Quote from: Rodal on 06/03/2015 12:11 pmQuote from: rfmwguy on 06/03/2015 11:56 amJune 2, 2015 new buzzkill paper: http://arxiv.org/pdf/1506.00494.pdf FYI only"IV. CONCLUSIONSThe fact that the EM drive, or any other reactionless drive that has a thrust-to-powerratio greater than a photon-emitting device, would enable a perpetual motion machine of thefirst kind suggests that such a device cannot exist. This objection is not as easily explainedaway as the conservation of momentum objection to a reactionless drive, because this resultsuggests than a source of free and infinite energy is already at our technological disposal.Any conditions placed on the operation of the hypothetical “space drive” in order to makeis consistent with the First Law would also render it useless as a propulsion device; if it canwork as a propulsion device, it can also function as a perpetual motion machine of the firstkind. Further investment into investigating this concept should be tempered by the historyof attempts to realize perpetual motion machines."One does wonder if much of the buzzkill is a thinly disguised funding suggestion It looks like a repetition of all the arguments already published by @frobnicat's in his discussions in these NSF EM Drive threads, but fails to give any credit to @frobnicat.Unless frobnicat is Higgins which is unlikely . Good catch Doc.
Quote from: rfmwguy on 06/03/2015 11:56 amJune 2, 2015 new buzzkill paper: http://arxiv.org/pdf/1506.00494.pdf FYI only"IV. CONCLUSIONSThe fact that the EM drive, or any other reactionless drive that has a thrust-to-powerratio greater than a photon-emitting device, would enable a perpetual motion machine of thefirst kind suggests that such a device cannot exist. This objection is not as easily explainedaway as the conservation of momentum objection to a reactionless drive, because this resultsuggests than a source of free and infinite energy is already at our technological disposal.Any conditions placed on the operation of the hypothetical “space drive” in order to makeis consistent with the First Law would also render it useless as a propulsion device; if it canwork as a propulsion device, it can also function as a perpetual motion machine of the firstkind. Further investment into investigating this concept should be tempered by the historyof attempts to realize perpetual motion machines."One does wonder if much of the buzzkill is a thinly disguised funding suggestion It looks like a repetition of all the arguments already published by @frobnicat's in his discussions in these NSF EM Drive threads, but fails to give any credit to @frobnicat.
June 2, 2015 new buzzkill paper: http://arxiv.org/pdf/1506.00494.pdf FYI only"IV. CONCLUSIONSThe fact that the EM drive, or any other reactionless drive that has a thrust-to-powerratio greater than a photon-emitting device, would enable a perpetual motion machine of thefirst kind suggests that such a device cannot exist. This objection is not as easily explainedaway as the conservation of momentum objection to a reactionless drive, because this resultsuggests than a source of free and infinite energy is already at our technological disposal.Any conditions placed on the operation of the hypothetical “space drive” in order to makeis consistent with the First Law would also render it useless as a propulsion device; if it canwork as a propulsion device, it can also function as a perpetual motion machine of the firstkind. Further investment into investigating this concept should be tempered by the historyof attempts to realize perpetual motion machines."One does wonder if much of the buzzkill is a thinly disguised funding suggestion
...Instead of the stored energy (5000J) being released out the back, it is attenuated and absorbed at the front. The result is the same, the frustum absorbs 5000J of energy as work done on it's mass, preferably all on one side.Todd
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)
Quote from: dustinthewind on 06/03/2015 03:11 am the near field propagates faster than light? I'm not sure I can bring myself to swallow that just yet. Superluminal Group Velocity of Electromagnetic Near-fieldhttp://arxiv.org/abs/physics/0311061
the near field propagates faster than light? I'm not sure I can bring myself to swallow that just yet.
Quote from: OttO on 06/03/2015 11:38 amQuote from: dustinthewind on 06/03/2015 03:11 am the near field propagates faster than light? I'm not sure I can bring myself to swallow that just yet. Superluminal Group Velocity of Electromagnetic Near-fieldhttp://arxiv.org/abs/physics/0311061 There are dozens of papers reporting experiments measuring superluminal propigation of evanescent EM waves. Use Google to find your favorites. It happens that the solution of the wave equations (Maxwell) are very similar, if not identical to the equations discribing the tunneling phenomona. I wonder if tunneling and superluminal propagation may be in fact the same phenomona? Does anyone know of any experimental measurements of momentum resulting from electron tunneling?
Quote from: rfmwguy on 06/03/2015 12:14 pmQuote from: Rodal on 06/03/2015 12:11 pmQuote from: rfmwguy on 06/03/2015 11:56 amJune 2, 2015 new buzzkill paper: http://arxiv.org/pdf/1506.00494.pdf FYI only"IV. CONCLUSIONSThe fact that the EM drive, or any other reactionless drive that has a thrust-to-powerratio greater than a photon-emitting device, would enable a perpetual motion machine of thefirst kind suggests that such a device cannot exist. This objection is not as easily explainedaway as the conservation of momentum objection to a reactionless drive, because this resultsuggests than a source of free and infinite energy is already at our technological disposal.Any conditions placed on the operation of the hypothetical “space drive” in order to makeis consistent with the First Law would also render it useless as a propulsion device; if it canwork as a propulsion device, it can also function as a perpetual motion machine of the firstkind. Further investment into investigating this concept should be tempered by the historyof attempts to realize perpetual motion machines."One does wonder if much of the buzzkill is a thinly disguised funding suggestion It looks like a repetition of all the arguments already published by @frobnicat's in his discussions in these NSF EM Drive threads, but fails to give any credit to @frobnicat.Unless frobnicat is Higgins which is unlikely . Good catch Doc.Be interesting to see what the former has to say about this matter.
Nothing is moving "backwards". Momentum is flowing INTO the boundary, NOT OUT of the boundary. It works both ways. Divergence is not zero when the source is turned on. The Poynting vector is not zero. The momentum put inside is then attenuated asymmetrically, and the resulting forces and amplitudes depend on the relative phase of the waves, not simply their time-averaged pressure. The conservation law says is that there must be divergence through the boundary, it can be in either direction, in or out. It isn't ONLY expelling something out that satisfies this condition.Todd
Quote from: WarpTech on 06/03/2015 05:16 amI had similar ideas nearly 20 years ago! The conclusion I came to back then was that there is always the "hidden momentum" creating an equal and opposite force. If you use a 1/4-wave coupling of the electric field and the charge, you will have an opposite force between the magnetic field and the current, and in the end you have a photon rocket resulting from the leakage inductance and capacitance....In regards to the underlined statement. I know what you mean because static charge builds up and the force is counter to the magnetic. Concerning a cylindrical cavity in TE01 mode, does the charge build up so as to provide that counter force? It doesn't appear to me that there is a static charge build up in that mode. ...
I had similar ideas nearly 20 years ago! The conclusion I came to back then was that there is always the "hidden momentum" creating an equal and opposite force. If you use a 1/4-wave coupling of the electric field and the charge, you will have an opposite force between the magnetic field and the current, and in the end you have a photon rocket resulting from the leakage inductance and capacitance....
...If it can help, here you find and old and "classical" demonstration of the impossibility of accelerating a closed system by converting the system internal energy into kinetic energy. Let's assimilate the spacecraft (including thruster, PPU, a.s.o.) to a particle having a rest mass m0 and 4-velocity V=(c/alpha, v/alpha) in an arbitrary Lorentzian frame. The 4-momentum of the particle, by definition is P=(mc, mv) with m=mo/alpha; if the particle is isolated (no interaction nor mass/energy exchange with the surrounding medium), then the relativistic conservation of momentum implies dP=(dm c, dm v)=0, i.e., dm=0 and d(m v)=0, so dv=0. Total energy is conserved and 3-momentum is also conserved, the former implying that according to the latter the system cannot accelerate.
Quote from: MyronQG on 06/03/2015 03:07 pm...If it can help, here you find and old and "classical" demonstration of the impossibility of accelerating a closed system by converting the system internal energy into kinetic energy. Let's assimilate the spacecraft (including thruster, PPU, a.s.o.) to a particle having a rest mass m0 and 4-velocity V=(c/alpha, v/alpha) in an arbitrary Lorentzian frame. The 4-momentum of the particle, by definition is P=(mc, mv) with m=mo/alpha; if the particle is isolated (no interaction nor mass/energy exchange with the surrounding medium), then the relativistic conservation of momentum implies dP=(dm c, dm v)=0, i.e., dm=0 and d(m v)=0, so dv=0. Total energy is conserved and 3-momentum is also conserved, the former implying that according to the latter the system cannot accelerate.If you have a "Lorentzian frame", this is correct. However, in the frustum this is not true because you have a variable refractive index. It is no longer "Lorentzian" because there is an attenuation (acceleration) over a narrow bandwidth of the EM spectrum.Todd
Quote from: WarpTech on 06/03/2015 03:34 pmQuote from: MyronQG on 06/03/2015 03:07 pm...If it can help, here you find and old and "classical" demonstration of the impossibility of accelerating a closed system by converting the system internal energy into kinetic energy. Let's assimilate the spacecraft (including thruster, PPU, a.s.o.) to a particle having a rest mass m0 and 4-velocity V=(c/alpha, v/alpha) in an arbitrary Lorentzian frame. The 4-momentum of the particle, by definition is P=(mc, mv) with m=mo/alpha; if the particle is isolated (no interaction nor mass/energy exchange with the surrounding medium), then the relativistic conservation of momentum implies dP=(dm c, dm v)=0, i.e., dm=0 and d(m v)=0, so dv=0. Total energy is conserved and 3-momentum is also conserved, the former implying that according to the latter the system cannot accelerate.If you have a "Lorentzian frame", this is correct. However, in the frustum this is not true because you have a variable refractive index. It is no longer "Lorentzian" because there is an attenuation (acceleration) over a narrow bandwidth of the EM spectrum.ToddJust take a marker and draw a spot on the spacecraft hull. The theory works equally well for the motion of that spot, irrespective of what's happening inside, provided nothing is coming out of the enclosing control volume. I hate to say that this is basic theory of propulsion (Koëlle, Handbook of Astronautical Engineering, 1962).
Quote from: aero on 06/03/2015 02:43 pmQuote from: OttO on 06/03/2015 11:38 amQuote from: dustinthewind on 06/03/2015 03:11 am the near field propagates faster than light? I'm not sure I can bring myself to swallow that just yet. Superluminal Group Velocity of Electromagnetic Near-fieldhttp://arxiv.org/abs/physics/0311061 There are dozens of papers reporting experiments measuring superluminal propigation of evanescent EM waves. Use Google to find your favorites. It happens that the solution of the wave equations (Maxwell) are very similar, if not identical to the equations discribing the tunneling phenomona. I wonder if tunneling and superluminal propagation may be in fact the same phenomona? Does anyone know of any experimental measurements of momentum resulting from electron tunneling?I agree.SUBJECTIVE OPINION: I much prefer the wording " tunneling phenomena" to "superluminal propagation" as it does not necessarily involve the need to invoke the existence of tachyons. QUESTION 1: The group velocity is superluminal. Is the phase velocity subluminal ?The number of photons in a photon gas is not a thermodynamic constant but it is proportional to the cube of the temperature of the photon gas. In the Photonic Laser Thruster, collimated photons are reused by mirrors, multiplying the force by the number of bounces. QUESTION 2: Under Q resonance can the number of photons able to achieve "tunneling phenomena", be greater than the number of photons emitted by a traditional photon rocket?
With regard to the same experiments, Guenter Nimitz claimed very recently [10] that those results with evanescent waves, or "tunnelling photons", do really imply Superluminal signal and impulse transmission.
Quote from: rfmwguy on 06/03/2015 11:56 amJune 2, 2015 new buzzkill paper: http://arxiv.org/pdf/1506.00494.pdf FYI only"IV. CONCLUSIONSThe fact that the EM drive, or any other reactionless drive that has a thrust-to-powerratio greater than a photon-emitting device, would enable a perpetual motion machine of thefirst kind suggests that such a device cannot exist. This objection is not as easily explainedaway as the conservation of momentum objection to a reactionless drive, because this resultsuggests than a source of free and infinite energy is already at our technological disposal.Any conditions placed on the operation of the hypothetical “space drive” in order to makeis consistent with the First Law would also render it useless as a propulsion device; if it canwork as a propulsion device, it can also function as a perpetual motion machine of the firstkind. Further investment into investigating this concept should be tempered by the historyof attempts to realize perpetual motion machines."One does wonder if much of the buzzkill is a thinly disguised funding suggestion It looks like an egregious repetition of the arguments previously published by @frobnicat's in discussions in these NSF EM Drive threads, but failing to give any credit to @frobnicat.It is due @frobnicat's coherent and well formulated arguments that we decided to compare all EM Drive experimental force reports to the one of a perfectly collimated photon rocket, ever since we started to compile experimental records.EDIT: The author of the above-mentioned article: http://arxiv.org/pdf/1506.00494.pdf is no @frobnicat
Quote from: Rodal on 06/03/2015 12:11 pmQuote from: rfmwguy on 06/03/2015 11:56 amJune 2, 2015 new buzzkill paper: http://arxiv.org/pdf/1506.00494.pdf FYI only"IV. CONCLUSIONSThe fact that the EM drive, or any other reactionless drive that has a thrust-to-powerratio greater than a photon-emitting device, would enable a perpetual motion machine of thefirst kind suggests that such a device cannot exist. This objection is not as easily explainedaway as the conservation of momentum objection to a reactionless drive, because this resultsuggests than a source of free and infinite energy is already at our technological disposal.Any conditions placed on the operation of the hypothetical “space drive” in order to makeis consistent with the First Law would also render it useless as a propulsion device; if it canwork as a propulsion device, it can also function as a perpetual motion machine of the firstkind. Further investment into investigating this concept should be tempered by the historyof attempts to realize perpetual motion machines."One does wonder if much of the buzzkill is a thinly disguised funding suggestion It looks like an egregious repetition of the arguments previously published by @frobnicat's in discussions in these NSF EM Drive threads, but failing to give any credit to @frobnicat.It is due @frobnicat's coherent and well formulated arguments that we decided to compare all EM Drive experimental force reports to the one of a perfectly collimated photon rocket, ever since we started to compile experimental records.EDIT: The author of the above-mentioned article: http://arxiv.org/pdf/1506.00494.pdf is no @frobnicat No I'm not the author of this paper, as dr Rodal who knows my "secret" identity can confirm. BTW it is secret not because of connection of my job with aerospace but complete lack thereof. Anyway, I don't claim originality on this line of reasoning since it appears rather straightforward to me, and I think to a lot of people who haven't cared to write on that : silent dismissal of fringe science. Actually, I saw it made independently at other places, at least on talk polywell, by "believers" of propellantless ME scheme that dare go to the bold but consistent conclusions, and also by various sceptics on forums around. Neither more than me the author of this paper could really claim originality as I'm sure the objection is as old as the first claims of thrust/power>1/c... he is just putting it black on white, which has the merit of serving as a later reference. Though may be, as a reference, it would have benefited from a longer bibliography... and yes I would have appreciated a small citation (provided the author was aware of my communication efforts here).My only original contribution on this line of refutation might be to illustrate how to put the break even velocity Vbe at 1/(thrust/power) rather than 2/(thrust/power) for Newtonian mechanics, i.e. low speeds, for instance with thrust/power=1N/kW yielding a Vbe of 1km/s instead of 2km/s, the CoE apparent breaking appears at more modest velocities when considering constant thrust/constant velocity rather than acquired velocity relative to starting frame. Even that I remember having seen elsewhere. This should appear in the paper, but maybe the author don't care about polishing the argument thus far, as from "this is breaking CoE" standpoint, Vbe=2/(thrust/power) is good enough.Anyway, apart from Mach effect (Woodward) and QV plasma (White) contenders, both approaches being somehow compatible with tapping in a practically limitless energy source, and making possible a device such as the one depicted above (which is more or less publicly acknowledged by some followers), I saw none convincing argument that it could be possible to render compatible 1/ a working propellantless drive with averaged thrust/power>>1/c (useful for deep space flight)2/ that don't act as a limitless energy source (for all practical purpose)That is, for those wanting 1/ and 2/ : what would make the above depicted device fail (or equivalently, what would be the flaw in the cited paper) ? Obviously, just claiming that it does 1/ and still respects 2/ is not convincing by itself when those aspect are treated inconsistently. It is to be expected as propellantless propulsion phenomenological claims gain in attention that more and more sceptics find the motivation to publish refutations that otherwise would have been kept in the realm of polite pass over. Unfortunately there is still not enough incentive right now for big labs to hunt for experimental null results. What is the point to confirm the inexistence of something that the overwhelming majority of establishment is knee jerkedly considering bogus ? When (if) apparent positives pile up, then this incentive will rise and maybe we will start to see more null results published. I'm convinced there are already a lot of null results out there, just not published/advertised.ps. Thanks rfmwguy & dr Rodal, et al.
...Regarding space-time. Believe me when I tell you, what we are doing here with attenuation and superposition of EM waves "is" modifying space-time at this narrow bandwidth of the EM spectrum. It is NOT in any way going to generate a gravitational field where clocks, rulers, or lasers will be affected. What is going on at the microwave frequencies close to the cut-off is conceptually, and physically the same as-if space-time were curved at these frequencies. If you try to curve space-time at "all" the frequencies of the ZPF spectrum, such that it affects protons, etc.., the amount of energy required is enormous, as GR will tell you. Having a frequency dependent metric is something I predicted at least 15 years ago, when I first started modeling the PV as a quantum field theory. I had no idea how to do it back then. Now we do! Todd