Author Topic: EM Drive Developments Thread 1  (Read 764041 times)

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #940 on: 09/23/2014 03:14 PM »
Still just poking around.  This ref from another list (Polywell ?)
http://www.ccsenet.org/journal/index.php/apr/article/view/10455

Suggests to me that the dielectric may not be there because of "flux capacitors", but rather to make that surface look as close to a superconducive surface as possible (perfect reflectivity).  This is done all the time by adding a dielectric layer onto an existing reflective surface.  (in extreme cases we've made neutron mirrors w/ 1300 layers, but I digress)  You need all 3 complex indices at the wavelength of interest to get "perfect" reflectivity.  Typical telescope reflector is Al/SiO2,  etc etc

No way of telling unless someone tells what the model is.
Interesting:  <<During the discharges, the devices were strongly pushed in the direction opposed to the electron flow. The layered devices were apparently propelled by their emission of a momentum-bearing flux of an unknown nature.>>

But this reference is  for <<Devices at 77 K>>.  While the NASA and Woodward experiments are at room temperature  298 K, ~220 K degrees above that reference.

It doesn't make sense to me that the PTFE ("Teflon") in the NASA experiments would be in a superconducting state. All the experimental data available shows that PTFE is not superconducting at room temperature

But, as difficult it is to digest invoking superconductivity at room temperature, this is at least much more palatable than invoking Woodward's assumptions (equating fluctuating input electric power of a few watts with fluctuations in rest energy -without nuclear reactions-) or White's assumption (virtual particles from the quantum vacuum made real in a few-watts mundane microwave instead of a petawatt class picosecond laser)

Very strange (but understandable, given the unsatisfactory nature of Woodward and White's explanations) to witness the desperate attempts that people in other forums (polywell in this case) must go through to try to justify the microNewton forces measured at NASA using an inverted torsional pendulum known to exhibit parasitic modes and therefore needing magnetic damping....

« Last Edit: 09/23/2014 03:39 PM by Rodal »

Offline aero

  • Senior Member
  • *****
  • Posts: 2740
  • 92129
  • Liked: 704
  • Likes Given: 237
Re: EM Drive Developments
« Reply #941 on: 09/23/2014 03:27 PM »
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.

Don't forget (what to me looks like) the (most likely) explanation:

the measured thrust forces are due to spurious testing effects and these tested EM drives will not generate any (translational motion) thrust in space.

Speaking to that- What do you suppose the chances are that this is just a very obscure implementation of a "Dean Drive?"

Obviously the reaction is not due to bouncing on the ground. They used liquid metal contacts to avoid forces transmitted via the conductors. What about forces transmitted via the RF wave guide or was that question addressed already? I note that the wave guide is common to all of the devices but the attachment coordinates do seem to be different with different devices.
« Last Edit: 09/23/2014 03:30 PM by aero »
Retired, working interesting problems

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #942 on: 09/23/2014 03:35 PM »
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.

Don't forget (what to me looks like) the (most likely) explanation:

the measured thrust forces are due to spurious testing effects and these tested EM drives will not generate any (translational motion) thrust in space.

Speaking to that- What do you suppose the chances are that this is just a very obscure implementation of a "Dean Drive?"

Obviously the reaction is not due to bouncing on the ground. They used liquid metal contacts to avoid forces transmitted via the conductors. What about forces transmitted via the RF wave guide or was that question addressed already?

Yes, NASA in their report did not perform a (parasitic and coupling motion) analysis of their experimental set-up, nor an analysis of interaction between the diverse electric power components and the magnetic damping.  As I have posted previously, the scientific community is going to ignore these tests until at least:

1) The tests are independently verified in a hanging pendulum of the type used to perform gravitational (inverse square law) tests as the one suggested to be performed at John Hopkins with their Cavendish type pendulum. 

2) If they insist in performing further tests at JPL with an inverted pendulum, JPL should modify their inverted pendulum (as already done at the Aeronautics and Astronautics department at MIT by Prof. Martinez-Sanchez) to ensure that the EM drive remains horizontal at all times (to eliminate the parasitic swinging modes of the pendulum rotating the supporting platform).

3) To have all electric power components of the drive together-on-one-side in the supported platform of the measuring equipment.
« Last Edit: 09/23/2014 03:48 PM by Rodal »

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #943 on: 09/23/2014 04:09 PM »
The practical problem with independent verification (at John Hopkins or other universities) is that the scientific community has dismissed the NASA propellant-less tests (either vocally as done by John Baez and Sean Carroll, or quietly as done by most other academics in Aerospace Engineering -and quietly dismissing these results at other NASA propulsion centers-).  The academic community -particularly nowadays- knows that it is not considered to be an advancement to their career to produce independent experimental data that nullifies esoteric claims (claims that run contrary to conservation of momentum and known physics) that the rest of the community will meet with "I could have told you that".  So academics at MIT, Stanford, CalTech, etc., are negatively motivated, they actually have a disincentive  to spend their time and effort to examine these exotic claims. 

It was a different case for Cold Fusion because in 1989 Martin Fleischmann -the Cold Fusion proponent- was considered to be one of the world's leading electrochemists and because the world has much more interest in a cheap form of power production than they have on a quicker trip to Enceladus.
« Last Edit: 09/23/2014 04:26 PM by Rodal »

Offline Notsosureofit

  • Full Member
  • ****
  • Posts: 656
  • Liked: 704
  • Likes Given: 1362
Re: EM Drive Developments
« Reply #944 on: 09/23/2014 04:23 PM »
We could do that here (non-academic) but who in their right mind would put up the 100k or more to cover the time and overhead even if it was done at cost ?

Offline mheney

  • The Next Man on the Moon
  • Global Moderator
  • Full Member
  • *****
  • Posts: 733
  • Silver Spring, MD
  • Liked: 338
  • Likes Given: 190
Re: EM Drive Developments
« Reply #945 on: 09/23/2014 05:23 PM »
We could do that here (non-academic) but who in their right mind would put up the 100k or more to cover the time and overhead even if it was done at cost ?

I dunno - the folks at "Solar FREAKIN' Roadways" has raised $2.2M via indegogo:
https://www.indiegogo.com/projects/solar-roadways
even though the concept has been panned by Real Civil Engineers (tm).

I wouldn't be surprised if a professionally done (and mildly over-hyped) video couldn't raise a couple hundred kilobucks ...


Offline Notsosureofit

  • Full Member
  • ****
  • Posts: 656
  • Liked: 704
  • Likes Given: 1362
Re: EM Drive Developments
« Reply #946 on: 09/23/2014 05:32 PM »
Always a thought !

Still pokin', COMSOL EM models ?

http://www.microwavejournal.com/ext/resources/BGDownload/4/d/3D%20Electromagnetic%20Field%20Simulation.pdf?1326826605

"Respective to the boundary conditions, the
walls of the cavity are considered as perfect
conductors, represented by the boundary
condition
0
=

E
n
r
r
. That is, the tangential
electric field component is zero. To simulate the
temperature variation in a ceramic material in the
cavity, we used a symmetry cut as a mirror
symmetry for the electric field, which is
represented by the boundary condition
0
=

H
n
r
r
. "

Hmmmm.  Need to figure out how to copy formulas, but you get the idea.
« Last Edit: 09/23/2014 05:48 PM by Notsosureofit »

Offline raketa

  • Full Member
  • **
  • Posts: 211
  • Liked: 36
  • Likes Given: 24
Re: EM Drive Developments
« Reply #947 on: 09/23/2014 05:44 PM »
Photon could reach speed of light because, photon weight is 0 if it didn't move. Photon probably didn't consist Higgs particle that carry weight property base on the today's understanding. When speed of matter reach light could be that instead of increasing speed, it is feeding generation of Higgs particle and make it heavier and heavier. Could it be posible that process will be suppress?

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #948 on: 09/23/2014 05:59 PM »
Always a thought !

Still pokin', COMSOL EM models ?

http://www.microwavejournal.com/ext/resources/BGDownload/4/d/3D%20Electromagnetic%20Field%20Simulation.pdf?1326826605

"Respective to the boundary conditions, the
walls of the cavity are considered as perfect
conductors, represented by the boundary
condition
0
=

E
n
r
r
. That is, the tangential
electric field component is zero. To simulate the
temperature variation in a ceramic material in the
cavity, we used a symmetry cut as a mirror
symmetry for the electric field, which is
represented by the boundary condition
0
=

H
n
r
r
. "

Hmmmm.  Need to figure out how to copy formulas, but you get the idea.

Excellent source.  Thank you for posting high quality materials and high quality thoughts  @Notsosureofit   :)

This addresses my suspicion of how people are modeling the walls with COMSOL: <<the walls of the cavity are considered as perfect conductors, represented by the boundary condition>>.  Probably NASA Eagleworks did the same for the Copper walls.  But what about simulating the ends, that seem to have PCB circuit board on them ?

The conclusions:
<<The simulated results, obtained using COMSOL software, showed that, both the complex permittivity (real and imaginary parts) and the frequency of the microwave source have a strong influence on the field spatial distribution. This dependence could have important consequences in efforts to optimize the conditions for processing materials using microwave radiation.
We can obtain the evolution of the thermal profile of the sample using the energy absorption, which can be computed from those electromagnetic simulations.
To illustrate the useful of the used numerical technique, the thermal behaviour in a ceramic material was simulated, where 4 hot spotís was observed. This phenomenon presents a challenge for microwave engineers, since sample cracking are often exhibited, mainly because the formation of hot spotís due an inhomogeneous electromagnetic field distribution.>>

[Dielectric resonator] sample cracking means the strong possibility of dielectric breakdown and the field emission of real electrons, as we had discussed earlier on !
« Last Edit: 09/23/2014 06:00 PM by Rodal »

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #949 on: 09/23/2014 06:19 PM »
But, if electrons are emitted by field emission from a dielectric-resonator experiencing breakdown under the electric field, what happens to the electrons in the air?  Is the air also ionized by the electric field?  How could that generate propulsion, unless we have a leaky microwave cavity ?
« Last Edit: 09/23/2014 06:20 PM by Rodal »

Offline JasonAW3

  • Senior Member
  • *****
  • Posts: 2409
  • Claremore, Ok.
  • Liked: 374
  • Likes Given: 10
Re: EM Drive Developments
« Reply #950 on: 09/23/2014 06:36 PM »

[Dielectric resonator] sample cracking means the strong possibility of dielectric breakdown and the field emission of real electrons, as we had discussed earlier on !

So, the actual thrust seen is essentially like the recoil from some sort of electron gun?

     Doesn't this indicate that thrust is being produced by the decay of matter from a microwave gun?

     Wouldn't that make this a sort of highly effecient ion drive?  Much lower power requirements, solid matter being converted to high energy ions from a solid instead of from a gas.  That is, If I understand what you're saying correctly.

     If so, then they DO has a sort of working high effeciency EM drive that is essentially a Solidstate Ion Thruster.

     Or am I not understanding what you're saying.
My God!  It's full of universes!

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #951 on: 09/23/2014 06:41 PM »

[Dielectric resonator] sample cracking means the strong possibility of dielectric breakdown and the field emission of real electrons, as we had discussed earlier on !

So, the actual thrust seen is essentially like the recoil from some sort of electron gun?

     Doesn't this indicate that thrust is being produced by the decay of matter from a microwave gun?

     Wouldn't that make this a sort of highly effecient ion drive?  Much lower power requirements, solid matter being converted to high energy ions from a solid instead of from a gas.  That is, If I understand what you're saying correctly.

     If so, then they DO has a sort of working high effeciency EM drive that is essentially a Solidstate Ion Thruster.

     Or am I not understanding what you're saying.
Take a look at my subsequent comment:

<<But, if electrons are emitted by field emission from a dielectric-resonator experiencing breakdown under the electric field, what happens to the electrons in the air?  Is the air also ionized by the electric field?  How could that generate propulsion, unless we have a leaky microwave cavity ?>>

These are my malformed , incomplete, thoughts in "poking around" looking for different explanations of the measurements. 

If the propulsion is the result of ionized air leaking from the cavity, I see this as much less effective than present ion rockets.  Also take into account that they tested thrust pulses for only ~30 sec duration and that would not get us anywhere.  A cracked dielectric resonator emitting electrons and/or ionization of air won't work long enough or effectively enough...

Also as far as specific force, the results from the Cannae and Frustum testing were not too encouraging.  The Boeing/DARPA specific force tests show an impulse instead of a rectangular pulse.  The trips to the moons of Saturn and Jupiter are predicated on very optimistic extrapolations...
« Last Edit: 09/23/2014 06:52 PM by Rodal »

Offline Notsosureofit

  • Full Member
  • ****
  • Posts: 656
  • Liked: 704
  • Likes Given: 1362
Re: EM Drive Developments
« Reply #952 on: 09/23/2014 07:13 PM »
Where are the Boeing/DARPA specific force tests ?

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #953 on: 09/23/2014 07:20 PM »
« Last Edit: 09/23/2014 07:33 PM by Rodal »

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #954 on: 09/23/2014 07:43 PM »
« Last Edit: 09/23/2014 07:46 PM by Rodal »

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #955 on: 09/23/2014 07:50 PM »
Also see this, which reproduces the contents of the Boeing/DARPA information supplied by Dr. White:

http://forum.nasaspaceflight.com/index.php?topic=29276.msg1255210#msg1255210

Offline Star One

  • Senior Member
  • *****
  • Posts: 8008
  • UK
  • Liked: 1278
  • Likes Given: 168
EM Drive Developments
« Reply #956 on: 09/23/2014 08:09 PM »
The practical problem with independent verification (at John Hopkins or other universities) is that the scientific community has dismissed the NASA propellant-less tests (either vocally as done by John Baez and Sean Carroll, or quietly as done by most other academics in Aerospace Engineering -and quietly dismissing these results at other NASA propulsion centers-).  The academic community -particularly nowadays- knows that it is not considered to be an advancement to their career to produce independent experimental data that nullifies esoteric claims (claims that run contrary to conservation of momentum and known physics) that the rest of the community will meet with "I could have told you that".  So academics at MIT, Stanford, CalTech, etc., are negatively motivated, they actually have a disincentive  to spend their time and effort to examine these exotic claims. 

It was a different case for Cold Fusion because in 1989 Martin Fleischmann -the Cold Fusion proponent- was considered to be one of the world's leading electrochemists and because the world has much more interest in a cheap form of power production than they have on a quicker trip to Enceladus.

That's depressing to read, sounds like its going to be hard to get anyone to stick their head above the parapet and actually look into this from a neutral third party viewpoint.
« Last Edit: 09/23/2014 08:10 PM by Star One »

Online Rodal

  • Senior Member
  • *****
  • Posts: 5836
  • USA
  • Liked: 5915
  • Likes Given: 5254
Re: EM Drive Developments
« Reply #957 on: 09/23/2014 08:23 PM »
That's depressing to read, sounds like its going to be hard to get anyone to stick their head above the parapet and actually look into this from a neutral third party viewpoint.

1) I think that independent testing with null results of EM drives has already been done and reported, utilizing a classical testing device.  I will be posting shortly negative results already reported in the literature, performed by a third party, that I am presently reviewing.

2) Regardless of positive or negative results by third parties, it is noteworthy that Boeing/DARPA as recently as 2013 had their device tested at NASA/Eagleworks who reported a specific force orders of magnitude above the 2014 campaign featuring the Cannae and Frustum devices (albeit with an impulse response rather than a rectangular pulse, which may be problematic for practical propulsion applications).  If the Boeing/DARPA results were indeed valid, I think that both Boeing and DARPA would be pursuing further, perhaps secret, work, don't ya think?
« Last Edit: 09/23/2014 08:28 PM by Rodal »

Offline Star One

  • Senior Member
  • *****
  • Posts: 8008
  • UK
  • Liked: 1278
  • Likes Given: 168
Re: EM Drive Developments
« Reply #958 on: 09/23/2014 08:38 PM »

That's depressing to read, sounds like its going to be hard to get anyone to stick their head above the parapet and actually look into this from a neutral third party viewpoint.

1) I think that independent testing with null results of EM drives has already been done and reported, utilizing a classical testing device.  I will be posting shortly negative results already reported in the literature, performed by a third party, that I am presently reviewing.

2) Regardless of positive or negative results by third parties, it is noteworthy that Boeing/DARPA as recently as 2013 had their device tested at NASA/Eagleworks who reported a specific force orders of magnitude above the 2014 campaign featuring the Cannae and Frustum devices (albeit with an impulse response rather than a rectangular pulse, which may be problematic for practical propulsion applications).  If the Boeing/DARPA results were indeed valid, I think that both Boeing and DARPA would be pursuing further, perhaps secret, work, don't ya think?

And you've just highlighted another frustration with this that there is the suggestion of a forest of NDAs around this work. We could end up in the situation of positive results being produced but no one outside of select few ever knowing about it.

Offline frobnicat

  • Full Member
  • ****
  • Posts: 518
  • Liked: 500
  • Likes Given: 151
Re: EM Drive Developments
« Reply #959 on: 09/23/2014 09:50 PM »
Or a lot of negative results being kept secret while positive ones (or apparently positive ones) are published.

Was thinking : how the presence or absence of the dielectric part alters the coupling of the generator with the resonant cavity ? And in particular how much power feedback is there from the cavity to the generator and how the absence of dielectric might change that ?

The electromagnetic fields in the cavity are excited via external coupling. An external power source is usually coupled to the cavity by a small aperture, a small wire probe or a loop.[2] External coupling structure has an effect on cavity performance and needs to be considered in the overall analysis.[3]

Even if very high Q of 1e6 is done, the steady state when power loss = power input (of the wave) is reached very quickly, the time it takes light to bounce 1e6 times along the cavity, say 1ns for a 30cm trip, that's about 1ms to reach this equilibrium. The total RF EM energy in the cavity then stabilizes at (power x 1ms), at 20W that's .02 J

System wide (generator +cavity but not the chamber) 20W DC input, 20W (thermal+radiation) output
The thermal effect is at first (temperature equilibrium would have a time constant much longer than 1ms) at each location a constant rate of temperature change (inversely proportional to thermal capacity). Radiations (leaked) would be much faster at filling the cavity around the system (chamber) and reach equilibrium at a given energy density (different because different volume, smaller leaked input power and probably different Q factor). At which point (when the chamber reaches RF equilibrium) this power fraction of power radiated by a leak of the system would be all thermal output to heat the outer walls of the system and the inner walls of the chamber at constant rate also. I'm assuming the chamber is thick enough a conducting vessel to not leak any RF radiation. So after at most a few ms, the 20W DC power input is entirely dissipated thermally, with at start (after a few ms and before thermal conductivity/convection/IR radiation starts to even out the temperatures) constant rates of temperature change at every location of system (generator + cavity) and experiment overall (+chamber and fixed parts).

What am I aiming at ? Don't know... just saying, follow the power system wide, and in particular don't expect the generator to cavity link to be a one way power transmission line : this is a coupling. And in this coupling the presence or absence of dielectric thing might make a difference, and we know from first hand that power radiating (IR radiation) from the generator heats the flex bearings to affect measurements at a level comparable in magnitude to the measured thrust signals (albeit not in a way that could readily explain a square signal, just a ramp up or down...)

edit : I should add that any effect due to something happening at the generator would hardly be compatible with the apparent fact that the thrust is reversed when turning the cavity alone...

« Last Edit: 09/23/2014 10:09 PM by frobnicat »

Tags: