Apparently DARPA has granted Dr. Mike McCulloch $1.5m to build a demo QI based propellant less drive for them.https://twitter.com/PeterlooPete/status/1020597177029201920Should be interesting.
Quote from: TheTraveller on 07/23/2018 04:38 pmApparently DARPA has granted Dr. Mike McCulloch $1.5m to build a demo QI based propellant less drive for them.https://twitter.com/PeterlooPete/status/1020597177029201920Should be interesting.I wonder what that might look like? E.g.A) 15 people @100k for 1 yearB) 7 people for 2 yearsC) 3 people for 4 yearsI suppose it might be something like B) or C) with extra PhD students and unpaid interns.Or maybe some of that budget is for cubesat? Perhaps DARPA has a place on their shuttle-like space vehicle I think they have.
Quote from: Mark7777777 on 07/23/2018 09:03 pmQuote from: TheTraveller on 07/23/2018 04:38 pmApparently DARPA has granted Dr. Mike McCulloch $1.5m to build a demo QI based propellant less drive for them.https://twitter.com/PeterlooPete/status/1020597177029201920Should be interesting.I wonder what that might look like? E.g.A) 15 people @100k for 1 yearB) 7 people for 2 yearsC) 3 people for 4 yearsI suppose it might be something like B) or C) with extra PhD students and unpaid interns.Or maybe some of that budget is for cubesat? Perhaps DARPA has a place on their shuttle-like space vehicle I think they have.If it proves out, money will not be an object and the real space race will begin.
Quote from: TheTraveller on 07/23/2018 04:38 pmApparently DARPA has granted Dr. Mike McCulloch $1.5m to build a demo QI based propellant less drive for them.https://twitter.com/PeterlooPete/status/1020597177029201920Should be interesting.Is the Q thruster emdrive? Or is it a working medium microwave propeller?
Is the Q thruster emdrive? Or is it a working medium microwave propeller?
I think with some of the claims that the EM drive is changing the frequency of light by transference of its energy to some unseen medium (acceleration of light) could be tested. Injection into the cavity could be chosen to be continuous and at a set frequency. One can then use the frequency injected to compare that frequency that exists inside the cavity via a sensing antenna. Lower Q allows some bandwidth to exist in the cavity so it might be there. Shift the phase of the injected frequency and amplify/attenuate the wave so the sensed frequency in the cavity cancels with the injected frequency. What remains would be what ever is left that changed in frequency.
Quote from: dustinthewind on 07/24/2018 11:57 pmI think with some of the claims that the EM drive is changing the frequency of light by transference of its energy to some unseen medium (acceleration of light) could be tested. Injection into the cavity could be chosen to be continuous and at a set frequency. One can then use the frequency injected to compare that frequency that exists inside the cavity via a sensing antenna. Lower Q allows some bandwidth to exist in the cavity so it might be there. Shift the phase of the injected frequency and amplify/attenuate the wave so the sensed frequency in the cavity cancels with the injected frequency. What remains would be what ever is left that changed in frequency. Hi, As an EmDrive accelerates, the gained KE is from the internal photons energy loss, which causes the emitted photons to have a longer wavelength than on impact. Nothing new here. Happens with solar sails.Using short pulse Rf injection (limited to 5x cavity TC) and allowing the cavity to accelerate while the cavity energy rings down, enables this increasing wavelength effect to be measured.During acceleration, other effects occur such as decreased Q due to some cavity energy conversion into KE and impedance changes due to increased photon wavelength moving away from ideal resonant freq.
Quote from: TheTraveller on 07/25/2018 12:15 amQuote from: dustinthewind on 07/24/2018 11:57 pmI think with some of the claims that the EM drive is changing the frequency of light by transference of its energy to some unseen medium (acceleration of light) could be tested. Injection into the cavity could be chosen to be continuous and at a set frequency. One can then use the frequency injected to compare that frequency that exists inside the cavity via a sensing antenna. Lower Q allows some bandwidth to exist in the cavity so it might be there. Shift the phase of the injected frequency and amplify/attenuate the wave so the sensed frequency in the cavity cancels with the injected frequency. What remains would be what ever is left that changed in frequency. Hi, As an EmDrive accelerates, the gained KE is from the internal photons energy loss, which causes the emitted photons to have a longer wavelength than on impact. Nothing new here. Happens with solar sails.Using short pulse Rf injection (limited to 5x cavity TC) and allowing the cavity to accelerate while the cavity energy rings down, enables this increasing wavelength effect to be measured.During acceleration, other effects occur such as decreased Q due to some cavity energy conversion into KE and impedance changes due to increased photon wavelength moving away from ideal resonant freq.Ok. You talk as if you have taken measurements of this ring down? Do you have any measurements of this change in frequency you could share? Thanks. Also I am assuming that your thinking that more reflections at the top lead to more momentum transfer than a single reflection below. Even though multiple reflections at top, add less forward momentum per strike via the angle of reflection. So multiple strikes and photon energy loss win out causing the back strike not to be able to finish momentum cancellation.
Momentum transfer is highly dependent on the angle of incidence, which is also the angle of emission. So there is a double cosine loss function at work. As the angle of incidence varies with the diameter, this is why the rad pressure drops in a very non linear way as the diameter drops.
Quote from: TheTraveller on 07/25/2018 03:56 amMomentum transfer is highly dependent on the angle of incidence, which is also the angle of emission. So there is a double cosine loss function at work. As the angle of incidence varies with the diameter, this is why the rad pressure drops in a very non linear way as the diameter drops.In this (overly simplistic) view where the photons are particles rather than distributed waves, you have made a couple mistakes.-The cosine should not be squared, the incident equals reflected angle is handled by the factor of 2 in your equation.-You are talking about radiation pressure reducing as the diameter decreases, but you ignore the fact that if that is what happened, the drive would accelerate in the wrong direction-You are ignoring that since the pressure on the sidewalls includes a component in the axial direction, this adds additional force that exactly makes up the difference between the force on the small and large ends.Now stop demonstrating that you have trouble with entry level physics, stop claiming that NASA or other agency agree with Shawyer on anything (no one competent agrees with his theory, because it is obviously inconsistent) That chart from Shawyer is meaningless, it is just one more set of claims from him that is almost certainly not representative of reality in any way, shape, or form. And seriously stop with claims like "it has been measured and will be shared" You have not given a shred of evidence that you have ever built anything. Either share the data, or stop with the false promises.
The equation is correct:https://en.wikipedia.org/wiki/Radiation_pressure see attached.
Note that Roger has explained how the rad pressure at the end plates is different as in slides 8 & 9. BTW do you have any issues with those 2 attached slides?
I did not make any claims about Roger's recent presentation. What I did was share what I read from his slides. Maybe you should email Roger and tell him to stop making such claims? Or maybe email the USAF and tell them that Roger is making false claims about their Flight Certification of the SPR Flight Thruster and false claims that they agree with SPR on the 3G EmDrive theory?
....Yes it has been measured and the data will be shared when the KISS drive build and testing is completed. ...
....Note that Roger has explained how the rad pressure at the end plates is different as in slides 8 & 9. BTW do you have any issues with those 2 attached slides?... Or maybe email the USAF and tell them that Roger is making false claims about their Flight Certification of the SPR Flight Thruster and false claims that they agree with SPR on the 3G EmDrive theory?
Different dog, same leg action....
Quote from: oyzw on 07/24/2018 12:47 amQuote from: TheTraveller on 07/23/2018 04:38 pmApparently DARPA has granted Dr. Mike McCulloch $1.5m to build a demo QI based propellant less drive for them.https://twitter.com/PeterlooPete/status/1020597177029201920Should be interesting.Is the Q thruster emdrive? Or is it a working medium microwave propeller?Hi Oyzw,Neither. Something else. Based on Mike's Qi theory.While Mike does have a thrust equation that works with some EmDrive data, his theory is not the SPR theory.
Quote from: TheTraveller on 07/25/2018 07:38 amThe equation is correct:https://en.wikipedia.org/wiki/Radiation_pressure see attached.That equation is for a fixed area plate in fixed irradiance (energy per area) radiation field, where the total amount of energy that hits the plate per area is a function of the projected area of the plate into the field. The result is the pressure on the plate (force per physical area of the plate). The equation you gave is a function of total energy hitting the surface, not energy per area. As a result the second factor of cos is already built in to the energy. This makes sense, because inside the cavity, all of the energy will be reflected off something, you don't need to reduce it by the extra factor, since non of the energy can miss the walls entirely....
Quote from: meberbs on 07/25/2018 01:40 pmQuote from: TheTraveller on 07/25/2018 07:38 amThe equation is correct:https://en.wikipedia.org/wiki/Radiation_pressure see attached.That equation is for a fixed area plate in fixed irradiance (energy per area) radiation field, where the total amount of energy that hits the plate per area is a function of the projected area of the plate into the field. The result is the pressure on the plate (force per physical area of the plate). The equation you gave is a function of total energy hitting the surface, not energy per area. As a result the second factor of cos is already built in to the energy. This makes sense, because inside the cavity, all of the energy will be reflected off something, you don't need to reduce it by the extra factor, since non of the energy can miss the walls entirely....Maybe somebody on the forum can recall that a few years ago a German student wrote a simulation of EMDrive based on bouncing photons with a probability of being absorbed. He obtained thrust and posted the document and code here. I reviewed his code and found probably exactly the same problem (square or not of the cos(theta)). After he corrected the problem, the thrust was reduced to input momentum. I tried but I can not find his post nor my review.