Quote from: DIYFAN on 02/10/2015 03:11 amQuote from: sanman on 02/09/2015 05:27 amIs copper the ideal material for the frustum? Or are there even better materials, theoretically?I think maybe it was Mulletron that previously pointed out this paper:https://hal.archives-ouvertes.fr/hal-01074608/documentThe conjecture in that paper is that building the larger diameter plate (R1) out of metglas 2714A, a significant amplification of the effect would result. Perhaps there is a courageous person or group with some funds to put this to the test. It would be interesting to see an experiment with the partial metglas construction to rule the theory in or out.Given that metglas 2714A is a room-temperature material, it would be considerably easier to achieve an amplification that way than lining the interior of the test article with superconducting film and cooling to liquid nitrogen temperatures. As far as building the cavity itself, copper is good enough. It is easy to get and work with and has great electrical properties. Anything better would be precious metals which isn't worth the money. And superconductors aren't exactly "home workshop" compatible for most. As far as something in place of the polyethylene dielectric, I'd suggest something that exhibits a higher relative permittivity or even a material that exhibits magnetochiral dichroism. http://www.academia.edu/1084905/Probing_magnetochirality
Quote from: sanman on 02/09/2015 05:27 amIs copper the ideal material for the frustum? Or are there even better materials, theoretically?I think maybe it was Mulletron that previously pointed out this paper:https://hal.archives-ouvertes.fr/hal-01074608/documentThe conjecture in that paper is that building the larger diameter plate (R1) out of metglas 2714A, a significant amplification of the effect would result. Perhaps there is a courageous person or group with some funds to put this to the test. It would be interesting to see an experiment with the partial metglas construction to rule the theory in or out.Given that metglas 2714A is a room-temperature material, it would be considerably easier to achieve an amplification that way than lining the interior of the test article with superconducting film and cooling to liquid nitrogen temperatures.
Is copper the ideal material for the frustum? Or are there even better materials, theoretically?
Copper may very well be good enough for the cavity itself. Or maybe not. There is at least a theory that metglass would be better if used for one of the frustrum's plates (i.e., the larger plate). Do you see a reason why someone shouldn't make an experiment along these lines?
If the microwave source radiates pulses with 10 megawatts power then the thrust canreach up to 100kN.
Any time the K/Ko exceeds 1.0 … is the point where almost all physicists will pause, turn their heads and say, what? Yep. The K/Ko in the lowest wattage, highest Q experiment was not just a little bit greater than 1.0, but was an almost implausible 6,388× larger.If this were SETI, we'd call that the “Wow! signal”
Quote from: DIYFAN on 02/10/2015 03:11 amQuote from: sanman on 02/09/2015 05:27 amIs copper the ideal material for the frustum? Or are there even better materials, theoretically?I think maybe it was Mulletron that previously pointed out this paper:https://hal.archives-ouvertes.fr/hal-01074608/documentThe conjecture in that paper is that building the larger diameter plate (R1) out of metglas 2714A, a significant amplification of the effect would result. Perhaps there is a courageous person or group with some funds to put this to the test. It would be interesting to see an experiment with the partial metglas construction to rule the theory in or out.Given that metglas 2714A is a room-temperature material, it would be considerably easier to achieve an amplification that way than lining the interior of the test article with superconducting film and cooling to liquid nitrogen temperatures. Interesting conjecture. Did the author of the paper advocating the use of Metglas 2714A take into account that its ultra-high magnetic permeability which he quotes in the paper (apparently for his calculations) as μ=1,000,000 occurs at very low frequencies and that its magnetic permeability decreases significantly at higher frequencies ? See the attached plot, unfortunately the available data ( http://www.metglas.com/assets/pdf/2714a.pdf ) goes up to only 10^5 Hz while the EM Drive operates at 20000 times higher frequency: 2*10^9 Hz. At the much lower frequency of 10^5 Hz the magnetic permeability has decreased by a factor of 50 from the maximum DC permeability of μ =1,000,000 to μ =20,000. If it decreases by another factor of 50 (it will probably decrease more due to the steepening shape of the curve ?) the magnetic permeability at 2*10^9 Hz may be μ ~ 400 instead of 1,000,000.(Optimistically ?) assuming that μ ~ 400 for Metglas 2714A at 2*10^9 Hz, then the author's prediction of 1,000 times higher "thrust" (?) than Shawyer’s thruster would be reduced by Sqrt[(10^6)/400]=50 times, so that the increase in thrust would be 20 times over Shawyer's experiments (assuming that the author's conjecture and theory are correct, and assuming that the EM Drive can be (practically) tuned to stay in Q resonance at a suitable mode-shape with such a material).Still, a factor of 20 times higher force is nothing to ignore, if the author's theory is correct, and if the magnetic permeability is at least μ ~ 400 for Metglas 2714A at 2*10^9 Hz, this material may enable to exceed the minimum requirements for testing the Eagleworks frustum at NASA's Glenn.
I still favor direct application of the Equivalence Principle ...night all
(Optimistically ?) assuming that μ ~ 400 for Metglas 2714A at 2*10^9 Hz, then the author's prediction of 1,000 times higher "thrust" (?) than Shawyer’s thruster would be reduced by Sqrt[(10^6)/400]=50 times, so that the increase in thrust would be 20 times over Shawyer's experiments (assuming that the author's conjecture and theory are correct, and assuming that the EM Drive can be (practically) tuned to stay in Q resonance at a suitable mode-shape with such a material).Still, a factor of 20 times higher force is nothing to ignore, if the author's theory is correct, and if the magnetic permeability is at least μ ~ 400 for Metglas 2714A at 2*10^9 Hz, this material may enable to exceed the minimum requirements for testing the Eagleworks frustum at NASA's Glenn.This paper (http://infoscience.epfl.ch/record/55950/files/76.pdf ) has data up to 30 MHz (that is 67 times lower than the frequency of operation of the EM Drive, hence much closer to the EM Drive's frequency than the data from the manufacturer at 100KHz, considering that the drop of magnetic permeability depends on the Log of frequency, the EM Drive Log frequency is just 1.8 times higher) showing a magnetic relative permeability of μ =6000 at 30 MHz, indicating about μ =2400 at 2*10^9 HzIf the author's conjecture and theory are correct, this extrapolated value ( μ =2400 at 2*10^9 Hz) would result in an improvement of 1000/Sqrt[(10^6)/2400] = 1000/20.4 = 49 times greater thrust force than Shawyer's experiments.This information, coupled with the one in the previous post, indicates that that (if Aquino's theory is correct) using amorphous metal (http://en.wikipedia.org/wiki/Amorphous_metal) Metglas 2714A sheet ( http://en.wikipedia.org/wiki/Metglas ) may result in 20 to 50 times greater thrust force than using copper sheet.
Quote from: Notsosureofit on 02/08/2015 02:31 amI still favor direct application of the Equivalence Principle ...night all@Notsosureofit Concerning <<I still favor direct application of the Equivalence Principle >> I would appreciate your comments/observations concerning Univ. of Massachusetts, John F. Donoghue, Barry R. Holstein, R. W. Robinett's 1985 (awarded ?) paper "The principle of equivalence at finite temperature" (http://www.gravityresearchfoundation.org/pdf/awarded/1984/donoghue_holstein_robinett.pdf) citation history here:http://inspirehep.net/record/14777/citationswhere they claim to demonstrate that the equivalence principle is violated by radiative corrections to the gravitational and inertial masses at finite temperature. (How about Unruh radiation as per Dr. McCulloch's theory ?).They argue that this result can be attributed to the Lorentz noninvariance of the finite temperature vacuum.Max Jammer refers to Donoghue's paper in an authoritative manner with very interesting discussion in pages 138 to 140 of Jammer's classic book "Concepts of Mass in Contemporary Physics and Philosophy" (see: this link http://bit.ly/1y8vaCO )
The fundamental ideas which led to the equivalence principle include the impossibility of defining absolute motion through the vacuum and the indistinguishability of acceleration and gravitational force. However, one can measure absolute velocity and acceleration relative to the heat bath (as has been done for the velocity of the Earth in the 3°K photon distribution left over from the early universe). Thus the conditions under which the equivalence principle was formulated are not met at finite temperature. The fact that we do live in a universe at a nonzero ternperature could in principle have led to unexpected results in the Eotvos experiments if it were not for the fact that the correction is too small to be detected at present temperatures.
@ RODALMy understanding was that the Doppler shifted radiation of the cosmic background would constitute an increasing drag (and thus a limit) on the accelerated system, (as Unruh) not that it invalidated the equivalence principle. But, I'll look and see what they say.
Quote from: Notsosureofit on 02/10/2015 09:00 pm@ RODALMy understanding was that the Doppler shifted radiation of the cosmic background would constitute an increasing drag (and thus a limit) on the accelerated system, (as Unruh) not that it invalidated the equivalence principle. But, I'll look and see what they say.Yes, you are entirely correct. Sorry if my poor wording conveyed that impression. I brought up Donoghoue's paper because it may give yet another possibility: escaping the equivalence principle (but the effect appears to be very small )
Quote from: Rodal on 02/10/2015 09:08 pmQuote from: Notsosureofit on 02/10/2015 09:00 pm@ RODALMy understanding was that the Doppler shifted radiation of the cosmic background would constitute an increasing drag (and thus a limit) on the accelerated system, (as Unruh) not that it invalidated the equivalence principle. But, I'll look and see what they say.Yes, you are entirely correct. Sorry if my poor wording conveyed that impression. I brought up Donoghoue's paper because it may give yet another possibility: escaping the equivalence principle (but the effect appears to be very small )A quick read but you can probably get their results by using the photon bath as a viscous fluid exchanging energy at a given temperature. Nice quantum argument. In any event, the cosmic background does not constitute a temperature "bath" under velocity (or acceleration) because of the vector form (directionality) of the velocity. Have to look at the citations..
It appears that TM modes are the top dogs now and at the same time performance has gone down significantly since vacuum testing began.
BTW, the copper frustum is vented, so its internal pressure matches the chamber pressure after a short time period at vacuum.
We report the first observation of the anisotropy of the velocity of light, induced in a gas by electricand magnetic fields.....Using a high finesse ring cavity, we havemeasured the magneto-electric directional anisotropy of molecular Nitrogen at ambient temperatureand atmospheric pressure
Moreover, the same effect is expected in quantum vacuum......Our long term goal is to search forthe magneto-electric directional anisotropy of quantum.
..I don't think the answer is fully due to the elimination of air currents, as the thrust signature rise and fall times were instantaneous during the non vacuum tests reported last summer. ...
...I accidentally stumbled upon this report:https://hal.archives-ouvertes.fr/hal-00551421v1/documentQuoteWe report the first observation of the anisotropy of the velocity of light, induced in a gas by electricand magnetic fields.....Using a high finesse ring cavity, we havemeasured the magneto-electric directional anisotropy of molecular Nitrogen at ambient temperatureand atmospheric pressure This alone is an amazing result. Note that it is an observation....
As far as heat goes, Eagleworks repeatedly reported that heat was controlled for and wasn't an issue. So I'm forced to trust the experiment was legit. Vacuum eliminates hot air currents but not radiation.
A simple falsification of all this transferring momentum from the qv business is simply to evacuate all the air from the resonant cavity and remove the dielectric and see if the thrust goes away.
Is 50 watts worth of ir radiation enough to mimic the thrust signal? You established that the measured thrust is in excess of a photon rocket. So all that is left is the thermal instability you mentioned. Hope Paul comments on that.
Quote from: Mulletron on 02/11/2015 12:09 amIs 50 watts worth of ir radiation enough to mimic the thrust signal? You established that the measured thrust is in excess of a photon rocket. So all that is left is the thermal instability you mentioned. Hope Paul comments on that.I wish that NASA Glenn would pay, now, to have several EM Drives tested in their unit, to be able (in principle) to generate enough thrust force to get a reading at Glenn with all the drives together being pointed in the same direction. My reading of what Paul March wrote is that this would mean at least 3 EM Drives. With three (or more) EM Drives one could also conduct several interesting tests with orientation of each drive: all of them oriented in parallel, oriented in series (is there any measurable wake ?), oriented opposite to each other, etc.Edison conducted >10,000 experiments for the incandescent light bulb, thousands of tests for the alkaline battery, etc.