May I suggest that people interested in "Mach effect" (reality of which having obvious consequences on directions advanced spaceflight can take) contribute on a thread with a more appropriate explicit topic (and historical content) : Propellantless Field Propulsion and application. The risk in splitting the somewhat frozen propellantless discussion of late would be to make it even harder to revive some activity, but EM and ME approaches are two very different kind of theories and devices, interwining of both topic discussion in a single thread was one of the reason of the chaos that plagued the 1st EM drive thread.Anyhow, for those interested in Mach effect, here are two versions of results from attempt of Woodward (2008...) at "proof of effect" exhumed from Propellantless thread:http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=13020.0;attach=260412http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=13020.0;attach=260481Haven't read in detail yet.I won't crosspost here my posts about that (if I have the courage to address some of it deeper)http://forum.nasaspaceflight.com/index.php?topic=13020.msg1304798#msg1304798
Quote from: frobnicat on 12/19/2014 10:43 amMay I suggest that people interested in "Mach effect" (reality of which having obvious consequences on directions advanced spaceflight can take) contribute on a thread with a more appropriate explicit topic (and historical content) : Propellantless Field Propulsion and application. The risk in splitting the somewhat frozen propellantless discussion of late would be to make it even harder to revive some activity, but EM and ME approaches are two very different kind of theories and devices, interwining of both topic discussion in a single thread was one of the reason of the chaos that plagued the 1st EM drive thread.Anyhow, for those interested in Mach effect, here are two versions of results from attempt of Woodward (2008...) at "proof of effect" exhumed from Propellantless thread:http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=13020.0;attach=260412http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=13020.0;attach=260481Haven't read in detail yet.I won't crosspost here my posts about that (if I have the courage to address some of it deeper)http://forum.nasaspaceflight.com/index.php?topic=13020.msg1304798#msg1304798Good points, frobnicat, besides the PropellantLess thread:http://forum.nasaspaceflight.com/index.php?topic=13020.0the Woodward effect fans have had their own threads @ NASASpaceFlight, for example this one, completely dedicated to the Woodward effect:http://forum.nasaspaceflight.com/index.php?topic=31037.0The reported "thrust" force/(power input) of the latest Woodward experiments (Fearn, Zachar, Woodward & Wanser) is about 2000 times less than the NASA Brady et.al TE mode and about 20,000 times less than the Shawyer Demo In other words, it takes (for the latest Woodward experiments) 3 to 4 orders of magnitude greater input power to produce the same level of what is reported as "thrust" force
Quote from: Rodal on 12/19/2014 01:53 pmThe reported "thrust" force/(power input) of the latest Woodward experiments (Fearn, Zachar, Woodward & Wanser) is about 2000 times less than the NASA Brady et.al TE mode and about 20,000 times less than the Shawyer Demo In other words, it takes (for the latest Woodward experiments) 3 to 4 orders of magnitude greater input power to produce the same level of what is reported as "thrust" forceWhy does this matter? I was under the impression that while both lines of inquiry hold incredible promise. They still require more research and testing to get to the point where a wider audience would be willing to accept them.
The reported "thrust" force/(power input) of the latest Woodward experiments (Fearn, Zachar, Woodward & Wanser) is about 2000 times less than the NASA Brady et.al TE mode and about 20,000 times less than the Shawyer Demo In other words, it takes (for the latest Woodward experiments) 3 to 4 orders of magnitude greater input power to produce the same level of what is reported as "thrust" force
focus on space flight applications to ensure this can have a healthy home here.
Quote from: birchoff on 12/19/2014 11:31 pmQuote from: Rodal on 12/19/2014 01:53 pmThe reported "thrust" force/(power input) of the latest Woodward experiments (Fearn, Zachar, Woodward & Wanser) is about 2000 times less than the NASA Brady et.al TE mode and about 20,000 times less than the Shawyer Demo In other words, it takes (for the latest Woodward experiments) 3 to 4 orders of magnitude greater input power to produce the same level of what is reported as "thrust" forceWhy does this matter? I was under the impression that while both lines of inquiry hold incredible promise. They still require more research and testing to get to the point where a wider audience would be willing to accept them.As Chris Bergin made clear, the purpose of this forum is to deal with SPACEFLIGHT APPLICATIONS (of EM Drives: those propellantless drives comprised of a microwave cavity as the devices tested by Shawyer in the UK, Prof. Juan Yang in China and Brady, March, White, et.al. at NASA):Quote from: Chris Bergi focus on space flight applications to ensure this can have a healthy home here.It matters because the amount of power required to produce a given level of thrust is of vital importance for spaceflight applications. The fact that the latest Woodward experiments (Fearn, Zachar, Woodward & Wanser) show that it takes 20,000 times more power to produce a given level of thrust than the power required to produce the same thrust for the EM Drive (Shawyer demo) is extremely important for spaceflight applications.
May I suggest that people interested in "Mach effect" (reality of which having obvious consequences on directions advanced spaceflight can take) contribute on a thread with a more appropriate explicit topic (and historical content) :>> << As reminded by managing editor, NSF is about space flight. Given the turn taken by the thread, the admin intervention is quite understandable, and most of the content wasn't thrashed, thanks. While the "space drives" in general are on topic here if proven, the reality of any effect at all (and with what possible backing theories) is still controversial, and this open question is more a matter of fundamental science and has interest in and by itself beyond space flight. Since discussing those theoretical and experimental aspects are only marginally appropriate on this forum then that could proceed "preemptively" at other more appropriate place. Otherwise some talks will be rather contrived ( how make comment sound "space flight relevant" while it's not directly )
After carrying out a variety of experiments designed to exploit the presumed existence of Mach effects to produce small thrusts that yielded varying results, the decision was taken to carry out an experiment to test for the existence of such effects in the simplest of all possible circumstances. The aim was to settle the question of the existence the effects. Underlying physics suggests that these effects should exist; but in some experiments the effects expected were either not present, or much smaller than predicted. Without experimental evidence that the predicted Mach effects in fact do exist, situations in which they are small or not present may be taken as evidence that Mach effects do not exist.
...That said since you also wrote a critique of the Eagle Works test showing that the results could be thermal effects I would think the Thrust figures of either EM Drives or MET thrusters would be consider as simply a measure of how far both approaches have to go to be useful. It could be that a large part of the EM Drive thrust numbers are thermal and will be reduced when tested in vacuum. ...
It could be that a large part of the EM Drive thrust numbers are thermal and will be reduced when tested in vacuum.
Some things don't scale - Woodward is one. Another with a much better chance is the Sagnac effect, the only challenge is getting anything useful out of them. At a larger scale it would be awesome if Stirling engines would scale.EmDrive will stay in the lab
First, thanks to Chris for opening this new thread.That said, some definitions might be in order to avoid confusion.Stirling Engine: The version I am familiar with is proven old line technology, essentially a temperature difference engine. I have seen DIY versions on You-Tube and elsewhere, and read of others that can act as low power solar generators, but have no idea how this might pertain to spaceflight. What is 'ASRG?'Sagnac effect. I have not heard of this before.
...the system of EM wave and waveguide can be regarded as an open system, with the EM wave and the waveguide having separate frames of reference.A similar approach is necessary to explain the principle of the laser gyroscope, where open system attitude information is obtained from an apparently closed system device.
There is a description of the Sagnac effect on wikipedia, this is the basis of a laser gyroscope. Interestingly Newtonian physics and relativity give the same answer for this. I isn't related to the microwave drive. I think they mention it because laser gyroscopes are conceptually complicated and they hope that the reader won't understand them, and therefor not understand that if anything they are yet more evidence that this trick doesn't work.
There is some similarity of the EMDrive to the Sagnac oscillator if the optical fiber has a linear variation in the index of refraction. The frames of reference are stationary and accelerating rather than constant velocity. But, I havn't seen any reference or calculation giving rotary forces as yet. At the moment I'm chasing old photon to graviton papers.
Quote from: Notsosureofit on 12/22/2014 01:17 amThere is some similarity of the EMDrive to the Sagnac oscillator if the optical fiber has a linear variation in the index of refraction. The frames of reference are stationary and accelerating rather than constant velocity. But, I havn't seen any reference or calculation giving rotary forces as yet. At the moment I'm chasing old photon to graviton papers. The Sagnac effect compares the (rotating) velocity frame of reference in which the opposing photons show the same frequency w/ the (stationary) frame in which the doppler photons are observed.The Shawyer cavity photons can be compared in the (stationary) dispersion frame w/ the same frequency and in an (accelerated) frame which balances out the dispersion and expresses the doppler shifts.
Post admits in his great review article: “The search for a physically meaningful transformation for rotationis not aided in any way whatever by the principle of general space-time covariance (relativity), nor is it true that the space-time theory of gravitation (general relativity) plays any role in establishing physically correct transformations (relevant to the Sagnac effect).”
In 1925 Michelson and Gale built a huge earth-fixed Sagnac Interferometer in Illinois demonstrating that the light velocity is anisotropic on the rotating earth. For Sagnac this result did not come as a surprise having explained the underlying effect on the basis of the ether theory in 1913. The Special Relativity Theory (SRT), however, had predicted on the basis of the Lorentz Transformation (LT) that the velocity of light is isotropic in all inertial systems
http://www.mehtapress.com/mehtapress/Journals/Journal-of-Space-Exploration/Volume-3-Issue-1/vol_3_issue_1_file_2.pdfI'm not qualified to judge the space flight applicability of the above article by Dr. Woodward as it pertains to this forum. A brief history, theory and recent experiments are detailed. It also contains a critique of quantum vacuum explanations for emdrive propulsion. Just thought I should bring it to this groups attention and I'll return to lurking. I've passively appreciated this discussion for a long time. Some of the most contentious moments have been the most educational. I'll miss the perspectives of Ron Stahl and Mullertron assuming they don't return. Thanks to everyone who has contributed. Truly fascinating.
the purpose of this forum is to deal with SPACEFLIGHT APPLICATIONS (of EM Drives: those propellantless drives comprised of a microwave cavity as the devices tested by Shawyer in the UK, Prof. Juan Yang in China and Brady, March, White, et.al. at NASA)...and therefore these experiments do not constitute "EM Drive Spaceflight Applications" (as instructed by Chris Bergin) Woodward fans persist on carrying a debate on this thread rather than their own Woodward thread. Frankly, I don't understand what is the goal being pursued here by Woodward-effect fans to insist to carry arguments concerning Woodward's theory and experiments in this thread.
