Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1801266 times)

Offline Mulletron

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http://dlib.eastview.com/browse/doc/12472752

Russians......

Well this is in the public domain so it means that if these thrusters truly work, the race among nations has been going on for a while. There is no way the Western world didn't notice this  :)

I remember reading other stuff about reports of Russian satellites making anomalous maneuvers. Moving satellites around costs precious propellant and is generally avoided if it isn't absolutely necessary....unless.

http://www.iflscience.com/space/mysterious-satellite-sparks-concerns-russia-has-developed-space-weapon
« Last Edit: 05/26/2015 03:38 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline StrongGR

Maybe I missed some information due to my delay on following these threads. What are the characteristics of the cavities used by NASA? I mean the physical dimensions, the input power (I know this is around tenth of W) and the relative dielectric constant of the material used as a dielectric (HDPE). Could the latter be similar to conjugate polymers or some ceramic material with this value ranging to some 10^5?

Please find the physical dimensions of NASA's truncated cone (they have only one) here: 

...

Thanks a lot!

Offline saucyjack

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While I am in favor of this Wiki, it is unfair to attribute it to me as I did not create it.

That being said, I encourage all of the more advanced members of this forum to contribute, discuss, and correct issues on the wiki so that it can serve as an introduction to the topics at hand, and also show where the theoretical disagreement exist, with references to back them up.

@RW - not sure why you were attributed as the author on that page, I'll try to fix that.

@Chris B - Good idea to add the wiki link to the first post of this thread.  Is that possible?  Thanks to @streppa, you can now also access it at the somewhat more memorable URL: http://emdrive.wiki

As always we appreciate any and all help on the wiki.  Particularly in light of today's discussion about the missing video from the Russian experimenter, please add any relevant external links to the wiki that you come across; you can upload any files as well.  If you have other suggestions for how to make the wiki better please PM me.

-Rolf

Offline SeeShells

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Thought experiment: Can people please supply thoughts/feedback on the following


This is what White and his team did with a rectangular box. The effect is there as they observed satellite frequencies of the input laser beam. I have shown this in my paper too. When you apply the idea to the computation of the thrust, for the current geometries and input powers, the gravitational effect appears to be too minuscule to account for the measured one.
I know Dr. white did it for a rectangular box, did you do it for the EM Frustum cavity and take into account the geometry of the cavity? And does the gravitational effect scale  through the Frustum as the geometry of the cavity changes?
Thanks... back to reading. Shell

Offline Rodal

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...@Chris B - Good idea to add the wiki link to the first post of this thread.  Is that possible?  ...
Link to EM Drive wiki is now added to the initial post on this thread. :)

Offline StrongGR

Thought experiment: Can people please supply thoughts/feedback on the following


This is what White and his team did with a rectangular box. The effect is there as they observed satellite frequencies of the input laser beam. I have shown this in my paper too. When you apply the idea to the computation of the thrust, for the current geometries and input powers, the gravitational effect appears to be too minuscule to account for the measured one.
I know Dr. white did it for a rectangular box, did you do it for the EM Frustum cavity and take into account the geometry of the cavity? And does the gravitational effect scale  through the Frustum as the geometry of the cavity changes?
Thanks... back to reading. Shell

The problem here is that, for gravity, all scales as G/c^4, something like 10^-43. Geometry, dielectric and all that help to mitigate by several orders of magnitude such a small number but I cannot see how to recover a thrust of the order of tenths of micronewton.

Offline Rodal

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Thought experiment: Can people please supply thoughts/feedback on the following


This is what White and his team did with a rectangular box. The effect is there as they observed satellite frequencies of the input laser beam. I have shown this in my paper too. When you apply the idea to the computation of the thrust, for the current geometries and input powers, the gravitational effect appears to be too minuscule to account for the measured one.
I know Dr. white did it for a rectangular box, did you do it for the EM Frustum cavity and take into account the geometry of the cavity? And does the gravitational effect scale  through the Frustum as the geometry of the cavity changes?
Thanks... back to reading. Shell

The problem here is that, for gravity, all scales as G/c^4, something like 10^-43. Geometry, dielectric and all that help to mitigate by several orders of magnitude such a small number but I cannot see how to recover a thrust of the order of tenths of micronewton.
For whatever it's worth, I tried also on my own using Mathematica , based on your paper, and I arrived at your same above conclusions
« Last Edit: 05/26/2015 03:50 PM by Rodal »

Offline VAXHeadroom

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How the Maser was invented also is useful to get us to think about the nature of the EM Drive in more conventional ways.  There are three keys to the Maser's operation:
...
It was crucial to success that the inventor of the Maser understood there would have to be a way to intensify the action.  The inventor realized that this amplification could be obtained by harnessing the phenomenon of resonance of a cavity: high Q.  The cavity was designed to resonate with standing waves at the same frequency of 24 GHz at which the ammonia gas energetically emits.  In the reverberant space of the cavity the photons are kept rocketing back and forth through the energy-loaded gas so as to build a vigorous sustained oscillation.  The 24 GHz vibration entering the cavity is amplified 100 times in power. 

Hm.  As has been noted many times both Sawyer and Yangs experiments are ran at atmospheric pressure and are furthermore (as far as anyone can tell) well sealed...One defence for this hypotheses is the difference in measured effects between the Yang and Sawyer devices and the Eagleworks vacuum tests.

To me, this is a really crucial bit of info.  If these devices loose this much performance in a vacuum, then are they really all that superior to a photon rocket?  ...

It is indeed noteworthy that although Shawyer has been working on the EM Drive for decades, that no experiment in a vacuum has been reported by Mr. Shawyer.

Prof. Yang has been working on EM Drive experiments since prior to 2010, yet we are in 2015 and we have not yet heard of her performing experiments in a vacuum.

It took NASA Eagleworks less than a year to perform an EM Drive experiment in a vacuum and the results showed significantly less thrust/InputPower than the one measured in air.

So it definitely has to be considered whether the gas molecules inside the EM Drive may not indeed be undergoing segregation between high-energy and low-energy, and whether the gas molecules may be playing a role (beyond the obvious one of air convection, gas exiting the EM Drive under higher pressure than ambient, buoyancy due to higher temperature, etc.)
...
http://b.gatech.edu/1cX7sXj
http://www.mike-willis.com/Tutorial/gases.htm
http://www.jpier.org/PIERB/pierb15/09.09041706.pdf
http://www1.lsbu.ac.uk/water/microwave_water.html



I really think this is a critical insight.  The microwave frequencies being used are specifically tailored to heat water (as everybody is basically using a home microwave oven emitter) - this may indeed be a water molecule amplified maser.  The humidity at time of testing in the various locations should be measured and considered as a data point in the measured thrust.
Emory Stagmer
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Offline StrongGR


For whatever it's worth, I tried also on my own using Mathematica , based on your paper, and I arrived at your same above conclusions

Indeed, general relativity yields a too small contribution and so, one can conclude that whatever approach one uses to recover the third principle just fails. If there will be a confirmation of this effect it will be really interesting to find a theoretical account for it. Personally, I am unconvinced.

...1kW photon thrust makes for only about 3N, unless it is efficiently recycled (like photonic laser thruster by BAE) which I doubt is the case, the setup looked open enough to leak microwaves copiously around. If this is the video in question, I recall the scale registering a gram force or so, from those values I doubt this was due to just EM beamed force...
I didn't recall the measured force and I couldn't find the video again to be able to check it.  If he measured 1 gram, that's thousands of times better performance than a photon rocket, and as you said, it would be very noteworthy (if the measurement was not  an artifact). 

So perhaps he pulled the video out of YouTube once he realized that what he was measuring was an artifact.

I hope he didn't get hurt during the experiment.

Thanks for pointing this out.

Yes, this is the video I am talking about.
I am pretty sure the measured thrust in the video was about 1 gramm.
Probably you are right, the author saw an artefact and pulled the video. Thanks!

Offline TheTraveller

I really think this is a critical insight.  The microwave frequencies being used are specifically tailored to heat water (as everybody is basically using a home microwave oven emitter) - this may indeed be a water molecule amplified maser.  The humidity at time of testing in the various locations should be measured and considered as a data point in the measured thrust.

The Flight Thruster EM Drive Shawyer built for Boeing was a sealed unit and operates at 3.85GHz.
http://www.emdrive.com/flightprogramme.html

Have been told Boeing, in 2014, still had that unit.
« Last Edit: 05/26/2015 04:13 PM by TheTraveller »
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Offline Rodal

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I really think this is a critical insight.  The microwave frequencies being used are specifically tailored to heat water (as everybody is basically using a home microwave oven emitter) - this may indeed be a water molecule amplified maser.  The humidity at time of testing in the various locations should be measured and considered as a data point in the measured thrust.

The Flight Thruster EM Drive Shawyer built for Boeing was a sealed unit and operates at 3.85GHz.
http://www.emdrive.com/flightprogramme.html

The effect we are discussing will certainly take place in a sealed unit, if the gas inside the sealed cavity has the properties required for the effect to take place.  All that is required is for the gas inside the cavity to have these properties.  As per Prof. Yang's analysis in her 2010 paper.
« Last Edit: 05/26/2015 04:17 PM by Rodal »

Offline deltaMass

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I wonder if "sealed" and "gas tight" are truly synonymous here. After all, there is an RF connector (at least)

Offline TheTraveller

I wonder if "sealed" and "gas tight" are truly synonymous here. After all, there is an RF connector (at least)

I'll ask Shawyer.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
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Offline SeeShells

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For whatever it's worth, I tried also on my own using Mathematica , based on your paper, and I arrived at your same above conclusions

Indeed, general relativity yields a too small contribution and so, one can conclude that whatever approach one uses to recover the third principle just fails. If there will be a confirmation of this effect it will be really interesting to find a theoretical account for it. Personally, I am unconvinced.
Honestly, I got the old pencil and eraser out and hacked my way through it and saw the same miniscule effect. I guess I needed verification. Thanks guys

Offline Star One

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Isn't there some conference set for mid-September where we might hear more one way or the other on this topic? Unfortunately for the life of me I've forgotten what it's called but, I'm sure Mr Shawyer did a presentation at it in 2013 if that helps identify it.
« Last Edit: 05/26/2015 04:35 PM by Star One »

Offline VAXHeadroom

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I wonder if "sealed" and "gas tight" are truly synonymous here. After all, there is an RF connector (at least)

I'll ask Shawyer.

It wouldn't matter unless the test was done in a vacuum.  In ambient, the partial vapor pressure of the water wouldn't change (well...not much...heating MIGHT drive the moisture out somewhat).  This is a potential explanation of why there is a difference between tests at ambient pressure and those in a vacuum (if the device is NOT a pressure vessel).  Is it possible to get to White as well to ask about their test unit?
Emory Stagmer
  Executive Producer, Public Speaker UnTied Music - www.untiedmusic.com

Offline StrongGR


For whatever it's worth, I tried also on my own using Mathematica , based on your paper, and I arrived at your same above conclusions

Indeed, general relativity yields a too small contribution and so, one can conclude that whatever approach one uses to recover the third principle just fails. If there will be a confirmation of this effect it will be really interesting to find a theoretical account for it. Personally, I am unconvinced.
Honestly, I got the old pencil and eraser out and hacked my way through it and saw the same miniscule effect. I guess I needed verification. Thanks guys

I hope tomorrow to post the latest version. With this, I will post also the corresponding Maple worksheet to tinkering about, if one likes. The effect is there but really too small. My guess is that more mundane explanations could be at work.

Online birchoff

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For whatever it's worth, I tried also on my own using Mathematica , based on your paper, and I arrived at your same above conclusions

Indeed, general relativity yields a too small contribution and so, one can conclude that whatever approach one uses to recover the third principle just fails. If there will be a confirmation of this effect it will be really interesting to find a theoretical account for it. Personally, I am unconvinced.
Honestly, I got the old pencil and eraser out and hacked my way through it and saw the same miniscule effect. I guess I needed verification. Thanks guys

I hope tomorrow to post the latest version. With this, I will post also the corresponding Maple worksheet to tinkering about, if one likes. The effect is there but really too small. My guess is that more mundane explanations could be at work.

Are you saying that given the reasoning and calculations depicted in your paper. After doing some numerical analysis on the equations for the frustum configuration you are left with a really small effect orders of magnitude below that which has been reported so far by Shawyer, Yang, Cannae, EW, and jullian (The ukranian replicator, I am sure I probably butchered his name.)?

Just want to make sure I am understanding what your saying.

Offline Rodal

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@WarpTech raises a very good point.  Any system which provides propellant-less acceleration should also work as an accelerometer.   Photon resonators are already used as accelerometers. (and by extension, gravity wave detectors)

Exactly, that's where Dr. McCulloch's work comes in, though I'm not well versed in his model yet. Accelerating a cavity full of energy, oscillating in modes will cause a doppler shift to propagate through. Here, that doppler shift is being caused by energy lost to the cavity.

Momentum is being input to the cavity via the microwaves, dp_in/dt, and is stored in the oscillating modes, Q*dp_in/dt. The rate of dissipation of that momentum, -dp/dt = F, will determine the forces on each surface. If that rate is not simply a constant of the metal, but a variable of the geometry, there will be asymmetrical forces, velocities and doppler shifts. Agreed?

Todd

One thing I had almost forgotten about that Accelerometer because it's been so long since I've worked on it. IF it were possible to create a device that, when simply placed in an accelerated reference frame, it would output a voltage from which constant power could be extracted. It implies (deltaMass?) that if it were sitting on the floor in my garage, I could extract infinite energy from the gravitational field, which is an accelerated reference frame relative to the Accelerometer sitting on the floor.

What happens instead is, the accelerometer becomes polarized and the charge density on the "charged objects" is no l longer evenly distributed. It cannot output more than the amount of power required to polarize it. I can input energy to depolarize it, and then extract it as it polarizes again, but I can't get free energy from it.

Therefore, any propellant-less propulsion device, must have some means of becoming depolarized. In the case of the frustum, stored energy is lost to heat as well as thrust, and this eventually depolarizes it so it can be re-charged and thrust again. Once again, it can only work in a pulsed mode, when power is ramping up and down quickly.

Todd
What do people think of the idea of driving the EM Drive with a TEmnp mode (transverse electric mode) such that the axial field is magnetic along the longitudinal direction.

Then the idea would be to make the EM Drive more of a "one-way" street (1-way directional waves rather than a 2-way street with standing waves) by placing tiny ferrite beads (magnets) along so as to minimize reflections (as done in the solid state ruby maser).

The number and size of the ferrite beads would control the fine tradeoff between Q resonance (needed for reverberation) and directionality (needed for thrust).

Perhaps this would allow the use of a cylindrical waveguide (instead of a truncated cone), one could control the amount of reflections by the size and number of ferrite beads along the axis.  (The size of the ferrite bead could be functionally graded such that the size of ferrite would monotonically increase in one direction, for example).

Also the use of a solid state material (such as the ruby used in the ruby maser) that can emit in a very wide range of microwave frequencies may allow much higher power to thrust force conversion.

Please notice as per the history of the Ruby Maser chart, that many Ruby Masers operated at similar microwave frequencies (2.4 GHz) as used for magnetrons for home cooking microwave ovens:
« Last Edit: 05/26/2015 06:13 PM by Rodal »

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