what is being discussed here is an EM Drive copper cavity that is several centimeters long at optical frequencies, with 1 mm tolerance being able to have a Q >9 million.
Quote from: Rodal on 03/11/2016 03:43 pmThe situation is worse: Monomorphic has accepted that he is aiming for a tolerance of only 1 mm. There is no way that a resonance is going to be achieved at optical frequencies that have a wavelength 200,000 times smaller than the frequencies of a typical EM Drive.There is no way that you are going to have reflection and resonance, with well-formed standing waves with a tolerance of only 1 mm at optical frequencies.How can one have resonance in a cavity having 1 mm tolerance, with an optical wavelength of 0.0006 mm As far as I understand, Monomorphic stated that his microwave frustum will have a tolerance (better than) 1mm, not the optical one. Most likely, the optical one will have optically aligned mirrors. Optical cavities can easily have Q of several millions, see: https://www.rp-photonics.com/q_factor.html Therefore, if we are to take Shawyer's theory as guide, it makes total sense that the thrust of an optical system with: -input power ~ 10W -quality factor > 1e6will be easily measurable. Like RonM, I too think that the optical EmDrive is a legitimate path to explore, at least in light of what we know so far. Of course, there might be other arguments against an optical EmDrive, in this case, let's hear them.
The situation is worse: Monomorphic has accepted that he is aiming for a tolerance of only 1 mm. There is no way that a resonance is going to be achieved at optical frequencies that have a wavelength 200,000 times smaller than the frequencies of a typical EM Drive.There is no way that you are going to have reflection and resonance, with well-formed standing waves with a tolerance of only 1 mm at optical frequencies.How can one have resonance in a cavity having 1 mm tolerance, with an optical wavelength of 0.0006 mm
Therefore, if we are to take Shawyer's theory as guide, it makes total sense that the thrust of an optical system with: -input power ~ 10W -quality factor > 1e6will be easily measurable.
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific radii. As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.
Does this have side-walls ? if so, what material is used for the side walls?
It is important for the readers to understand that an optical cavity uses optical mirrors at both ends. It is important for the readers to understand that the mode shape resonance is not due to a frustum of a cone shape, and it is not related to mode shapes in Shawyer's EM Drive.
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific diameter and radii.
Latest email from Roger:Hi Phil... The Horizon programme will be transmitted in the UK at 20:00 on Wed 23 March. It is called Project Greenglow the search for gravity control.Not sure how much reference to EmDrive there will be after it was reviewed by USAF and UK MOD.Best regardsRoger
Dr. Rodal,I am still curious to what you see as a resonate mode with your Mathcad or Wolfram on RFPlumbers dimentions and frequency in his cavity.https://drive.google.com/folderview?id=0B3jbXEyEMvU8RmZGNk9pVF9GRk0&usp=drive_webIt would be a good data point to a intriguing question.ThanksShell
...Consider these points.I wondered when RFPlumber's test when he first ran his tests he deformed the large plate from heating. I also wondered how a TE012 mode could provide the thermal profile on the large plate to warp it. It didn't match his COMSOL sim of a TE012. ...
Quote from: SeeShells on 03/11/2016 07:12 pmDr. Rodal,I am still curious to what you see as a resonate mode with your Mathcad or Wolfram on RFPlumbers dimentions and frequency in his cavity.https://drive.google.com/folderview?id=0B3jbXEyEMvU8RmZGNk9pVF9GRk0&usp=drive_webIt would be a good data point to a intriguing question.ThanksShellWhat are the dimensions and material?Flat Ends? Yes X No _Interior Small End Diameter: Interior Big End Diameter:Interior Distance between Flat Ends (measured along axis of axisymmetry, perpendicular to the flat ends):Cavity metal: Believe it was Aluminum Thickness of cavity's metal:Were the dimensions of the frustum actually measured? (A file reads:D_big: 264 mmD_small: 162 mmL_center: 196 mmbut I don't know whether those are interior or exterior dimensions)I would hope these are the interior measurements but he doesn't state that. Although the 15MHz difference in what monomorphic reported as resonance is quite large compared to the walls measured on the outside. Run them both. When arguing about a small difference in natural frequency it is important to accurately know what are the actual dimensions of what was tested ...
Quote from: SeeShells on 03/11/2016 07:12 pmDr. Rodal,I am still curious to what you see as a resonate mode with your Mathcad or Wolfram on RFPlumbers dimentions and frequency in his cavity.https://drive.google.com/folderview?id=0B3jbXEyEMvU8RmZGNk9pVF9GRk0&usp=drive_webIt would be a good data point to a intriguing question.ThanksShellWhat are the dimensions and material?Flat Ends? Yes _ No _Interior Small End Diameter: Interior Big End Diameter:Interior Distance between Flat Ends (measured along axis of axisymmetry, perpendicular to the flat ends):Cavity metal:Thickness of cavity's metal:Were the dimensions of the frustum actually measured? (A file reads:D_big: 264 mmD_small: 162 mmL_center: 196 mmbut I don't know whether those are interior or exterior dimensions)When arguing about a small difference in natural frequency it is important to accurately know what are the actual dimensions of what was tested ...
Cavity metal: Believe it was Aluminum
I come to the same conclusion for TE012 using flat end plates.
Quote from: X_RaY on 03/11/2016 07:53 pmI come to the same conclusion for TE012 using flat end plates.X-RaY, what dimensions does your spreadsheet say are the best dimensions for TE311 @ precisely 2.45Ghz?
Please give me two them, I will calculate the missing one.
Quote from: SeeShells on 03/11/2016 04:16 pm...Consider these points.I wondered when RFPlumber's test when he first ran his tests he deformed the large plate from heating. I also wondered how a TE012 mode could provide the thermal profile on the large plate to warp it. It didn't match his COMSOL sim of a TE012. ...Shell, I noticed you keep mentioning that the large plate in my tests has been deformed from heating, I am not sure what makes you think so. I recall the exchange when someone asked whether the end plates on my frustum were flat or warped and I measured it and replied that they were maybe 1 mm warped in the center. My assumption back then was that the question referred to the quality of construction, and not to any deformation caused by the actual test. And my reply was also with an implicit assumption that this 1mm warping has been there from the start, and it was not the result of RF heating. I doubt one can cause any real warping on the plates with only 30W of energy (where a portion of it is then further leaking out as plain RF). Also, if I were to get any non-trivial amount of induction heating inside the frustum, I would have most likely witnessed "thrust" from all the hot air escaping through the gaps around side walls. It is possible that some of the thermal force I am attributing to the RF amplifier hot plate air convection could be coming from said hot air escaping from the frustum, but again, 30W is hardly enough to make any lasting deformation on the 0.5mm copper plates.
Quote from: TheTraveller on 03/11/2016 04:00 pmLatest email from Roger:Hi Phil... The Horizon programme will be transmitted in the UK at 20:00 on Wed 23 March. It is called Project Greenglow the search for gravity control.Not sure how much reference to EmDrive there will be after it was reviewed by USAF and UK MOD.Best regardsRogerProject Greenglow is a name I have not heard in a decade.Engines for alien spaceships. UFO (Unidentified Flying Objects) research.EMDrive research is sufficiently controversial I suggest that we publicly say away from a group that are even more controversial. Although if EMDrives can be made to work the Greenglow people may be willing to fly using them.
"I find it rather peculiar that they've done this," said Bob Park from the American Physical Society, in reaction to the BAe Systems admission. "One can only conclude that at the higher levels of these organisations there are people who don't have a very sound grounding in fundamental physics."
2.7" for TE311.Note this is an approximation only!
