Dr. Rodal:Thanks for the concern over my employment, but everyone is replaceable to one degree or another. And there are at least two federal civil servants involved with the Eagleworks Lab that will carry on, albeit a bit more slowly, if I have to find other activities to fill my golden years. Activities like finishing my home lab that has been on hold since going back to work at the NASA/JSC/Eagleworks Lab for the last four years helping mature Dr. White's QVF vision. What will be, will be. Now back to trying to understand how these EM-Drives might actually work... Best, Paul M.

Quote from: DIYFAN on 02/23/2015 02:51 AMBy the looks of things, there will be another "sputnik" moment--but this time it will be the Chinese not the Russians, and the EM Drive not the satellite. As much as I'd like to see the US stay out ahead on this one, if the new sputnik-EM Drive-China moment needs to happen to revive the support of the US government and spur a corresponding rise in NASA's budget, then let's hope it happens, and soon.Well if the reports from China are true, if we don't roll out something impressive soon, they already beat us to the punch. http://www.economist.com/node/11791539

By the looks of things, there will be another "sputnik" moment--but this time it will be the Chinese not the Russians, and the EM Drive not the satellite. As much as I'd like to see the US stay out ahead on this one, if the new sputnik-EM Drive-China moment needs to happen to revive the support of the US government and spur a corresponding rise in NASA's budget, then let's hope it happens, and soon.

Dear excellent NSF forum. This is just to say (for those who don't know) that I've suggested a specific new model for inertia that predicts galaxy rotation without dark matter (it is called MiHsC) and I recently compared its predictions with the 9 EmDrive results with 'some' (not perfect) success. You can see the results by looking at the Table here:http://physicsfromtheedge.blogspot.co.uk/2015/02/mihsc-vs-emdrive-data-3d.htmlI've also published a paper summarising this comparison (slightly out of date now) herehttp://www.ptep-online.com/index_files/2015/PP-40-15.PDFI'd encourage those with other interesting explanations of the EmDrive to make a similar comparison between predictions and data, so we can compare using the facts. If you have any more data points to add, or if you disagree with the numbers in my Table, please let me know.

The sciences do not try to explain, they hardly even try to interpret, they mainly make models. By a model is meant a mathematical construct which, with the addition of certain verbal interpretations, describes observed phenomena. The justification of such a mathematical construct is solely and precisely that it is expected to work.

Quote from: Notsosureofit on 02/17/2015 11:36 AMQuote from: Rodal on 02/17/2015 01:40 AMQuote from: Notsosureofit on 02/17/2015 12:01 AM@ RODALArrgh, Mondays !Looked over my bleary weekend, noticed I was using diameters AGAIN !Mode Frequency (MHz) Quality Factor, Q Input Power (W) Mean Thrust (μN) Calculated w/o dielectricTE012 1880.4 22000 2.6 55.4 10.8TM212 1932.6 7320 16.9 91.2 38.5TM212 1936.7 18100 16.7 50.1 93.5TM212 1937.115 6726 50 66 104.0Anyway, shows it pays to rewrite everything in the same place !....Great !In order to understand the above, (please correct me if I am wrong), you used in your formula the actual frequency and mode shapes that took place in the EM Drive experiment with the dielectric so in that sense you did calculate with the dielectric in a very restricted sense.FYICleanup and de-typo of the take on applying the Equivalence Principle.The proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator. (to 1st order using massless, perfectly conducting cavity, no dielectric)Starting with the expressions for the frequency of a cylindrical RF cavity:f = (c/(2*Pi))*((X/R)^2+((p*Pi)/L)^2)^.5For TM modes, X = X[sub m,n] = the n-th zero of the m-th Bessel function.[1,1]=3.83, [0,1]=2.40, [0,2]=5.52 [1,2]=7.02, [2,1]=5.14, [2,2]=8.42, [1,3]=10.17, etc.and for TE modes, X = X'[sub m,n] = the n-th zero of the derivative of the m-th Bessel function.[0,1]=3.83, [1,1]=1.84, [2,1]=3.05, [0,2]=7.02, [1,2]=5.33, [1,3]=8.54, [0,3]=10.17, [2,2]=6.71, etc.Rotate the dispersion relation of the cavity into Doppler frame to get the Doppler shifts, that is to say, look at the dispersion curve intersections of constant wave number instead of constant frequency.df = (1/(2*f))*(c/(2*Pi))^2*X^2*((1/Rs^2)-(1/Rb^2))and from there the expression for the acceleration g from:g = (c^2/L)*(df/f) such that:g = (c^2/(2*L*f^2))*(c/(2*Pi))^2*X^2*((1/Rs^2)-(1/Rb^2))Using the "weight" of the photon in the accelerated frame from:"W" = (h*f/c^2)*g => "W" = T = (h/L)*dfgives thrust per photon:T = (h/(2*L*f))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))If the number of photons is (P/hf)*(Q/2*pi) then:NT = P*Q*(1/(4*pi*L*f^3))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))This does fit (as far as I've gotten) the concept of a self-accelerating Dirac wavepacket (which does conserve momentum).Slow goin', thanks for your patience.Excellent! Thank you for posting the complete equations.One suggestion: In the expression NT = P*Q*(1/(4*pi*L*f^3))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))the speed of light in vacuum "c" appears in the numerator without being divided by the SquareRoot of the relative electric permittivity and relative magnetic permeability.Since the relative electric permittivity of the dielectric is 2.3, this would decrease the values in the table by a factor of Sqrt[2.3]=1.52 if the whole cavity would be occupied by the dielectric. Granted that only a portion of the truncated cone contains the dielectric, which will decrease the dividing factor, but any amount will reduce the effective value of c in the medium, giving lower thrust and hence values closer to the experimental measurements. For example, very roughly, assuming that 1/3 of the longitudinal length is occupied by the dielectric, and using the average as a medium with those average properties, Sqrt[(2.3*1/3)+1*(2/3)]=1.20, the thrust values would be reduced by a factor of 1.20, so for the most important test (the one in recently performed in vacuum, -the other experimental values may have been affected by thermal convection effects in the air and are therefore less reliable-), instead of 104 μN you would get 87 μN, which better compares with the experimental value of 66 μN.

Quote from: Rodal on 02/17/2015 01:40 AMQuote from: Notsosureofit on 02/17/2015 12:01 AM@ RODALArrgh, Mondays !Looked over my bleary weekend, noticed I was using diameters AGAIN !Mode Frequency (MHz) Quality Factor, Q Input Power (W) Mean Thrust (μN) Calculated w/o dielectricTE012 1880.4 22000 2.6 55.4 10.8TM212 1932.6 7320 16.9 91.2 38.5TM212 1936.7 18100 16.7 50.1 93.5TM212 1937.115 6726 50 66 104.0Anyway, shows it pays to rewrite everything in the same place !....Great !In order to understand the above, (please correct me if I am wrong), you used in your formula the actual frequency and mode shapes that took place in the EM Drive experiment with the dielectric so in that sense you did calculate with the dielectric in a very restricted sense.FYICleanup and de-typo of the take on applying the Equivalence Principle.The proposition that dispersion caused by an accelerating frame of reference implied an accelerating frame of reference caused by a dispersive cavity resonator. (to 1st order using massless, perfectly conducting cavity, no dielectric)Starting with the expressions for the frequency of a cylindrical RF cavity:f = (c/(2*Pi))*((X/R)^2+((p*Pi)/L)^2)^.5For TM modes, X = X[sub m,n] = the n-th zero of the m-th Bessel function.[1,1]=3.83, [0,1]=2.40, [0,2]=5.52 [1,2]=7.02, [2,1]=5.14, [2,2]=8.42, [1,3]=10.17, etc.and for TE modes, X = X'[sub m,n] = the n-th zero of the derivative of the m-th Bessel function.[0,1]=3.83, [1,1]=1.84, [2,1]=3.05, [0,2]=7.02, [1,2]=5.33, [1,3]=8.54, [0,3]=10.17, [2,2]=6.71, etc.Rotate the dispersion relation of the cavity into Doppler frame to get the Doppler shifts, that is to say, look at the dispersion curve intersections of constant wave number instead of constant frequency.df = (1/(2*f))*(c/(2*Pi))^2*X^2*((1/Rs^2)-(1/Rb^2))and from there the expression for the acceleration g from:g = (c^2/L)*(df/f) such that:g = (c^2/(2*L*f^2))*(c/(2*Pi))^2*X^2*((1/Rs^2)-(1/Rb^2))Using the "weight" of the photon in the accelerated frame from:"W" = (h*f/c^2)*g => "W" = T = (h/L)*dfgives thrust per photon:T = (h/(2*L*f))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))If the number of photons is (P/hf)*(Q/2*pi) then:NT = P*Q*(1/(4*pi*L*f^3))*(c/(2*pi))^2*X^2*((1/Rs^2)-(1/Rb^2))This does fit (as far as I've gotten) the concept of a self-accelerating Dirac wavepacket (which does conserve momentum).Slow goin', thanks for your patience.

Quote from: Notsosureofit on 02/17/2015 12:01 AM@ RODALArrgh, Mondays !Looked over my bleary weekend, noticed I was using diameters AGAIN !Mode Frequency (MHz) Quality Factor, Q Input Power (W) Mean Thrust (μN) Calculated w/o dielectricTE012 1880.4 22000 2.6 55.4 10.8TM212 1932.6 7320 16.9 91.2 38.5TM212 1936.7 18100 16.7 50.1 93.5TM212 1937.115 6726 50 66 104.0Anyway, shows it pays to rewrite everything in the same place !....Great !In order to understand the above, (please correct me if I am wrong), you used in your formula the actual frequency and mode shapes that took place in the EM Drive experiment with the dielectric so in that sense you did calculate with the dielectric in a very restricted sense.

@ RODALArrgh, Mondays !Looked over my bleary weekend, noticed I was using diameters AGAIN !Mode Frequency (MHz) Quality Factor, Q Input Power (W) Mean Thrust (μN) Calculated w/o dielectricTE012 1880.4 22000 2.6 55.4 10.8TM212 1932.6 7320 16.9 91.2 38.5TM212 1936.7 18100 16.7 50.1 93.5TM212 1937.115 6726 50 66 104.0Anyway, shows it pays to rewrite everything in the same place !....

This stuff is all an interesting thought exercise, but there's no way it's a Sputnik moment when bulk of the physics community are scoffing at it. Just as with the Hafnium controversy, it would be nice to see the mainstream physics community roped in to at least do an authoritative disproof on it, rather than leaving things to linger on under imagination and speculation.

http://forum.nasaspaceflight.com/index.php?topic=36313.msg1326608#msg1326608

Anyway, still thinking about a possible experiment in vacuum using:https://www.dropbox.com/s/cmxyj7re8rrb6dh/IMAG0361.jpg?dl=0to make a stack chamber like:https://www.dropbox.com/s/wf8wv226h8138n1/IMAG0360.jpg?dl=0but on an isolation stand.The idea would be to then balance a tapered oscillator (Gunn Diode ?) cavity and a battery pack w/ a remote photo-switch on a beam held by a suspension fiber and monitor the rotation. I'm thinking one could get some sensitivity multiplication by switching the cavity on and off in time w/ the oscillation frequency of the assembly (easy to do w/ a digital camera) and see if the oscillation amplitude increases w/ time.Anyone want to try a sensitivity calculation ? Comments ?

.....The idea would be to then balance a tapered oscillator (Gunn Diode ?) cavity