Quote from: zen-in on 06/29/2015 04:31 PMOne note I would like to add on this subject: If Shawyer's em-drive does not produce any thrust in the absence of vibration then it will not work in outer space. Space is a vacuum and sound waves don't travel in space. There would be no vibrations to "stimulate" the em-drive. Attaching a vibrator to the drive is not hard.Although when the press finds out the spacecraft needs a vibrator to come we will get lots of dildo jokes.

One note I would like to add on this subject: If Shawyer's em-drive does not produce any thrust in the absence of vibration then it will not work in outer space. Space is a vacuum and sound waves don't travel in space. There would be no vibrations to "stimulate" the em-drive.

Quote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=45) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE mode

Views of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.

Quote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=45) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE mode6) How can that be? An examination of the eigenvalue problem using Mathematica and the exact solution shows:TE114 = 2.434 GHzTM114 = 2.479 GHzCONCLUSION: TE114 is excited with strong participation of TM114 We see the strength of Meep: while all the other analysis (including COMSOL FEA by NASA) have been eigenvalue analyses, the Meep solution is a transient solution in time, hence it automatically incorporates a spectrum analysis: it looks at participation of nearby modes. (This can also be done with COMSOL FEA and other FEA programs of course, but nobody else has reported transient solutions up to now).Having two modes with equal m, n, p, nearby results in participation of both modes (having 114 mode shape).

Quote from: Rodal on 06/29/2015 07:40 PMQuote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=45) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE modeI am not sure with p=4. Some times it looks like p=3, a few frames later it looks like p=4 like you mean.Maybe this is a degenerate state of 2 different modes close to each other?

Quote from: X_RaY on 06/29/2015 07:51 PMQuote from: Rodal on 06/29/2015 07:40 PMQuote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=4Question: Is it possible that such "superposition" of several modes caused the propagated trust if one mode is located in the bigger region and the other all over the cone? There are more field-nodes at the bigger end in the x-direction...5) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE modeI am not sure with p=4. Some times it looks like p=3, a few frames later it looks like p=4 like you mean.Maybe this is a degenerate state of 2 different modes close to each other?Excellent point !I agree. It is the result of a lot of modes nearby and the dipole antenna being used is not favoring one mode over another:TE114 = 2.43 GHzTE013 = 2.45 GHzTM114 = 2.47 GHzp=3 comes from TE013

Quote from: Rodal on 06/29/2015 07:40 PMQuote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=4Question: Is it possible that such "superposition" of several modes caused the propagated trust if one mode is located in the bigger region and the other all over the cone? There are more field-nodes at the bigger end in the x-direction...5) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE modeI am not sure with p=4. Some times it looks like p=3, a few frames later it looks like p=4 like you mean.Maybe this is a degenerate state of 2 different modes close to each other?

Quote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=4Question: Is it possible that such "superposition" of several modes caused the propagated trust if one mode is located in the bigger region and the other all over the cone? There are more field-nodes at the bigger end in the x-direction...5) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE mode

...Question: Is it possible that such "superposition" of several modes caused the propagated trust if one mode is more located in the bigger region and the other all over the cone? There are more field-nodes at the bigger end in the x-direction... that looks realy different to the small end.

Quote from: X_RaY on 06/29/2015 08:27 PM...Question: Is it possible that such "superposition" of several modes caused the propagated trust if one mode is more located in the bigger region and the other all over the cone? There are more field-nodes at the bigger end in the x-direction... that looks realy different to the small end.Yes, as happens with parametric vibrations, we could have coupling of modes favoring some nonlinear response.For example: think of the coupling between torsional vibration and bending vibration leading to aeroelastic flutter and aerolastic divergence.Imagine Shawyer trying to make sense of aeroelastic flutter back in WWI ) . How would he describe it?To understand aeroelastic flutter one has to solve coupled systems of differential equations: nobody with the EM Drive is doing this. Instead we get talk about "the EM Drive likes vibration" "the EM Drive likes background forces" "The EM Drive has thrust pointing in the opposite direction than acceleration" This valuable Meep run adds to pointing out another source of lack of robustness in the EM Drive research:1) only one organization has actually verified the mode shape: (NASA that verified TM212). Neither Shawyer or Yang ever provided any experimental verification of mode shapes being excited2) the EM Drive researchers up to now have not analyzed theoretically or numerically a spectrum superposition. They have performed eigenvalue analysis assuming that only one mode was being excited. Shawyer who has been working on this the longest, according to TT uses a kludgy spreadsheet that assumes cylindrical cut-off of modes, pure mode shape excitation and cylindrical formulas. 3) the fact that multiple mode participation is practically possible makes the analysis of the EM Drive data more difficult to interpret. 4) add this to the already known issues of thermal expansion shifting the natural frequencies5) add to this the effect of the RF feed: Yang using a waveguide, many using a magnetron, others not, and so on and on.6) no wonder that robustness in measured results is so elusive and that the statistical distribution of results is so huge...... hopefully continued analysis can shed further light into this. I usually get as a response : just wait for more experiments... Well yes, if the experiments are well-controlled. Otherwise the confusion persists. So we need all three types of analysis: theoretical, numerical and experimental all hand-in-hand to understand what is going on.

...Ack.For a start, it would be good to simulate the effect of changing the dimensions a bit. Does it dramatically affect the results ?Same for frequency: does a small change in freq affects the results in sigificant way?Same for antenna length.Etc.This could provide valuable information for experimenters.

Folks - I really applaud the work going on here. However, I see no obvious progress on the problem of thrust being greater than a photon rocket, namely P/E = 1/c.At the risk of stating the blindingly obvious, for a moving particle P/E = (mv)/(0.5mv^2) = 2/vand so for slow v, P/E is much larger than a photon rocket.So what? Well, if the EM field transfers energy to kinetic energy of electrons within the copper, which then collide with the frustrum (copper atoms) transferring momentum to it, then the ratio of momentum to energy could be high.I'm not sure if this type of interaction would be captured in Lorentz forces generated by the EM field on the Frustrum and its eddy currents.Does not explain how momentum leaves the frustrum...

Quote from: X_RaY on 06/29/2015 08:27 PM...Question: Is it possible that such "superposition" of several modes caused the propagated trust if one mode is more located in the bigger region and the other all over the cone? There are more field-nodes at the bigger end in the x-direction... that looks realy different to the small end.Yes, as happens with parametric vibrations, we could have coupling of modes favoring some nonlinear response.For example: think of the coupling between torsional vibration and bending vibration of a wing leading to aeroelastic flutter and aerolastic divergence.Imagine Shawyer trying to make sense of aeroelastic flutter back in WWI ) . How would he describe it?To understand aeroelastic flutter one has to solve coupled systems of differential equations: nobody with the EM Drive is doing this. Instead we get talk about "the EM Drive likes vibration" "the EM Drive likes background forces" "The EM Drive has thrust pointing in the opposite direction than acceleration" This valuable Meep run adds to pointing out another source of lack of robustness in the EM Drive research:1) only one organization has actually verified the mode shape: (NASA that verified TM212). Neither Shawyer or Yang ever provided any experimental verification of mode shapes being excited2) the EM Drive researchers up to now have not analyzed theoretically or numerically a spectrum superposition. They have performed eigenvalue analysis assuming that only one mode was being excited. Shawyer who has been working on this the longest, according to TT uses a kludgy spreadsheet that assumes cylindrical cut-off of modes, pure mode shape excitation and cylindrical formulas. 3) the fact that multiple mode participation is practically possible makes the analysis of the EM Drive data more difficult to interpret. 4) add this to the already known issues of thermal expansion shifting the natural frequencies5) add to this the effect of the RF feed: Yang using a waveguide, many using a magnetron, others not, and so on and on.6) add to this the never settled, always fluctuating nature of the response due to the RF feed always being on, emitting more and more photons: there is never a state of just standing waves, as assumed by Egan. We have travelling waves, standing waves and evanescent waves.7) no wonder that robustness in measured results is so elusive and that the statistical distribution of results is so huge...... hopefully continued analysis can shed further light into this. We need all three types of analysis: theoretical, numerical and experimental all hand-in-hand to understand what is going on.

Quote from: X_RaY on 06/29/2015 07:51 PMQuote from: Rodal on 06/29/2015 07:40 PMQuote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=45) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE modeI am not sure with p=4. Some times it looks like p=3, a few frames later it looks like p=4 like you mean.Maybe this is a degenerate state of 2 different modes close to each other?IMO, it's most likely due to the antenna being 1/2 wavelength from the small end instead of the 1/4 wavelength needed for resonance. This will cause a "beat" superimposed on the resonant wave. I can see in the pattern the 1/2 wavelength coming into play, and that's not going to resonate well off a reflector.Todd

Quote from: X_RaY on 06/29/2015 07:51 PM...I am not sure with p=4. Some times it looks like p=3, a few frames later it looks like p=4 like you mean.Maybe this is a degenerate state of 2 different modes close to each other?IMO, it's most likely due to the antenna being 1/2 wavelength from the small end instead of the 1/4 wavelength needed for resonance. This will cause a "beat" superimposed on the resonant wave. I can see in the pattern the 1/2 wavelength coming into play, and that's not going to resonate well off a reflector.Todd

...I am not sure with p=4. Some times it looks like p=3, a few frames later it looks like p=4 like you mean.Maybe this is a degenerate state of 2 different modes close to each other?

Quote from: WarpTech on 06/29/2015 09:37 PMQuote from: X_RaY on 06/29/2015 07:51 PM...I am not sure with p=4. Some times it looks like p=3, a few frames later it looks like p=4 like you mean.Maybe this is a degenerate state of 2 different modes close to each other?IMO, it's most likely due to the antenna being 1/2 wavelength from the small end instead of the 1/4 wavelength needed for resonance. This will cause a "beat" superimposed on the resonant wave. I can see in the pattern the 1/2 wavelength coming into play, and that's not going to resonate well off a reflector.ToddThe problem is that when people discuss "1/4 wavelength" or "1/2 wavelength" what wavelength are they talking about ?As I have shown, and you can also see in Meep's results the wave-patterns do not form equal-1/4-wavelength inside the frustum. The functions governing the distribution are not sines and cosines. They are spherical Bessel functions that support unequal wavelength.And you don't know ahead of time whether you are going to have 3 or 4 wave-patterns in the longitudinal direction (it alternates between both in this latest case)So, in order to know the optimal location of the antenna one has to know the solution, which depends on the antenna location. So it is an iterative process where one has to model many antenna locations.And since I'm talking about antennas, Yang did not use an antenna, she used a waveguide to couple the power to the EM Drive, and she got the highest response ever.And how do particle accelerators feed power to their cavities ? Yes, you guessed it: using waveguides instead of antennas.

@SeeShellsYes, I can add as many sources as I want. But someone else must tell me what and where. And will that help the experimenters or theorists? I wonder if the experimenters here will be able to do add many different sources. Just the problem of coming up with the equipment and materials applied in such a way as to avoid degrading the measurements.And what is the noise bandwidth of a magnetron?http://file.scirp.org/Html/8-9801080%5C7aa0f806-9c62-4bf5-ae30-1c09e7756ab9.jpgThis help?Company... need to get but will be back.Shell

Quote from: aero on 06/29/2015 10:21 PM@SeeShellsYes, I can add as many sources as I want. But someone else must tell me what and where. And will that help the experimenters or theorists? I wonder if the experimenters here will be able to do add many different sources. Just the problem of coming up with the equipment and materials applied in such a way as to avoid degrading the measurements.And what is the noise bandwidth of a magnetron?http://file.scirp.org/Html/8-9801080%5C7aa0f806-9c62-4bf5-ae30-1c09e7756ab9.jpgThis help?Company... need to get but will be back.Shell

I just read Mr. Traveller claim on reddit that the vibration increase the thrust of the EmDrive. May I ask you folks if there was already a debate about it here? I would be glad to read about it bit more.

The magnitude and frequency of the vibration that facilitates the measurement of the EM Drive is never addressed.

Is the EM Drive an equal opportunity friend of all magnitudes and frequencies of vibration? This is implied, but it leads to absurd nonsense: is nanometer amplitude vibration enough ? How about picometer amplitude vibration? At what level the boundary between vibration in continuum mechanics and quantum mechanics uncertainty is breached ?

Quote from: A_M_Swallow on 06/29/2015 07:34 PMQuote from: zen-in on 06/29/2015 04:31 PM(...)Attaching a vibrator to the drive is not hard. (...)That presumes that all you have to do to get space propulsion is to have internally generated forces (in this case vibration), internal to the spacecraft, that further violates the principle of conservation of momentum. I think that zen-in was looking at externally-forced vibration, in order to try to not break conservation of momentum.

Quote from: zen-in on 06/29/2015 04:31 PM(...)Attaching a vibrator to the drive is not hard. (...)

(...)