what is the mesh size in these plots? I think the rule of thumb is < lambda / 40, which is a little less than 4 mm.
Have any tests been done reversing the drive?
They have now confirmed that there is a thrust signature in a hard vacuum (~5.0x10^-6 Torr) in both the forward direction, (approx. +50 micro-Newton (uN) with 50W at 1,937.115 MHz), and the reversed direction, (up to -16uN with a failing RF amp), when the thruster is rotated 180 degrees on the torque pendulum.
.....Have any tests been done reversing the drive?
Quote from: TMEubanks on 02/16/2015 04:06 pm.....Have any tests been done reversing the drive?Yes, and they have done it (reversing the drive) under hard vacuum.
Which seems to be a rather significant point.
QuoteThey have now confirmed that there is a thrust signature in a hard vacuum (~5.0x10^-6 Torr) in both the forward direction, (approx. +50 micro-Newton (uN) with 50W at 1,937.115 MHz), and the reversed direction, (up to -16uN with a failing RF amp), when the thruster is rotated 180 degrees on the torque pendulum.This needs to be redone. +50 and -16 is evidence of systematic errors. It is simply not good enough to say (or imply), well, if we could redo it properly, it would be +- 50. That needs to be demonstrated (or not).
Quote from: TMEubanks on 02/16/2015 04:20 pmQuoteThey have now confirmed that there is a thrust signature in a hard vacuum (~5.0x10^-6 Torr) in both the forward direction, (approx. +50 micro-Newton (uN) with 50W at 1,937.115 MHz), and the reversed direction, (up to -16uN with a failing RF amp), when the thruster is rotated 180 degrees on the torque pendulum.This needs to be redone. +50 and -16 is evidence of systematic errors. It is simply not good enough to say (or imply), well, if we could redo it properly, it would be +- 50. That needs to be demonstrated (or not).Give them a chance. Your enthusiasm is good but time is the best response here. Anyway Star Drive may if he is able to answer more specifically.
Quote from: TMEubanks on 02/16/2015 03:20 pmWell, you can calculate it, or you can try and devise better experiments (e.g., the same test in a fiberglass chamber). In the end, I suspect it will take a test in space to really be sure, but that's expensive, so it is entirely proper to make it jump through all kinds of hoops here on the ground first. (And, note, it is quite possible that it will either be rejected or just fade away in the process.)Marshall, how about these methods proposed by Mulletron to test whether the EM Drive thrust is due to evanescent wave interaction:Quote from: Mulletron on 02/14/2015 11:51 pmI can think of 3 ways to test the evanescent wave theory. 1) Is the measured thrust the same with the chamber door open and closed? 2) Is the thrust still there when the test article is rolled out of the chamber. Not sure if 2 is possible.....3) Change the conditions near the resonant cavity; like wrap the thing in thick foam and then wrap all that with foil, see what the thrust does. ...
Well, you can calculate it, or you can try and devise better experiments (e.g., the same test in a fiberglass chamber). In the end, I suspect it will take a test in space to really be sure, but that's expensive, so it is entirely proper to make it jump through all kinds of hoops here on the ground first. (And, note, it is quite possible that it will either be rejected or just fade away in the process.)
I can think of 3 ways to test the evanescent wave theory. 1) Is the measured thrust the same with the chamber door open and closed? 2) Is the thrust still there when the test article is rolled out of the chamber. Not sure if 2 is possible.....3) Change the conditions near the resonant cavity; like wrap the thing in thick foam and then wrap all that with foil, see what the thrust does. ...
...Have any tests been done reversing the drive?
Yes, evanescent waves are propagating waves. They propagate in the direction of the interface, so their momentum is parallel to the boundary. It is just their amplitude that decays exponentially away from the interface layer.
They are formed at the boundary between two media with different wave motion properties, and are most intense within one third of a wavelength from the surface of formation.
Momentum and spin represent fundamental dynamic properties of quantum particles and fields. In particular, propagating optical waves (photons) carry momentum and longitudinal spin determined by the wave vector and circular polarization, respectively. Here we show that exactly the opposite can be the case for evanescent optical waves. A single evanescent wave possesses a spin component, which is independent of the polarization and is orthogonal to the wave vector. Furthermore, such a wave carries a momentum component, which is determined by the circular polarization and is also orthogonal to the wave vector.
Shawyer's statement, "The small end diameters are set just above the cut-off diameter corresponding to the mode and frequency of the design."
Quote from: TMEubanks on 02/16/2015 04:06 pm...Have any tests been done reversing the drive?Both the test run that was reported on in Brady et al and the test run that Star-Drive talked about have included running the drive in a reverse orientation.
Quote from: birchoff on 02/16/2015 08:43 pmQuote from: TMEubanks on 02/16/2015 04:06 pm...Have any tests been done reversing the drive?Both the test run that was reported on in Brady et al and the test run that Star-Drive talked about have included running the drive in a reverse orientation.To be thorough, if "the drive" means the pillbox-shaped cavity that's correct, if the "the drive" means the truncated cone (frustum), no:Only the Cannae pillbox cavity was reported to run in a reversed configuration in the Brady et.al. report ( http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf ), on test runs 1B and 2B, as reported in the text, and summarized in Table 1. Cannae Testing: Summary of Results and Conclusions and illustrated on Figure 11. Cannae Test Article on Torsion Pendulum (thrust to the right, a.k.a. reverse orientation).The Brady et.al. paper does not report a single test with the truncated cone (frustum) run in the reverse configuration.The first instance in which the truncated cone was reported to have been run in a reverse configuration is the recent disclosure by Paul March, under hard vacuum.
Aside from re running the reverse orientation tests. Are there any other tests that Eagleworks needs to run. I am aware that they need to get to a certain performance level before then can hand off for replication attempt. But for the life of me the only other test case I can think of wanting results for is * Re Run frustum reverse orientation in Hard vacuum* Run forward and reverse orientation of frustum in a null configuration
Quote from: birchoff on 02/16/2015 09:38 pmAside from re running the reverse orientation tests. Are there any other tests that Eagleworks needs to run. I am aware that they need to get to a certain performance level before then can hand off for replication attempt. But for the life of me the only other test case I can think of wanting results for is * Re Run frustum reverse orientation in Hard vacuum* Run forward and reverse orientation of frustum in a null configurationIf it is handed off for a replication attempt, is this to be done in more than one other location, in other words are multiple teams to attempt this or just one?
How hard would it be to put the 1165 inside a more vacuum resilient container?http://www.empowerrf.com/pdfs/1165.pdfNotice the paper says max altitude 50K feet! It is operating beyond specs in that vacuum.....why they keep dying!We gotta figure this out, pronto!
Quote from: Mulletron on 02/16/2015 07:53 pmHow hard would it be to put the 1165 inside a more vacuum resilient container?http://www.empowerrf.com/pdfs/1165.pdfNotice the paper says max altitude 50K feet! It is operating beyond specs in that vacuum.....why they keep dying!We gotta figure this out, pronto!This appears to be a great finding, Mulletron, thanks for pointing it out. If the Amp that Eagleworks has been using is not rated for the hard vacuum (5*10^(-4) Torr) in their tests, do you have a best suggestion on how they should proceed?