Wouln't the acoustic propulsion (hat tip to Prof Uno Ingard at MIT) of a tapered bottle be a better acoustic analogue to the EM Drive than a string?
...P.S. A corollary thought is: if the material matters (it interacts) with respect to the flux escape, then should SeeShells' copper mesh EMDrive show increased performance in with respect to cone size and power input compared with a sheet copper EMDrive?
Quote from: Rodal on 06/26/2015 07:46 pmWouln't the acoustic propulsion (hat tip to Prof Uno Ingard at MIT) of a tapered bottle be a better acoustic analogue to the EM Drive than a string?Hm... Not really, because we know the bottle is open-ended and there is air emission/influx in an asymmetric pattern (as I think somebody pointed out a number of posts ago).The EmDrive is allegedly a closed cavity. Similarly, the wave in a string does not "escape".Rocking jokes aside, I'm semi-serious with this.If the effect is only due to standing waves in a variable refraction medium, it should exist with confined acoustic waves.Of course, the EmDrive is a much more complex beast. But, if we prove that there is no effect with a string, then we can exclude the effect comes from just the standing waves and we can focus our effort elsewhere (e.g. evanescent waves).
Quote from: dustinthewind on 06/26/2015 05:01 pmQuote from: dustinthewind on 06/20/2015 07:01 pmQuote from: SeeShells on 06/19/2015 06:54 pmhttps://hal.archives-ouvertes.fr/jpa-00246781/documentOn the other hand, the 60 mm length of this region corresponds to a delay time of 0.2 nsec of light in vacuum, this is clearly longer than the measured delay in the first 5 nsec duration of the pulse superluminal conditions are present both for the center of gravity and the maximum value of the electromagnetic packet. Furthermore this confirmes the correctness of the frequency domain data and the corresponding Fourier evaluation [2, 3]. The zerc-time traversal described in references [2] and [3] proves to be correct, I-e- there is no additional time delay caused by an additional length of the evanescent region.<end quote>I know group velocities can appear greater than the speed of light but because the wave form information was previously propagated at light speed. I suspect that may be what is happening and maybe this is what this paper is also suggesting. https://scholar.google.com/scholar?cluster=3707515693059191286&hl=en&as_sdt=5,48&sciodt=0,48It is an interesting question. hmm on a second maybe they are implying that group velocity can't explain the results? "Finally, we discussed a pos-sible interpretation of the results, favoring the argument that the group velocity cannot be interpreted as a tunneling ve-locity." Fascinating. I guess I am still skeptical that near field's can travel faster than light. If that were so I don't know what would stop us from building a circular array and sending messages back in time. That is actual signals that move faster than light would travel back in time like tachyons. I used to be not just skeptical, but, Ahem, hostile, to this idea of superluminal transmission, because of violation of causality, and the appearance that a tachyonic telephone could be constructed.However, upon examining the papers in detail, there is no doubt in my mind that it is impossible to send information using this superluminal transmission. It has been shown a number of times, by different authors that this is impossible, just as it is impossible to use the coherence phenomenon of instantaneous action at a distance to send information. This is precluded by quantum mechanics, in both cases. There is nothing deterministic about the superluminal evanescent wave transmission that can be used to send any information superluminally, as what will be received superluminally will be scrambled up randomly in a non-deterministic way. The signal received at the other end would be incomprehensible and contain no information.Hence I no longer have any problem with this type of superluminal action. Besides the impossibility to use it to send information, the superluminal aspect is restricted to the group velocity and not to the phase velocity, so one has to be careful about the physical interpretation of this superluminal effect.
Quote from: dustinthewind on 06/20/2015 07:01 pmQuote from: SeeShells on 06/19/2015 06:54 pmhttps://hal.archives-ouvertes.fr/jpa-00246781/documentOn the other hand, the 60 mm length of this region corresponds to a delay time of 0.2 nsec of light in vacuum, this is clearly longer than the measured delay in the first 5 nsec duration of the pulse superluminal conditions are present both for the center of gravity and the maximum value of the electromagnetic packet. Furthermore this confirmes the correctness of the frequency domain data and the corresponding Fourier evaluation [2, 3]. The zerc-time traversal described in references [2] and [3] proves to be correct, I-e- there is no additional time delay caused by an additional length of the evanescent region.<end quote>I know group velocities can appear greater than the speed of light but because the wave form information was previously propagated at light speed. I suspect that may be what is happening and maybe this is what this paper is also suggesting. https://scholar.google.com/scholar?cluster=3707515693059191286&hl=en&as_sdt=5,48&sciodt=0,48It is an interesting question. hmm on a second maybe they are implying that group velocity can't explain the results? "Finally, we discussed a pos-sible interpretation of the results, favoring the argument that the group velocity cannot be interpreted as a tunneling ve-locity." Fascinating. I guess I am still skeptical that near field's can travel faster than light. If that were so I don't know what would stop us from building a circular array and sending messages back in time. That is actual signals that move faster than light would travel back in time like tachyons.
Quote from: SeeShells on 06/19/2015 06:54 pmhttps://hal.archives-ouvertes.fr/jpa-00246781/documentOn the other hand, the 60 mm length of this region corresponds to a delay time of 0.2 nsec of light in vacuum, this is clearly longer than the measured delay in the first 5 nsec duration of the pulse superluminal conditions are present both for the center of gravity and the maximum value of the electromagnetic packet. Furthermore this confirmes the correctness of the frequency domain data and the corresponding Fourier evaluation [2, 3]. The zerc-time traversal described in references [2] and [3] proves to be correct, I-e- there is no additional time delay caused by an additional length of the evanescent region.<end quote>I know group velocities can appear greater than the speed of light but because the wave form information was previously propagated at light speed. I suspect that may be what is happening and maybe this is what this paper is also suggesting. https://scholar.google.com/scholar?cluster=3707515693059191286&hl=en&as_sdt=5,48&sciodt=0,48It is an interesting question. hmm on a second maybe they are implying that group velocity can't explain the results? "Finally, we discussed a pos-sible interpretation of the results, favoring the argument that the group velocity cannot be interpreted as a tunneling ve-locity." Fascinating.
https://hal.archives-ouvertes.fr/jpa-00246781/documentOn the other hand, the 60 mm length of this region corresponds to a delay time of 0.2 nsec of light in vacuum, this is clearly longer than the measured delay in the first 5 nsec duration of the pulse superluminal conditions are present both for the center of gravity and the maximum value of the electromagnetic packet. Furthermore this confirmes the correctness of the frequency domain data and the corresponding Fourier evaluation [2, 3]. The zerc-time traversal described in references [2] and [3] proves to be correct, I-e- there is no additional time delay caused by an additional length of the evanescent region.<end quote>
Quote from: Rodal on 06/26/2015 07:46 pmWouln't the acoustic propulsion (hat tip to Prof Uno Ingard at MIT) of a tapered bottle be a better acoustic analogue to the EM Drive than a string?I don't see how. Put a bottlecap on those bottles, and if they still work, then it could be called an analog. Those bottles are spinning because the compression wave created by the speaker is forcing the bottles shape to change, and puff air out the openings in a preferential direction.
...Just read this and you're right no information can be transmitted FTL but I'm not ready to throw the baby out with the bath water ...
Quote from: sghill on 06/26/2015 06:47 pmQuote from: WarpTech on 06/26/2015 04:59 pmThe only way these things will work is to interact with an outside environment. I believe I've figured out that this mechanism is the finite conductivity of copper + heat, allowing voltage drop to form on the conductor, AKA "Ohm's Law". Where there is voltage and current there are volt-seconds, or magnetic flux that is passing through that open window. So heat and poor conductivity allow flux to escape (tunnel) through the copper.So, with the increased wall thickness of the baby EMDrive with respect to the cone size and power input, should we expect no meaningfully significant thrust measurements, or is the copper "transparent" to the tunneling flux?P.S. A corollary thought is: if the material matters to the flux escape, then should SeaShells' copper mesh EMDrive show increased performance in with respect to cone size and power input?Was out in my highly envied "shop" today and haven't been able to follow post to post and I'll catch up to where I left off reading in a bit. You're right in thinking I feel that the copper has the magic squirrel sauce that makes it work and one reason I shelved the other two (for now) designs to push on the perforated copper design and testing.One time I had access to a very sharp staff and we were contemplating on using "light Tweezers" to move very small gold wires on a semiconductor chip, it was a viable project, but because of things that were not related to "it's not a good idea" it had to be shelved.The things that intrigued us was the ability of an evanescent wave to manipulate an object, a wave that couldn't carry information or couldn't do work with it, hmmmm, it seemed to do. It still does intrigue me and I believe it can be a clue of why this cavity works the way it does.Nice clue, thanks Dr. Rodal!http://arxiv.org/ftp/arxiv/papers/1308/1308.0547.pdfI'm still digging into it and I know they are much smarter people here than me that have a more detailed knowledge in depth and breadth and right now I'm trying to be a one girl band and finding it hard.Love for you all to beat this idea up and kick it around. I think the evanescent waves due to their extraordinary nature and spooky weird actions can impart a directional momentum and thrust to the EMdrive.Back to reading a little and then into my playground. Shell
Quote from: WarpTech on 06/26/2015 04:59 pmThe only way these things will work is to interact with an outside environment. I believe I've figured out that this mechanism is the finite conductivity of copper + heat, allowing voltage drop to form on the conductor, AKA "Ohm's Law". Where there is voltage and current there are volt-seconds, or magnetic flux that is passing through that open window. So heat and poor conductivity allow flux to escape (tunnel) through the copper.So, with the increased wall thickness of the baby EMDrive with respect to the cone size and power input, should we expect no meaningfully significant thrust measurements, or is the copper "transparent" to the tunneling flux?P.S. A corollary thought is: if the material matters to the flux escape, then should SeaShells' copper mesh EMDrive show increased performance in with respect to cone size and power input?
The only way these things will work is to interact with an outside environment. I believe I've figured out that this mechanism is the finite conductivity of copper + heat, allowing voltage drop to form on the conductor, AKA "Ohm's Law". Where there is voltage and current there are volt-seconds, or magnetic flux that is passing through that open window. So heat and poor conductivity allow flux to escape (tunnel) through the copper.
...Those bottles are spinning because the compression wave created by the speaker is forcing the bottles shape to change, and puff air out the openings in a preferential direction.
Quote from: SeeShells on 06/26/2015 08:04 pm...Just read this and you're right no information can be transmitted FTL but I'm not ready to throw the baby out with the bath water ...On the contrary, the fact that information cannnot be transmitted FTL is a plus for the theory and not a reason to feel like throwing babys out the windows There is no need whatsoever for the evanescent waves to carry information anymore than there is a need for the isentropic supersonic exit from a rocket nozzle needing to carry information and convey messages out of the nozzle. All that is needed is to have enough momentum (not information) exit the spaceship in one direction asymmetrically, for the spaceship to accelerate.https://www.grc.nasa.gov/www/k-12/airplane/isentrop.htmlI like babies
Quote from: WarpTech on 06/26/2015 06:21 pmWhen I've checked, rechecked, and validated my equations, I'll let you know. I ran a spreadsheet last night to determine the required stored energy for a given force. The numbers seem reasonable given the available data, "IFF" there were no plate on the big end and the flux could get out. With the big end sealed, the force is there, but it's cancelled at the big end. It's not going to do anything unless the flux can get out.One of the key issues I've tried to answer is, what is the drift velocity of an Xnm mode in a tapered cylinder cavity? In a straight cylindrical cavity, a resonant TExx mode at position "x" along the cylinder doesn't move down the pipe, it's velocity is zero and it's frequency doesn't shift due to it's position. In a cone it does.ToddPlease elaborate as to why you think that the velocity of a resonant TEmn is not zero, that it moves down, and that the frequency shifts. Are you talking about phase shift due to geometrical attenuation? And what do you mean by the TEmn moving down?
When I've checked, rechecked, and validated my equations, I'll let you know. I ran a spreadsheet last night to determine the required stored energy for a given force. The numbers seem reasonable given the available data, "IFF" there were no plate on the big end and the flux could get out. With the big end sealed, the force is there, but it's cancelled at the big end. It's not going to do anything unless the flux can get out.One of the key issues I've tried to answer is, what is the drift velocity of an Xnm mode in a tapered cylinder cavity? In a straight cylindrical cavity, a resonant TExx mode at position "x" along the cylinder doesn't move down the pipe, it's velocity is zero and it's frequency doesn't shift due to it's position. In a cone it does.Todd
Quote from: aero on 06/26/2015 06:35 pmI don't recall whether or not I've posted this video, so here it is. I was fooling around back in April trying to create evanescent waves when I came across this very unusual pattern. I don't know that evanescent waves are involved at all but something unusual is showing up. You tell me? Superluminal velocity? Well, strange things do happen.Yes, in the acoustic analogue, this would be tantamount to shock waves due to exit speeds faster than the speed of sound. The shock waves would look like that.
I don't recall whether or not I've posted this video, so here it is. I was fooling around back in April trying to create evanescent waves when I came across this very unusual pattern. I don't know that evanescent waves are involved at all but something unusual is showing up. You tell me? Superluminal velocity? Well, strange things do happen.
Quote from: Mike-F on 06/26/2015 03:47 pmI am not sure if the attached has been covered on here before but it states"EmDrive Licence: 10 year exclusive master licence £100,000,000 comprised of2 years development to Flight Qualified status @ £10m per year pro rata, plusconsultancy from Roger Shawyer to divest expertise.Break clause at 2 years, if project fails to achieve FQ status all rights revert to SPR.A further 3 year exclusive use of EmDrive @ £10m per annum.After 3 years of exclusive use, master licensee is required to sub licence technology onsimilar terms, if requested, to third parties.For 10 years, royalties of £150k per space vehicle using EmDrive (equivalent to 10% ofthe saving on build cost).After 10 years, master licensee has first right of refusal on renewing master licence"I know this possibly quite old but may be of interest.Mike.Source: http://ind-tech.com/wp-content/uploads/2014/11/Investment-Memorandum-final.pdfThis is an Investment Memorandum. The quote comes from section six "Financial Information", and is preceded by, "The company believes that in the next 9 months it can negotiate an exclusive licence and royalty structured in the following way."~Kirk
I am not sure if the attached has been covered on here before but it states"EmDrive Licence: 10 year exclusive master licence £100,000,000 comprised of2 years development to Flight Qualified status @ £10m per year pro rata, plusconsultancy from Roger Shawyer to divest expertise.Break clause at 2 years, if project fails to achieve FQ status all rights revert to SPR.A further 3 year exclusive use of EmDrive @ £10m per annum.After 3 years of exclusive use, master licensee is required to sub licence technology onsimilar terms, if requested, to third parties.For 10 years, royalties of £150k per space vehicle using EmDrive (equivalent to 10% ofthe saving on build cost).After 10 years, master licensee has first right of refusal on renewing master licence"I know this possibly quite old but may be of interest.Mike.
Quote from: sghill on 06/26/2015 08:03 pmQuote from: Rodal on 06/26/2015 07:46 pmWouln't the acoustic propulsion (hat tip to Prof Uno Ingard at MIT) of a tapered bottle be a better acoustic analogue to the EM Drive than a string?I don't see how. Put a bottlecap on those bottles, and if they still work, then it could be called an analog. Those bottles are spinning because the compression wave created by the speaker is forcing the bottles shape to change, and puff air out the openings in a preferential direction.Except sound moves through a medium which has mass and can flow. More importantly, the flowing of air can be blocked by plastic barriers.If electromagnetic waves are moving through a medium capable of flowing, I don't imagine copper would necessarily impede the flow of that medium. If it did, we would put copper propellers onto our space ships and fly them like airplanes to other planets.I think it is better to imagine the above video as if the bottle could change the propagation of sound waves without blocking the flow of air.
@Aero,Been doing some numbers and I'll post new ones in the morning for you if you wouldn't mind and are still interested.Shell
Regarding resonant modes in the frustum. Would there still be resonant modes if;1. the frustum were open on the big end only?2. the frustum were open on both ends?IF I understand these modes correctly, the TExx0 modes resonate with the pointing vector radial in/out-ward from the axis to the walls. It seems to me, that a cone that is open on both ends would still support the same TEnm modes, just not the p modes. Correct?If it's closed at the small end, it should still support odd harmonics of p modes. Correct?Thank you!Todd