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#1680 by flux_capacitor on 06 Sep, 2015 11:22
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...
PA Thanks Dr. Rodel! You were right but if is from EW. Now out to the shop. Got a drive to build and as much as I'd love to spend a Saturday chatting with all you great people I have to get booking.
Sorry, but I find this confusing, the image (reproduced now at the left for TE013) is not one I recall from NASA Eagleworks. Is it is something that came from NASA, what is the context in which it was produced? It is also important to establish what are the conditions for the image. Does it include dielectric inserts? What is the natural frequency?
I attach below the original report by Frank Davis (that I am familiar with, that Paul March made available in thread 2) to verify that the image at the left is NOT something that was in the report from NASA that Paul March made available in thread 2
* There are only 27 pages in Frank Davis report, there is no page 28
* There is no TE013 displayed by Frank Davis in his report, as TE013 for the NASA frustum without dielectric has a natural frequency amply exceeding 2.45 GHz
I attach below the image for TE012 that originated with NASA Eagleworks
I would appreciate anybody being able to trace it to its original message, so that we can verify who is the author, and most relevant what are the conditions for that plot
All these images come from Eagleworks.
The one you show is indeed from Frank Davies' 2014 progress report, posted by Paul March in this message of the EM Drive Thread 2. The document is entitled "Copper Frustum modes" and the file name is "Frustrum modes overview 2A.pdf". Paper reattached below. TE012 mode is page 18 and calculated for a frequency of 2.1794 GHZ without dielectric. The image shows magnetic H-field vectors in blue and electric E-field vectors in red:
"Without a dielectric" because the caption is 2.1794 GHZ, which is the frustum resonant frequency for this mode, whereas the resonant frequency measured by Eagleworks with 2 PE discs inside was 1.8803 GHz for the same TE012 mode.
See also Eagleworks' 2014 main paper, figure 15 page 12, which also shows TE012 mode with a dielectric:
"With a dielectric" because the text states:QuoteThe COMSOL analysis iteration process was used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster. The geometry of the RF resonator disc is a function of the resonator material’s relative permittivity, dissipation factor, and target resonance mode.
You can see the H and E vectors are quite similar with or without a dielectric, for this TE012 mode.
The TE012 mode published by SeeShells and I (along the TE013 version), showing magnetic streamlines in blue, are also from Eagleworks. Those images come from another 2014 report by Davies entitled "Notes on fields in a frustrum type chamber". I can't find where it has been posted the first time (I think by TheTraveller), so I reattach the paper to this message. Whatever I don't understand how streamlines would be a problem instead of field vectors, since streamlines show the path drawn if you link the vectors together, like in a "connecting the dot" game. To me it is the same thing:
Retrieving this file I am shocked to find an important information I didn't see before: those TE/TM modes simulations by Davies (25 March 2014) are based not on Eagleworks' frustum, but Yang's frustum with "proportions estimated from Chinese paper" by Davies!!!!!
Chinese proportions which would be, according to Davies:
Db = L and Ds = Db/2
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#1681 by X_RaY on 06 Sep, 2015 12:19
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Interesting are the modes shapes like "TM0(1.5)2" in that document....
PA Thanks Dr. Rodel! You were right but if is from EW. Now out to the shop. Got a drive to build and as much as I'd love to spend a Saturday chatting with all you great people I have to get booking.
Sorry, but I find this confusing, the image (reproduced now at the left for TE013) is not one I recall from NASA Eagleworks. Is it is something that came from NASA, what is the context in which it was produced? It is also important to establish what are the conditions for the image. Does it include dielectric inserts? What is the natural frequency?
I attach below the original report by Frank Davis (that I am familiar with, that Paul March made available in thread 2) to verify that the image at the left is NOT something that was in the report from NASA that Paul March made available in thread 2
* There are only 27 pages in Frank Davis report, there is no page 28
* There is no TE013 displayed by Frank Davis in his report, as TE013 for the NASA frustum without dielectric has a natural frequency amply exceeding 2.45 GHz
I attach below the image for TE012 that originated with NASA Eagleworks
I would appreciate anybody being able to trace it to its original message, so that we can verify who is the author, and most relevant what are the conditions for that plot
All these images come from Eagleworks.
The one you show is indeed from Frank Davies' 2014 progress report, posted by Paul March in this message of the EM Drive Thread 2. The document is entitled "Copper Frustum modes" and the file name is "Frustrum modes overview 2A.pdf". Paper reattached below. TE012 mode is page 18 and calculated for a frequency of 2.1794 GHZ without dielectric. The image shows magnetic H-field vectors in blue and electric E-field vectors in red:
"Without a dielectric" because the caption is 2.1794 GHZ, which is the frustum resonant frequency for this mode, whereas the resonant frequency measured by Eagleworks with 2 PE discs inside was 1.8803 GHz for the same TE012 mode.
See also Eagleworks' 2014 main paper, figure 15 page 12, which also shows TE012 mode with a dielectric:
"With a dielectric" because the text states:QuoteThe COMSOL analysis iteration process was used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster. The geometry of the RF resonator disc is a function of the resonator material’s relative permittivity, dissipation factor, and target resonance mode.
You can see the H and E vectors are quite similar with or without a dielectric, for this TE012 mode.
The TE012 mode published by SeeShells and I (along the TE013 version), showing magnetic streamlines in blue, are also from Eagleworks. Those images come from another 2014 report by Davies entitled "Notes on fields in a frustrum type chamber". I can't find where it has been posted the first time (I think by TheTraveller), so I reattach the paper to this message. Whatever I don't understand how streamlines would be a problem instead of field vectors, since streamlines show the path drawn if you link the vectors together, like in a "connecting the dot" game. To me it is the same thing:
Retrieving this file I am shocked to find an important information I didn't see before: those TE/TM modes simulations by Davies (25 March 2014) are based not on Eagleworks' frustum, but Yang's frustum with "proportions estimated from Chinese paper" by Davies!!!!!
Chinese proportions which would be, according to Davies:
Db = L and Ds = Db/2
I had some thoughts in something like that sometimes ago(but never post that). Really enlightening!
Thanks for this quote.
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#1682 by Rodal on 06 Sep, 2015 12:32
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[...
All these images come from Eagleworks.
....
The TE012 mode published by SeeShells and I (along the TE013 version), showing magnetic streamlines in blue, are also from Eagleworks. Those images come from another 2014 report by Davies entitled "Notes on fields in a frustrum type chamber". I can't find where it has been posted the first time (I think by TheTraveller), so I reattach the paper to this message. Whatever I don't understand how streamlines would be a problem instead of field vectors, since streamlines show the path drawn if you link the vectors together, like in a "connecting the dot" game. To me it is the same thing:...
Thank you so much for going through the trouble to find out this report:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1064610
by Davies (?) entitled "Notes on fields in a frustrum type chamber"
I note that you could not find either any post by Paul March introducing this report.
It is also my recollection that these images first made it into the thread by a post by TheTraveller.
I have been here since thread 1 and I do NOT recall any post from Paul March, or any discussion with Paul March about this report. I carefully read every post by Paul March and I don't recall this report being attached or discussed by Paul March. On the other hand I do NOT read as carefully many of TheTraveller's posts. So I don't understand how this report by Davis became public.
So the question still stands: how did this internal NASA report and its images make it into the thread and become public
////////////////////////////////////
Concerning the question:QuoteWhatever I don't understand how streamlines would be a problem instead of field vectors, since streamlines show the path drawn if you link the vectors together, like in a "connecting the dot" game. To me it is the same thing
The answer is simple: SeeShells asked me how to reconcile my contour plots with the images posted by TheTraveller, it is an excellent question, because the images were NOT posted with any title indicating whether these were contour lines or streamlines. They are NOT the same thing, they are completely different.
If you have a plot with lines, and NO title indicating whether it is contour plot or a streamline plot, you cannot ascertain whether it is a contour plot or a streamline plot.
The contour plot of the electromagnetic field components are completely different from the streamline plots of the field vectors.
Frank Davis makes this distinction clear on page 4 of his report, where he writes
<<Notice how streamlines can mislead about where field strength is highest. Electric field is concentrated at the wide part>>
yes, streamlines can be very MISLEADING, particularly when they are not labeled as such. I have only shown contour line plots, or alternatively I have shown field vectors for my plots, but never streamlines without vectors, for that reason.
This distinction is very important for the discussion with Shell and Aero, regarding where to place the antenna loop and what the dimensions of the loop should be.
Without a title indicating what the plot is (whether a contour plot or a streamline plot) one is lost. Of course, if the field vectors are shown on top of the streamlines one can ascertain that the lines are streamlines. But here we had a plot just with lines on the left, and another plot with field vectors on the right. Without a title one could think that one plot was a contour plot or a streamline plot. One wouldn't know.
Of course, upon further examination one concludes that it is a streamline plot because the plot as shown would be an incorrect contour plot (this is the conclusion at which I arrived independently in a previous post, without having the benefit of seeing the report).
//////////////////////////////
It is so evident that this report was not ever introduced or discussed by Paul March into this thread that you yourself are shocked to find out that this report refers to a Yang fustrum and NOT to the Eagleworks frustum
To refresh people's minds, we had a long discussion regarding Yang/Shell frustum, in that discussion I was of the firm opinion that the 6 degree cone angle geometry could NOT be the geometry of the Yang shell. Most other people in the thread at that time were disagreeing with me saying that I was overinterpreting Yang's drawings.
At the time of those discussions, none of us knew about the existence of this report, that actually gives the geometry for Yang's frustum
This report agrees with my interpretation: the Yang/Shell 6 degree geometry is NOT the geometry of the Yang shell, the geometry of the Yang shell has a much greater cone angle, and hence the ratio between the big base and the small base is signficantly greater than 1.
The dimensions chosen by Frank Davis are similar to the dimensions I concluded that Yang's frustum should have:
Length = 0.24 m
Big Base = 0.247 m
Small Base = 0.114425 m
In other words:
Length ~ Big Base
Small Base ~ (Big Base)/2
Completely different from the Yang/Shell 6 degree geometry.
Furthermore, when we were discussing these images with Shell, not knowing whether the lines were streamlines or contour lines, the assumption was that the geometry represented was that of the Eagleworks frustum. Looking at this report, that assumption was completely incorrect: those images are not for the Eagleworks frustum, instead they are for the Chinese frustum !!!!!
So, I am sure glad that I asked where did these images come from, and that you found the report, as the images were not of the Eagleworks frustum, but instead they were of the Chinese frustum.
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#1683 by ElizabethGreene on 06 Sep, 2015 13:50
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I understand it is normal for the magnetron to get very hot during operation, and this is exacerbated if there is a large impedance mismatch.
Is there a similar expectation that a resonator will also get warm or even hot?
Thanks. -
#1684 by deltaMass on 06 Sep, 2015 14:01
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Yes, you certainly have the right idea here. With a perfect match, no power is reflected back to the magnetron, and that naturally minimises magnetron heating. Correspondingly, all the power is dissipated as real heat in the conducting walls of the cavity. This is just the same as a perfect match to any circuit, where all power is dissipated as heat in the ESR of the circuit.
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#1685 by SeeShells on 06 Sep, 2015 14:04
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http://ayuba.fr/images/emdrive/TE012_from_Frustum_modes_overview_2A.png
Looking at the geometry of this frustum I came up with a ratio Be to Se of 1.8 to 1.
Using a arbitrary number with a ruler tool for generating the % of size difference in the Be vs Se by pasting the file into Sketchup and getting diameter measurements of Be=2.7 and Se 1.5, it is a 1.8:1 ratio.
Interestingly enough the current CE design is 1.8 to 1. ~ 300mm/165mm 1.81:1 when I'm finalized with building it. Although the center plate to plate ratio is different I think I can fine tune the TE012 in with the adjustable floating top plate if needed.
Shell
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#1686 by deltaMass on 06 Sep, 2015 14:44
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Since EmDrive is well out on the fringe in any case, one might as well go whole hog and seek to relate all ratios to the Golden Ratio.
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#1687 by SeeShells on 06 Sep, 2015 14:50
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Since EmDrive is well out on the fringe in any case, one might as well go whole hog and seek to relate all ratios to the Golden Ratio.
1.618 
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#1688 by Eer on 06 Sep, 2015 14:54
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Since EmDrive is well out on the fringe in any case, one might as well go whole hog and seek to relate all ratios to the Golden Ratio.
1.618
So - mystical numerology - applying the golden ratio to the dimensions of a frustum, what harmonic frequency will resonate? Or, inversely, given the golden ratio as a gigahertz frequency, what shape of a frustum will resonate at that frequency?
Inquiring minds want to know ... -
#1689 by SeeShells on 06 Sep, 2015 15:08
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I need to measure this engine first to give you an answer.Since EmDrive is well out on the fringe in any case, one might as well go whole hog and seek to relate all ratios to the Golden Ratio.
1.618
So - mystical numerology - applying the golden ratio to the dimensions of a frustum, what harmonic frequency will resonate? Or, inversely, given the golden ratio as a gigahertz frequency, what shape of a frustum will resonate at that frequency?
Inquiring minds want to know ...
http://www.projectrho.com/public_html/rocket/images/reactionlessdrive/propulsion.jpg
Maybe I'll ask my assistant.
http://www.gifwave.com/media/816070_halloween-young-frankenstein-igor-halloweeen-countdown_200s.gif -
#1690 by Rodal on 06 Sep, 2015 15:25
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Maybe this will make some waves
But will it hold water?
http://www.science20.com/hammock_physicist/swimming_through_empty_space
http://news.sciencemag.org/2003/02/swimming-through-spacetime
Here is the original article by Prof. Jack Wisdom (MIT):
http://web.mit.edu/wisdom/www/swimming.pdf
For a meter-sized object performing meter-sized deformations at the surface of the Earth, the
displacement is of order 10^(-23) m
Nevertheless, here is an example of how General Relativity allows propellant-less motion in space.Quote from: Jack WisdomThe curvature of spacetime is very slight,
so the ability to swim in spacetime is unlikely
to lead to new propulsion devices. For a
meter-sized object performing meter-sized
deformations at the surface of the Earth, the
displacement is of order 10^(-23) m . Nevertheless,
the effect is interesting as a matter
of principle. You cannot lift yourself by pulling
on your bootstraps, but you can lift yourself
by kicking your heels.
Notice that all the "frame independence absolutists" that like to write ad nauseam about trivial frame-independence, are all of a sudden speechless concerning this paper by an MIT Professor showing that one can actually use General Relativity to swim in space (albeit at an extremely small "stroke" of 10^(-23) m )
No need for negative mass !!
No need for Woodward's Mach Effect !!
No need for Quantum Vacuum !!
to do this.
What is required is a deformable object (I always noticed that "frame independent absolutists" invariable portray bodies as rigid and isotropic !!! ) and a gravitational field in General Relativity
So much for their "frame independence" absolutism that an astronaut cannot swim in space. So much ink in here and in Reddit has been wasted about "frame-independence" arguments. How do they deal with this counter-example?
Contrary to the "self-appointed experts on frame-independence", General Relativity allows, rather than prevents, swimming in space
Here is more: http://physics.stackexchange.com/questions/46180/can-a-deformable-object-swim-in-curved-space-time
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#1691 by Rodal on 06 Sep, 2015 16:03
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Maybe this will make some waves
But will it hold water?
http://www.science20.com/hammock_physicist/swimming_through_empty_space
http://news.sciencemag.org/2003/02/swimming-through-spacetime
Here is the original article by Prof. Jack Wisdom (MIT):
http://web.mit.edu/wisdom/www/swimming.pdf
For a meter-sized object performing meter-sized deformations at the surface of the Earth, the
displacement is of order 10^(-23) m
Nevertheless, here is an example of how General Relativity allows propellant-less motion in space.Quote from: Jack WisdomThe curvature of spacetime is very slight,
so the ability to swim in spacetime is unlikely
to lead to new propulsion devices. For a
meter-sized object performing meter-sized
deformations at the surface of the Earth, the
displacement is of order 10^(-23) m . Nevertheless,
the effect is interesting as a matter
of principle. You cannot lift yourself by pulling
on your bootstraps, but you can lift yourself
by kicking your heels.
Notice that all the "frame independence absolutists" that like to write ad nauseam about trivial frame-independence, are all of a sudden speechless concerning this paper by an MIT Professor showing that one can actually use General Relativity to swim in space (albeit at an extremely small "stroke" of 10^(-23) m )
No need for negative mass !!
No need for Jim Woodward !!
No need for Quantum Vacuum !!
to do this.
What is required is a deformable object (I always noticed that "frame independent absolutists" invariable portray bodies as rigid and isotropic !!! ) and a gravitational field in General Relativity
So much for their "frame independence" absolutism that an astronaut cannot swim in space. So much ink in here and in Reddit has been wasted about "frame-independence" arguments. How do they deal with this counter-example?
Contrary to the "self-appointed experts on frame-independence", General Relativity allows, rather than prevents, swimming in space
Here is more: http://physics.stackexchange.com/questions/46180/can-a-deformable-object-swim-in-curved-space-time
Another unproven mantra repeated ad-nauseam in these threads and in Reddit is that "New Physics" are needed.
This swimming in space counter-example shows the opposite: NO new Physics needed. All that is needed for swimming in space is General Relativity. NOT new. It has been around for 100 years.
What is needed is for people to stop modeling bodies as being rigid and isotropic. -
#1692 by SeeShells on 06 Sep, 2015 16:03
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At least something makes sense, even if it's a tiny bit of sense and a tiny bit of movement.Maybe this will make some waves
But will it hold water?
http://www.science20.com/hammock_physicist/swimming_through_empty_space
http://news.sciencemag.org/2003/02/swimming-through-spacetime
Here is the original article by Prof. Jack Wisdom (MIT):
http://web.mit.edu/wisdom/www/swimming.pdf
For a meter-sized object performing meter-sized deformations at the surface of the Earth, the
displacement is of order 10^(-23) m
Nevertheless, here is an example of how General Relativity allows propellant-less motion in space.Quote from: Jack WisdomThe curvature of spacetime is very slight,
so the ability to swim in spacetime is unlikely
to lead to new propulsion devices. For a
meter-sized object performing meter-sized
deformations at the surface of the Earth, the
displacement is of order 10^(-23) m . Nevertheless,
the effect is interesting as a matter
of principle. You cannot lift yourself by pulling
on your bootstraps, but you can lift yourself
by kicking your heels.
Notice that all the "frame independence absolutists" that like to write ad nauseam about trivial frame-independence, are all of a sudden speechless concerning this paper by an MIT Professor showing that one can actually use General Relativity to swim in space (albeit at an extremely small "stroke" of 10^(-23) m )
No need for negative mass !!
No need for Jim Woodward !!
No need for Quantum Vacuum !!
to do this.
What is required is a deformable object (I always noticed that "frame independent absolutists" invariable portray bodies as rigid and isotropic !!! ) and a gravitational field in General Relativity
So much for their "frame independence" absolutism that an astronaut cannot swim in space. So much ink in here and in Reddit has been wasted about "frame-independence" arguments. How do they deal with this counter-example?
Contrary to the "self-appointed experts on frame-independence", General Relativity allows, rather than prevents, swimming in space
Here is more: http://physics.stackexchange.com/questions/46180/can-a-deformable-object-swim-in-curved-space-time
Doc, you should tell those "self-appointed experts on frame-independence" .
"Come over to the Dark Side"
"You Have Cookies".
Shell
PS: I know I made a joke of a very serious matter you pointed out, but trying to convince some of those guys is silly in itself. I've said extraordinary claims need extraordinary evidence not more extraordinary claims. -
#1693 by deltaMass on 06 Sep, 2015 16:23
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Although swimming in spacetime is indeed possible per GR (and it goes much faster close to a black hole event horizon btw
) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
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#1694 by SeeShells on 06 Sep, 2015 16:30
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Although swimming in spacetime is indeed possible per GR (and it goes much faster close to a black hole event horizon btw
Aren't we squeezing things up a little like a black hole in the frustum with the wave actions? So it should "Go Faster"? ) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
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#1695 by Rodal on 06 Sep, 2015 16:35
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Although swimming in spacetime is indeed possible per GR (and it goes much faster close to a black hole event horizon btw
Concerning Noether, she just formalized something that was already known before her. Repeating "Noether" ad nasueam is not informative or clarifying. ) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
The point is that one can swim in space, all you need is General Relativity.
No "New Physics" are required and the mistake that deniers make is to invoke trivial assumptions of bodies as being rigid and isotropic. The point is that people making trivial statements about conservation and rigidity state that no motion such as swimming in space is possible, and this has been proven to be incorrect.
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#1696 by Rodal on 06 Sep, 2015 16:46
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Although swimming in spacetime is indeed possible per GR (and it goes much faster close to a black hole event horizon btw
Concerning Noether, she just formalized something that was already known before her. Repeating "Noether" ad nasueam is not informative or clarifying. ) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
The point is that one can swim in space, all you need is General Relativity.
No "New Physics" are required and the mistake that deniers make is to invoke trivial assumptions of bodies as being rigid and isotropic. They make trivial statements about conservation of Energy and Momentum. Of course they are conserved.
The point is that people making trivial statements about conservation and rigidity state that no motion such as swimming in space is possible, and this has been proven to be incorrect.
.
Understanding of the consequences of a nonlinear theory like General Relativity only comes from exploration of mathematical solutions (and their eventual experimental confirmation) rather than from general statements.
Physics is not a Legal profession where one learns "laws", physics is an experimental and mathematical subject of exploration of Nature, not one of regurgitation of Laws.
Prof. Jack Wisdom at MIT has a wonderful book on Functional Differential Geometry, that rather than invoke Noether, emphasizes obtaining mathematical solutions, The approach taken and used in their classes at MIT for many years differs from the conventional one in several ways, mainly Wisdom's integration of computer programming into their explanations, from the very beginning. By programming a computer to interpret a formula, the student soon learns whether or not a formula is correct. Students are led to improve their program, and as a result improve their understanding richer language of vector fields and differential forms. -
#1697 by deltaMass on 06 Sep, 2015 17:10
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In all fairness to the subject matter it needs to be mentioned that interpretation of conservation laws in the context of GR has been the subject of a protracted, educated, passionate and often bitter controversy.
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#1698 by SeeShells on 06 Sep, 2015 18:23
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I found my steampunk magnetron. Love this!
http://www.ebay.com/itm/Rare-Western-Electric-Type-5780-Magnetron-NOS-Radar-Vacuum-Tube-Vintage-JAN-/181609285094?hash=item2a48c1c5e6 -
#1699 by aero on 06 Sep, 2015 18:26
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Here are my test results for evaluating my changes to the loop antenna, measuring in meters and not wavelengths. It turns out that using wave lengths was easy, using meters was easy too, after I calculated the number of wave lengths per meter lengths. I think it is right but here is some data to check. Use 0.3 meters per meep length unit.
For frequency ~2.50 GHz, (fsi = 2.495e9) loop parameters are:
start making a loop antenna
Number of points, NP = 283.0
half wave length meep = 0.20026216299265198
loop diameter meep = 0.18
loop circumference meep = 0.5654866776461628
periods around the loop = 1.4118659990377505
meep frequency = 2.496727252558168
Loop antenna created
And for frequency ~ 5.0 GHz (fsi = 4.99e9) loop parameters are:
start making a loop antenna
Number of points, NP = 283.0
half wave length meep = 0.10013108149632599
loop diameter meep = 0.18
loop circumference meep = 0.5654866776461628
periods around the loop = 2.823731998075501
meep frequency = 4.993454505116336
Loop antenna created
Attached are images of the loop at the end of the 3 cycle run.
Plot scale is the same so as you can see, the loop size is independent of wavelength. This is Dr. Rodal's loop, 0.054 meters in diameter. With the fixed circumference in meters, the number of points around the loop depend only on the meep resolution (=250) so are the same in these two runs.
I think it's right. Evaluations?
1.618 
) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
