...Photons are in a different frame of reference. The above system should move to the left.The above system as well as EmDrive is like a cavity with an externally attached pendulum. The pendulum's ball (represents light wave or microwave) bounces in it. And moves the light/MW cavity to the side where it bounces the most.

For the same reason the MW cavity shouldn't exert any directional force.

But it does.

And if so, then probably/maybe a similarly built light cavity with large mirrors on one side and bent optical fiber or small mirror on the other side should produce thrust as well.

The number of light bounces (mirror reflectance) would then represent the photonic thrust multiplication factor similar to Q in EmDrive thrust formula devised by Shawyer.

---Another issue: why not use Peltier element to cool the superconducting cavity instead of liquid gas? The vehicle will need electric power anyway, so why add heavy liquid hydrogen reservoir? The additional electric energy for Peltier cooling shouldn't require as much mass and space as the hydrogen.It may be economical even for satellites, because the large increase in Q and resulting smaller required input power and smaller engine size would justify additional Peltier module.Please kindly excuse me if this is an incorrect way of thinking for some reason I am not aware of.

Because Peltier effect can't quite reach cryogenic temperatures, for some thermodynamic reason I forgot. Maybe it changed with recent progress on the subject ? Please inquire : what are the limits of low temp. with Peltier effect, now and tomorrow ? Isn't the Peltier effect still quite low in efficiency ?

Spacetime has stiction? Say it ain't so!

Interesting that breaking CofM means that translational invariance dies, and breaking Einstein's SR core principle means that inertial frame invariance dies. Interesting because you may notice that one is essentially the time derivative of the other. And further that breaking CofE means that time invariance dies.Perhaps that's a deep observation, but I'm not smart enough to know what it means. All I know is that, for a propellantless propulsor, we are forced to choose between killing off one or the other. If we got creative we could kill off both, maybe!I'm sure my physics friends down the pub here in Cupertino would simply shrug and say that, since momentum appears not be conserved in the first place, there's ample room for odd statements to be correspondingly made about energy conservation (and I have made them here on this forum).Perhaps there's an exit route out of this bind via playing off conservation of momentum against conservation of energy. Just a wild thought.

1st component: A symmetrical resonator cavity that is optimized to store energy at high Q, and plays no role in thrust. Here, we want to store the lowest order mode that the waveguide can sustain because it has the slowest wave velocity inside the waveguide.

Is this design analogous to the "Modified Aluminum Cavity for TE011 Mode Resonance" previously presented by Paul March? Note, there appears to be two chambers separated by a 1/16" plate (aluminum?). As an avid follower of this thread I have not noticed any comments about this dual chamber design. However, I could be misinterpreting the attached image. This has been a truly fascinating discussion which has never ceased capturing my attention. I feel fortunate to passively witness. Thank you all, especially the replicators. -Matthew Trimble

Quote from: Rodal on 05/07/2015 09:58 pmQuote from: TheTraveller on 05/07/2015 08:46 pmQuote from: Rodal on 05/07/2015 07:59 pmQuote from: TheTraveller on 05/07/2015 07:54 pm....Did you or anyone else ever write an excel spreadsheet to calc Shawyers Design Factor? If so pls link it or if not please consider doing it as your skills there are much better than mine.Yes I have calculated it, but it is a Mathematica program, not an Excel spreadsheet. I posted (earlier in the thread) comparisons of the measurements vs. predictions using Shawyer's and McCulloch's formulas.You may want to PM @aero to ask whether he did it with Excel (if my memory is correct @aero also calculated Shawyer's Design Factor, as I recall having exchanges in this forum with him).And of course, when running your program, you will first check your results vs. Shawyer's published Design Factor results, etc., to make sure that your program is correct.Mathematica looks interesting but maybe later as I suspect there would be a learning curve.Is this still your Design Factor equation?Thanks for your assistance. Most appreciated.I recognize that equation is my Mathematica-writing, but I need a link to the message where I posted it, in order to remember the context. Too long ago Apologies for the delay. Requested link here:http://forum.nasaspaceflight.com/index.php?topic=29276.msg1276053#msg1276053Aero did reply but his Design Factor equation did not include RfQuoteI did, but the Excel file is not suitable for distribution, having all of my work scattered throughout a 500 line file with little or no embedded explanations. That is, it's un-usable even for me, without considerable time discovering what I intended to do. For example, here is my design factor, Df, equations. I think the variables are: Lo - lengthLg1-diameterLg2-diameterDf = 0.844 Df=S_o*Lo((1/Lg1) - (1/lg2)) where S_o = (1-(Lo^2/(Lg1*Lg2)))^-1 Combining Df = Lo*( 1 - (Lo^2/(Lg1*Lg2)))^-1 *((1/Lg1)-(1/Lg2)) So before turning either your or Aero's equation to Excel and posting it to the Wiki for all replicators to use, wpuld you please give some feedback on which is correct?From my trying to follow the Shawyer DF equations, it seems your equation which uses Rf imay be correct?Would appreciate a set of data variables that I can use to verify my excel equation gives the same results as your Mathematica equation.As always, thanks for the assistance.Appreciated.

Quote from: TheTraveller on 05/07/2015 08:46 pmQuote from: Rodal on 05/07/2015 07:59 pmQuote from: TheTraveller on 05/07/2015 07:54 pm....Did you or anyone else ever write an excel spreadsheet to calc Shawyers Design Factor? If so pls link it or if not please consider doing it as your skills there are much better than mine.Yes I have calculated it, but it is a Mathematica program, not an Excel spreadsheet. I posted (earlier in the thread) comparisons of the measurements vs. predictions using Shawyer's and McCulloch's formulas.You may want to PM @aero to ask whether he did it with Excel (if my memory is correct @aero also calculated Shawyer's Design Factor, as I recall having exchanges in this forum with him).And of course, when running your program, you will first check your results vs. Shawyer's published Design Factor results, etc., to make sure that your program is correct.Mathematica looks interesting but maybe later as I suspect there would be a learning curve.Is this still your Design Factor equation?Thanks for your assistance. Most appreciated.I recognize that equation is my Mathematica-writing, but I need a link to the message where I posted it, in order to remember the context. Too long ago

Quote from: Rodal on 05/07/2015 07:59 pmQuote from: TheTraveller on 05/07/2015 07:54 pm....Did you or anyone else ever write an excel spreadsheet to calc Shawyers Design Factor? If so pls link it or if not please consider doing it as your skills there are much better than mine.Yes I have calculated it, but it is a Mathematica program, not an Excel spreadsheet. I posted (earlier in the thread) comparisons of the measurements vs. predictions using Shawyer's and McCulloch's formulas.You may want to PM @aero to ask whether he did it with Excel (if my memory is correct @aero also calculated Shawyer's Design Factor, as I recall having exchanges in this forum with him).And of course, when running your program, you will first check your results vs. Shawyer's published Design Factor results, etc., to make sure that your program is correct.Mathematica looks interesting but maybe later as I suspect there would be a learning curve.Is this still your Design Factor equation?Thanks for your assistance. Most appreciated.

Quote from: TheTraveller on 05/07/2015 07:54 pm....Did you or anyone else ever write an excel spreadsheet to calc Shawyers Design Factor? If so pls link it or if not please consider doing it as your skills there are much better than mine.Yes I have calculated it, but it is a Mathematica program, not an Excel spreadsheet. I posted (earlier in the thread) comparisons of the measurements vs. predictions using Shawyer's and McCulloch's formulas.You may want to PM @aero to ask whether he did it with Excel (if my memory is correct @aero also calculated Shawyer's Design Factor, as I recall having exchanges in this forum with him).And of course, when running your program, you will first check your results vs. Shawyer's published Design Factor results, etc., to make sure that your program is correct.

....Did you or anyone else ever write an excel spreadsheet to calc Shawyers Design Factor? If so pls link it or if not please consider doing it as your skills there are much better than mine.

I did, but the Excel file is not suitable for distribution, having all of my work scattered throughout a 500 line file with little or no embedded explanations. That is, it's un-usable even for me, without considerable time discovering what I intended to do. For example, here is my design factor, Df, equations. I think the variables are: Lo - lengthLg1-diameterLg2-diameterDf = 0.844 Df=S_o*Lo((1/Lg1) - (1/lg2)) where S_o = (1-(Lo^2/(Lg1*Lg2)))^-1 Combining Df = Lo*( 1 - (Lo^2/(Lg1*Lg2)))^-1 *((1/Lg1)-(1/Lg2))

Hey everyone,Based on the advice from the forum we have reformulated our experimental design . We have been given permission to use one of the vacuum chambers at Cal Poly which can pull about 1mT using a mechanical pump. By mounting everything on a pendulum we can measure a displacement using a reflected laser. I am not experienced with laser measurements and would greatly appreciate any advice for improving this measurement. With a simple setup it seems we will be able to see 100 mN easily, hopefully this is within reason at powers ~1200 W. We have also been considering using aluminum for the frustum to minimize the mass of the pendulum. This would coincide with Todd's theory that a lower Q in the frustum is more desirable. We could easily implement a symmetric copper resonant cavity to between the magnetron and the frsutum:Quote from: WarpTech on 05/08/2015 05:51 am1st component: A symmetrical resonator cavity that is optimized to store energy at high Q, and plays no role in thrust. Here, we want to store the lowest order mode that the waveguide can sustain because it has the slowest wave velocity inside the waveguide. I did some basic solutions for a resonant rectangular chamber and found that to isolate the TE 011 mode at a frequency of 2.4503 GHz we would need a box 7.068 x 7.068 x 12.24 cm. Would we want to match the end of this box to the small end of the frustum? What should the interface look like?Perhaps we should keep our experiment simple and introduce this complication later...Also, does anyone know the dimensions of the aluminum cavity being constructed at Eagleworks? I believe the picture posted is missing a dimension required to solve for the others, or maybe my geometry is lacking. Quote from: Econocritic on 05/08/2015 08:18 pmIs this design analogous to the "Modified Aluminum Cavity for TE011 Mode Resonance" previously presented by Paul March? Note, there appears to be two chambers separated by a 1/16" plate (aluminum?). As an avid follower of this thread I have not noticed any comments about this dual chamber design. However, I could be misinterpreting the attached image. This has been a truly fascinating discussion which has never ceased capturing my attention. I feel fortunate to passively witness. Thank you all, especially the replicators. -Matthew Trimble Hopefully we can use EW's dimensions and not have to worry about FEA. The electrical connections into the chamber will allow the circuit to be kept outside and connected with slack to a magnetron on the pendulum. I am concerned that the magnetron will overheat quickly due to a lack of convection cooling, but maybe we can run shorter tests to compensate. Any thoughts?Glad to see everyone still asking questions and presenting ideas! It is quite an amazing discussion and I look forward to contributing some data. Kurt Zeller

I was wondering in your testing did you use a smoke stick also called a smoke pencil to check for air flows around the EM Drive in ambient air conditions?

Quote from: Notsosureofit on 05/08/2015 08:05 pmQuote from: Notsosureofit on 05/08/2015 06:28 pmEdit: I used to have Penrose, Roger (1965). "A remarkable property of plane waves in general relativity". Rev. Mod. Phys. 37: 215–220. Bibcode:1965RvMP...37..215P. doi:10.1103/RevModPhys.37.215around here somewhere, I'll look.Amazing ! Found it after all these years. I have to re-read and re-understand it of course, but check Fig. 1. "The sandwich wave" where you have a section of curved space-time sandwiched between flat. That alone is closer to this situation than anything I've seen so far.The previous article, Rosen, Joe. "Embedding of Various Relativistic Riemannian Spaces in Pseudo-Euclidean Spaces" contains tables of transforms. That could prove invaluable !An earlier paper, this time by Bondi, on sandwich waves and plane gravitational waves, that, unlike the other ones, has a PDF with a link :http://www.itp.kit.edu/~schreck/general_relativity_seminar/Gravitational_waves_in_general_relativity_exact_plane_waves.pdfGravitational waves in general relativityIII. Exact plane wavesBY H. BONDI* AND F. A. E. PIRANItKing's College, LondonAND T. ROBINSONLately of University College of Wales, Aberystwyth(Communicated by W H. McCrea, F.R.S.-Received 18 October 1958)Plane gravitational waves are here defined to be non-flat solutions of Einstein's empty spacetimefield equations which admit as much symmetry as do plane electromagnetic waves,namely, a 5-parameter group of motions. A general plane-wave metric is written down andthe properties of plane wave space-times are studied in detail. In particular, their characterizationas 'plane' is justified further by the construction of 'sandwich waves' bounded on bothsides by (null) hyperplanes in flat space-time. It is shown that the passing of a sandwich waveproduces a relative acceleration in free test particles, and inferred from this that such wavestransport energy.

Quote from: Notsosureofit on 05/08/2015 06:28 pmEdit: I used to have Penrose, Roger (1965). "A remarkable property of plane waves in general relativity". Rev. Mod. Phys. 37: 215–220. Bibcode:1965RvMP...37..215P. doi:10.1103/RevModPhys.37.215around here somewhere, I'll look.Amazing ! Found it after all these years. I have to re-read and re-understand it of course, but check Fig. 1. "The sandwich wave" where you have a section of curved space-time sandwiched between flat. That alone is closer to this situation than anything I've seen so far.The previous article, Rosen, Joe. "Embedding of Various Relativistic Riemannian Spaces in Pseudo-Euclidean Spaces" contains tables of transforms. That could prove invaluable !

Edit: I used to have Penrose, Roger (1965). "A remarkable property of plane waves in general relativity". Rev. Mod. Phys. 37: 215–220. Bibcode:1965RvMP...37..215P. doi:10.1103/RevModPhys.37.215around here somewhere, I'll look.

As previously pointed out by one of us (Bondi I957), this relative acceleration andconsequent relative velocity prove that gravitational waves transport energy, sinceit is in principle possible, utilizing this effect, to construct a device which will extractenergy from a wave. The simplest such device consists of a stiff rod (the rod need notbe rigid in the technical sense, and the difficulties surrounding the consideration ofrigid bodies in relativity theory are not relevant here) and a bead which slides on therod with some friction. If the rod lies in a suitable direction transverse to thedirection of wave propagation, and if the bead is at rest relative to the rod at aposition well displaced from the rod's centre of mass, the passing of the wave willresult in some relative motion of the rod and the bead, for in the first approximationthe bead and the mass centre of the rod will each move on a geodesic. This relativemotion will generate heat, and thus locally available energy may be extracted fromthe wave.In these considerations, the effect of the device on the wave has been neglected.This is a test device-a device constructed out of test particles. Consequently, suchconsiderations cannot be used to calculate the total amount of available energy inthe wave.[snip]...............................................................................It is clear from the relative acceleration acquired by test particles, as described in sections 3 and 4, that energyis transferred to test particles by a plane wave, but this does not enable us to makequantitative assertions about energy transport in general. The present fluid stateof the theory of the energy pseudo-tensor would not appear to justify a discussion ofenergy transport in terms of this concept.

Quote from: SeeShells on 05/09/2015 12:00 amI was wondering in your testing did you use a smoke stick also called a smoke pencil to check for air flows around the EM Drive in ambient air conditions?Although a Google search reveals that this has been brought up before, for example here by @aero: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1275034#msg1275034 there is no entry I could find in the threads as to whether any of the research groups actually used smoke to check air flow. Perhaps others can try separate searches either using their memories or using Google (anything but the poorly functioning "Search" button between "Unread Topics" and "Profile" )

Quote from: frobnicat on 05/08/2015 11:36 pmBecause Peltier effect can't quite reach cryogenic temperatures, for some thermodynamic reason I forgot. Maybe it changed with recent progress on the subject ? Please inquire : what are the limits of low temp. with Peltier effect, now and tomorrow ? Isn't the Peltier effect still quite low in efficiency ?The Peltier limits are below 100K, which is enough for high-temparature superconductors. The efficiency in such temperature is low, but probably that could be economically viable because of much smaller MW input power and smaller superconducting engine size. That said, I must sadly admit, that this engine won't probably move in free space. It may move on air cushion though, as in the experiments conducted so far on Earth.Anyway, if so, then it is at least good for new generation of rotorless helicopters, here on Earth.