...I believe the only way this is applicable to Shawyer's cutoff statement is if you begin with the assumption that there is no thrust. His statement seems tied to a cutoff frequency associated with generating thrust.Separately...Something that might be interesting is if rfmwguy were to rerun the initial test (without the steel wool) and instead of closing the mouth piece end with a plate, terminate it into a faraday cage with ground isolated from the baritone. Maybe even try to set up some means of determining if any microwaves in the range produced by the magnetron even escape through the mouth piece end. The diameter and geometry of the instrument may wind up grounding out all microwaves before they reach a open mouth piece. This would experimentally confirm the last comment above.
Quote from: OnlyMe on 12/15/2015 04:32 pm...I believe the only way this is applicable to Shawyer's cutoff statement is if you begin with the assumption that there is no thrust. His statement seems tied to a cutoff frequency associated with generating thrust.Separately...Something that might be interesting is if rfmwguy were to rerun the initial test (without the steel wool) and instead of closing the mouth piece end with a plate, terminate it into a faraday cage with ground isolated from the baritone. Maybe even try to set up some means of determining if any microwaves in the range produced by the magnetron even escape through the mouth piece end. The diameter and geometry of the instrument may wind up grounding out all microwaves before they reach a open mouth piece. This would experimentally confirm the last comment above.The valves are missing so there is not an unbroken path from the bell to the mouthpiece fitting. He could try detecting RF in the valve tubes. Earlier I thought that was an E♭ tuba. I stand corrected it is a baritone. A BB♭ tuba would have an appropriate sized bell for these experiments and sometimes they are Silver plated. My personal opinion however, as a former BB♭ tuba player, is it would be a sin to destroy such a melodious instrument.
There is no statement in Shaywer's papers (that I have seen) stating that his cut-off equations are only applicable to anomalous thrust effects. Shawyer makes the statements about cut-off frequency without any such "thrust dependence" justification in his papers. Actually, Shawyer conflates open waveguides and resonating cavities in his papers and presents his equations (including quoting Prof. Cullen's Ph.D. thesis out of context for a resonating cavity) without such modifiers in his papers. If anyone is to interpret Shawyer's equations (including his strange special relativity modifications) as only applicable to thrust, such "thrust dependent" constraint on special relativity and "thrust dependent" constraint on resonance should be proven (or at least discussed) by Shawyer, rather than assumed ab ibnitio by the reader of his papers.
Quote from: Rodal on 12/15/2015 04:37 pmThere is no statement in Shaywer's papers (that I have seen) stating that his cut-off equations are only applicable to anomalous thrust effects. Shawyer makes the statements about cut-off frequency without any such "thrust dependence" justification in his papers. Actually, Shawyer conflates open waveguides and resonating cavities in his papers and presents his equations (including quoting Prof. Cullen's Ph.D. thesis out of context for a resonating cavity) without such modifiers in his papers. If anyone is to interpret Shawyer's equations (including his strange special relativity modifications) as only applicable to thrust, such "thrust dependent" constraint on special relativity and "thrust dependent" constraint on resonance should be proven (or at least discussed) by Shawyer, rather than assumed ab ibnitio by the reader of his papers. There is no disagreement that Shawyer does not seem to me to have ever provided sufficient detail to support his claims... And his theory paper was enough for me to dismiss his EMDrive, long before I was ever aware of these discussions.Personally I am not yet convinced there is any thrust that will not be explainable or that this will lead to a functional drive system component.., but I am hopeful that My skepticism is misplaced and that some truly significant New Physics may be discovered in the experimental process, currently underway.So, I am skeptical... Still the very basis of Shawyer's claims, establishes a baseline from which any of his statements should be evaluated, whether he makes the claims explicitly or not. Since he is claiming that thrust is developed, any statement declaring that a cutoff frequency is important, has to be associated with the fundamental claim. The connection is implied. Even if I agree that the information he has shared publicly, is shoddy, at best.
Quote from: Tellmeagain on 12/15/2015 02:48 pmQuote from: Tellmeagain on 12/15/2015 02:43 pmI didn't comment on Paul's statement. Yes we mimicked their second generation damper, but it was not emphasized enough in the paper. It is shown in fig 1 of our paper, where the damper is enclosed. We also have photos in supplemental materials, which is available with request. I attach them here so you can see that we used the closed face magnet damper. As it always happens, nothing is perfect in engineering, so there is still leaked magnetic field, as we have shown in the first two attached photos.It was not very different from NASA's second generation damper, seen athttp://nextbigfuture.com/2014/09/paul-march-is-providing-more.htmlIn early threads, I advocated the use of a simple oil damper (as used in classical physics experiments to measure gravitational forces a long time ago) instead of any magnetic damper.Brito Marini and Galian (and later on Marini and Galian) nullified the claims of propellant-less thrust from a Mach-Lorentz Woodward effect thruster using a simple pendulum with the thruster all self-contained and using oil damping:http://arc.aiaa.org/doi/abs/10.2514/6.2009-5070 http://arc.aiaa.org/doi/abs/10.2514/1.46541?journalCode=jpphttps://www.researchgate.net/profile/Ricardo_Marini
Quote from: Tellmeagain on 12/15/2015 02:43 pmI didn't comment on Paul's statement. Yes we mimicked their second generation damper, but it was not emphasized enough in the paper. It is shown in fig 1 of our paper, where the damper is enclosed. We also have photos in supplemental materials, which is available with request. I attach them here so you can see that we used the closed face magnet damper. As it always happens, nothing is perfect in engineering, so there is still leaked magnetic field, as we have shown in the first two attached photos.It was not very different from NASA's second generation damper, seen athttp://nextbigfuture.com/2014/09/paul-march-is-providing-more.html
I didn't comment on Paul's statement. Yes we mimicked their second generation damper, but it was not emphasized enough in the paper. It is shown in fig 1 of our paper, where the damper is enclosed. We also have photos in supplemental materials, which is available with request. I attach them here so you can see that we used the closed face magnet damper. As it always happens, nothing is perfect in engineering, so there is still leaked magnetic field, as we have shown in the first two attached photos.
"I went with a antifreeze glycerol mix in the water which doesn't."At 20 degrees in the shop, probably a good idea!
...OK.To me it sounds like Shawyer is engaged in a contradiction in his papers, whenever he invokes equations for open waveguides (for example: 1) equations for cut-off, 2) quoting, out of context, equations from Prof. Cullen's PhD thesis or 3) quoting radiation pressure equations that are only applicable to waveguides with one end open and the other end closed). I don't see any way out of Shawyer's contradiction unless someone would be able to explain in what sense is a closed cavity like an open waveguide that is open at one end.NASA has attempted to differentiate the ends by asymmetric placement of a dielectric inside the EM Drive and has reported in its 2014 report that no thrust force measurements were measurable without the dielectric.Notsosureofit has addressed the possible asymmetry from a different perspective than Shawyer (Notsosureofit present an interesting mode dependence that is not discussed by Shawyer).Aquino made a valiant theoretical effort in this regard: differentiating both ends of the EM Drive, suggesting the use of a ferromagnetic end at one of the ends of the EM Drive. Why is it that no institutional tester, or DIY tester has yet attempted to conduct measurements with one EM Drive end made of a ferromagnetic coating to test Aquino's conjecture ?Isn't it simple enough to just replace one of the diamagnetic (copper) ends with a ferromagnetic end (or a ferromagnetic coated end, to save weight) and measure the force (to compare both cases)
It can be shown that there are reflections at the open end of a waveguide back into the direction of the source because of the different i.e. discontinuity of the impedance between waveguide and free space. Of course this reflection is very small. A horn antenna makes this transition into free space much smoother...
Spent a good chunk of the day playing around with baritone bell tuning. Its natural resonance is 2.14 ghz. I can tune to 2.7 ghz but return loss (match) suffers greatly.Here's what I've determined...a seamless brass frustum without much exponential taper would be ideal. RL is above 30db is achievable This is significantly better than my copper mesh. Q and Qr are impressive. Soooo...I'm about ready to contact musical instrument makers...locally...and see if they might whip something up for me in non-laquered brass using my original dimensions plus factoring in the tuning bands...will be slightly exponential and I'll give them the dimensions.Seems like a good way to go for next year...NSF-1701 was a great homebrew project...time to take it to the next level...NSF-1701A in honor of all the peeps here that have supported and encouraged me: Doc, michelle, phil, glenn, deltamass, paul, chris b., roy, don and so many more.Onwards and upwards...
The terms dark energy and dark matter have become so common, the reason they are called dark is not always clear...
Quote from: OnlyMe on 12/15/2015 01:42 pmThe terms dark energy and dark matter have become so common, the reason they are called dark is not always clear...I thought the reason they call dark matter 'dark' is because it does not interact in any way with electro-magnetic spectrum (which is what gives us a sense of 'light' ). Basically, for certain gravitational lens effects the gravitational force required is a lot more than can be accounted for by all the matter visible in the region. Hence the theory that there must also be some non-visible, aka dark, matter which produces gravity but does not interact with EM.Yes, the same dark matter concept also helps explain certain observed anomalies with rotation of galaxies, etc. but for those anomalies there at least exist a few alternative theories. IMHO, the gravitational lens is the most compelling case for dark matter.
Quote from: RFPlumber on 12/15/2015 11:02 pmQuote from: OnlyMe on 12/15/2015 01:42 pmThe terms dark energy and dark matter have become so common, the reason they are called dark is not always clear...I thought the reason they call dark matter 'dark' is because it does not interact in any way with electro-magnetic spectrum (which is what gives us a sense of 'light' ). Basically, for certain gravitational lens effects the gravitational force required is a lot more than can be accounted for by all the matter visible in the region. Hence the theory that there must also be some non-visible, aka dark, matter which produces gravity but does not interact with EM.Yes, the same dark matter concept also helps explain certain observed anomalies with rotation of galaxies, etc. but for those anomalies there at least exist a few alternative theories. IMHO, the gravitational lens is the most compelling case for dark matter.They are unknown variables, which cannot be directly observed. What they are depends entirely on assumptions, that GR as we currently understand it, applies universally and some unobservable form of matter and energy exists, required such that GR remains valid in all cases.Don't get me wrong I am not saying either does not exist. Just that they must remain placeholders until proven.We (or others on this thread) can actually build frustums with the intent to prove or disprove thrust. Any tests we can conduct to determine the nature or even the existence of dark matter and dark energy will remain dependent on unprovable assumptions. At least for the present.but my original point or intent was just to correct the misunderstanding that either originated to resolve conservation issues. Though in some respects the accelerating expansion of space, rather than an accelerating recession velocity of things in space, could be thought of as an attempt to preserve the speed of light as a universal speed limit.
An update on our 100kW test project. Model using HFSS using eigenmode solver, TE013 mode 914.85MHz Q=133526. Loop coupled design for ease of build, cost and stress concerns. As we are planning to use a high power coax line and are designing as a pressure vessel, one recommendation is to use copper cladded stainless steel... does anyone see any objections to the use of this material so long as we clad the internals with copper? This would help us with vessel integrity and cooling; while I do think we will achieve resonance is there any EM-Drive Q thruster theories that say not to do this (i.e. impacting the quantum vacuum??).
Quote from: dustinthewind on 12/14/2015 09:01 pmQuote from: Rodal on 12/14/2015 08:10 pmQuote from: dustinthewind on 12/14/2015 07:09 pm...If we can say the cavity is some how pushing on space time then maybe we can avoid the whole CoM issue.OK, but then the proponents need to address the objections based on frame-indifference (is there a privileged frame? which frame? and why?) and conservation of energy, previously discussed by Frobnicat and DeltaMass.I am not sure it would work but one might consider the preferred frame at the edge of an event horzion as moving at the speed of light and as such light can't escape. That is if gravity actually drags space time for some reason. Problem is that suggests light going into the black hole could non-locally exceed the speed of light. I would think rather light should slow down near the event horizon till it comes to a stand-still. Maybe this makes sense if the non-local space is moving at the speed of light into the event horizon and that the light in that space, as a result, is time dilated and there fore, stands still. Maybe then away from gravity the space time is at rest with respect to the universe as a whole and contained in our sphere of the CMB? I am just guessing here. Some possible support for the CMB as an absolute reference frame for space time. http://physics.stackexchange.com/questions/25928/is-the-cmb-rest-frame-special-where-does-it-come-fromI think this guy is also arguing the same. I can't suggest it is 100% accurate but it looks legit at first glance. https://scholar.google.com/scholar?cluster=11591112244843703577&hl=en&as_sdt=5,48&sciodt=0,48If our space in a gravity well is flowing into the earth with respect to the space of the universe then as we rotate through our gravity well we may observe a slight shift in the dipole of the CMB as the earth rotates but I would have no idea if it would be something that would be observable or not with our weak gravity well compared to that of a large one....
Quote from: Rodal on 12/14/2015 08:10 pmQuote from: dustinthewind on 12/14/2015 07:09 pm...If we can say the cavity is some how pushing on space time then maybe we can avoid the whole CoM issue.OK, but then the proponents need to address the objections based on frame-indifference (is there a privileged frame? which frame? and why?) and conservation of energy, previously discussed by Frobnicat and DeltaMass.I am not sure it would work but one might consider the preferred frame at the edge of an event horzion as moving at the speed of light and as such light can't escape. That is if gravity actually drags space time for some reason. Problem is that suggests light going into the black hole could non-locally exceed the speed of light. I would think rather light should slow down near the event horizon till it comes to a stand-still. Maybe this makes sense if the non-local space is moving at the speed of light into the event horizon and that the light in that space, as a result, is time dilated and there fore, stands still. Maybe then away from gravity the space time is at rest with respect to the universe as a whole and contained in our sphere of the CMB? I am just guessing here.
Quote from: dustinthewind on 12/14/2015 07:09 pm...If we can say the cavity is some how pushing on space time then maybe we can avoid the whole CoM issue.OK, but then the proponents need to address the objections based on frame-indifference (is there a privileged frame? which frame? and why?) and conservation of energy, previously discussed by Frobnicat and DeltaMass.
...If we can say the cavity is some how pushing on space time then maybe we can avoid the whole CoM issue.
Could the following note maybe explain why the EMDrive could work?Professor of Physics, A. P. French, has a relevant note in his very informative book, SpecialRelativity (1968), p. 242-243; 267 "Relativity and electricity":"Now the electric field due to a stationary source charge is radial and, of course, sphericallysymmetrical; that is, it is the same in all directions. It is simply the Coulomb field . . . . If thesource charge is moving uniformly, the electric field is no longer spherically symmetrical. Itsstrength is different in different directions. But, at each instant, the direction of the electric fieldis still radial with respect to the position of the source charge at that same instant.If you think about this last result a bit—that at each instant the electric field due to a uniformlymoving source charge is directed radially away from the position of the source charge at thatsame instant—you may begin to realize that this is a very surprising result."