This is useful for those still arguing over group vs phase velocity.http://www-math.mit.edu/~stevenj/papers/PovinelliIb04.pdfSlow-light enhancement of radiation pressurein an omnidirectional-reflector waveguide.
It doesn't matter if there is a more momentum at one vs the other. This theory of operation will not result in the frustum moving because....The small end and the large end are physically connected, so the total momentum is ZERO.
Quote from: Mulletron on 08/07/2015 10:54 amThis is useful for those still arguing over group vs phase velocity.http://www-math.mit.edu/~stevenj/papers/PovinelliIb04.pdfSlow-light enhancement of radiation pressurein an omnidirectional-reflector waveguide.What does this paper confirm for you?
Quote from: Rodal on 08/07/2015 02:47 amAny way, whether using 30 degrees or 30.0412 degrees this geometry is going to resonate at TE012 at a lower natural frequency than the 2.45 GHz TheTraveller calculated.So what do your exact solutions give for each value of the possible angles we found (30° and 30.0412°) for TE012 and TE013? Are they really different with such a slight difference?I think TheTraveller may have accounted for that lower natural frequency, as he also noted on his drawing: "Min operational frequency 2.3 GHz".
Any way, whether using 30 degrees or 30.0412 degrees this geometry is going to resonate at TE012 at a lower natural frequency than the 2.45 GHz TheTraveller calculated.
2) Using TE01X modes as the model, the radiation pressure per unit area is greatest at the small end where Vg is slowest (not the other way around).
I have also arrived at the conclusion that I cannot trust any experimental claims that TheTraveller may present.
Quote from: Mulletron on 08/07/2015 11:58 am2) Using TE01X modes as the model, the radiation pressure per unit area is greatest at the small end where Vg is slowest (not the other way around).At the small end, the guide wavelength is the longest, the group velocity is the slowest and the radiation pressure is the smallest. Power per end plate area is the same at each end plate.As example see the attached, which is from my latest frustum design.
Quote from: TheTraveller on 08/07/2015 12:18 pmQuote from: Mulletron on 08/07/2015 11:58 am2) Using TE01X modes as the model, the radiation pressure per unit area is greatest at the small end where Vg is slowest (not the other way around).At the small end, the guide wavelength is the longest, the group velocity is the slowest and the radiation pressure is the smallest. Power per end plate area is the same at each end plate.As example see the attached, which is from my latest frustum design.Shawyer has been wrong before. At least others think so. Is it possible he has it backwards?
Quote from: flux_capacitor on 08/07/2015 08:21 amQuote from: Rodal on 08/07/2015 02:47 amAny way, whether using 30 degrees or 30.0412 degrees this geometry is going to resonate at TE012 at a lower natural frequency than the 2.45 GHz TheTraveller calculated.So what do your exact solutions give for each value of the possible angles we found (30° and 30.0412°) for TE012 and TE013? Are they really different with such a slight difference?I think TheTraveller may have accounted for that lower natural frequency, as he also noted on his drawing: "Min operational frequency 2.3 GHz".Given his announced commercial (licensing) relationship with Shawyer and unwillingness to consider anything that deviates from what is prescribed by Shawyer, it has become apparent that it is a waste of my time to spend any further time discussing anything related to TheTraveller. I have also arrived at the conclusion that I cannot trust any experimental claims that TheTraveller may present.I look forward to the experiments of rfmwguy and SeeShells and hopefully to any further news from NASA Eagleworks and Tajmar.
Given his announced commercial (licensing) relationship with Shawyer and unwillingness to consider anything that deviates from what is prescribed by Shawyer, it has become apparent that it is a waste of my time to spend any further time discussing anything related to TheTraveller. I have also arrived at the conclusion that I cannot trust any experimental claims that TheTraveller may present.I look forward to the experiments of rfmwguy and SeeShells and hopefully to any further news from NASA Eagleworks and Tajmar.
Quote from: WarpTech on 08/07/2015 02:19 amQuote from: ElizabethGreene on 08/06/2015 10:10 pmQuote from: WarpTech on 08/06/2015 09:13 pmQuote from: ElizabethGreene on 08/06/2015 07:22 pm...I played with the numbers yesterday for F=2P/Vg -> F=2*P*Sqrt(1-(c/(2*(a+x)*f))^2) and found ......Disclaiming again, I probably broke the math.The equation would be F = (Vg/c^2)*P = P/Vp. IF you use standard waveguide physics that is. In the case of the EM Drive, this may be, F = (Vg*K/c^2)*P, where K is a function TBD by experiment.ToddIf F=P/Vp is correct for traditional physics, then Mr. Shawyer's theory falls apart. Specifically, as the size of the waveguide decreases Vp increases. An increase in Vp decreases F. That would make the force on the little end --smaller-- than the force on the big end.Is that right?Pretty much... It is that the momentum of an EM wave depends on the phase velocity and Planck's constant. It is the phase velocity, Vp = w/k that give us the momentum per photon, p=h*k. So if Vp is increasing, p is decreasing, and if Vp is decreasing, p is increasing. Either way, the force on the frustum is in the same direction in order to conserve momentum. The momentum is "forward rectified" by the gradient. It is only the reflection at the big end that is opposing this force. Anything that reduces the force on the big end, will result in forward thrust. In order for the big end to 100% cancel these forces, the force on the big end would have to be larger than the force at the small end. Definitely not smaller. If it is smaller by hook or by crook, or by leakage or heat, then the frustum will feel a thrust forward. The real question is still, how does it get thrust greater than a photon rocket? I see 3 possibilities:1. A group velocity that is faster than light in free space.2. A phase velocity that is slower than light in free space.3. A means to change the speed of light such that Vg*Vp = (c/K)2, in which case the group velocity could be faster than light in a frustum, but slower than light in free space and result in an amplified ratio;Vg/c2 -> K*Vg/c2, where K > 1 This way, nothing ever exceeds c in free space, but it reduces both the phase velocity and the group velocity to be much less than c. It is consistent with the PV Model of gravity. I just don't know how to derive it yet. I have 2 key pieces to the puzzle. Squeezed light behaves this way, and what Zeng and Fan show for an impedance curve looks almost exactly like a Reissner Nordstrom "charged" metric refractive index. Somehow, this all seems to make sense to me, but not well enough to write down the correct equations. Todd Why do you and others keep referring to phase velocity inside a waveguide as it is above c. Inside a waveguide energy moves at group velocity, which is determined from the guide wavelength, which is determined from the cutoff wavelength. The momentum in the wave varies as the guide wavelength varies, longer at the small end and shorter at the big end.http://www.microwaves101.com/encyclopedias/waveguide-mathematics#velocityCullen 15, attached, is based on this and proved that it is correct, so please stop talking above phase velocity inside a waveguide as it is above c and nothing travels above c.
Quote from: ElizabethGreene on 08/06/2015 10:10 pmQuote from: WarpTech on 08/06/2015 09:13 pmQuote from: ElizabethGreene on 08/06/2015 07:22 pm...I played with the numbers yesterday for F=2P/Vg -> F=2*P*Sqrt(1-(c/(2*(a+x)*f))^2) and found ......Disclaiming again, I probably broke the math.The equation would be F = (Vg/c^2)*P = P/Vp. IF you use standard waveguide physics that is. In the case of the EM Drive, this may be, F = (Vg*K/c^2)*P, where K is a function TBD by experiment.ToddIf F=P/Vp is correct for traditional physics, then Mr. Shawyer's theory falls apart. Specifically, as the size of the waveguide decreases Vp increases. An increase in Vp decreases F. That would make the force on the little end --smaller-- than the force on the big end.Is that right?Pretty much... It is that the momentum of an EM wave depends on the phase velocity and Planck's constant. It is the phase velocity, Vp = w/k that give us the momentum per photon, p=h*k. So if Vp is increasing, p is decreasing, and if Vp is decreasing, p is increasing. Either way, the force on the frustum is in the same direction in order to conserve momentum. The momentum is "forward rectified" by the gradient. It is only the reflection at the big end that is opposing this force. Anything that reduces the force on the big end, will result in forward thrust. In order for the big end to 100% cancel these forces, the force on the big end would have to be larger than the force at the small end. Definitely not smaller. If it is smaller by hook or by crook, or by leakage or heat, then the frustum will feel a thrust forward. The real question is still, how does it get thrust greater than a photon rocket? I see 3 possibilities:1. A group velocity that is faster than light in free space.2. A phase velocity that is slower than light in free space.3. A means to change the speed of light such that Vg*Vp = (c/K)2, in which case the group velocity could be faster than light in a frustum, but slower than light in free space and result in an amplified ratio;Vg/c2 -> K*Vg/c2, where K > 1 This way, nothing ever exceeds c in free space, but it reduces both the phase velocity and the group velocity to be much less than c. It is consistent with the PV Model of gravity. I just don't know how to derive it yet. I have 2 key pieces to the puzzle. Squeezed light behaves this way, and what Zeng and Fan show for an impedance curve looks almost exactly like a Reissner Nordstrom "charged" metric refractive index. Somehow, this all seems to make sense to me, but not well enough to write down the correct equations. Todd
Quote from: WarpTech on 08/06/2015 09:13 pmQuote from: ElizabethGreene on 08/06/2015 07:22 pm...I played with the numbers yesterday for F=2P/Vg -> F=2*P*Sqrt(1-(c/(2*(a+x)*f))^2) and found ......Disclaiming again, I probably broke the math.The equation would be F = (Vg/c^2)*P = P/Vp. IF you use standard waveguide physics that is. In the case of the EM Drive, this may be, F = (Vg*K/c^2)*P, where K is a function TBD by experiment.ToddIf F=P/Vp is correct for traditional physics, then Mr. Shawyer's theory falls apart. Specifically, as the size of the waveguide decreases Vp increases. An increase in Vp decreases F. That would make the force on the little end --smaller-- than the force on the big end.Is that right?
Quote from: ElizabethGreene on 08/06/2015 07:22 pm...I played with the numbers yesterday for F=2P/Vg -> F=2*P*Sqrt(1-(c/(2*(a+x)*f))^2) and found ......Disclaiming again, I probably broke the math.The equation would be F = (Vg/c^2)*P = P/Vp. IF you use standard waveguide physics that is. In the case of the EM Drive, this may be, F = (Vg*K/c^2)*P, where K is a function TBD by experiment.Todd
...I played with the numbers yesterday for F=2P/Vg -> F=2*P*Sqrt(1-(c/(2*(a+x)*f))^2) and found ......Disclaiming again, I probably broke the math.
It doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector.
Lambda/lambda_g*c = 1/Vp Mr. T. It is "You" who prefer to use the term Guide Wavelength. I prefer to use the term Phase Velocity. The resulting equation is identical. It is a matter of preference, not mathematics.F = 2*P/Vp = 2*P*lambda/lambda_g*cCall it what you like, but phase velocity is what it "is".Todd
Quote from: Mulletron on 08/07/2015 02:04 pmIt doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector.We have a great opportunity to understand what is going on in the near future because we have two very trustworthy people working on independent objective tests (rfmwguy and SeeShells). It is a very unusual opportunity because (just as we did for a while with Paul March at NASA) both rfmwguy and SeeShells are active in this thread. Their approach to testing is unbiased and objective. Unlike what happened with NASA we are under no threat of the communication being interrupted, and unlike what happened with Iulian they are active in the thread and we are under no threat of rfmwguy or SeeShells suddenly stopping their experiments.PS: coincidentally, I had also been looking to friction as well. To be explicit: related to the boundary conditions between air and the frustum and between the electromagnetic field and the frustum.
It doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector*.* http://forum.nasaspaceflight.com/index.php?topic=37642.msg1401370#msg1401370
Quote from: Rodal on 08/07/2015 02:19 pmQuote from: Mulletron on 08/07/2015 02:04 pmIt doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector.We have a great opportunity to understand what is going on in the near future because we have two very trustworthy people working on independent objective tests (rfmwguy and SeeShells). It is a very unusual opportunity because (just as we did for a while with Paul March at NASA) both rfmwguy and SeeShells are active in this thread. Their approach to testing is unbiased and objective. Unlike what happened with NASA we are under no threat of the communication being interrupted, and unlike what happened with Iulian they are active in the thread and we are under no threat of rfmwguy or SeeShells suddenly stopping their experiments.PS: coincidentally, I had also been looking to friction as well. To be explicit: related to the boundary conditions between air and the frustum and between the electromagnetic field and the frustum.Yeah true. I have a frustum too and about a thousand dollars invested so far on everything, but there for a while I got so burned out on this that I had to take a break. That combined with all the "anti West" comments from Shawyer in the media, I simply ran out of _'s.I'm slowly getting back in the game again. I really need to find a cheap USB signal generator. @TT. I really need you to question everything here. I don't want to see you loose cred by being viewed as a amazing people and not a scientist. Find the truth on your own, don't let the truth be revealed to you.I mean, if EMdrive does in fact work, then Shawyer is a hero and deserves credit for it. But there is likely a reason this thing has been stagnant for so long, he could have gotten things wrong too.
Theories. They abound and we're at what? Close to a dozen right now? the way I see it each and every one has its good points and bad and if you're here to discover the truth you can't strap yourself to just one. You might be eating your hat. I have my favorite but that cannot and will not detract or bias me in finding the why. The only real data that is true is mother natures and she trumps and belittles us all, she wrote the book we can barely read.I've been quite surprised by the simulations in meep and even though meep has it's limits it's enough to allow me to setup several testing criteria to test for different data. One is if this was a normal waveguide or resonant chamber you would expect a stable mode generation and a clean traveling wave locked into Q or traveling down the wave guide. This hasn't been the case. Because of the frustum's variable geometry I see in just a short run for a few cycles in meep mode changes and decays up and down the frustum. Can anyone explain to me when I see a mode shift in the meep time slices the time it seems to happen... it's within the meep data sample rate. The modes shift from top to bottom or side to side and if actions within the cavity still obey basic laws how can I see a full mode shift top to bottom in less than 1 ns (from sample rate to sample rate which is 1/10th of a cycle?) Light and most actions travels about ~11 inches in 1 ns. I'm so trying to gork opps grok this. I guess I need someone to give me a primmer.Shell
We how have 6 EMDrive peer reviewed papers, positive published results from Shawyer, Prof Yang, Eagleworks & Prof Tajmar yet still it is denied the EMDrive can work as claimed. Why? Just maybe some have dug a very deep hole for themselves.All that is really happening is Shawyer has discovered a way to convert some internal EM wave momentum into external frustum momentum, yet for most believing that is possible is a "bridge too far", even though the momentum lost to the EM wave is exactly the momentum gained by the frustum.