Quote from: WarpTech on 05/04/2015 03:55 amQuote from: LasJayhawk on 05/03/2015 05:43 amSo this made me think about the time I took a 3 port circulator apart. For those that are not familiar with circulators, the work like this:Put power in port 1 and it comes out port 2, put it in 2 and it comes out 3, put it in 3 and it comes out 1. All with out much loss. But if you try to go backwards, say 3 to 2, you loose 99% of the power. Cool little device. So when I take it apart all it is is a flat triangle of copper, 2 triangle shaped pieces of ferrite, and a magnet.If you don't know the math behind it, is looks at first blush as "silly" as the emdrive. No way could it do that. But it does. This thing may well work, we just don't know the math.I'm an Engineer and I've studied the Polarizable Vacuum Model of General Relativity. What it would say is the following;As a waveguide, the group velocity is something like;v_g = c x sqrt(1 - (c/2d*f)^2)Where, c is the usual speed of light, d is the diameter of the cylinder, and f is the frequency of the microwave excitation.c/2d = fc, is the Low cut-off frequency of the waveguide. The refractive index depends on the Low cut-off frequency as a function of the diameter, K = 1/sqrt( 1 - (fc/f)^2)For f >> fc, K~1. But for frequencies in the band fc1 < f <~ fc2, K is much larger.There is a strong gradient in the refractive index from one end of the cone to the other. This "mimics" gravity, as interpreted in the PV Model.Therefore, we can assume there is a "gravitational" gradient in the microwave band refractive index, along the length of the cone. At one end they have diameter d1, and at the other end they have diameter d2, and d1 > d2. Below fc1, the mode frequencies exponentially decay to zero. Just like the Casimir effect.Here is how it conserves momentum;In the PV Model, momentum transforms as,p => p*sqrt(K)In a resonant cavity, p is the SUM of all the photons “in phase", minus the losses of the cavity. However, as photons “fall” from the large end toward the small end, they gain momentum, which is passed on to the cone when they are reflected from the small end. The photon then loses momentum as it travels back to the large end, where it imparts “less” momentum to the large end. The result is a NET propulsion in the direction of the small end. In other words, the photons are blue-shifted falling forward, and red-shifted going backwards, due to the gradient in the refractive index. It is literally gravitational red & blue shift, according to the PV Model.The interesting thing is, the refractive index in the waveguide does not depend on the power of the microwaves, or the energy density. It is simply a matter of the geometry and frequency band relative to the cut-off. What matters more, is having enough resonant momentum stored to make the effect noticeable.That’s IMHO as an engineer of course. Any comments?See PV Model: https://www.researchgate.net/publication/223130116_Advanced_Space_Propulsion_Based_on_Vacuum_%28Spacetime_Metric%29_EngineeringTodd D.In what sense does this conserve momentum?Treat the device as a black box. I don't know or care what is happening inside it. At time T0 it has no momentum. Turn it on and let it accelerate so that it has some velocity and so momentum at time T1. Unless you can point to something with the same amount of momentum going in the other direction then by definition you have violated conservation of momentum. What happens inside the box simple does not affect that fact.

Quote from: LasJayhawk on 05/03/2015 05:43 amSo this made me think about the time I took a 3 port circulator apart. For those that are not familiar with circulators, the work like this:Put power in port 1 and it comes out port 2, put it in 2 and it comes out 3, put it in 3 and it comes out 1. All with out much loss. But if you try to go backwards, say 3 to 2, you loose 99% of the power. Cool little device. So when I take it apart all it is is a flat triangle of copper, 2 triangle shaped pieces of ferrite, and a magnet.If you don't know the math behind it, is looks at first blush as "silly" as the emdrive. No way could it do that. But it does. This thing may well work, we just don't know the math.I'm an Engineer and I've studied the Polarizable Vacuum Model of General Relativity. What it would say is the following;As a waveguide, the group velocity is something like;v_g = c x sqrt(1 - (c/2d*f)^2)Where, c is the usual speed of light, d is the diameter of the cylinder, and f is the frequency of the microwave excitation.c/2d = fc, is the Low cut-off frequency of the waveguide. The refractive index depends on the Low cut-off frequency as a function of the diameter, K = 1/sqrt( 1 - (fc/f)^2)For f >> fc, K~1. But for frequencies in the band fc1 < f <~ fc2, K is much larger.There is a strong gradient in the refractive index from one end of the cone to the other. This "mimics" gravity, as interpreted in the PV Model.Therefore, we can assume there is a "gravitational" gradient in the microwave band refractive index, along the length of the cone. At one end they have diameter d1, and at the other end they have diameter d2, and d1 > d2. Below fc1, the mode frequencies exponentially decay to zero. Just like the Casimir effect.Here is how it conserves momentum;In the PV Model, momentum transforms as,p => p*sqrt(K)In a resonant cavity, p is the SUM of all the photons “in phase", minus the losses of the cavity. However, as photons “fall” from the large end toward the small end, they gain momentum, which is passed on to the cone when they are reflected from the small end. The photon then loses momentum as it travels back to the large end, where it imparts “less” momentum to the large end. The result is a NET propulsion in the direction of the small end. In other words, the photons are blue-shifted falling forward, and red-shifted going backwards, due to the gradient in the refractive index. It is literally gravitational red & blue shift, according to the PV Model.The interesting thing is, the refractive index in the waveguide does not depend on the power of the microwaves, or the energy density. It is simply a matter of the geometry and frequency band relative to the cut-off. What matters more, is having enough resonant momentum stored to make the effect noticeable.That’s IMHO as an engineer of course. Any comments?See PV Model: https://www.researchgate.net/publication/223130116_Advanced_Space_Propulsion_Based_on_Vacuum_%28Spacetime_Metric%29_EngineeringTodd D.

So this made me think about the time I took a 3 port circulator apart. For those that are not familiar with circulators, the work like this:Put power in port 1 and it comes out port 2, put it in 2 and it comes out 3, put it in 3 and it comes out 1. All with out much loss. But if you try to go backwards, say 3 to 2, you loose 99% of the power. Cool little device. So when I take it apart all it is is a flat triangle of copper, 2 triangle shaped pieces of ferrite, and a magnet.If you don't know the math behind it, is looks at first blush as "silly" as the emdrive. No way could it do that. But it does. This thing may well work, we just don't know the math.

Quote from: WarpTech on 05/04/2015 04:46 amQuote from: ppnl on 05/04/2015 04:14 am<snip>In what sense does this conserve momentum?Treat the device as a black box. I don't know or care what is happening inside it. At time T0 it has no momentum. Turn it on and let it accelerate so that it has some velocity and so momentum at time T1. Unless you can point to something with the same amount of momentum going in the other direction then by definition you have violated conservation of momentum. What happens inside the box simple does not affect that fact.When you drop an object and it falls to the ground. Relative to you, it gained momentum from the gravitational field. It did not expel any propellant to fall. The gravitational field is simply a gradient in the refractive index of the vacuum surrounding the Earth. If you can explain conservation of momentum for falling objects in a gravitational field, then you have your answer.(Edit) In other words, if the cavity were not tapered, then you have equal momentum inside traveling left and right. At T0, it will go nowhere. However, because it is tapered such that you have a gradient in the refractive index, then "just like gravity", photons will be blue shifted moving into higher K, and red shifted moving into lower K, because momentum,p => p*sqrt(K)THIS is a violation of conservation of momentum. Therefore, the cavity must move to conserve momentum, as it tries to establish equilibrium with it's own internal stress.Regards,Todd D.Gravity certainly conserves momentum.When I drop a brick it falls to the earth. But the earth also falls toward it. True, by only a tiny amount but multiplied by the huge mass of the earth and it gains as much momentum as the brick and in the opposite direction. Did you really think that orbital mechanics did not conserve momentum?

Quote from: ppnl on 05/04/2015 04:14 am<snip>In what sense does this conserve momentum?Treat the device as a black box. I don't know or care what is happening inside it. At time T0 it has no momentum. Turn it on and let it accelerate so that it has some velocity and so momentum at time T1. Unless you can point to something with the same amount of momentum going in the other direction then by definition you have violated conservation of momentum. What happens inside the box simple does not affect that fact.When you drop an object and it falls to the ground. Relative to you, it gained momentum from the gravitational field. It did not expel any propellant to fall. The gravitational field is simply a gradient in the refractive index of the vacuum surrounding the Earth. If you can explain conservation of momentum for falling objects in a gravitational field, then you have your answer.(Edit) In other words, if the cavity were not tapered, then you have equal momentum inside traveling left and right. At T0, it will go nowhere. However, because it is tapered such that you have a gradient in the refractive index, then "just like gravity", photons will be blue shifted moving into higher K, and red shifted moving into lower K, because momentum,p => p*sqrt(K)THIS is a violation of conservation of momentum. Therefore, the cavity must move to conserve momentum, as it tries to establish equilibrium with it's own internal stress.Regards,Todd D.

<snip>In what sense does this conserve momentum?Treat the device as a black box. I don't know or care what is happening inside it. At time T0 it has no momentum. Turn it on and let it accelerate so that it has some velocity and so momentum at time T1. Unless you can point to something with the same amount of momentum going in the other direction then by definition you have violated conservation of momentum. What happens inside the box simple does not affect that fact.

Quote from: ppnl on 05/04/2015 05:04 amQuote from: WarpTech on 05/04/2015 04:46 amQuote from: ppnl on 05/04/2015 04:14 am<snip>In what sense does this conserve momentum?Treat the device as a black box. I don't know or care what is happening inside it. At time T0 it has no momentum. Turn it on and let it accelerate so that it has some velocity and so momentum at time T1. Unless you can point to something with the same amount of momentum going in the other direction then by definition you have violated conservation of momentum. What happens inside the box simple does not affect that fact.When you drop an object and it falls to the ground. Relative to you, it gained momentum from the gravitational field. It did not expel any propellant to fall. The gravitational field is simply a gradient in the refractive index of the vacuum surrounding the Earth. If you can explain conservation of momentum for falling objects in a gravitational field, then you have your answer.(Edit) In other words, if the cavity were not tapered, then you have equal momentum inside traveling left and right. At T0, it will go nowhere. However, because it is tapered such that you have a gradient in the refractive index, then "just like gravity", photons will be blue shifted moving into higher K, and red shifted moving into lower K, because momentum,p => p*sqrt(K)THIS is a violation of conservation of momentum. Therefore, the cavity must move to conserve momentum, as it tries to establish equilibrium with it's own internal stress.Regards,Todd D.Gravity certainly conserves momentum.When I drop a brick it falls to the earth. But the earth also falls toward it. True, by only a tiny amount but multiplied by the huge mass of the earth and it gains as much momentum as the brick and in the opposite direction. Did you really think that orbital mechanics did not conserve momentum? You are referring to Newtonian gravity. I'm referring to a form of GR, where it is the curvature of the manifold intersecting the object that causes it to fall, not some "action at a distance" or exchange of gravitons. In this case, that curvature is simply the gradient in the refractive index. Inside the cone, photons are moving in a variable refractive index. This causes red & blue shift and an imbalance in momentum. This is exactly what the Earth does to the vacuum surrounding it, it filters field modes and that causes the refractive index to increase. The cone is like the falling object, falling relative to the imbalance in the internal momentum which is the curved manifold.I agree, this is not standard GR, it is certainly not accepted physics. It is based on my own understanding of the Polarizable Vacuum Model of GR which I referenced earlier, as well as the Quantum Vacuum by Milonni, and my own work. Which predicted some 10 years ago, that it is easier to mimic gravity in over a limited bandwidth, than it is to create artificial gravity that affects all frequencies of light and matter.Todd D.

EM drive is a very clear case of pseudoscience. Not because it contradicts physics, as we know it. Questioning current science is a normal scientific endeavour - provided that the questioner knows what he/she is doing. It is pseudoscience because of the double-talk about acceptance, or non-acceptance, of the "usual" physics.Chris' article explains that the EM drive supposedly exchanges momentum with the so called "Quantum Vacuum". The well-established physics knows absolutely nothing about this possibility. That is, they propose existence of a completely new physical phenomenon, which may, or may not exist. (Probably not.) However, look this site:http://emdrive.com/principle.htmlHere they explain EM drive without the slightest mention of the revolution they propose in physics. The attached theory paper makes specific calculations about the operation of the drive, apparently on the basis of the usual physics. Again, there is no mention of a momentum exchange with the "Quantum Vacuum". Chris' paper mentions also a "new computational code that models the EM Drive’s thrust". Again, this implies that their thinking is based on a known theory, instead of some speculation about a currently unknown phenomenon.So, do they revolutionize physics? Or, they just apply the existing ones? In the first case, how can they make calculations without developing the quantum theory of their alleged momentum exchange to "Quantum Vacuum"? There is no such thing in their their theory paper. In the second case, momentum conservation prohibits EM drive to work and they calculations must be wrong. Momentum conservation is not something optional: Within the framework of the known quantum physics, momentum conservation is a direct consequence of translation invariance. You cannot tamper it without questioning the very basics of quantum physics.It is pseudoscience.

... Something is wrong here.

Quote from: tea monster on 04/30/2015 01:11 pmQuote from: Chris Bergin on 04/30/2015 12:40 pmPage 21 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20130011213.pdfThanks for the answer Chris. My applogies, I should have been more specific, I meant the one that's labled 'Warpstar 1' and looks (probably more accurately) like the main cabin of the Fireball XL5. Sorry for the confusion.The picture of "Warpstar 1" was posted by Paul March (an engineer at NASA Eagleworks) in the EM Drive threadsee: https://forum.nasaspaceflight.com/index.php?topic=36313.msg1331771#msg1331771In his own words:QuoteI have no doubt now that this quantum vacuum derived propulsion system will be able to meet and ultimately surpass my conjectured WarpStar-I concept vehicle performance that I wrote about in my STAIF-2007 paper based on Woodward's Mach Lorentz Thrusters (MLT) of the day. A vehicle that could go from the surface of the Earth to the surface of the Moon with a crew of two and six passengers with luggage in under four hours and then return to the surface of the Earth in another 4 hours with the same payload using just one load of H2/O2 fuel cell derived electrical power assuming 500-to-1,000 N/kWe efficiency MLTs or Q-Thrusters. And yes, I know that's a mighty big leap from the 1.0uN/Watt we currently have demonstrated at the Eagleworks Lab, but if Dr. White's QVF/MHD conjecture is anywhere close to reality, it will be doable, at least in the long term.Best, Paul M.Note that Paul's statement " I know that's a mighty big leap from the 1.0uN/Watt we currently have demonstrated at the Eagleworks Lab" refers to the measured force in a vacuum per input electric power at NASA Eagleworks. The highest measured force per input power was 1 Newton/kiloWatt for the experiments by Prof. Yang in China with a non-superconducting truncated cone EM Drive and by Cannae LLC in the USA for their superconducting EM Drive shaped like a pillbox.

Quote from: Chris Bergin on 04/30/2015 12:40 pmPage 21 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20130011213.pdfThanks for the answer Chris. My applogies, I should have been more specific, I meant the one that's labled 'Warpstar 1' and looks (probably more accurately) like the main cabin of the Fireball XL5. Sorry for the confusion.

Page 21 of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20130011213.pdf

I have no doubt now that this quantum vacuum derived propulsion system will be able to meet and ultimately surpass my conjectured WarpStar-I concept vehicle performance that I wrote about in my STAIF-2007 paper based on Woodward's Mach Lorentz Thrusters (MLT) of the day. A vehicle that could go from the surface of the Earth to the surface of the Moon with a crew of two and six passengers with luggage in under four hours and then return to the surface of the Earth in another 4 hours with the same payload using just one load of H2/O2 fuel cell derived electrical power assuming 500-to-1,000 N/kWe efficiency MLTs or Q-Thrusters. And yes, I know that's a mighty big leap from the 1.0uN/Watt we currently have demonstrated at the Eagleworks Lab, but if Dr. White's QVF/MHD conjecture is anywhere close to reality, it will be doable, at least in the long term.Best, Paul M.

EM drive is a very clear case of pseudoscience. ...................................................It is pseudoscience.

The theory papers out there are clearly not the issue to debate here. The device producing anomalous thrust is the issue here. Anybody can come up with a bunk theory. The Emdrive is still a black box deserving expert attention.Everybody assumes that this thing is acting like a quantum rocket (and taking all sorts of liberties with established science to justify that), based off what I see, it is a sail.

This thrust should not exist according to physics, as we know it.

An unquestionable experimental result would mean a scientific revolution.

Quote from: Mulletron on 05/04/2015 11:56 amThe theory papers out there are clearly not the issue to debate here. The device producing anomalous thrust is the issue here. Anybody can come up with a bunk theory. The Emdrive is still a black box deserving expert attention.Everybody assumes that this thing is acting like a quantum rocket (and taking all sorts of liberties with established science to justify that), based off what I see, it is a sail.A sail in what medium?