Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1871888 times)

Offline aceshigh

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The only one claiming "propellant-less" in that absolutist way is Shawyer.  Everybody else (McCulloch, White, etc.) no matter how unusual their theories, claims an interaction with the outside

true, but it´s quite different to claim an interaction with something that doesn´t care about the engine/ship walls, in other words, the engine push "it" but "it" doesn´t interact with the the rest of the ship... like virtual particles in White's Theory or "the rest of the mass of the universe", in Mach Effect Theory...

... and pushing air... which in that case, EM Drive is not a propellantless propulsion, but just a propeller-less air engine.

Offline SeeShells

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Have confirmed the EW dielectric copper frustum does generate Force big end to small end. The latest Shawyer summary is incorrect. Have informed Shawyer.
Good! I mentioned a bazillion pages ago it didn't make any sense.
Shell

Offline SeeShells

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...We now have two separate sets of experiments that confirm that thrust decreases significantly in air, and yet we still see the numbers for Yang and Shawyer (4 N/kW of 1 N/kW) bandied around.  With the knowledge that thrust drops in air (but by an inconsistent/indeterminate amount), aren't we forced to essentially ignore any numerical results that come from either Yang or Shawyer?  We know they are less, but how much less is impossible to tell.

Any comment that extrapolates thrust results, or linearity of results wrt to Q, etc, using Yang and Shawyers results, is ignoring the experimental proof from two labs that thrust drops in vacuum. At the very least, from what Shell has said with the best being 10%, we have to throw away an order of magnitude, meaning the "best" thrust to power achieved so far was actually 0.4 N/kW, if that.

No, see:  http://emdrive.wiki/Experimental_Results

Best reported thrust/InputPower in vacuum is 0.001 N/kW

Your number is 400 times larger

4 N/kW is 4,000 times larger

Yeah, I took the best result Yang reported (4 N/kW) and took Shell's reported 10% decrease in vacuum, to report a sort of "vacuum adjusted" best thrust to power ratio of 0.4 N/kW (in the best case scenario of only losing 90% of thrust in a vacuum, as per Shell).

But you're right in that my "vacuum adjusted" methodology isn't winning any experimental honesty awards, and the only honest thing to do is to throw out Yang and Shawyer's results completely (at least their numerical results) and only focus on results that come from vacuum.

Quote from: SeeShells
No one has showed a working EMDrive in a vacuum that has decent thrust. The best I've seen is about 10% of the thrust in a air test.


I suggest we need to wait to see what the latest EW vacuum data shows.

In my opinion it is the Tajmar vacuum data that needs to be thrown out as it was a comedy of multiple measurement errors.
There is no bad data and even though the test was fraught with issues there is enough in it ti glean useful data. the Thrust differential saw was about 10% in the vacuum and that's a good guess.

Offline SeeShells

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>>Dr. White's theory of virtual particles is the only one I can think of right now that gets momentum from inside
>>(creating VPs) to the outside but lacks a good explanation of explaining air/no air test results.  Back to ground zero so
>>far.

this isn't quite true, there is the possibility of a warp field as claimed to be detected by the laser interferometer results
but whether a small warp field or spacial distortion with a concave shape could produce the measured thrust is beyond me to tell. i think the warp effect should be included in the possibilities at this stage, it's no more outlandish that the quantum soup theory and actually has some evidence. i don't understand why no-one is talking about this
What the tests showed it that the laser was delayed going through a simple RF resonant cavity, in air. Test it in vacuum then I'll be more convinced of a real effect.

Shell

Offline SeeShells

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Back on track - Frustum, funnel, vortices and my initial theory.

While building and thinking (dangerous combination), a theory has been brewing that is not ready for peer review, but is ready for my pals here at NSF. Nature often leads to answers. Growing up in the tornado belt has lead me to think about the known forces within a funnel cloud that touches the earth. A frustum is a portion of that funnel.

Swirling electromagnetic waves, as with air, could create suction in the direction of the narrow end of the vortex. Thus, I've been reluctant to quantify the force as "thrust". Visualizing what occurs in a non-static frustum lead me to explore some papers on a electromagnetic vortices .

Be aware, there are 4th dimensional properties going on here and its not for the faint of heart.

Here is one of those papers: http://arxiv.org/ftp/arxiv/papers/1008/1008.3994.pdf

"From the above it is possible to conclude: the state and evolution of the electro-magnetic field in a macroscopic approximation to the selected reference frame is clearly described by four-dimensional vector, which includes potential and solenoidal components and satisfies four-dimensional Dalamber equation."

My emphasis Solenoidal, aka ratchet.

Meepers will no doubt have issues with 4th dimensional properties as well as non-steady state EM waves in a Rotational propogation...just what fires naturally out of a magnetron's radome.

There you have it. Its where I'll be spending my theory time. Comments and critiques welcomed.

p.s. Yes, I know, a Z axis rotation needs to be measured along the longitudinal axis. To date, no one has tried this.
Oh I think it needs to be investigated, I gleaned the same thought sitting in the hot tub months ago swirling the water seeing vortexes form. One reason I started researching helical antennas and when aero is done with his current runs we should see if he could do a 1/4 wave shifted Dipole in the large end simulating a rotating wave pattern.

Dr. rodal, what does this look like to you???
http://d1czgh453hg3kg.cloudfront.net/content/royprsa/467/2133/2500/F2.large.jpg
Figure 2.
Projection of Poynting vector direction (equation (3.2)) from a circularly polarized dipole, in the plane Embedded Image, showing swirl near the dipole axis and divergence far away.
Ref...
http://rspa.royalsocietypublishing.org/content/467/2133/2500

I think it's a great idea RFMWGUY!

Shell

Offline rfmwguy

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...Dr. rodal, what does this look like to you???
http://d1czgh453hg3kg.cloudfront.net/content/royprsa/467/2133/2500/F2.large.jpg
Figure 2.
Projection of Poynting vector direction (equation (3.2)) from a circularly polarized dipole, in the plane Embedded Image, showing swirl near the dipole axis and divergence far away.
Ref...
http://rspa.royalsocietypublishing.org/content/467/2133/2500

I think it's a great idea RFMWGUY!

Shell
Since you asked, here is my answer: I don't see how these ideas address the main question:

* Conservation of Momentum and balance of forces

If they do address it, and I missed it, I would appreciate knowing how they address conservation of momentum and balance of forces
The paper I referenced invokes 4th dimensional physics. It is from this realm that a Solenoidal, or ratchet effect occurs:

"From the above it is possible to conclude: the state and evolution of the electro-magnetic field in a macroscopic approximation to the selected reference frame is clearly described by four-dimensional vector, which includes potential and solenoidal components and satisfies four-dimensional Dalamber equation. No problems with system of equations’ certainty at such approach arise."

Offline SeeShells

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Back on track - Frustum, funnel, vortices and my initial theory.

Oh I think it needs to be investigated, I gleaned the same thought sitting in the hot tub months ago swirling the water seeing vortexes form. One reason I started researching helical antennas and when aero is done with his current runs we should see if he could do a 1/4 wave shifted Dipole in the large end simulating a rotating wave pattern.

Dr. rodal, what does this look like to you???
http://d1czgh453hg3kg.cloudfront.net/content/royprsa/467/2133/2500/F2.large.jpg
Figure 2.
Projection of Poynting vector direction (equation (3.2)) from a circularly polarized dipole, in the plane Embedded Image, showing swirl near the dipole axis and divergence far away.
Ref...
http://rspa.royalsocietypublishing.org/content/467/2133/2500

I think it's a great idea RFMWGUY!

Shell
Since you asked, here is my answer: I don't see how these ideas address the main question:

* Conservation of Momentum and balance of forces

If they do address it, and I missed it, I would appreciate knowing how they address conservation of momentum and balance of forces
I didn't ask. :)

I just think it's an good idea to see if using a helical rotating wave we could keep the modes from switching polarities inside the frustum, increasing poynting vectors thereby the stress. And if I'm seeing this wrong just know I'm still learning.

Offline WarpTech

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...Dr. rodal, what does this look like to you???
http://d1czgh453hg3kg.cloudfront.net/content/royprsa/467/2133/2500/F2.large.jpg
Figure 2.
Projection of Poynting vector direction (equation (3.2)) from a circularly polarized dipole, in the plane Embedded Image, showing swirl near the dipole axis and divergence far away.
Ref...
http://rspa.royalsocietypublishing.org/content/467/2133/2500

I think it's a great idea RFMWGUY!

Shell
Since you asked, here is my answer: I don't see how these ideas address the main question:

* Conservation of Momentum and balance of forces

If they do address it, and I missed it, I would appreciate knowing how they address conservation of momentum and balance of forces

I think it is not that you missed it. I feel it is that you don't believe it. The group velocity, phase velocity and the speed of light, are not the same at both ends of the cavity. The momentum carried by EM waves depends on the refractive index and the phase velocity. It is not "free space" inside the cavity. Light is being squeezed at the small end and expands toward the big end. In doing so, there is a force created by this gradient that is not symmetrical because dp/dt is not symmetrical. Nothing has to escape for this to be true, it only needs to be dissipated by doing work to thrust the frustum. It is GR, it is geometry, it is Maxwell's equations in curved space-time, acting over a narrow bandwidth near the cut-off.

That is what all 4 equations are saying. How each of us interpreted the geometry and it's effects on these velocities is different, but we all agree that this is how momentum is conserved. Space-time is being curved at this frequency, which per the PV Model is "identical" to a variable refractive index. Until you "accept this", you will continue to expect CoM to be violated, because there is NO OTHER explanation. Puthoff & Davis have done experiments with squeezed light, in an attempt to create exotic matter.

http://www.earthtech.org/publications/davis_STAIF_conference_1.pdf
Squeezed Light: http://arxiv.org/abs/1401.4118

E. Davis might actually stop knocking the EM Drive if he understood what I'm talking about. It is right up his alley!
Todd
 

Offline Rodal

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...Dr. rodal, what does this look like to you???
http://d1czgh453hg3kg.cloudfront.net/content/royprsa/467/2133/2500/F2.large.jpg
Figure 2.
Projection of Poynting vector direction (equation (3.2)) from a circularly polarized dipole, in the plane Embedded Image, showing swirl near the dipole axis and divergence far away.
Ref...
http://rspa.royalsocietypublishing.org/content/467/2133/2500

I think it's a great idea RFMWGUY!

Shell
Since you asked, here is my answer: I don't see how these ideas address the main question:

* Conservation of Momentum and balance of forces

If they do address it, and I missed it, I would appreciate knowing how they address conservation of momentum and balance of forces

I think it is not that you missed it. I feel it is that you don't believe it. The group velocity, phase velocity and the speed of light, are not the same at both ends of the cavity. The momentum carried by EM waves depends on the refractive index and the phase velocity. It is not "free space" inside the cavity. Light is being squeezed at the small end and expands toward the big end. In doing so, there is a force created by this gradient that is not symmetrical because dp/dt is not symmetrical. Nothing has to escape for this to be true, it only needs to be dissipated by doing work to thrust the frustum. It is GR, it is geometry, it is Maxwell's equations in curved space-time, acting over a narrow bandwidth near the cut-off.

That is what all 4 equations are saying. How each of us interpreted the geometry and it's effects on these velocities is different, but we all agree that this is how momentum is conserved. Space-time is being curved at this frequency, which per the PV Model is "identical" to a variable refractive index. Until you "accept this", you will continue to expect CoM to be violated, because there is NO OTHER explanation. Puthoff & Davis have done experiments with squeezed light, in an attempt to create exotic matter.

http://www.earthtech.org/publications/davis_STAIF_conference_1.pdf
Squeezed Light: http://arxiv.org/abs/1401.4118

E. Davis might actually stop knocking the EM Drive if he understood what I'm talking about. It is right up his alley!
Todd
Yes, you are correct.  It is that I don't believe it.

I have written a program with Wolfram Mathematica, and for Yang/Shell (which is much closer to a cylinder and much further from the cone vertex) I get a net force (taking into account all stresses) to be practically zero.  Nada. Zilch.

But for NSF-1701 geometry (which has a small base much closer to the vertex), I'm getting a net force pointing from the big base towards the small base, and the major component is coming from the copper conical lateral surface.  I'm trying to make sense out of this, because as you say, I don't believe it.

In General Relativity momentum is part of the energy-momentum tensor, which transforms as a covariant quantity, not as an invariant.  Hence it is difficult to have intuition about it. 


So here is my question: can you think of another phenomenon in Nature where something will accelerate only due to internal electromagnetic fields without anything ejecting to the outside?
« Last Edit: 07/30/2015 05:22 PM by Rodal »

Offline mittelhauser


Don't know about the others but my EMDrive will soon be on a rotary turntable accelerating from 0 rpm to 120 rpm.

I propose we rename "The Traveller" as "Nostradamus" since he believes that he knows the future.  Nothing like going into an experiment knowing the results.  Makes life so much easier, eh?

-Jon

Offline Moe Grills

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   Hmmm....EM Drive sounds a lot like the claims of anomalist theorists (I'm being charitable) who speculate that so-called 'flying saucers' (no proof they exist) are supposedly propelled by microwaves.

But back to the issue of a genuine EM Drive. Rodal and Seeshells are now arguing in circles when the only way to settle the issue is?...Is for some (eccentric perhaps) millionaire or billionaire to provide funds to build (at least) a small-scale 'working' prototype to be sent into LEO to see if it works; and if it works, to see if it has any real advantage over VASIMR, or
even an ordinary ion rocket-motor.

Offline lmbfan

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I don't know much about loop antenna.  This file makes a giant 2-D source (24 units X 24 units, infinitely thin) and a square metal loop 2.928 X .7 units (center line), the "wire" width is .2, height of .1 units.  The loop is called a "scatterer" and is not generated by default.  Does any of that sound right for a loop antenna?

If I (or someone else) were to make a square loop antenna somehow, how would we know if it was a loop?  What fields would we look at and what would they look like?  Quickly testing different ideas can be painful if I use the truncated cone geometry/steps with long calculation times.
This may help
http://www.silabs.com/Support%20Documents/TechnicalDocs/AN639.pdf

I read that when you posted it before (thanks, BTW, it was a good read) - that's the "much" of "I don't know much." :)  The source of EM radiation is the square loop from what I understand.  In the meep file, the source is a giant square, radiating towards the square loop.  That doesn't sound to me like the right approach, but I really don't know.  I also don't really know what the EM radiation should look like, if I did, I could compare it to the meep output and see if it matches.

Offline SeeShells

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...Dr. rodal, what does this look like to you???
http://d1czgh453hg3kg.cloudfront.net/content/royprsa/467/2133/2500/F2.large.jpg
Figure 2.
Projection of Poynting vector direction (equation (3.2)) from a circularly polarized dipole, in the plane Embedded Image, showing swirl near the dipole axis and divergence far away.
Ref...
http://rspa.royalsocietypublishing.org/content/467/2133/2500

I think it's a great idea RFMWGUY!

Shell

Yes, you are correct.  It is that I don't believe it.

I have written a program with Wolfram Mathematica, and for Yang/Shell (which is much closer to a cylinder and much further from the cone vertex) I get a net force (taking into account all stresses) to be practically zero.  Nada. Zilch.

But for NSF-1701 geometry (which has a small base much closer to the vertex), I'm getting a net force pointing from the big base towards the small base, and the major component is coming from the copper conical lateral surface.  I'm trying to make sense out of this, because as you say, I don't believe it.

Momentum is conserved in General Relativity.
So here is my question: can you think of another phenomenon in Nature where something will accelerate only due to internal electromagnetic fields without anything ejecting to the outside?

Interestingly enough Doc it doesn't agree with the data published about thrusts. Is the data from the Yang tests totally bogus? Or we don't have the matter of the RF injection correct yet?

I'd be wondering what your stress / poynting vector analysis is really showing? As of now it is only showing a asymetrical differential of stress levels from one end vs the other.  What are you looking for your asymmetrical stress figures to do I guess would be the question?

Right now I can take a enclosed can of air, put a air pump in it blowing at one end and the can sits still, but the pressure is higher at one end vs the other. If your saying that the increased stress in one end compresses and acts like a gravity induced gradient at that end and that causes the can to "squirt" along in it's own micro gravity well trying to equalize itself than that's a gravity warp drive.

shell

Offline RonM

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The only one claiming "propellant-less" in that absolutist way is Shawyer.  Everybody else (McCulloch, White, etc.) no matter how unusual their theories, claims an interaction with the outside

true, but it´s quite different to claim an interaction with something that doesn´t care about the engine/ship walls, in other words, the engine push "it" but "it" doesn´t interact with the the rest of the ship... like virtual particles in White's Theory or "the rest of the mass of the universe", in Mach Effect Theory...

... and pushing air... which in that case, EM Drive is not a propellantless propulsion, but just a propeller-less air engine.

A propeller-less air engine would be great for drones and helicopters, but no so much for spaceflight.

Anyway, I still don't get these astronomical Q values required for EM drives. In real world engineering, aren't the highest practical Q values in the thousands? Even if the theory did work, how could someone build a device that needed Q several orders of magnitude higher?

Offline Rodal

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...
Interestingly enough Doc it doesn't agree with the data published about thrusts. Is the data from the Yang tests totally bogus? Or we don't have the matter of the RF injection correct yet?

I'd be wondering what your stress / poynting vector analysis is really showing? As of now it is only showing a asymetrical differential of stress levels from one end vs the other.  What are you looking for your asymmetrical stress figures to do I guess would be the question?

Right now I can take a enclosed can of air, put a air pump in it blowing at one end and the can sits still, but the pressure is higher at one end vs the other. If your saying that the increased stress in one end compresses and acts like a gravity induced gradient at that end and that causes the can to "squirt" along in it's own micro gravity well trying to equalize itself than that's a gravity warp drive.

shell

These are my views on the subject, submitted for whatever little (or nothing :) ) they may be worth. 

I submit them now, since you still have time to change the geometry of what you are going to test, and you may want to consider the following points in selecting your geometry.

<<Interestingly enough Doc it doesn't agree with the data published about thrusts. Is the data from the Yang tests totally bogus?>>

1) My statement above that the net force is zero for Yang/Shell is based on a completely different program using the energy-momentum covariant tensor in General Relativity.  This program is NOT the program that processes the Meep output to come up with the stress tensor and forces. Not based on the Meep runs

2) The Yang-Shell geometry should not be assumed to be the geometry used by Yang in her tests 
I should know, since I was the one that calculated the Yang/Shell geometry as the best estimate of her dimensions based on her early theoretical paper, and then placed those dimensions in the EM Drive wiki (explaining where they came from). Those dimensions were a best effort at inferring what the geometry was in one of her earlier papers:

a) Yang has several papers, the geometry for which Yang/Shell is based on is from a different paper where she  reports the highest forces reported.  The assumption that the geometry applies to both is just an assumption.

b) Yang does not explicitly give all the dimensions of her frustum.   Tajmar gave the dimensions for his EM Drive and it turns out that they were off by a factor of 2.  It is quite possible that something was lost in translation and the dimensions of her frustrum are different.  The geometry in her drawings looks quite different than the geometry assumed in Yang/Shell.  Her drawings show shorter length and a much larger cone angle than the cone angle in Yang/Shell.

c) IMO I think that conducting experiments based on the Yang/Shell geometry is more risky because:

c1) The Yang/Shell geometry was not provided by Yang.  Better to use a geometry provided by one of the researchers.  For example the geometry provided by NASA, which we know 100% as to being the true geometry being tested.

c2) The Yang/Shell geometry is the closest to a cylinder, having the smallest cone-angle and the largest distance between the small base and the apex of the cone.  I would use a geometry having the small base much closer to the apex: the NASA geometry or the Shawyer Demonstrator

c3) the Meep runs and my separate runs show the NSF-1701 geometry as more sensitive to test than the Yang/Shell geometry.  The Meep runs show NSF-1701 to be much more sensitive to antenna placement: very different behavior of NSF-1701, force orientation when antenna is placed at one end vs the other end.  My separate computations of Yang/Shell show it to be very close to a cylinder in its behavior, self-balanced force distribution.

c4) Based on the following formulas, the Yang/Shell geometry should be the one producing lowest thrust because:

c4A) Marco Frasca General Relativity derivation: the closest to the vertex the better.  Yang/Shell is the geometry furthest away from vertex of the cone

c4B) Todd "WarpTech" Zang and Fan paper: critical parameter is kr.  Yang/Shell has highest kr, which is worse, according to the theory

c4C) McCulloch and Notsosureofit thrust is highly dependent on the difference between the radii of the bases.  Yang/Shell is the closest to a cylinder: should generate the least thrust.

<<I'd be wondering what your stress / poynting vector analysis is really showing? As of now it is only showing a asymetrical differential of stress levels from one end vs the other.  What are you looking for your asymmetrical stress figures to do I guess would be the question? >>

The stress analysis based on the Meep runs is completely independent of the Poynting vector analysis.  The stress analysis is not at all based on the Poynting vector. 

What is more intuitive to look at are the forces calculated and displayed.  The forces are the integral of the normal stress over the cross-sectional areas.  Forces is what people talk about when discussing the EM Drive.  It is most important to understand what the forces are, how they behave vs. time and how they confirm or nullify the very simplified theories that are being thrown around.

<<Right now I can take a enclosed can of air, put a air pump in it blowing at one end and the can sits still, but the pressure is higher at one end vs the other>>

The air pressure should not be higher at one end than the other (at least in steady state, which I expect to be rapidly reached).  The equilibirum pressure should be uniformly distributed inside, no matter what the shape.  PV = nRT.  I don't understand the thought-experiment as to why the air pressure varies on the inner surface of the air can.

I can show that if one has uniform pressure inside an EM Drive, the normal stress (which is the same thing as pressure) being constant on the inner surfaces, translates to a balanced zero net force.  This is NOT what the Maxwell's equations solutions show.  The electromagnetic fields do NOT result in a uniform pressure on the inside.

IMHO based on the analysis, and as discussed above the NSF-1701 geometry is the one I would test because it has the same diameters as the NASA frustum and the one tested by Iulian Berca, and because the Meep analysis shows it to be more sensitive, while the Yang/Shell geometry is unknown whether it is representative of any EM Drive tested by Yang, and the computer results shows it to be much less sensitive, and its geometry is much closer to a cylinder, and has the small base very distant from the vertex:

http://emdrive.wiki/Experimental_Results

                               r1 (distance from small base to vertex of the cone)

Yang/Shell               0.6953 m               
NASA Eagleworks     0.3111 m  (similar to NSF-1701 and to the one of Iulian Berca)
Shawyer Demo        0.2260 m


Since rfmwguy is testing a geometry close to NASA, to be complementary, and since we don't quite know the Yang geometry, but we seem to have a better fix on the Shawyer geometry (from TheTraveller's communication with Shawyer) I would probably choose Shawyer's Demonstrator as the geometry, based on present information, IMHO.  :)

SeeShell, I think you have a fabulous testing set-up and testing approach, that's why I spent this time in giving you this lengthy opinion.
« Last Edit: 07/30/2015 10:21 PM by Rodal »

Offline aero

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@SeeShells

I can't get h5topng to color the dielectric plug so that it shows in the same image with the antenna and the frustum border. But there is one there and you can see that the copper border doesn't connect on either side of the plug so the hole is all the way through the copper. I expect that the field images may indicate the existence of the dielectric plug, and HDFveiw shows it nicely, but not the antenna - so - see the attached.
Retired, working interesting problems

Offline Ricvil

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...Dr. rodal, what does this look like to you???
http://d1czgh453hg3kg.cloudfront.net/content/royprsa/467/2133/2500/F2.large.jpg
Figure 2.
Projection of Poynting vector direction (equation (3.2)) from a circularly polarized dipole, in the plane Embedded Image, showing swirl near the dipole axis and divergence far away.
Ref...
http://rspa.royalsocietypublishing.org/content/467/2133/2500

I think it's a great idea RFMWGUY!

Shell
Since you asked, here is my answer: I don't see how these ideas address the main question:

* Conservation of Momentum and balance of forces

If they do address it, and I missed it, I would appreciate knowing how they address conservation of momentum and balance of forces

I think it is not that you missed it. I feel it is that you don't believe it. The group velocity, phase velocity and the speed of light, are not the same at both ends of the cavity. The momentum carried by EM waves depends on the refractive index and the phase velocity. It is not "free space" inside the cavity. Light is being squeezed at the small end and expands toward the big end. In doing so, there is a force created by this gradient that is not symmetrical because dp/dt is not symmetrical. Nothing has to escape for this to be true, it only needs to be dissipated by doing work to thrust the frustum. It is GR, it is geometry, it is Maxwell's equations in curved space-time, acting over a narrow bandwidth near the cut-off.

That is what all 4 equations are saying. How each of us interpreted the geometry and it's effects on these velocities is different, but we all agree that this is how momentum is conserved. Space-time is being curved at this frequency, which per the PV Model is "identical" to a variable refractive index. Until you "accept this", you will continue to expect CoM to be violated, because there is NO OTHER explanation. Puthoff & Davis have done experiments with squeezed light, in an attempt to create exotic matter.

http://www.earthtech.org/publications/davis_STAIF_conference_1.pdf
Squeezed Light: http://arxiv.org/abs/1401.4118

E. Davis might actually stop knocking the EM Drive if he understood what I'm talking about. It is right up his alley!
Todd
Yes, you are correct.  It is that I don't believe it.

I have written a program with Wolfram Mathematica, and for Yang/Shell (which is much closer to a cylinder and much further from the cone vertex) I get a net force (taking into account all stresses) to be practically zero.  Nada. Zilch.

But for NSF-1701 geometry (which has a small base much closer to the vertex), I'm getting a net force pointing from the big base towards the small base, and the major component is coming from the copper conical lateral surface.  I'm trying to make sense out of this, because as you say, I don't believe it.

In General Relativity momentum is part of the energy-momentum tensor, which transforms as a covariant quantity, not as an invariant.  Hence it is difficult to have intuition about it. 


So here is my question: can you think of another phenomenon in Nature where something will accelerate only due to internal electromagnetic fields without anything ejecting to the outside?

Dr Rodal
The fields you are using comes from Meep, right?
You're  already calculated the force on the antenna?
The antenna ( a dipole )  is metallic and has a scattering cross section bigger than it's physical dimensions.
In a real physical setup, the antenna is fixed to structure of the cavity and not floating inside it.
Verify the force on the antenna because the force on it must be accounted for the evaluation of total net force of the system.

Offline BL

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Re rfmwguy Post #5685
“Ps to dm...is dark matter floobie dust?”

I am certainly not qualified to critique ‘dark matter/dark energy’ from a scientific perspective.

What bothers me about it is that it is merely one example, in a variety of ‘scientific’ fields, in which the universe is not behaving according to established theory and, rather than adjusting the theory to fit observations the universe is adjusted to conform to established theory.  In this case, it required that 95+% of the universe consist of ‘stuff’ for which the only evidence of its existence is the requirement that the universe conform to EXISTING theory.

Meanwhile, Dr. McCulloch has a theory, which I am equally unqualified to critique, which he claims explains observations without the requirement of unobservable, undetectable ‘stuff’.  He is dismissed as a ‘kook’ and his theory is not even given cursory consideration.  Why?  Because his theory conflicts with ‘established theory’. 

Is dark matter real or not?  Is Dr. McCulloch’s theory right or wrong?  Haven’t the foggiest.  I do know though that rejecting new theories because they are in conflict with old theories, even to the point in the case of DM/DE of inventing an undetectable 95% of the universe to force the universe to conform to theory, seems to me to be a singularly unpromising method of ‘advancing science’. 

In my case that goes a long way toward explaining why I am rooting against ‘established science’ in the case of the EmDrive.  I am an aficionado of manned space travel, but unless EmDrive or something functionally equivalent is real, we ain’t goin’ nowhere and we ain’t gonna do nothin’ when we get there.  So I HOPE that it is real and that one or more of the DIY’ers demonstrate measurable, repeatable thrust after accounting for experimental artifacts.  If not, maybe the NEXT 'fringe effort' WILL work. 

Offline WarpTech

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...Dr. rodal, what does this look like to you???
http://d1czgh453hg3kg.cloudfront.net/content/royprsa/467/2133/2500/F2.large.jpg
Figure 2.
Projection of Poynting vector direction (equation (3.2)) from a circularly polarized dipole, in the plane Embedded Image, showing swirl near the dipole axis and divergence far away.
Ref...
http://rspa.royalsocietypublishing.org/content/467/2133/2500

I think it's a great idea RFMWGUY!

Shell
Since you asked, here is my answer: I don't see how these ideas address the main question:

* Conservation of Momentum and balance of forces

If they do address it, and I missed it, I would appreciate knowing how they address conservation of momentum and balance of forces

I think it is not that you missed it. I feel it is that you don't believe it. The group velocity, phase velocity and the speed of light, are not the same at both ends of the cavity. The momentum carried by EM waves depends on the refractive index and the phase velocity. It is not "free space" inside the cavity. Light is being squeezed at the small end and expands toward the big end. In doing so, there is a force created by this gradient that is not symmetrical because dp/dt is not symmetrical. Nothing has to escape for this to be true, it only needs to be dissipated by doing work to thrust the frustum. It is GR, it is geometry, it is Maxwell's equations in curved space-time, acting over a narrow bandwidth near the cut-off.

That is what all 4 equations are saying. How each of us interpreted the geometry and it's effects on these velocities is different, but we all agree that this is how momentum is conserved. Space-time is being curved at this frequency, which per the PV Model is "identical" to a variable refractive index. Until you "accept this", you will continue to expect CoM to be violated, because there is NO OTHER explanation. Puthoff & Davis have done experiments with squeezed light, in an attempt to create exotic matter.

http://www.earthtech.org/publications/davis_STAIF_conference_1.pdf
Squeezed Light: http://arxiv.org/abs/1401.4118

E. Davis might actually stop knocking the EM Drive if he understood what I'm talking about. It is right up his alley!
Todd
Yes, you are correct.  It is that I don't believe it.

I have written a program with Wolfram Mathematica, and for Yang/Shell (which is much closer to a cylinder and much further from the cone vertex) I get a net force (taking into account all stresses) to be practically zero.  Nada. Zilch.

But for NSF-1701 geometry (which has a small base much closer to the vertex), I'm getting a net force pointing from the big base towards the small base, and the major component is coming from the copper conical lateral surface.  I'm trying to make sense out of this, because as you say, I don't believe it.

In General Relativity momentum is part of the energy-momentum tensor, which transforms as a covariant quantity, not as an invariant.  Hence it is difficult to have intuition about it. 


So here is my question: can you think of another phenomenon in Nature where something will accelerate only due to internal electromagnetic fields without anything ejecting to the outside?

The force acting on the conical surface is exactly what you should get. It has very little to do with what is striking the end plates and everything to do with the tapered walls causing the EM waves to expand and contract along the gradient.

Yes I can, Gravity. It is also a gradient. It does not exchange photons or gravitons with the Earth to "fall". Space-time (ZPF) drives the harmonic oscillation of the particle. It doesn't radiate to "fall" it simply shifts frequency due to the shift in equilibrium between the driving force and the damping force. This is represented by Gravitational Time Dilation. Which is precisely what is happening to the EM waves inside the frustum, frequency shift causes a change in momentum, which results in thrust.

Literally, it is a frequency dependent gravitational field in a can. I'm sorry you don't believe it, but that is what it is.
Todd
« Last Edit: 07/30/2015 07:57 PM by WarpTech »

Offline Prunesquallor

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   Hmmm....EM Drive sounds a lot like the claims of anomalist theorists (I'm being charitable) who speculate that so-called 'flying saucers' (no proof they exist) are supposedly propelled by microwaves.

But back to the issue of a genuine EM Drive. Rodal and Seeshells are now arguing in circles when the only way to settle the issue is?...Is for some (eccentric perhaps) millionaire or billionaire to provide funds to build (at least) a small-scale 'working' prototype to be sent into LEO to see if it works; and if it works, to see if it has any real advantage over VASIMR, or
even an ordinary ion rocket-motor.

I know I've said this before, but if folks believe LEO is some pristine environment that will remove any unknowns that might affect performance, I suggest considering solar particle events, orbital drag, gravity gradients, atomic oxygen, geomagnetism, thermal cycling, radiation pressure, gravitational harmonics, spacecraft outgassing and avionics EMI.  Yes, you CAN do experiments like Gravity Probe B, but they ain't easy.

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