance there are no external reactive components of the load and the LC circuit looks to the generator as a resistor.

You are correct. The "load" at the end of the transmission line, as seen by the "generator" looks like a resistor. No argument there, TT. But the cavity itself, is equivalent to an LC circuit. "inside the LC circuit, there is no load. It is stored energy that oscillates from inductive to capacitive stored energy. The voltage and current "inside" the LC circuit, as it is inside the frustum, are 90 degrees out of phase. You are confusing the lumped component impedance, with what is going on at the individual components.

In the case of the frustum, or any EM field, use the following definitions:

1. An inductor is a tube of magnetic flux. Nothing more.
2. A capacitor is a tube of electric flux. Nothing more.

If you understand these definitions, that these components "are" the flux they store, it should become clear. You are taking about the lumped impedance, and I am talking about the component representation of the E and B fields inside it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/07/2016 09:11 pm
..... “The E and B fields should stagger in time.  At one instant the energy is in the E field and thats all that exists in the cavity at that time.  At another time both E and B fields exist but are each weaker together.  At another time all the energy is in the B field.  But these are all superimposed counter-propagating light waves which is the time evolution of the system as old photons die out, new ones are introduced.” ....

Well, I wouldn’t bet on that.  All the em wave models up to now are based on E and B alternatively shaking hands in a perfectly “empty” vacuum. Now, we know better. The vacuum is an electromagnetic tissue, a medium. It is therefore more likely that the em waves are actually gliding as a travelling variation in one property of the medium, like all the other waves we know. .. Time to update the model to fit Casimir and all other clues we have about this medium.

From the start I knew the vacuum was not empty. Logically, how can “nothing” have properties like permeability and permittivity? (and half a dozen more properties..)

Food for thought...
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: otlski on 12/08/2016 12:07 am
The Eagleworks torsion pendulum

Doing some calculations, I realised how little we know about the measurement device the Eagleworks team used. Below, I do some estimations and calculations.

What I should like to know, are: moment of inertia, resonant frequency, how much does the frustum moves at a given force, dynamic response.

Information we have: internal dimensions of the vacuum vessel (914 mm long) [Brady et al., 2014; White et al., 2016], mass of the complete frustum system (9.3 kg)  and figures from which we can estimate the frequency of the pendulum.

Calculation of the moment of inertia (MoI):
-   the pendulum arm, if symmetrical, can be at most ~ 900 mm long. But you have to subtract at least the radius of the frustum (including flange ~160 mm), so the centre-of-gravity of the frustum is then at 900-160)/2 = 370 mm mm from the centre of rotation.
-   The mass of the frustum and counterweight are given, e.g., in the attached figure [1]: 9.3 kg with a counterweight of 8 kg (OK, it is probably a bit asymmetrical, but we need only orders of magnitude).

⇨   I = 2 x (0.37^2 x 9.3) ≈ 2.5 kg m^2

the torsion pendulum beam and several parts will give a little contribution, maybe 0.1 kg m^2 in total, so say

I total = 2.6 kg m^2

In the first figure a number of calibration pulses are given [F1]. It can be seen that in this configuration the system is a little overdamped (bigger damping than critical, because it has no ‘overshoot’).
In some other figures overshoots after a stepfunction force can be seen. [F2] for instance, a measurement with a dummy load, shows some ringing which points to a slightly underdamped system. Probably this is because the MoI of the pendulum was less than in the configuration with the full frustum.
From this figure [2] a period of ~ 4 s can be estimated (neglecting the influence of damping).
However, in this configuration the frustum seems to be not present, only a big fat dummy load and a weight (1 kg?). So let’s suppose on both sides there is a mass of 3 kg (at distances of 0.4 m from the centre of rotation), this gives a MoI:

I = 2 x (0.37^2 x 3.0) = 0.8 N m rad^-1

Together with the calculated MoI above, the torsion constant can be calculated:
K = 2.0 N m rad^-1. From some other figures [e.g., F3], the pendulum frequency seems to be closer to 5 s, then I = 1.3 N m rad^-1, so let’s say

K (the torsion constant) = 1.7(3) N m rad^-1 .

This torsion constant corresponds to a steel wire of 5 mm diameter (k = πGd^4 / 32l [ref?]). Quite a thick ‘torsion wire’, but White et al. refer to it as a ‘flexure bearing’, which seems quite justified.

angle of rotation = force x arm length/K,   approx. angle = tan(angle) = displacement/arm length

⇨   displacement @ a force of 65 µN ≈ 5 µm

That aint much. I guess (from the figures) the optical displacement sensor has submicrometer resolution (but we don’t know the type).

Are these numbers approximately correct, Paul?

References
White et al., 2016.

Attached figures (I think they all come from Paul March / Star-Drive)
[F1] August 18, 2015_Copper Frustum Forward & Reverse Tests_9.3kg Integrated Copper Frustum Test Article with 8kg Counter Balance Force Calibrations.jpg
[F3] TE012NoDielectric.jpg

Peter,

In response to a previous post of mine, Paul posted a pdf datasheet for the Bendix style flexures.  The spring constant is listed at 0.007 lb-in/deg.  I assumed that EW used two of them, one at the top and one at the bottom, for a combined spring constant of 0.014 lb-in-deg.  With this in mind I used the EW calibration pulse of 29 Newtons and the resultant displacement of 2 uM to determine the achieved spring rate.  My result was 0.32 lb-in/deg which disagreed significantly with the flexure assumption.  I concluded that I either made a mistake or that the purposeful gravity pendulum that EW set-up to "stabilize" the apparatus was the majority contributor to the system's torsional response.  I considered the magnetic damper's effect but since the cal pulse appeared to reach its final flat-top value, the damper's contribution was negligible.

Dan
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/08/2016 12:11 am
As many of you know, SSI hosted the Estes Park Breakthrough Propulsion Workshop last September 20-22, 2016. At that time we said that videos and presentation materials would be available at the SSI site and on YouTube in early December.  Thanks to the efforts of our volunteer audio-visual team (Robert Smith, SSI Chief Archivist and Evangelist and Robin Snelson, SSI Executive Director), plus Drs. Heidi Fearn and Lance Williams, among others, we have met that self-imposed deadline.  Thanks to all concerned!

Videos will be posted in sequence over the next few days.  PDFs of papers and presentations will be available on the SSI site in a few weeks, and we should be able to generate hardcopy books of the proceedings by early next year for those who are interested.

Thanks again for your patience.  I hope Chris Bergin will forgive a minor plug for SSI donations, as well.  For those who are interested, go to our home page at www.ssi.org and select your favorite project from the sidebar.
Thank you for hosting the Advanced Propulsion workshop, Thank you for inviting me.

It took me a week,  to calm down and be able to sleep all night without waking up at 3AM and going, "OMG, it makes sense". Quite sure after refreshing and renewing my memory with your videos, I'll be in the same pattern for another week. Not complaining, but thanking you for being hosts for a fantastically brilliant group dedicated to the next giant leap for mankind.

My Very Best,
Shell

Watching these videos really gets my brain going too. I can't wait to see the rest of them and refresh my memories!
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: dustinthewind on 12/08/2016 01:11 am
Your not holding constant the power your feeding in which equals the losses.  I thought the point of using a superconducting cavity was to store more power for the same amount of power fed in.

If you change your input power when you change Q then your stored power Energy may stay the same. Power loss=power supplied [Q(w)*9]*[power_supplied*(1/9)]/w=(Maximum_Energy_Stored)

Dustin,

Cavities store energy and not power.

...

Err.  Yeah, that was a typo.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Stormbringer on 12/08/2016 01:28 am
http://phys.org/news/2016-12-mars-days-expert-discusses-nasa.html

comments from the professional peanut gallery.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/08/2016 02:51 am
Well, I wouldn’t bet on that.  All the em wave models up to now are based on E and B alternatively shaking hands in a perfectly “empty” vacuum. Now, we know better. The vacuum is an electromagnetic tissue, a medium. It is therefore more likely that the em waves are actually gliding as a travelling variation in one property of the medium, like all the other waves we know. .. Time to update the model to fit Casimir and all other clues we have about this medium.

From the start I knew the vacuum was not empty. Logically, how can “nothing” have properties like permeability and permittivity? (and half a dozen more properties..)

Food for thought...
When you describe the vacuum as a medium, that terminology goes back to aether theory, which we know is wrong. Permeability and Permitivity are fundamental constants of nature, not properties of the vacuum. They are called vacuum values to distinguish them from the modifications that result when you try to measure them in the presence of matter. The way a medium perturbs the apparent values of these constants is distinct from the underlying universal constants. (Similar to trying to measure the mass of something by measuring its acceleration under a constant applied horizontal force, you will get a different value if it is sitting on a surface with friction. You would measure a larger apparent mass than the true value, and can do certain calculations with that value, but that doesn't mean that the real mass of the object changes with the friction of what it sits on.)

As far as updating electrodynamics models for quantum effects like Casimir, it is called "quantum electrodynamics," and physicists have already done it. That is why the Casimir effect was predicted before it was measured.

There is no "food for thought" in your post, it is only stuff that has already been considered by physicists and either incorporated or discarded as wrong. From the perspective of someone who has actually studied physics, it comes across as rather rude to physicists when you say that models should be updated to account for something predicted by the models nearly 70 years ago. If you don't know what you are talking about and want to learn, then you should be asking questions, not making statements that make it sound like you think you know more than the collective body of knowledge of the physicists on this planet.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: spupeng7 on 12/08/2016 04:14 am
2b. A = Grad(Phi).  We don't know what the Grad(Phi) is, inside the frustum as a function of time or position. I can't say it is a solution or not since I don't have a function for it, only that this is the type of solution we are looking for. I can assume that over a small enough region, it will hold but I don't have an exact solution. Only these general equations.

Ok. And how is the magnetic field related to A?

"A" can be a superposition of vector fields, both rotational and non-rotational. "B = curl(A)", "E = -dA/dt". "Phi = Integral(A)ds", where "s" is a closed path around the flux being measured. There are many ways the field "A" can be expressed. From the color plots produced by the modelers, we can estimate "A" from "E". That is the easiest way to visualize it for me.  In QM, the 4-vector field Au is the EM field, and Maxwell's equations are derived from it. In the Lorenz gauge, <|duAu|> = 0, is generally covariant.

I don't know your level of understanding of these things. Some of your statements imply you are well versed in Maxwell's equations, but others show you're not so familiar with the electrical engineering terms that I use. What is your level of EM Theory and QM comprehension? I do not consider myself an expert, but rather someone with a good intuition and knows just enough of the Math to be dangerous.  8)

If B=curl(A) and A=Grad(\Phi), then B=0 (this is just a vector calculus identity which holds for any twice differentiable scalar field \Phi).

I'm (astro)physicist so engineering terms and to some extent notation is unfamiliar to me.

Punctilious statement of variables is the only solution to this recurrent problem.
We can all understand each other better if we remember that math is the Rosetta stone provided it is adequately decoded by STATING YOUR VARIABLES.

As for asking questions, the questioner may sometimes have to answer her own :D
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Peter Lauwer on 12/08/2016 10:32 am
The Eagleworks torsion pendulum

Doing some calculations, I realised how little we know about the measurement device the Eagleworks team used. Below, I do some estimations and calculations.

....
K (the torsion constant) = 1.7(3) N m rad^-1 .

This torsion constant corresponds to a steel wire of 5 mm diameter (k = πGd^4 / 32l [ref?]). Quite a thick ‘torsion wire’, but White et al. refer to it as a ‘flexure bearing’, which seems quite justified.

angle of rotation = force x arm length/K,   approx. angle = tan(angle) = displacement/arm length

⇨   displacement @ a force of 65 µN ≈ 5 µm
....

Peter,

In response to a previous post of mine, Paul posted a pdf datasheet for the Bendix style flexures.  The spring constant is listed at 0.007 lb-in/deg.  I assumed that EW used two of them, one at the top and one at the bottom, for a combined spring constant of 0.014 lb-in-deg.  With this in mind I used the EW calibration pulse of 29 Newtons and the resultant displacement of 2 uM to determine the achieved spring rate.  My result was 0.32 lb-in/deg which disagreed significantly with the flexure assumption.  I concluded that I either made a mistake or that the purposeful gravity pendulum that EW set-up to "stabilize" the apparatus was the majority contributor to the system's torsional response.  I considered the magnetic damper's effect but since the cal pulse appeared to reach its final flat-top value, the damper's contribution was negligible.

Dan

?? If I convert that, I get 0.0453   N m rad^-1 (I was lazy, I used http://www.numberfactory.com/nf%20torque.htm )
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/08/2016 11:00 am
Two important news announced publicly by Dave elsewhere.
Quote from: rfmwguy
Per request by Harold White, they will not be presenting a video by Paul March. Go figure...

By "they" Dave means the Space Studies Institute (http://ssi.org/ssi-releases-bpw2016-videos/) and by the "video" he means Paul's presentation at the Estes Park Breakthrough Propulsion Workshop on 21 September 2016.

Paul retired from Eagleworks at the end of September. Before or after the workshop?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/08/2016 11:04 am
Now, the good news for DIYers:

EmDrive Builders Alert - New Macom Solid State Solution - Magnetron Replacement

https://youtu.be/wGnuN00RxIw

This is a new ultra compact 2.5GHz solid-state narrowband microwave amp for new generations ovens: GaN Power Transistor, 18dB gain, fed with only 4W to output 300W!

MAGe-102425-300 product page: https://www.macom.com/products/product-detail/MAGe-102425-300
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Monomorphic on 12/08/2016 01:05 pm
Now, the good news for DIYers:

EmDrive Builders Alert - New Macom Solid State Solution - Magnetron Replacement

This is a new ultra compact 2.5GHz solid-state narrowband microwave amp for new generations ovens: GaN Power Transistor, 18dB gain, fed with only 4W to output 300W!

We have looked at these types of transistors before. I picked up one of these for $104: http://tinyurl.com/h568esp If they were available mounted on a finished board that only required soldering power leads, heat sink, and plugging in the coax, that would be even better! The manufacturer returned my emails and recommended their more rugged scientific/industrial version. I have its spec sheet linked below. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Keith Ness on 12/08/2016 01:21 pm All of the operators in your diagram must send the cue balls back to their original position. Maybe you could provide a sketch showing how they do this while "deliberately not scattering" the momentum of the cue balls on the return trip. I don't think it can be done. Well the point is they keep it to a minimum. Any simple thrust then counterthrust will more-or-less cancel itself out. So throwing a ball and then stopping it will more-or-less cancel itself out. Push off one wall to move to the center, put the ball in the mechanical arm which has re-extended, and then continue moving to and impact the opposite wall will more-or-less cancel out (although things like rotational motion from the occasional off-center impact could be a hassle to deal with and eventually cancel out). For a simpler reset example, each ball has a string attached to its top and bottom, each string is attached to a spool system in the floor or ceiling, and each spool system can let out or reel in line as necessary. Of course, ultimately, I'm just talking about the randomization of direction of momentum that would occur in particle scattering from particle-on-particle collision. It seems to me that, as long as I divert some of the rearward momentum of the propellant to lateral, then it should be especially clear that some of the rearward momentum of the propellant will have been diminished. Something you need to understand, is that the definition of conservation of momentum means that any time you get net motion through a setup like this, it means you made a mistake. In this case, it seem that you don't understand that momentum is a vector quantity. When the ball with momentum X hits the 2 balls and send them off at 45 degree angles, each of the other 2 balls will have momentum X/sqrt(2), not X/2. This is because the horizontal component of momentum for each is X/2 in order to conserve momentum in that direction. Work this through to the end, and you'll see no pressure difference. If you find my use of the term "momentum" wrong because I pair it with a direction and that sounds redundant because momentum includes a direction, then I see lots of sources using phrases like "forward momentum", even physics lessons; but if that's not enough for you, then please feel free to substitute in the word "push" or something like that where I use "momentum". If "X/sqrt(2)" means "divide X by 1.41...", then my point will remain the same, since the quotient will still be smaller than X. All I need to do is have some of the propellant's rearward momentum diverted to lateral to make it really clear that not all of the momentum is going rearward anymore. Beyond that, since I'm suggesting limits on the accuracy of the phrase, "and opposite," it would not be surprising if I were to run into trouble with any math based on that phrase, so could you please explain, from an empirical rather than theoretical standpoint, how I have not diverted some of the rearward momentum of the propellant to lateral? It seems quite obvious that I have diverted momentum as such, assuming that conservation of energy holds. In my seven billiard balls example specifically, do you deny that: -- objects can collide such that momentum transfers from one to the other in a different direction than before the collision, and thus, successive collisions and changes in direction of momentum such as in my diagram can occur? -- the two balls moving directly towards the top and bottom walls have momentum relative to those walls because of their motion relative to those walls? -- those two balls inevitably took that momentum away from the cue ball's momentum, and, if conservation of energy is to hold, then rightward momentum has overall been reduced? Surely you're not suggesting that the balls which are travelling directly towards the top and bottom walls (i.e., parallel to the right wall) have any momentum to the right? (To determine the angles they will go at, you need to apply energy conservation, in this case with equal mass balls, opposing 45 degrees angles with the original ball coming to a complete stop is the right answer for a perfectly elastic collisionn.) This sounds like what my example says (and then those two balls travelling in opposing 45 degree angles likewise hit two more balls each, which are in turn likewise positioned so they travel in opposing 45 degree angles to the trajectories of the balls which hit them). If you ddin't intend it to concur with my example, then could you please provide more detail, maybe a diagram? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: graybeardsyseng on 12/08/2016 01:31 pm IAC, Adelaide, Australia, Sept, 2017 Hi Guys, I'm very seriously considering setting up an exhibit booth, so to demo my non cryo S band thruster happily spinning and accelerating on a rotary test rig during the conference. Will any of you guys be going and/or will any of you have a product in the market by then? All the best, Phil of course assuming my health will support that plan Phil, I am working on getting there. Haven't been to an IAC in years but now that I'm (mostly) retired it may work out. And Adelaide is one of my favorite cities in the world - seriously a friendly and beautiful place I recommend to everyone. Won't have a product to market yet but look forward to seeing your demo - hope your health etc facilitate your attending and demonstrating. Herman Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Keith Ness on 12/08/2016 02:01 pm A photon rocket is not a gradient in an effective potential energy per kg of field mass. So I'd have to say, no. Thrust in this theory depends on the field mass and the potential gradient it can fall through from one end to the other, and/or from one time to another. For what it's worth, I saw the temperature difference in a diagram in this link: http://www.nextbigfuture.com/2015/02/more-emdrive-experiment-information.html ...and thought that the smaller end was, for whatever reason, converting radiation pressure more into linear momentum, and the larger end was converting radiation pressure more into heat. In this video: https://www.youtube.com/watch?v=wBtk6xWDrwY ...Shawyer mentions that group velocity decreases with aperture size down to a cutoff point at which waves do not pass through, and says microwave oven screens are a good example, letting visible light through, but blocking the longer microwaves. I do also remember someone saying that cutoff varies with wavelength. Shawyer also says radiation pressure drops off with decrease in group velocity, but what happens at cutoff? I assume reflection, or some other transfer of momentum. So maybe the waves hitting the small end do so with less radiation pressure than the large end, but the waves which are cutoff before reaching the small end still impact at various points on the lateral surface where they get cutoff, in stages based on wavelength, giving radiation pressure in the direction of the small end as they do so. Also, because the lateral surface is cone-shaped, the waves pushing towards the small end hit over a larger surface area than the large end (maybe they also hit less directly but more frequently on average, as there's more surface area but at a less oppositional angle to the resonance than the large end?). So maybe the impacts pushing towards the small end have the same force overall but are more widely distributed overall than those pushing toward the large end, and so more of the force pushing toward the large end converts to more-or-less omni-directional force in the form of thermal motion (heat, which more-or-less cancels itself out) than the force pushing toward the small end. Shawyer also says the two ends are spherical sections (concentric from what I can see), at least ideally, and so there may also be differences in how convex/concave the surfaces are which make a difference in how well they handle impact. It's kind of like if a tow-truck driver were to drive up to assist your stalled vehicle, and say, “I can either push your car with my hand for a few minutes, or compact all that energy into one rifle shot at your car. It’s the same amount of energy, so it shouldn’t matter which one I use on your car, right?” Wrong, of course. The rifle shot will convert more of its energy into lateral momentum expressed as tearing a hole through your car, and won’t do much to move your car in one direction. The long hand push will move your car in one direction though, because it converts less into lateral momentum of your car. So maybe the EmDrive is essentially a photon rocket with the benefit of some resonance, as the large end is "giving way" (in the form of heat) to the resonant waves more than the small end and lateral surface are. Regardless of the reason the temperature difference exists, it should make people go, "Hmm." Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: meberbs on 12/08/2016 03:16 pm If you find my use of the term "momentum" wrong because I pair it with a direction and that sounds redundant because momentum includes a direction, then I see lots of sources using phrases like "forward momentum", even physics lessons; but if that's not enough for you, then please feel free to substitute in the word "push" or something like that where I use "momentum". If "X/sqrt(2)" means "divide X by 1.41...", then my point will remain the same, since the quotient will still be smaller than X. ... Since you didn't mention vectors at all in your response, I assume that you don't know what vectors are or how to work with them. Please go learn this on your own. I have updated your diagram below to show that when you do the calculations correctly, everything balances perfectly. You probably won't understand this next sentence until you go learn about vectors, but I'll include it just in case: The balls travelling at 45 degree angles have a horizontal component of momentum of X/2 and a vertical component of momentum of X/2 (or -X/2 for the one going downwards). This gives them a magnitude of sqrt((X^2)/4 + (X^2)/4) = X/sqrt(2). Since the horizontal components add to X, and the vertical components cancel due to opposite direction, momentum is conserved. -- those two balls inevitably took that momentum away from the cue ball's momentum, and, if conservation of energy is to hold, then rightward momentum has overall been reduced? This is your mistake, as I described above, the horizontal components still add up to the original value. If you are confused by the talk about components, go learn about vectors, here is not the right place to try to teach that. (To determine the angles they will go at, you need to apply energy conservation, in this case with equal mass balls, opposing 45 degrees angles with the original ball coming to a complete stop is the right answer for a perfectly elastic collision.) This sounds like what my example says (and then those two balls travelling in opposing 45 degree angles likewise hit two more balls each, which are in turn likewise positioned so they travel in opposing 45 degree angles to the trajectories of the balls which hit them). If you ddin't intend it to concur with my example, then could you please provide more detail, maybe a diagram? The point was that by chance you got the angles right, but you should have used energy conservation to determine the angles. Edit: I always forget to include the attachment... Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: HMXHMX on 12/08/2016 03:27 pm Two important news announced publicly by Dave elsewhere. First, the sad news: Quote from: rfmwguy Per request by Harold White, they will not be presenting a video by Paul March. Go figure... By "they" Dave means the Space Studies Institute (http://ssi.org/ssi-releases-bpw2016-videos/) and by the "video" he means Paul's presentation at the Estes Park Breakthrough Propulsion Workshop on 21 September 2016. Paul retired from Eagleworks at the end of September. Before or after the workshop? The video will be available, but our disclaimer is it represents Paul's personal views and not NASA's. No JSC Eagleworks endorsement is expressed or implied. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: LowerAtmosphere on 12/08/2016 04:20 pm Excellent posts Keith Ness! This is precisely what I tried to clumsily suggest earlier in this thread. If you try to forget all the surface currents, impedance and atmospherics for a second and focus on radiation pressure: it is not equal along the length of the cavity! (Pardon the missing Latex mathematical notation, writing on mobile so this will be quick and dirty) Radiation pressure is a function of: Intensity=(Emax)(Bmax)/area Relative Power=(2I/C)*adjusted local Q Now we consider one simple question: if Q is more or less constant along the entire cavity - ignoring dielectric situation and antennas - where will more reflections/absorptions occur per unit time? Assuming volumetrically equal loading and constant power it is trivial to see based on existing sims and experimental thrust results that higher E/B fields will generally occur towards the small end. If more momentum transfers to the small end than the large end it should accelerate in that direction. The kinetic energy is then slowly dissipated as heat. However to confirm that this mechanism works we need experimental data comparing field extrema and wall heating. Obviously meberbs and others will jump to say that this should not yield higher efficiencies than a photon rocket, but I ask: do photon rockets resonate/recycle photonic inertia yielding 2I/c many times per unit time/smaller area? The more conical the resonant cavity the more imbalance there should be. This also means builders should aim for many robust high energy cavities with maximum recycling. Not to toot my own horn here but my earlier honeycomb carbon nanotube thruster sketch would incorporate both high energy densities per unit area, high recycling and decent (improvable) Q. So why discourage the klystron canon approach of 100kw if it is done in short (tuned!!) pulses? According to warptech's formula you'd see lift-off for a relatively light cavity and that would shut the skeptics up rather fast :) All this is congruous with what I believe Shawyer , TT and others are trying to explain. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: rfmwguy on 12/08/2016 04:38 pm Two important news announced publicly by Dave elsewhere. First, the sad news: Quote from: rfmwguy Per request by Harold White, they will not be presenting a video by Paul March. Go figure... By "they" Dave means the Space Studies Institute (http://ssi.org/ssi-releases-bpw2016-videos/) and by the "video" he means Paul's presentation at the Estes Park Breakthrough Propulsion Workshop on 21 September 2016. Paul retired from Eagleworks at the end of September. Before or after the workshop? The video will be available, but our disclaimer is it represents Paul's personal views and not NASA's. No JSC Eagleworks endorsement is expressed or implied. This is great news. Perhaps I'll return to posting here more often someday. I've been elsewhere most of the time. Not really sure why, its just the way its worked out. Been mending some fences with those I've clashed with some time ago. Feel its time to move past that since the paper came out and we have an experiment to focus on rather than theory. As a "simple-minded" engineer, that seems to work better for me. I have no qualms about theory of operation, just as Lance said in his opening remarks, we have an experiment preceding theory and while uncomfortable to many, I enjoy this aspect. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Vesc on 12/08/2016 07:48 pm I have been away for a long time. Since Thread 7! And am getting caught up. I've seen many references to the Eagleworks AIAA paper and comments to the effect that it is published? But I've also read that it is due out in a December 2016 issue of an AIAA journal. I don't see any December 2016 issues yet on the AIAA website. Can anyone tell me me which AIAA journal this paper will be published in and when to expect to see the December 2016 issue? Or if there is already a link to the paper I would appreciate a reply with attached link. If this has already been discussed my apologies to the group. I just waded through several hundred posts and didn't find that needle in this haystack. Sorry. PS: Love the Estes Park conference photo. I could have identified Dr. Rodal and Michelle without attribution but no one else. Not even Paul March. Looking forward to the videos as they arrive. I'm a big fan of SSI... Have contributed to them in the past, probably should do so again.... ;) Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Vesc on 12/08/2016 08:01 pm I have been away for a long time. Since Thread 7! And am getting caught up. I've seen many references to the Eagleworks AIAA paper and comments to the effect that it is published? But I've also read that it is due out in a December 2016 issue of an AIAA journal. I don't see any December 2016 issues yet on the AIAA website. Can anyone tell me me which AIAA journal this paper will be published in and when to expect to see the December 2016 issue? Or if there is already a link to the paper I would appreciate a reply with attached link. Why does this always happen to me? Two minutes after I make the above request I find it! http://arc.aiaa.org/doi/pdf/10.2514/1.B36120 Will be in this months' AIAA Journal of Propulsion and Power. Oh well. In the words of E. Latella (sp?) Never mind! ::) Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/08/2016 08:25 pm The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume. Have there been any experiments that test the temperature difference between the two ends? Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't. Would this count as an experiment here: https://en.wikipedia.org/wiki/Pioneer_anomaly ? It's a different effect. I guess it's too off topic for anyone to argue about it? I'm planning on doing this experiment, since I haven't found any data that it has been done before. It's a lot cheaper than using MW's too! :) Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: flux_capacitor on 12/08/2016 10:43 pm The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume. Have there been any experiments that test the temperature difference between the two ends? Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't. Todd, your work in progress about your PV model of the EmDrive is very interesting, but it's still like an incomplete messy puzzle to me. May I ask you to answer some questions in layman terms? I understood the key is the asymmetric attenuation of RF power in the resonant cavity, which would trigger an accelerated reference frame near cutoff (small end). I don't understand how an accelerated reference frame could be generated, but the asymmetric attenuation is due to the asymmetric shape of the frustum, a gradient in the ohmic losses (more heat extracted out of the cavity at one end) and evanescent waves near cutoff (at small end) carrying momentum away. Correct? Now, I fail to understand what is going on with photons. In your model, does the momentum of photons trapped in a tapered cavity vary according to the cross-section of the cavity (a bit like Shawyer or McCulloch but on a different theoretical basis)? Or does the speed of light vary between the two ends? Then, you say that "the inertial center of mass-energy of the EM wave is continually shifted backwards so the cavity reacts forward" but is this inertial movement due to some mechanism triggering a variation of the momentum of travelling EM waves in a tapered cavity (see question above)? Or is the center of mass-energy of the EM wave simply shifted due to asymmetric thermal extraction outside of the cavity at one end? Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Josave on 12/08/2016 10:43 pm ... We have looked at these types of transistors before. I picked up one of these for$104: http://tinyurl.com/h568esp

If they were available mounted on a finished board that only required soldering power leads, heat sink, and plugging in the coax, that would be even better!
...

Very soon the manufacturers of LDMOS transistors will be offering a full board, including also the frequency generator capable of being computer controlled in phase and frequency:

https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: rq3 on 12/09/2016 12:42 am
...
We have looked at these types of transistors before. I picked up one of these for $104: http://tinyurl.com/h568esp If they were available mounted on a finished board that only required soldering power leads, heat sink, and plugging in the coax, that would be even better! ... Very soon the manufacturers of LDMOS transistors will be offering a full board, including also the frequency generator capable of being computer controlled in phase and frequency: https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems These are cool. NOT. They are specified as fairly narrow band devices, to comply with ISM standards when mounted on the board (i.e., you're almost, but not quite, tuning the frustum to the source). They require tens of amps of clean direct current (beware of Lorentz forces). Their efficiency is comparable to a magnetron, so expect to shed several HUNDRED watts of heat. A magnetron is a vacuum tube, and tolerates the heat. A solid state transistor, whether LDMOS like this one or GaN like the Macom device, nah, not so much. These devices are presented on evaluation boards optimized for a 50 ohm source and load for evaluation purposes. A frustum is not a 50 ohm load. S-parameters are strictly for linear purposes normalized to the network impedance. Beware S-parameters for non-linear devices launched into non-normalized conditions. Finally, these are amplifiers, not oscillators. They have a certain gain, at a certain frequency. You still have to drive them with a source of somewhere on the order of 4 watts of microwave RF. Keep in mind that the microstrip design of these protoboards radiates an E field quite well. Be safe. If you buy one of these devices, and build one of these amplifiers, and don't enclose it in a well shielded RF tight enclosure, you can expect to wake up the next morning with eyeballs that look like poached eggs. Forever. As a test, over-ride the interlocks on your microwave oven, stick your head inside, and turn it on medium for one minute. Don't do this. But do contemplate the result. A magnetron power supply will kill you, no questions asked, right now and right away just from the voltages and currents involved. A high power RF transistor may not shock you to death instantly, but will do so insidiously, and it most certainly can cook you or burn you to death. Or put you into a condition where you wished you were dead. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: WarpTech on 12/09/2016 01:37 am The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume. Have there been any experiments that test the temperature difference between the two ends? Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't. Todd, your work in progress about your PV model of the EmDrive is very interesting, but it's still like an incomplete messy puzzle to me. May I ask you to answer some questions in layman terms? I understood the key is the asymmetric attenuation of RF power in the resonant cavity, which would trigger an accelerated reference frame near cutoff (small end). I don't understand how an accelerated reference frame could be generated, but the asymmetric attenuation is due to the asymmetric shape of the frustum, a gradient in the ohmic losses (more heat extracted out of the cavity at one end) and evanescent waves near cutoff (at small end) carrying momentum away. Correct? It also depends on the mode shape and how energy is distributed, and where power is dissipated. Small end or big end, at this point, is a very difficult prediction, because there is practically no temperature data to compare between experiments. You have the gist of it correct. The thrust will be in the direction of the side which has the highest magnetic pressure and lowest power dissipation. There are cases however, where apparently all the energy is at one end, TM010 mode, and there is nothing going on at the other end. This adds complexity as there's no simple rule of this end or that end. Quote Now, I fail to understand what is going on with photons. In your model, does the momentum of photons trapped in a tapered cavity vary according to the cross-section of the cavity (a bit like Shawyer or McCulloch but on a different theoretical basis)? Or does the speed of light vary between the two ends? In my model, the photos "are" the lines of magnetic flux. They carry momentum when coupled to charge, p = q*A. Whether it is the speed of light or the frequency of the waves that varies (not photons), is all a matter perspective. It's not one or the other as one is dependent on the other. However, the "cause" is the dissipation, that is what matters. If you think about the dissipation, not the photons, there is no ambiguity. The magnetic flux (volt-seconds) escapes where ever there is voltage drop in one direction for a period of time. The voltage drop is V = I*R, and the current will cause the flux to pass through, carrying the momentum away with it. Now, whether that flux escapes the frustum to free space, or just gets trapped in the copper as heat, it doesn't matter. The momentum has been lost from the "inside", from the cavity. Quote Then, you say that "the inertial center of mass-energy of the EM wave is continually shifted backwards so the cavity reacts forward" but is this inertial movement due to some mechanism triggering a variation of the momentum of travelling EM waves in a tapered cavity (see question above)? Or is the center of mass-energy of the EM wave simply shifted due to asymmetric thermal extraction outside of the cavity at one end? Your second question would be closer. As I was questioning in my post above. There would be no argument if this were a sealed can full of pressurized air, and I punched a hole in one end to let the pressure out. Obviously, the can would move the other way. But if I have a pressurized can and I simultaneously heat the air at one end and cool it at the other end, so that it is the same gradient in pressure, it should move in the same way. There is a magnetic pressure exerted on the frustum, and the frustum is exerting pressure on the field. The forces are balanced. Where there are voltage drops, there are "leaks" that let the pressure out. The differential pressure will cause a flow and the frustum will go the other way. Also, in my current model, it's not just the spacial gradient. It is the 4-gradient. So the time derivative plays a big part in the thrust too. If I show that the thrust can happen with just hot air, then this will make testing EM drives very difficult since it would show they MUST be tested in a hard vacuum. On the other hand however, if I can make propulsion with hot/cold air, who needs MW's? :) Very good questions. Thank you! I have plans to do this experiment. I bought some Peltier Coolers and some USB Pressure/Temperature sensors. Now all I need is can to connect them to. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: Davinator on 12/09/2016 01:56 am A reminder, this is one thread in one section of what is a very large forum. This one is about EM Drive and applications to space flight. Everything else is off topic and we obviously have a thread for today's sad news. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: cosmo on 12/09/2016 02:06 am Now, the good news for DIYers: EmDrive Builders Alert - New Macom Solid State Solution - Magnetron Replacement <snip> This is a new ultra compact 2.5GHz solid-state narrowband microwave amp for new generations ovens: GaN Power Transistor, 18dB gain, fed with only 4W to output 300W! <snip> Also similar products here - http://www.ampleon.com/products/rf-energy/ (http://www.ampleon.com/products/rf-energy/) Check out the Plug and Play Evaluation Tools link (4th Paragraph) http://www.ampleon.com/news/news-articles/Credit-card-sized-250-Watt-2.4-2.5-GHz-reference-design-targets-RF-cooking-and-industrial-heating-applications.html (http://www.ampleon.com/news/news-articles/Credit-card-sized-250-Watt-2.4-2.5-GHz-reference-design-targets-RF-cooking-and-industrial-heating-applications.html) Evaluation Board - 250W output Looks like a number of semi manufacturers are getting into the power microwave market. FWIW, Ampleon was a spin-off from NXP semi. Edit - At this point in time, it appears the best solid state board level solution is that mentioned above by Josave, as it contains all the components (synthesizer, amps, monitoring, etc) already integrated in a package with a reasonable external control interface. https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems (https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems) Also, take heed of the warnings in the post by rq3. If you don't have experience dealing with high-power microwave energy, don't mess with it! BE SAFE! Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: mwvp on 12/09/2016 04:43 am The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume. Have there been any experiments that test the temperature difference between the two ends? Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't. Would this count as an experiment here: https://en.wikipedia.org/wiki/Pioneer_anomaly ? It's a different effect. I guess it's too off topic for anyone to argue about it? I'm planning on doing this experiment, since I haven't found any data that it has been done before. It's a lot cheaper than using MW's too! :) I posted this link a while back, FWIW: "Observations of an Anomalous Reversible Weight Change Effect in a System Containing a Thermo-electric Peltier Device." http://www.linux-host.org/energy/peltier.htm It may well be EMD related, since, AFAIK, a Peltier is a semiconductor junction, dispersive to electron De Broglie waves. I wonder about a potential thermal thrust effect. Isn't a thermal gradient a momentum gradient? Should be a no-brainer for a cube-sat. To the extent any cube-sat is a no-brainer, that is. A Peltier and a heat-sink/radiator. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: spupeng7 on 12/09/2016 05:20 am IAC, Adelaide, Australia, Sept, 2017 Hi Guys, I'm very seriously considering setting up an exhibit booth, so to demo my non cryo S band thruster happily spinning and accelerating on a rotary test rig during the conference. Will any of you guys be going and/or will any of you have a product in the market by then? All the best, Phil of course assuming my health will support that plan Phil, seriously bloke, this is my home town and I live 15 minutes walk from the conference center. Yes I will be there with bells on if either you or Roger can make it, what a treat. Am available as support if required and can recommend the local amenities. Sorry no reply last March, must have missed this post the first time around. Drinks on me if you or any other emdrive folk can be here, John Newell.. Attached photo of central Adelaide. Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/09/2016 05:53 am Attached is now to cool a thruster to 77K without immersing it in liquid LN2. I expect my spherical thrusters will gen around 0.6N/kW at room temp. Expect the Rs to drop around 3-4 times at 77K, which should lift the specific force to around 1.8 to 2.4N/kW. Phil Title: Re: EM Drive Developments - related to space flight applications - Thread 9 Post by: TheTraveller on 12/09/2016 06:03 am IAC, Adelaide, Australia, Sept, 2017 Hi Guys, I'm very seriously considering setting up an exhibit booth, so to demo my non cryo S band thruster happily spinning and accelerating on a rotary test rig during the conference. Will any of you guys be going and/or will any of you have a product in the market by then? All the best, Phil of course assuming my health will support that plan Phil, seriously bloke, this is my home town and I live 15 minutes walk from the conference center. Yes I will be there with bells on if either you or Roger can make it, what a treat. Am available as support if required and can recommend the local amenities. Sorry no reply last March, must have missed this post the first time around. Drinks on me if you or any other emdrive folk can be here, John Newell.. Attached photo of central Adelaide. Will cost me a min$15k to do the show. Will know by end June 2017 if it will happen.

Would be a lot lower cost to rent a suite in an adjacent hotel to do the demo. I know Dr Tajmar is going and we plan to catch up during the conference, so for sure he would spread the word that there was an EmDrive demo in an adjacent hotel suite. Also fairly simple to stand outside the entry doors and hand out a flyer.

Did talk with Roger & Gilo. They have no plans as of now to attend.

Unless someone else does a presentation at some other venue before Sept 2017, my S band thruster may be the 1st public demo.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: RERT on 12/09/2016 11:07 am
I posted this link a while back, FWIW: "Observations of an Anomalous Reversible Weight Change Effect
in a System Containing a Thermo-electric Peltier Device."
http://www.linux-host.org/energy/peltier.htm

Good read! Most interesting, they seem to have stopped when needing a torsion balance to measure a horizontal force. The thing seems an order of magnitude simpler than an EMDrive, and produces 1-5 mg force, which is 10-50 microNewton. If a DIYer has a torsion balance handy, it might be easy to get somewhere with this.

Admitting I don't really understand Warptech's theory, it does seem to chime with that...
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/09/2016 12:32 pm
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.

Todd, your work in progress about your PV model of the EmDrive is very interesting, but it's still like an incomplete messy puzzle to me. May I ask you to answer some questions in layman terms?

I understood the key is the asymmetric attenuation of RF power in the resonant cavity, which would trigger an accelerated reference frame near cutoff (small end).

I don't understand how an accelerated reference frame could be generated, but the asymmetric attenuation is due to the asymmetric shape of the frustum, a gradient in the ohmic losses (more heat extracted out of the cavity at one end) and evanescent waves near cutoff (at small end) carrying momentum away.
Correct?

It also depends on the mode shape and how energy is distributed, and where power is dissipated. Small end or big end, at this point, is a very difficult prediction, because there is practically no temperature data to compare between experiments. You have the gist of it correct. The thrust will be in the direction of the side which has the highest magnetic pressure and lowest power dissipation. There are cases however, where apparently all the energy is at one end, TM010 mode, and there is nothing going on at the other end. This adds complexity as there's no simple rule of this end or that end.

Quote
Now, I fail to understand what is going on with photons. In your model, does the momentum of photons trapped in a tapered cavity vary according to the cross-section of the cavity (a bit like Shawyer or McCulloch but on a different theoretical basis)? Or does the speed of light vary between the two ends?

In my model, the photos "are" the lines of magnetic flux. They carry momentum when coupled to charge, p = q*A. Whether it is the speed of light or the frequency of the waves that varies (not photons), is all a matter perspective. It's not one or the other as one is dependent on the other. However, the "cause" is the dissipation, that is what matters. If you think about the dissipation, not the photons, there is no ambiguity. The magnetic flux (volt-seconds) escapes where ever there is voltage drop in one direction for a period of time. The voltage drop is V = I*R, and the current will cause the flux to pass through, carrying the momentum away with it.

Now, whether that flux escapes the frustum to free space, or just gets trapped in the copper as heat, it doesn't matter. The momentum has been lost from the "inside", from the cavity.

Quote
Then, you say that "the inertial center of mass-energy of the EM wave is continually shifted backwards so the cavity reacts forward" but is this inertial movement due to some mechanism triggering a variation of the momentum of travelling EM waves in a tapered cavity (see question above)? Or is the center of mass-energy of the EM wave simply shifted due to asymmetric thermal extraction outside of the cavity at one end?

Your second question would be closer. As I was questioning in my post above. There would be no argument if this were a sealed can full of pressurized air, and I punched a hole in one end to let the pressure out. Obviously, the can would move the other way. But if I have a pressurized can and I simultaneously heat the air at one end and cool it at the other end, so that it is the same gradient in pressure, it should move in the same way.

There is a magnetic pressure exerted on the frustum, and the frustum is exerting pressure on the field. The forces are balanced. Where there are voltage drops, there are "leaks" that let the pressure out. The differential pressure will cause a flow and the frustum will go the other way.

Also, in my current model, it's not just the spacial gradient. It is the 4-gradient. So the time derivative plays a big part in the thrust too. If I show that the thrust can happen with just hot air, then this will make testing EM drives very difficult since it would show they MUST be tested in a hard vacuum. On the other hand however, if I can make propulsion with hot/cold air, who needs MW's? :)

Very good questions.  Thank you!

I have plans to do this experiment. I bought some Peltier Coolers and some USB Pressure/Temperature sensors. Now all I need is can to connect them to.

I look forward to watch your presentation given at the Estes Park workshop once it is available on the SSI website. I am sure many readers here do want to understand your model better; but very few people has the training to grasp all of the PV maths.

I think also updating the wiki article about your model (http://emdrive.wiki/Todd_Desiato_(@WarpTech)%27s_Evanescent_Wave_Theory) would be good thing, in particular explaining:
• What is exactly "dispersion" (group velocity dispersion?) and what is its relation with the creation of an artificial accelerated reference frame (i.e. which is a gravitational field generator!) and the notsosureofit Hypothesis,
• The difference between dissipation and attenuation in a cavity (I imagine attenuation of the EM energy as a consequence of power dissipation?),
• And why just extracting heat out of one particular end of a resonant cavity (or even, as recently suggested, out of a cylindrical metal can filled with just gas and no EM waves!), apparently a trivial thermodynamic process that does not seem at all related to advanced concepts like propellantless interstellar travel or flying cars, could generate such things as "an accelerated reference frame" and a "gravitoelectric field".
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: kaublezw on 12/09/2016 02:31 pm
I find it hard to believe that our ticket to the stars is as easy as creating a heat gradient on an enclosed metal cavity.  This could've been done easily over 100 years ago.   Surely such a discovery would've been stumbled upon accidentally by now.

But please prove me wrong.   :)  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: SeeShells on 12/09/2016 02:39 pm
...
We have looked at these types of transistors before. I picked up one of these for \$104: http://tinyurl.com/h568esp

If they were available mounted on a finished board that only required soldering power leads, heat sink, and plugging in the coax, that would be even better!
...

Very soon the manufacturers of LDMOS transistors will be offering a full board, including also the frequency generator capable of being computer controlled in phase and frequency:

https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems

These are cool. NOT. They are specified as fairly narrow band devices, to comply with ISM standards when mounted on the board (i.e., you're almost, but not quite, tuning the frustum to the source). They require tens of amps of clean direct current (beware of Lorentz forces). Their efficiency is comparable to a magnetron, so expect to shed several HUNDRED watts of heat. A magnetron is a vacuum tube, and tolerates the heat. A solid state transistor, whether LDMOS like this one or GaN like the Macom device, nah, not so much. These devices are presented on evaluation boards optimized for a 50 ohm source and load for evaluation purposes. A frustum is not a 50 ohm load. S-parameters are strictly for linear purposes normalized to the network impedance. Beware S-parameters for non-linear devices launched into non-normalized conditions. Finally, these are amplifiers, not oscillators. They have a certain gain, at a certain frequency. You still have to drive them with a source of somewhere on the order of 4 watts of microwave RF. Keep in mind that the microstrip design of these protoboards radiates an E field quite well.

Be safe. If you buy one of these devices, and build one of these amplifiers, and don't enclose it in a well shielded RF tight enclosure, you can expect to wake up the next morning with eyeballs that look like poached eggs. Forever. As a test, over-ride the interlocks on your microwave oven, stick your head inside, and turn it on medium for one minute. Don't do this. But do contemplate the result.

A magnetron power supply will kill you, no questions asked, right now and right away just from the voltages and currents involved. A high power RF transistor may not shock you to death instantly, but will do so insidiously, and it most certainly can cook you or burn you to death. Or put you into a condition where you wished you were dead.

VERY WELL SAID!

A great summary defining both the magnetron and SS device differences and the dangers of microwave energy production in both.

It needs to be said more often, I worry about someone getting seriously harmed or worse.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Monomorphic on 12/09/2016 03:13 pm
They are specified as fairly narrow band devices, to comply with ISM standards when mounted on the board (i.e., you're almost, but not quite, tuning the frustum to the source).

They have a certain gain, at a certain frequency. You still have to drive them with a source of somewhere on the order of 4 watts of microwave RF.

These evaluation boards have an integrated 2.4Ghz signal generator, with pre-driver, driver, and final stage. It is likely tunable from 2.4Ghz to 2.5Ghz, as the MACOM. Should be easy to build a frustum tuned within those margins.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/09/2016 03:57 pm
I find it hard to believe that our ticket to the stars is as easy as creating a heat gradient on an enclosed metal cavity.  This could've been done easily over 100 years ago.   Surely such a discovery would've been stumbled upon accidentally by now.

But please prove me wrong.   :)  ;)

The more I read it, the more it seems we would already have created a warp drive heating canned food in a microwave oven! ;D

Joking aside, WarpTech's theory is much more appealing when one consider the EM wave velocity or momentum variation mechanism triggering a variable refractive index, which is an accelerated frame of reference, thus an artificially generated gravitational potential. In this case, WarpTech's EmDrive would be… a reactionless warp drive.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Bob012345 on 12/09/2016 04:05 pm
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.

Would this count as an experiment here: https://en.wikipedia.org/wiki/Pioneer_anomaly ?

It's a different effect. I guess it's too off topic for anyone to argue about it? I'm planning on doing this experiment, since I haven't found any data that it has been done before. It's a lot cheaper than using MW's too! :)

I posted this link a while back, FWIW: "Observations of an Anomalous Reversible Weight Change Effect
in a System Containing a Thermo-electric Peltier Device."
http://www.linux-host.org/energy/peltier.htm

It may well be EMD related, since, AFAIK, a Peltier is a semiconductor junction, dispersive to electron De Broglie waves.

Should be a no-brainer for a cube-sat. To the extent any cube-sat is a no-brainer, that is. A Peltier and a heat-sink/radiator.

If the Cubesat works, are people going to claim it just interacts with Earth's magnetic field? Has anyone done the calculations to show that won't explain the thrust as just a Lorentz force?
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: RERT on 12/09/2016 04:15 pm
Hmm. Took a few million years from fire to the steam engine. Maybe there were extenuating circumstances, or perhaps we just blame homo habilis for most of that...
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: DusanC on 12/09/2016 04:22 pm
The equation below would seem to imply, that I can get thrust if I heat one end "Pin" and cool the other end, "Ploss" to form a temperature (pressure) gradient in the internal gas of a sealed cylinder of constant volume.

Have there been any experiments that test the temperature difference between the two ends?

Has such an experiment with a sealed cylinder been done? Probably not, since it would seem to violate CoM, but it doesn't.

Todd, your work in progress about your PV model of the EmDrive is very interesting, but it's still like an incomplete messy puzzle to me. May I ask you to answer some questions in layman terms?

I understood the key is the asymmetric attenuation of RF power in the resonant cavity, which would trigger an accelerated reference frame near cutoff (small end).

I don't understand how an accelerated reference frame could be generated, but the asymmetric attenuation is due to the asymmetric shape of the frustum, a gradient in the ohmic losses (more heat extracted out of the cavity at one end) and evanescent waves near cutoff (at small end) carrying momentum away.
Correct?

It also depends on the mode shape and how energy is distributed, and where power is dissipated. Small end or big end, at this point, is a very difficult prediction, because there is practically no temperature data to compare between experiments. You have the gist of it correct. The thrust will be in the direction of the side which has the highest magnetic pressure and lowest power dissipation. There are cases however, where apparently all the energy is at one end, TM010 mode, and there is nothing going on at the other end. This adds complexity as there's no simple rule of this end or that end.

Quote
Now, I fail to understand what is going on with photons. In your model, does the momentum of photons trapped in a tapered cavity vary according to the cross-section of the cavity (a bit like Shawyer or McCulloch but on a different theoretical basis)? Or does the speed of light vary between the two ends?

In my model, the photos "are" the lines of magnetic flux. They carry momentum when coupled to charge, p = q*A. Whether it is the speed of light or the frequency of the waves that varies (not photons), is all a matter perspective. It's not one or the other as one is dependent on the other. However, the "cause" is the dissipation, that is what matters. If you think about the dissipation, not the photons, there is no ambiguity. The magnetic flux (volt-seconds) escapes where ever there is voltage drop in one direction for a period of time. The voltage drop is V = I*R, and the current will cause the flux to pass through, carrying the momentum away with it.

Now, whether that flux escapes the frustum to free space, or just gets trapped in the copper as heat, it doesn't matter. The momentum has been lost from the "inside", from the cavity.

Quote
Then, you say that "the inertial center of mass-energy of the EM wave is continually shifted backwards so the cavity reacts forward" but is this inertial movement due to some mechanism triggering a variation of the momentum of travelling EM waves in a tapered cavity (see question above)? Or is the center of mass-energy of the EM wave simply shifted due to asymmetric thermal extraction outside of the cavity at one end?

Your second question would be closer. As I was questioning in my post above. There would be no argument if this were a sealed can full of pressurized air, and I punched a hole in one end to let the pressure out. Obviously, the can would move the other way. But if I have a pressurized can and I simultaneously heat the air at one end and cool it at the other end, so that it is the same gradient in pressure, it should move in the same way.

There is a magnetic pressure exerted on the frustum, and the frustum is exerting pressure on the field. The forces are balanced. Where there are voltage drops, there are "leaks" that let the pressure out. The differential pressure will cause a flow and the frustum will go the other way.

Also, in my current model, it's not just the spacial gradient. It is the 4-gradient. So the time derivative plays a big part in the thrust too. If I show that the thrust can happen with just hot air, then this will make testing EM drives very difficult since it would show they MUST be tested in a hard vacuum. On the other hand however, if I can make propulsion with hot/cold air, who needs MW's? :)

Very good questions.  Thank you!

I have plans to do this experiment. I bought some Peltier Coolers and some USB Pressure/Temperature sensors. Now all I need is can to connect them to.

I look forward to watch your presentation given at the Estes Park workshop once it is available on the SSI website. I am sure many readers here do want to understand your model better; but very few people has the training to grasp all of the PV maths.

I think also updating the wiki article about your model (http://emdrive.wiki/Todd_Desiato_(@WarpTech)%27s_Evanescent_Wave_Theory) would be good thing, in particular explaining:
• What is exactly "dispersion" (group velocity dispersion?) and what is its relation with the creation of an artificial accelerated reference frame (i.e. which is a gravitational field generator!) and the notsosureofit Hypothesis,
• The difference between dissipation and attenuation in a cavity (I imagine attenuation of the EM energy as a consequence of power dissipation?),
• And why just extracting heat out of one particular end of a resonant cavity (or even, as recently suggested, out of a cylindrical metal can filled with just gas and no EM waves!), apparently a trivial thermodynamic process that does not seem at all related to advanced concepts like propellantless interstellar travel or flying cars, could generate such things as "an accelerated reference frame" and a "gravitoelectric field".
Heating one end and cooling another end of closed cavity with trapped gas just shifts center of mass of gas to cold side and because of COM  cavity ''apparently'' moves to another side, but it's just a  closed system, center of mass stays in same spot, there's no thrust.

Same with heating the empty cavity, cavity just expands to one side but its center of mass doesn't move, there's no thrust.

Or I misunderstood something.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: RotoSequence on 12/09/2016 04:27 pm
Black body radiation is a real bear to work with... even with optimistic figures like vantablack radiators with a capacity of 2000 watts per square meter, a hypothetical, high thrust, EM drive powered spacecraft is going to look like a panel porcupine with anything less than newtons per kilowatt thrust. I can't imagine how you'd build a superconducting EM drive powered spacecraft. Significant capacity liquid helium cryo plants are huge!

On the other hand, I am not an engineer and I know I don't have a good grasp of refrigeration. For instance, I have no idea how much ammonia at what pressure and flow rate you'd need to get 2 kilowatts thermal to a square meter of radiator panel.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: flux_capacitor on 12/09/2016 04:32 pm
Heating one end and cooling another end of closed cavity with trapped gas just shifts center of mass of gas to cold side and because of COM  cavity ''apparently'' moves to another side, but it's just a  closed system, center of mass stays in same spot, there's no thrust.

Same with heating the empty cavity, cavity just expands to one side but its center of mass doesn't move, there's no thrust.

Or I misunderstood something.

You forgot heat can escape the cavity through thermal radiation (in a vacuum) and conduction (in the case of air) making it an open system, but you're right this is would not be a very advanced propulsion system.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Keith Ness on 12/09/2016 05:06 pm
Excellent posts Keith Ness! This is precisely what I tried to clumsily suggest earlier in this thread. If you try to forget all the surface currents, impedance and atmospherics for a second and focus on radiation pressure: it is not equal along the length of the cavity!

Thanks LowerAtmosphere.

meberbs, I hate to have to say it, but I find your revision of my diagram to be an astounding violation of energy conservation.

Folks, I don't know how the discussion got so strained.  Hopefully it will eventually be clear that all I am doing is creating a particle analogue of the following photon rocket variant.

Place a candle inside and near one end of a closed cylinder.  Make the near end maximally light-reflective, and the lateral surface and far end maximally light-absorbent.  The difference in absorbency of the surfaces causes an imbalance in pressure, resulting in more push on the near end than the other surfaces.  Furthermore, with the candle nearer to one end than the other, the wave sections travelling directly to either end will differ in amplitude, with those hitting the near end having greater amplitude than those hitting the far end (I'm not sure that this part helps overall, given that the lateral surface also interacts with the waves; but I think it probably does, because the two ends have the most direct influence on direction of travel of all the surfaces).

http://www.webassign.net/question_assets/buelemphys1/chapter22/section22dash3.pdf

...we have: "For electromagnetic waves, the pressure is twice as large when the wave reflects from a perfect reflector than when it is 100% absorbed."

From there, you should be able to see that we can do it with mechanical waves, sound waves for example, too.  Use an omnidirectional speaker, or two equal, non-omnidirectional speakers placed back-to-back near one end of the cylinder, with one facing the near end, and one facing the far end (you would use two non-omni-directional speakers as such because you need an omnidirectional source, or a simulation of one, so that the source itself isn't pushing more one way than the other).  Then just make the near end maximally sound-reflective, and the lateral surface and far end maximally sound-absorbent.  A nifty factor of these rockets is that the temperature of the more absorbent surfaces will rise more, but we can then harness that temperature increase to do work (heat the spacecraft for example).

And then we're back to the still simpler particle analogue I've made in my billiard balls example, in which all I'm effectively doing is making objects to the left of the omnidirectional (in this case, more bidirectional than omnidirectional) source more reflective overall (simply a hard wall) than objects to the right of the source (a hard wall, but intervened by free-floating billiard balls), and, conversely, making objects to the right of the source more absorbent overall than objects to the left of the source.

Beyond making this particle analogue, all I'm doing is pointing out that these designs point out limitations in the phrase, "and opposite," as the propellant will indeed be travelling with the ship (whether it be waves converted more or less into thermal motion, or particles diverted to lateral motion).  Difference in absorbency is the key.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/09/2016 05:16 pm
I find it hard to believe that our ticket to the stars is as easy as creating a heat gradient on an enclosed metal cavity.  This could've been done easily over 100 years ago.   Surely such a discovery would've been stumbled upon accidentally by now.

But please prove me wrong.   :)  ;)

Believe me, I agree. I find it hard to believe too! That is why I have to do the experiment and prove to myself, one way or the other.

That being said, the Unruh effect says that in an accelerated reference frame, the vacuum looks like a thermal field. As such, the vacuum is warmer in front and colder behind the accelerating detector. Also, a gravitational field is a gradient in the potential energy, and energy is temperature with a proportionality "constant". Therefore, a thermal gradient "is" equivalent to an accelerated reference frame. It makes sense to me. It also makes sense that a Peltier cooler can provide a propulsion effect all on it's own, because it has a thermal gradient.

I say, it could've been stumbled upon and probably was, but the effect is so small it was negligible for most "practical" purposes. :) We shall see soon enough. The components are on their way to me now.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/09/2016 05:28 pm
...
Your second question would be closer. As I was questioning in my post above. There would be no argument if this were a sealed can full of pressurized air, and I punched a hole in one end to let the pressure out. Obviously, the can would move the other way. But if I have a pressurized can and I simultaneously heat the air at one end and cool it at the other end, so that it is the same gradient in pressure, it should move in the same way. [/b]

There is a magnetic pressure exerted on the frustum, and the frustum is exerting pressure on the field. The forces are balanced. Where there are voltage drops, there are "leaks" that let the pressure out. The differential pressure will cause a flow and the frustum will go the other way.

Also, in my current model, it's not just the spacial gradient. It is the 4-gradient. So the time derivative plays a big part in the thrust too. If I show that the thrust can happen with just hot air, then this will make testing EM drives very difficult since it would show they MUST be tested in a hard vacuum. On the other hand however, if I can make propulsion with hot/cold air, who needs MW's? :)

Very good questions.  Thank you!

I have plans to do this experiment. I bought some Peltier Coolers and some USB Pressure/Temperature sensors. Now all I need is can to connect them to.

I look forward to watch your presentation given at the Estes Park workshop once it is available on the SSI website. I am sure many readers here do want to understand your model better; but very few people has the training to grasp all of the PV maths.

I think also updating the wiki article about your model (http://emdrive.wiki/Todd_Desiato_(@WarpTech)%27s_Evanescent_Wave_Theory) would be good thing, in particular explaining:
• What is exactly "dispersion" (group velocity dispersion?) and what is its relation with the creation of an artificial accelerated reference frame (i.e. which is a gravitational field generator!) and the notsosureofit Hypothesis,
• The difference between dissipation and attenuation in a cavity (I imagine attenuation of the EM energy as a consequence of power dissipation?),
• And why just extracting heat out of one particular end of a resonant cavity (or even, as recently suggested, out of a cylindrical metal can filled with just gas and no EM waves!), apparently a trivial thermodynamic process that does not seem at all related to advanced concepts like propellantless interstellar travel or flying cars, could generate such things as "an accelerated reference frame" and a "gravitoelectric field".
Heating one end and cooling another end of closed cavity with trapped gas just shifts center of mass of gas to cold side and because of COM  cavity ''apparently'' moves to another side, but it's just a  closed system, center of mass stays in same spot, there's no thrust.

Same with heating the empty cavity, cavity just expands to one side but its center of mass doesn't move, there's no thrust.

Or I misunderstood something.

I think you are missing the time derivative. My equation shows that what will cause thrust is the 4-gradient of the difference between Power in and Power lost. In the case of heating one end and cooling the other end "rapidly", the power lost is negative and we get a thrust proportional to 2Pin. It will eventually equalize, but not before it gets a push from the heat flow.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/09/2016 05:42 pm
Excellent posts Keith Ness! This is precisely what I tried to clumsily suggest earlier in this thread. If you try to forget all the surface currents, impedance and atmospherics for a second and focus on radiation pressure: it is not equal along the length of the cavity!

Thanks LowerAtmosphere.

meberbs, I hate to have to say it, but I find your revision of my diagram to be an astounding violation of energy conservation.

Folks, I don't know how the discussion got so strained.  Hopefully it will eventually be clear that all I am doing is creating a particle analogue of the following photon rocket variant.
...

@meberbs is correct. To conserve energy, the energy of the 1st ball is;

E = p2/2*m

When it collides with the 2 balls of equal mass, each ball will have 1/2 the energy,

E/2 = (p/sqrt(2))2/2*m

So the momentum is p/sqrt(2), and the two balls are still carrying the same total momentum p in the x direction.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Donosauro on 12/09/2016 05:43 pm

Place a candle inside and near one end of a closed cylinder.  Make the near end maximally light-reflective, and the lateral surface and far end maximally light-absorbent.  The difference in absorbency of the surfaces causes an imbalance in pressure, resulting in more push on the near end than the other surfaces.

Imagine a photon source in the middle of the cylinder. Have it send one photon leftward toward the perfectly absorbing end and another photon rightward toward the perfectly reflective end. All is in balance. The left-going photon will be absorbed, for one unit of leftward momentum. The right-going photon, on the other hand, will bounce off the perfectly reflective end, resulting in two units of rightward momentum ... and turning the right-going photon into a left-going photon which will travel to the left end and be absorbed, contributing another unit of leftward momentum, for an end-of-experiment total of two units of leftward momentum and two units of rightward momentum. All is still in balance.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: gargoyle99 on 12/09/2016 06:36 pm
meberbs, I hate to have to say it, but I find your revision of my diagram to be an astounding violation of energy conservation.

Do you? Since your diagram only uses classical Newtonian mechanics, we can easily calculate the kinetic energy and momentum of the system after each collision using Newton's laws with some vector math. Oh, you haven't done the math yourself yet, probably because you are extremely busy? NO PROBLEM! We can do it together.

All balls have mass m, initial velocity is v0, after first collision, 2 balls have velocity v1 and after second collision, v2. What are the kinetic energies and total momenta after each collision?

KE0 =  1/2 m v0^2
p0 = m v0 (this is a vector, going entirely to the right)

After first collision, two balls of mass m have velocity v1 going at an angle. The first ball stops.

KE1 = 1/2 m v1^2 + 1/2 m v1^2 (this uses magnitudes of the vector v1 and is a scalar)
p1 = m v1A + m v1B (these are vectors, so we can't just add them together as scalars)

What is magnitude of v1?
By COE, KE0 = KE1. Therefore v1 = sqrt(2) v0 / 2 (in magnitude)

To get direction, we use COM. The horizontal component must equal the initial momentum m v0 and the vertical components must cancel. Therefore, the angle from horizontal is 45 deg.

In units of v0, then

KE1 = 1/2 m v1^2 + 1/2 m v1^2  = 1/2 m ( sqrt(2) v0 )^2 + 1/2 m ( sqrt(2) v0 )^2 = 1/2 m v0^2

Thank God, energy is still conserved. Newton can rest easily in his grave. And momentum?

p1 = m v1A + m v1B
Break it down into x and y planes
p1x = m v1A cos 45 + m v1B cos 45 = m (sqrt(2) v0 / 2) cos 45 + m (sqrt(2) v0 / 2) cos 45 = m v0
p1y = m v1A cos 45 - m v1B cos 45 = 0

Momentum is conserved too. Newton has dodged another bullet, which would be helpful if he hadn't been dead for hundreds of years already.

How about the next collision? It's exactly the same math, done again. Let's work it out anyway. Now there are 4 balls of mass m, with velocity v2.

KE1 = 1/2 m v2^2 + 1/2 m v2^2 + 1/2 m v2^2 + 1/2 m v2^2 (this uses magnitudes of the vector v2 and is a scalar)
p1 = m v2C + m v2D + m v2E + m v2F (these are vectors, so we can't just add them together as scalars)

By COE, KE0 = KE2. By symmetry, all the balls have the save v2. Therefore v2 = v0 / 2 (in magnitude). That's an easy number.

KE2 = 1/2 m v2^2 + 1/2 m v2^2 + 1/2 m v2^2 + 1/2 m v2^2 = 1/8 m v0^2 + 1/8 m v0^2 + 1/8 m v0^2 + 1/8 m v0^2
KE2 = 1/2 m v0^2

It still works. Kinetic energy is still conserved.

Now for momentum. Two balls are heading in the original direction, and two are heading in opposite directions

p2 = m v2C + m v2D + m v2E + m v2F
p2x = m v2D + m v2E = m (1/2 v0) + m (1/2 v0) = m v0
p2y = m v2D + m v2E = m (1/2 v0) - m (1/2 v0) = 0

Momentum is still conserved too.

While we're on the subject of momentum and energy another response.

Quote
It's kind of like if a tow-truck driver were to drive up to assist your stalled vehicle, and say, "I can either push your car with my hand for a few minutes, or compact all that energy into one rifle shot at your car.  It’s the same amount of energy, so it shouldn’t matter which one I use on your car, right?"  Wrong, of course.  The rifle shot will convert more of its energy into lateral momentum expressed as tearing a hole through your car, and won’t do much to move your car in one direction.  The long hand push will move your car in one direction though, because it converts less into lateral momentum of your car.

The same amount of energy? Time for some more math!

Energy and momentum have very precise (and very different) mathematical definitions in classical physics (which applies to this example). I don't think you appreciate the distinction. While engines and machines can harness energy in systems where elements gain momentum relative to each other, it is vague to say things like "convert energy into momentum." That generally doesn't make sense in physics without more context. The kinetic energy and the momentum are both inherent in the velocity of the system element. They are not interchangeable or convertable. (That also applies to the EmDrive.) Instead, just do the math.

A rifle bullet in flight might have a mass of 10g and a velocity of 1000 m/s, which is a KE of 5000J and a momentum of 10kg m/s.

A hand push could be modeled as say a kettle bell or a medicine ball tossed at the car. Say a 10 kg mass moving at 1 m/s. KE is 5J and momentum is 10 kg m/s.

So, the rifle bullet has 1000 times as much energy, but the same momentum as the kettle bell. If the collisions are inelastic (no bouncing off and the bullet doesn't continue all the way through the vehicle), they will both transfer exactly the same amount of momentum to the car. The rifle bullet will transfer 1000 times as much energy, dissipated in structural damage, sound, vibrations, heat, etc., as well as kinetic energy of the car. Both collisions transfer 100% of the momentum to the car, since they are inelastic collisions (and conservation of momentum), and 100% of their energy to the system (because of conservation of energy). In general, pushing by hand on a stalled car will transfer much more momentum to the system than shooting it full of bullets and take far less energy. (The math is different if the car is already traveling at 1000 m/s and the pusher is not.) So what was your point again?

Ideally, this forum shouldn't have to be a place to learn about basic mechanics, but I can see how it could come across as rude to say, "You seem to be confused. Why don't you learn some physics and then come back and we'll talk more."

Nonetheless, here is an opportunity to learn some basic Newtonian physics and help demonstrate why physicists are cautious about claims for propellantless drives. Most physicists interested in the EmDrive are interested to know WHAT the drive pushes against, rather than blindly accepting that it doesn't push on anything. The quantum vacuum, gravitational waves, or perhaps it is experimental error? I have no personal insight, but I'm interested to know. A knowledge of basic mechanics will help find the answer, not get in the way.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: DusanC on 12/09/2016 07:27 pm
...
Your second question would be closer. As I was questioning in my post above. There would be no argument if this were a sealed can full of pressurized air, and I punched a hole in one end to let the pressure out. Obviously, the can would move the other way. But if I have a pressurized can and I simultaneously heat the air at one end and cool it at the other end, so that it is the same gradient in pressure, it should move in the same way. [/b]

There is a magnetic pressure exerted on the frustum, and the frustum is exerting pressure on the field. The forces are balanced. Where there are voltage drops, there are "leaks" that let the pressure out. The differential pressure will cause a flow and the frustum will go the other way.

Also, in my current model, it's not just the spacial gradient. It is the 4-gradient. So the time derivative plays a big part in the thrust too. If I show that the thrust can happen with just hot air, then this will make testing EM drives very difficult since it would show they MUST be tested in a hard vacuum. On the other hand however, if I can make propulsion with hot/cold air, who needs MW's? :)

Very good questions.  Thank you!

I have plans to do this experiment. I bought some Peltier Coolers and some USB Pressure/Temperature sensors. Now all I need is can to connect them to.

I look forward to watch your presentation given at the Estes Park workshop once it is available on the SSI website. I am sure many readers here do want to understand your model better; but very few people has the training to grasp all of the PV maths.

I think also updating the wiki article about your model (http://emdrive.wiki/Todd_Desiato_(@WarpTech)%27s_Evanescent_Wave_Theory) would be good thing, in particular explaining:
• What is exactly "dispersion" (group velocity dispersion?) and what is its relation with the creation of an artificial accelerated reference frame (i.e. which is a gravitational field generator!) and the notsosureofit Hypothesis,
• The difference between dissipation and attenuation in a cavity (I imagine attenuation of the EM energy as a consequence of power dissipation?),
• And why just extracting heat out of one particular end of a resonant cavity (or even, as recently suggested, out of a cylindrical metal can filled with just gas and no EM waves!), apparently a trivial thermodynamic process that does not seem at all related to advanced concepts like propellantless interstellar travel or flying cars, could generate such things as "an accelerated reference frame" and a "gravitoelectric field".
Heating one end and cooling another end of closed cavity with trapped gas just shifts center of mass of gas to cold side and because of COM  cavity ''apparently'' moves to another side, but it's just a  closed system, center of mass stays in same spot, there's no thrust.

Same with heating the empty cavity, cavity just expands to one side but its center of mass doesn't move, there's no thrust.

Or I misunderstood something.

I think you are missing the time derivative. My equation shows that what will cause thrust is the 4-gradient of the difference between Power in and Power lost. In the case of heating one end and cooling the other end "rapidly", the power lost is negative and we get a thrust proportional to 2Pin. It will eventually equalize, but not before it gets a push from the heat flow.
That equalizing part is bringing the system back to the beginning:
When cavity with heated gas equalizes in temperature everything center of mass of cavity and center of mass of gas will come back to the same spot as in T0, center of mass of the system will not move, only change will be higher temperature of the system because of the energy input, no thrust.

When empty cavity equalizes in temperature its parts that were heated/cooled will< just come back where they started from, center of mass will not move, just temperature rise, no thrust.

For any type of reaction less propulsion you have to have movement of the center of mass.

OFC I am intentionally forgetting about energy losses through radiation (we're talking about space propulsion so no convection) ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/09/2016 07:47 pm

I think you are missing the time derivative. My equation shows that what will cause thrust is the 4-gradient of the difference between Power in and Power lost. In the case of heating one end and cooling the other end "rapidly", the power lost is negative and we get a thrust proportional to 2Pin. It will eventually equalize, but not before it gets a push from the heat flow.
That equalizing part is bringing the system back to the beginning:
When cavity with heated gas equalizes in temperature everything center of mass of cavity and center of mass of gas will come back to the same spot as in T0, center of mass of the system will not move, only change will be higher temperature of the system because of the energy input, no thrust.

When empty cavity equalizes in temperature its parts that were heated/cooled will< just come back where they started from, center of mass will not move, just temperature rise, no thrust.

For any type of reaction less propulsion you have to have movement of the center of mass.

OFC I am intentionally forgetting about energy losses through radiation (we're talking about space propulsion so no convection) ;)

Possibly, but I don't see how it brings it back. When the internal pressure has a gradient, the container will accelerate until the pressure is equalized, then it will stop accelerating. There is never a condition where the gradient reverses and the container accelerates back the other way. So I do not think it will bring it back to the same location. The CG will shift because there is a source AND a sink, AND a gradient that does not reverse.

Go back and look at my derivation. Show me where it's wrong please.

https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0

Thank you.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: DusanC on 12/09/2016 08:11 pm

I think you are missing the time derivative. My equation shows that what will cause thrust is the 4-gradient of the difference between Power in and Power lost. In the case of heating one end and cooling the other end "rapidly", the power lost is negative and we get a thrust proportional to 2Pin. It will eventually equalize, but not before it gets a push from the heat flow.
That equalizing part is bringing the system back to the beginning:
When cavity with heated gas equalizes in temperature everything center of mass of cavity and center of mass of gas will come back to the same spot as in T0, center of mass of the system will not move, only change will be higher temperature of the system because of the energy input, no thrust.

When empty cavity equalizes in temperature its parts that were heated/cooled will just come back where they started from, center of mass will not move, just temperature rise, no thrust.

For any type of reaction less propulsion you have to have movement of the center of mass.

OFC I am intentionally forgetting about energy losses through radiation (we're talking about space propulsion so no convection) ;)

Possibly, but I don't see how it brings it back. When the internal pressure has a gradient, the container will accelerate until the pressure is equalized, then it will stop accelerating. There is never a condition where the gradient reverses and the container accelerates back the other way. So I do not think it will bring it back to the same location. The CG will shift because there is a source AND a sink, AND a gradient that does not reverse.

Go back and look at my derivation. Show me where it's wrong please.

https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0

Thank you.
When there's no Ein there's  -Eloss left and that brings the system over time back to equilibrium.

I pretty blatantly claimed that for t=0÷∞ J=∫Tv·dt=0  but I can't get a grip on your notation to mathematically prove it....... yet ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/09/2016 08:32 pm

I think you are missing the time derivative. My equation shows that what will cause thrust is the 4-gradient of the difference between Power in and Power lost. In the case of heating one end and cooling the other end "rapidly", the power lost is negative and we get a thrust proportional to 2Pin. It will eventually equalize, but not before it gets a push from the heat flow.
That equalizing part is bringing the system back to the beginning:
When cavity with heated gas equalizes in temperature everything center of mass of cavity and center of mass of gas will come back to the same spot as in T0, center of mass of the system will not move, only change will be higher temperature of the system because of the energy input, no thrust.

When empty cavity equalizes in temperature its parts that were heated/cooled will just come back where they started from, center of mass will not move, just temperature rise, no thrust.

For any type of reaction less propulsion you have to have movement of the center of mass.

OFC I am intentionally forgetting about energy losses through radiation (we're talking about space propulsion so no convection) ;)

Possibly, but I don't see how it brings it back. When the internal pressure has a gradient, the container will accelerate until the pressure is equalized, then it will stop accelerating. There is never a condition where the gradient reverses and the container accelerates back the other way. So I do not think it will bring it back to the same location. The CG will shift because there is a source AND a sink, AND a gradient that does not reverse.

Go back and look at my derivation. Show me where it's wrong please.

https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0

Thank you.
When there's no Ein there's  -Eloss left and that brings the system over time back to equilibrium.

I pretty blatantly claimed that for t=0÷∞ J=∫Tv·dt=0  but I can't get a grip on your notation to mathematically prove it....... yet ;)

Back to equilibrium "yes", back to where it started "no".

Geez, it seems like once someone learns to do tensors they forget how to work with vectors and scalars. My notation is correct, I'm just using the speed of light as c/K not c, but it holds true even if K~1, so you can ignore it. Other than that, it's a typical 4-gradient derivative.

In the case where I have a hot plate on one end and a cold plate on the other end. When I turn the power off, the hot side will get cooler and the cool side will get warmer, until they equalize but the heat is still flowing in the same direction. They will never create an equal and opposite gradient to bring the system back to the starting point. It will just stop accelerating. The CM should move. I don't see how it couldn't.

I really think the way conservation of momentum is taught is incorrect when there is damping and dissipation as part of the system. My derivation shows this is true. People are not familiar with this and the integral you quoted above does not include damping losses from the chaotic system of air flow and turbulence. I believe that is what will happen, so we shall see.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: M.LeBel on 12/09/2016 08:49 pm
Glenn was one of those early heroes and daredevils. Imagine going into space sitting on tons of explosives and return, as expected, as a burning meteor!... Oh, wait! We are still doing exactly that!

That is zooming 50 some years, passing year 2000, to now. Dont want to point finger, but.. There is a thin line between the champion spreading knowledge of physics and the guardian of our ignorance. There are lots of assumptions left unattended back there, that were “proven” by experiments...  Nothing against policing the small stuff, like vectors and defective maths. But the fundamental, remains unknown and, slapping loudly and dogmatically the book on the table will not go for progress. Consider new ideas, perspective, new angles ... Working with you, for you; all I’m asking for is an open mind ... This mind of ours always was and always will be our window to the stars.

“Food for thought...”
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: as58 on 12/09/2016 09:56 pm
Back to equilibrium "yes", back to where it started "no".

Geez, it seems like once someone learns to do tensors they forget how to work with vectors and scalars. My notation is correct, I'm just using the speed of light as c/K not c, but it holds true even if K~1, so you can ignore it. Other than that, it's a typical 4-gradient derivative.

In the case where I have a hot plate on one end and a cold plate on the other end. When I turn the power off, the hot side will get cooler and the cool side will get warmer, until they equalize but the heat is still flowing in the same direction. They will never create an equal and opposite gradient to bring the system back to the starting point. It will just stop accelerating. The CM should move. I don't see how it couldn't.

I really think the way conservation of momentum is taught is incorrect when there is damping and dissipation as part of the system. My derivation shows this is true. People are not familiar with this and the integral you quoted above does not include damping losses from the chaotic system of air flow and turbulence. Per Dr. Rodal's paper, if there is a chaotic system, it can have unbalanced forces. I believe that is what will happen, so we shall see.

Sorry, your derivation makes no sense to me. Things appear out of thin air, for example 'counter mass that the frustum pushes against'. Mathematics doesn't do anything to justify these things. (Though there are also some manipulations of equations that I don't quite understand and some formulae that to me seem just wrong.)

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/09/2016 10:11 pm
Back to equilibrium "yes", back to where it started "no".

Geez, it seems like once someone learns to do tensors they forget how to work with vectors and scalars. My notation is correct, I'm just using the speed of light as c/K not c, but it holds true even if K~1, so you can ignore it. Other than that, it's a typical 4-gradient derivative.

In the case where I have a hot plate on one end and a cold plate on the other end. When I turn the power off, the hot side will get cooler and the cool side will get warmer, until they equalize but the heat is still flowing in the same direction. They will never create an equal and opposite gradient to bring the system back to the starting point. It will just stop accelerating. The CM should move. I don't see how it couldn't.

I really think the way conservation of momentum is taught is incorrect when there is damping and dissipation as part of the system. My derivation shows this is true. People are not familiar with this and the integral you quoted above does not include damping losses from the chaotic system of air flow and turbulence. Per Dr. Rodal's paper, if there is a chaotic system, it can have unbalanced forces. I believe that is what will happen, so we shall see.

Sorry, your derivation makes no sense to me. Things appear out of thin air, for example 'counter mass that the frustum pushes against'. Mathematics doesn't do anything to justify these things. (Though there are also some manipulations of equations that I don't quite understand and some formulae that to me seem just wrong.)

The "counter mass" term is identical to the one used by @Notsosureofit, in his Theory. Do you disagree with his derivation as well? It is the total energy stored in the cavity, divided by c2. Does that require justification? It is simply, E = mc2.

Which formulae "seem just wrong"? gv is an acceleration vector. It is just the 4-gradient of the damping factor (scalar), and Tv is also a vector for force. It is just the mass stored inside, times the acceleration vector gv. How is this in any way hard to follow for someone who knows what a 4-gradient is?

If you want to understand this I'm happy to help, but please be specific and write down the equations to  determine what it is you do not follow. Thank you.

Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: as58 on 12/09/2016 10:33 pm
The "counter mass" term is identical to the one used by @Notsosureofit, in his Theory. Do you disagree with his derivation as well? It is the total energy stored in the cavity, divided by c2. Does that require justification? It is simply, E = mc2.

Which formulae "seem just wrong"? gv is an acceleration vector. It is just the 4-gradient of the damping factor (scalar), and Tv is also a vector for force. It is just the mass stored inside, times the acceleration vector gv. How is this in any way hard to follow for someone who knows what a 4-gradient is?

If you want to understand this I'm happy to help, but please be specific and write down the equations to  determine what it is you do not follow. Thank you.

I'm not familiar with Notsureofit's theory, in fact this is the first time I've heard about it.

I don't see how those wave equations for 'magnetic flux' and 'gravito-magnetic flux' can hold in general. Maybe there are some unstated assumptions.

What is N in the equation for damped power and more generally, where does that equation come from?

I (think I) know what four-gradient is, though maybe we are using different notations. Can you write out in component form what (\nabla, K/c \partial/\partial t) is? (And why is that K there? There's also at least one place where function P_in seems to jump inside differential operator with no other justification than \cong.)
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: WarpTech on 12/09/2016 11:04 pm
The "counter mass" term is identical to the one used by @Notsosureofit, in his Theory. Do you disagree with his derivation as well? It is the total energy stored in the cavity, divided by c2. Does that require justification? It is simply, E = mc2.

Which formulae "seem just wrong"? gv is an acceleration vector. It is just the 4-gradient of the damping factor (scalar), and Tv is also a vector for force. It is just the mass stored inside, times the acceleration vector gv. How is this in any way hard to follow for someone who knows what a 4-gradient is?

If you want to understand this I'm happy to help, but please be specific and write down the equations to  determine what it is you do not follow. Thank you.

I'm not familiar with Notsureofit's theory, in fact this is the first time I've heard about it.

I don't see how those wave equations for 'magnetic flux' and 'gravito-magnetic flux' can hold in general. Maybe there are some unstated assumptions.

What is N in the equation for damped power and more generally, where does that equation come from?

I (think I) know what four-gradient is, though maybe we are using different notations. Can you write out in component form what (\nabla, K/c \partial/\partial t) is? (And why is that K there? There's also at least one place where function P_in seems to jump inside differential operator with no other justification than \cong.)

My theory is very similar to @Notsosureofit's theory. I think the difference is that I am trying a covariant approach, by starting with the Lorenz gauge condition.

The only assumption is that the gravito-magnetic field can be modeled in an analogous way to a magnetic field, in a weak-field, linear approximation of GR.

N is the number of photons with energy hbar*w. The mean-square power per photon in QED is;

<PM2> = ((hbar/2)*w2)2

The equation in my notes comes from gravitational red shift. As light leaves a gravity well, it is red shifted. This is observed as a loss of power. The lost power is represented by (1 - Zeta2). Where, in the case of a gravity well, c2*Zeta2 would be is 2GM/r. It is the gravitational potential energy per unit of mass, but Zeta also represents a loss of power and is therefore a Damping factor. In the case of a frustum, the damping factor is frequency dependent, whereas for gravity it is not because the bandwidth of the gravitational field is much wider than the EM field in the frustum. That is the ONLY difference.

\nabla = (d/dx, d/dy, d/dz), is the gradient operator.

c/K is the speed of light in a variable refractive index, which is the solution to the equations of motion of the Lagrangian density equation I present at the top of the page. Using this as,

K/c * d/dt is the "covariant" time derivative operator in a variable refractive index. Since Zeta is a very small number, K ~1 and you can ignore it in the derivative operator and just use 1/c * d/dt, which is what I did in the last approximate equation.

Yes, I did pull in the term Pin from in front of the derivative to be part of the derivative. The justification is that the "counter mass" term is not a constant, it is a variable and as such, it should be part of the derivative. It was only out front because it was not included as the mass term in Zeta, as part of K in the beginning of the derivation. Good point however, in that regard the equations could be better formulated, but I do not believe what I did is wrong. It's just a shortcut. It can be formulated where this mass is part of Zeta to begin with and it (should) give the same answer.
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: mikegem on 12/09/2016 11:43 pm

If the Cubesat works, are people going to claim it just interacts with Earth's magnetic field? Has anyone done the calculations to show that won't explain the thrust as just a Lorentz force?
[/quote]

This is a potential source of artifactual results that needs to be accounted for. Attitude control of satellites using electromagnetic torquers acting on the earth's magnetic field have been around quite awhile.

https://en.wikipedia.org/wiki/Magnetorquer
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: meberbs on 12/10/2016 05:53 am
Possibly, but I don't see how it brings it back. When the internal pressure has a gradient, the container will accelerate until the pressure is equalized, then it will stop accelerating. There is never a condition where the gradient reverses and the container accelerates back the other way. So I do not think it will bring it back to the same location. The CG will shift because there is a source AND a sink, AND a gradient that does not reverse.

Go back and look at my derivation. Show me where it's wrong please.

https://www.dropbox.com/s/qlci6od1ed8lxsg/Damping%20and%20Fluctuations-v8.pdf?dl=0

Thank you.
There are a few issues with your theory that I can see.

The first issue I have is with your starting point. I need to do some more research on this myself, so this is something that I do not expect you to prove for me, since the answer might be out there, and I just haven't found it yet. I am only mentioning this for completeness. From what I can tell so far, the polarizable vacuum theory has known differences with general relativity. In some versions of it, supposedly it did not predict some observed general relativistic effects such as frame dragging. Also supposedly, there is a version that corrects some of these issues. I need to do some research to get rid of those "supposedly" in the previous sentences, but if your starting point does not predict results that general relativity can, then you have an issue.

On to issues that aren't related to me needing to do more research: On the line for Lorentz gauge EM, everything after the first equation doesn't have any discernible meaning. You have defined new terms without first having defined any physical meaning associated with them. You seem to have looked at their units and assigned meaning based on that, but that doesn't work. Especially when you are working with complex units like you are, just because something has units of angular momentum does not mean that it in any way represents an angular momentum. For example, you can have a device that stores a certain energy per unit length, but just because this has units of force does not mean it is a force.

The lack of proper definition of what Φ and Ω are really prevents anything past that point from being meaningful, but it seems like you make the same "this has units of X, so it must be X" mistake more than once. The lack of proper definitions seems to be why you haven't been able to give a single numerical prediction despite having a theory. You can't plug in numbers if you don't know what the variables represent.

In part of your responses you said:
The CM should move. I don't see how it couldn't.
I don't see how it could move. The final issue I have (for now) is that even if everything else is right, your interpretation of the final result can easily be off, and this conversation you were having seems to be related to the fact that there can be a temporary apparent force without the center of mass moving. This is easiest to work through by example. No one has worked through yet what was wrong with the example Keith Ness posted about a device with a reflecting surface on one end and an absorbing surface on the other. (they were too busy pointing out his other mistakes) I think working through this correctly might help you understand why your claims of center of mass moving don't make sense to the rest of us.

For simplicity, lets start with a symmetric cavity with 2 balls in the middle, with one end of the cavity rubber, and the other coated in instant adhesive. If you launch the balls with constant velocity in opposite directions, the cavity won't move until the balls hit the walls. When they hit, the one ball will stick to the wall, and the other will be reflected. The cavity and the still moving ball will be moving in opposite directions with the same magnitude of momentum. (While the reflected ball should have given the cavity twice the original momentum that the ball had, half of this was cancelled out by the other ball the stuck to the wall.) When the remaining ball hits the back wall, the momentum fully cancels and the cavity stops moving. While the cavity has stopped moving, its center of mass including the balls will be exactly where it started. (I can include math proving this in a future post, this one is too long as is) To repeat the experiment, the balls would have to be moved back to where they started, which would move the rest of the cavity back to where it started as well (assuming a mechanism internal to the cavity).

While I did this for balls, it also applies to light, you just have to account for special relativity properly, which replaces the concept of center of mass with center of energy to account for massless particles carrying momentum proportional to their energy. In this case, the mass-energy of the wall that absorbs the photons will have increased slightly to match the slight forward motion of the cavity. Since the center of energy doesn't move, no amount of repeating the process will get you useful motion.

Also, I don't think you will be able to get meaningful data from the experiment you are planning, at least not in the way you are thinking. The emDrive experiments so far have done a good job demonstrating that thermal effects such as thermal expansion will produce an apparent force, which is not actually useful for propulsion. Since standard physics predicts motion to keep the center of mass in place when asymmetric thermal expansion (and other thermal effects) occurs, I am not sure how you expect to show anything "new."
Title: Re: EM Drive Developments - related to space flight applications - Thread 9
Post by: Arnold_Pizzey on 12/10/2016 06:48 am
Dear all,

I’m a professional scientist but not a professional physicist so I am not in a position to comment on the physics of what may (or may not) be going on inside the drive frustrum but I would like to ask a a question or two of my physicist colleagues whose knowledge far exceeds my own.

I have the utmost respect for the professional and non-professional contributors to this list and I apologise if my questions/speculations are naive, that said, here we go...

For the purpose of this discussion let’s assume for a moment that the EMDrive is proven to generate thrust (and I have yet to see any robust,  peer-reviewed report that unequivocally  demonstrates reactionless thrust)

It has been speculated, the EMDrive is acting on dark matter, now I understand that WIMP dark matter has by definition, mass therefore, I suggest the following experiments may yield some interesting data:

Experiment
ia)
Mount an EMDrive cavity on a rotating frame with the direction of drive thrust inclined out of the plain of rotation by say 45’ and measure thr