...
Added: I'm currently building the second generation of this drive with the tune chamber and the Quartz rod through the center to test at a TE013 mode.
Exciting TE013 mode for your cavity dimensions and chosen frequency looks difficult, particularly using waveguides, according to numerical runs:
FEKO showed that instead of a TE013 mode, that a TM mode was going to be excited, using the waveguides, either entering at the base or entering on both lateral conical walls. The TM mode is dominant. Examination of the Meep run did not reveal TE013 mode excitation either. It was TheTraveller's opinion that to excite the TE013 mode a loop was needed, and FEKO modeling of TheTraveller's frustum showed that TE013 could be excited by a loop (although still difficult, when looking at the VSWR (Voltage Standing Wave Ratio) because of proximity of other more dominant modes).
I also recall that early on, it was X-Ray's opinion that the best way to excite the TE013 mode was to use a loop, and that NASA excited TE012 in their frustum using a loop (although it was so difficult to excite TE012 that NASA switched to a TM mode: TM212 for their subsequent testing).
Have there been later FEKO runs showing that TE013 could be excited for your frustum using waveguides and whether it is feasible to "hunt" for TEO13 adjusting the length of the cavity for your frustum dimensions at your chosen frequency?
Or are you going to use a loop instead of the waveguides?
...
5) Dr. Marco Frasca (NSF user StrongGR) was also very interested in these interferometer tests, perhaps he can also give us his recollection 
...
What motivated the writing of my paper was the news that people at EW shot a laser beam through a cavity filled with an e.m. field and observed a change in the interference pattern. This is somewhat a different way from the original use of the White-Juday interferometer and far removed from the criticisms by Zen-in. This idea by EW people is really original and worth to be analysed further. Nobody else, as far as I can tell, just did this before. The point of view of general relativity, as I have shown, is that they are right as already the simplest plane wave, as stated in the classical textbook "Gravitation", generates a deformation of space-time. So, if I fill a cavity with an e.m. field this effect should be observable and EW people seems to have shown that this is indeed the case.
From my perspective, that of a physicist, this is already a breakthrough. The reason is that this would be the first time that a gravitational effect could be possibly observed on a tabletop experiment. Extending this to the application case, we are able to form e.m. fields as we like and so, we could in principle form gravitational fields in the way we like: This would open up the way to space-time engineering.
I think that this was the original motivation for Harold White to put all this up: Using a strong e.m. field to act in small regions of space-time. The Alcubierre's idea has the serious drawback to require exotic matter and all the solutions of Einstein equations requiring it are suspect at best. But if you can replace such a kind of strange non-existing matter with a real thing there are possibilities.
Indeed, the possibility to do that, from a mathematical standpoint, can be traced back to a paper of mine published on 2006 (see http://arxiv.org/abs/hep-th/0508246) where I provided the mathematics to do that. This did not exist before and the only people trying to do such kind of studies were Belinski, Khalatnikov and Lifshitz that yielded what was dubbed "BKL conjecture". Indeed, these authors were the first to uncover a strong coupling expansion in general relativity. I have had the luck to be taught general relativity by Vladimir Belinski in person: A great physicist let me say. This was my first course where I was exposed to the matter.
I am awaiting, as most people in this forum, the official publication of results of people at EW. I think they are onto something. Then, NASA should assume an official position and it will be a great moment for everybody I believe.
Thanks for replying and helping to clear up some questions. Your input here is greatly appreciated.
Your paper is one reason I elected to go with the quartz rod through the center of the drive. It allows you to keep plate distance for tune and also will allow you to use the quartz rod to do a highly controlled laser interferometer test negating the need for testing in vacuum or through air.
Shell
Added: I'm currently building the second generation of this drive with the tune chamber and the Quartz rod through the center to test at a TE013 mode.
Would you so kind to post some explicit data, something more than the "I have thrust" statement of your first build? Or is it your plan to release it all together if you are done?
...
Would you so kind to post some explicit data, something more than the "I have thrust" statement of your first build? Or is it your plan to release it all together if you are done?
* The energy density for TE013 is completely dominated (by several orders of magnitude) by the
Magnetic Energy density that's why the total energy density looks exactly like the Magnetic Energy Density:
* The reason why the Magnetic Energy Density completely dominates is because of the frequency. It would be required for the EM Drive to be operating in TE013 (if it would be possible: requiring very small dimensions !) at >10^15 Hz or higher frequency instead of at 10^9 Hz, for the Electric Energy density to begin to dominate
* More to come, but there are important consequences from all this, that have been proposed by physicists, that no EM Drive tester has yet tested.
!
Shell gave me the paper of the modified loop antenna first. I was surprised because in my company we use another patented design at much higher frequencies,
but at least the basic idea is the same. As I said before it is not really a problem to excite this modeshape with the right antenna design.
There are ways to suppress the dominant mode (in this case TM11p, p>0) while forced to excite TE01p. I think one (good) option is the modified half loop. It will work as well described in the paper. http://www.ijiee.org/papers/343-I006.pdf
Instead of little pieces and parts of my test I'll post a detailed paper when I finish this round of testing. There will be three major sections to this testing and data posted for each test.
While I was excited to post something about thrust, it was too soon.
Shell
Time to get back to waiting, then.
It's hard when you're eager to hear more about something that sounds so promising.
Instead of little pieces and parts of my test I'll post a detailed paper when I finish this round of testing. There will be three major sections to this testing and data posted for each test.
While I was excited to post something about thrust, it was too soon.
Shell
Time to get back to waiting, then.
It's hard when you're eager to hear more about something that sounds so promising.
Awww poor Sponge Bob. In some ways I now know not to publish too soon or present data not well done. It can be more damaging to do so. Hang in there Sponge Bob.
Shell
...
Added: I'm currently building the second generation of this drive with the tune chamber and the Quartz rod through the center to test at a TE013 mode.
Exciting TE013 mode for your cavity dimensions and chosen frequency looks difficult, particularly using waveguides, according to numerical runs:
Sorry for your confusion Dr. Rodal but what IslandPlaya tested in FEKO was not the TE013 mode dimensional cavity.
Be 0.2950
Se 0.1680
Center length 0.2563
In Meters
I've verified this mode TE013 with my calculations, TT's spread sheet, and even X_Ray has verified the dimensions and mode. The closest mode to this cavity that it can excite is 69MHz higher and a TE411. Unlike the TE012 which can have other dominate TMxx modes to deal with.
The resonate mode of this stated cavity size is 2.4GHz which the top small endplate will tune right through with a 50mm adjustment.
FEKO showed that instead of a TE013 mode, that a TM mode was going to be excited, using the waveguides, either entering at the base or entering on both lateral conical walls. The TM mode is dominant. Examination of the Meep run did not reveal TE013 mode excitation either. It was TheTraveller's opinion that to excite the TE013 mode a loop was needed, and FEKO modeling of TheTraveller's frustum showed that TE013 could be excited by a loop (although still difficult, when looking at the VSWR (Voltage Standing Wave Ratio) because of proximity of other more dominant modes).
Currently there are some simulations running that I'm sure will show that is not the case. I'm convinced that waveguide insertion can be the key into letting the cavity create a very clean mode generation.
I also recall that early on, it was X-Ray's opinion that the best way to excite the TE013 mode was to use a loop, and that NASA excited TE012 in their frustum using a loop (although it was so difficult to excite TE012 that NASA switched to a TM mode: TM212 for their subsequent testing).
That's the truth Dr. Rodal. A TE012 mode is very hard to excite without having a very narrow BW source that can be phased locked and even then the TM modes will surface as ghost modes in the cavity. (see Frank Davies publication attached in his paper on the close interactive modes around a TE012).
Have there been later FEKO runs showing that TE013 could be excited for your frustum using waveguides and whether it is feasible to "hunt" for TEO13 adjusting the length of the cavity for your frustum dimensions at your chosen frequency?
Or are you going to use a loop instead of the waveguides?
New frustum walls same endplates. I pick up the copper tomorrow (weather permitting, Nasty weather hitting here).
I believe I can excite a TE mode with a waveguide and have the advantages of a dual waveguide insertion, I'll publish data on a basic build when I finish some simulation runs.
Shell
TE01p is degenerate with TM11p, therefore the dominant TM mode is TM11p. Take a look to TE011/TM111 in the diagram below.
Its not the only TE411 whats nearby for your new dimensions for true.
...
TE01p is degenerate with TM11p, therefore the dominant TM mode is TM11p. Take a look to TE011/TM111 in the diagram below.
Its not the only TE411 whats nearby for your new dimensions for true.
I noticed that in these dimensions given by SeeShells, the small diameter is 56% of the big diameter
Be 0.2950
Se 0.1680
It is very good that she chose the small diameter to be very different from the big diameter, as the degeneracy of TE011/TM111 occurs for a perfect cylinder with both diameters equal to each other.
The further difference in diameters the further apart will be TE01p from TM11p.
I wonder what dimensions IslandPlaya used for his FEKO analysis?
My guess is you'll have trouble getting the dimensional information from that redditor but I suppose you could try:
https://www.reddit.com/r/EmDrive/comments/43i74m/emdrive_verifier_program/czijl3nNote, if you go there be aware of Alan's (Morgan) 2nd Law of Newsgroups: Any sufficiently advanced troll is indistinguishable from a genuine kook.
http://www.itskeptic.org/content/intenet-discourse-becoming-unreal
...
TE01p is degenerate with TM11p, therefore the dominant TM mode is TM11p. Take a look to TE011/TM111 in the diagram below.
Its not the only TE411 whats nearby for your new dimensions for true.
I noticed that in these dimensions given by SeeShells, the small diameter is 56% of the big diameter
Be 0.2950
Se 0.1680
It is very good that she chose the small diameter to be very different from the big diameter, as the degeneracy of TE011/TM111 occurs for a perfect cylinder with both diameters equal to each other.
The further difference in diameters the further apart will be TE01p from TM11p.
I wonder what dimensions IslandPlaya used for his FEKO analysis?
Between you Frank Davies, and X_Ray plus collaborating papers on waveguides it became apparent that either I use a modified Loop(s) (sent X_Ray a paper that was sent to me by a great and very kind lurker here) or figure out how to use the advantages of the conical design to force in the mode shapes using modified waveguides.
IslandPlaya....
What I sent him...
LENGTH-x = 0.1761 m, BIG DIA.-y,z = 0.3077 m, Small dia. = 0.1727 m
I want to thank him for running the simulations.
On those first simulations IslandPlaya was inserting RF into the cavity without realizing the months of work you and aero and a host of others had done on loops, waveguides and dipoles in how he could build it into into the FEKO simulation. He has gotten better.
I wanted to verify what he was doing but I couldn't get a licence from FEKO as fast as he seemed to.
Shell
...
TE01p is degenerate with TM11p, therefore the dominant TM mode is TM11p. Take a look to TE011/TM111 in the diagram below.
Its not the only TE411 whats nearby for your new dimensions for true.
...
I wonder what dimensions IslandPlaya used for his FEKO analysis?
Between you Frank Davies, and X_Ray plus collaborating papers on waveguides it became apparent that either I use a modified Loop(s) (sent X_Ray a paper that was sent to me by a great and very kind lurker here) or figure out how to use the advantages of the conical design to force in the mode shapes using modified waveguides.
IslandPlaya....
What I sent him...
LENGTH-x = 0.1761 m, BIG DIA.-y,z = 0.3077 m, Small dia. = 0.1727 m
I want to thank him for running the simulations.
On those first simulations IslandPlaya was inserting RF into the cavity without realizing the months of work you and aero and a host of others had done on loops, waveguides and dipoles in how he could build it into into the FEKO simulation. He has gotten better.
I wanted to verify what he was doing but I couldn't get a licence from FEKO as fast as he seemed to.
Shell
I notice that the main difference from the initial geometry you sent to IslandPlaya and he run in FEKO and the new one is that you increased the length of your frustum from 0.1761 m to 0.2563 m, a large increase in length of 46%
The % difference in the diameters between the old geometry that IslandPlaya run for you and your new geometry is much smaller than the increase in length.
old new % change
Be(m) 0.3077 0.2950 - 4.13
Se(m) 0.1727 0.1680 - 2.72
L(m) 0.1761 0.2563 +45.54
r1(m) 0.233269 0.344168 +47.54
r2(m) 0.415615 0.604342 +45.41
θ(deg) 20.9721 13.9152 -33.65
This results also in a significant decrease of the cone half-angle, from 21 degrees to 14 degrees, making the frustum more like a cylinder in the new geometry. Also the spherical radii, are further away from the vertex in the new geometry, making the new geometry more like a cylinder.
The degeneracy of TE01p/TM11p occurs for a perfect cylinder with both diameters equal to each other.
Since the new geometry looks much more like a cylinder: the TE01p modes will be closer to the TM11p modes in the new geometry, than in the geometry run by IslandPlaya. In other words, it will be more difficult to separate TE01p from its degenerate brother TM11p in the new geometrySee:
https://forum.nasaspaceflight.com/index.php?topic=39004.msg1485928#msg1485928
Thanks dr frasca for weighing in on the ew interferometer tests. I like the idea of studying this further. Small scale space time distortions using em could yield small scale forces, which I believe is all we are talking about in this forum. It seems like a worthwhile endeavor and surprises me so few appear to be willing to take on the experimental challenge considering what it could mean. It does not seem like heresy to investigate further.
I suspect that the lack of experimentation is due to the universities not having any EM Drives. Now that they can be purchased this will change.
No, the NASA interferometer experiment only used a laser interferometer, a high dc electric field and separately, a cylindrical resonator which most Universities have, and otherwise are very easy to make. There was no frustum of a cone EM Drive used in the interferometer experiments at NASA. (See: https://forum.nasaspaceflight.com/index.php?topic=39004.msg1485460#msg1485460)
_____________
(*) And the EM Drive is just a truncated cone resonator which is very easy to make: the one at NASA was made by Paul March in his living room.
I am not sure this will be comparable to the NASA test configuration you give but in this video David appears to show that for large DC voltage across fine wires (or maybe fine edges), significant space time effects can occur.
He appears to have an online physics book here:
http://www.e-booksdirectory.com/details.php?ebook=6563I think it is possible WarpTech might have known him also.
...
I remember when David created that video. He and I were discussing this phased array idea and he figured out a way to rectify both fields. I commend him for it. However, as with all the phased array's in free space, the distance "d" is wavelength dependent and depends on the speed of light. The "on axis" dipole near-field falls off like ~1/d at best. To minimize d, the frequency must be in the GHz and the dipoles must be very small.
...
Todd
But he is referring to a different video by the same youtube poster.
There also appears to be an educational link to his book here:
http://physics.unm.edu/finley/links/Physics.htmlAnyways I just thought it was interesting they mentioned large DC voltages and "possible" space time disturbances measured. I am not sure the effects in the video would be significantly comparable to the NASA experiment.
There was some question about this thread here:
http://www.psyclops.com/hawking/forum/printmsg.cgi?period=&msg=59801 but I am uncertain what to make of it.
A paper from Francisco Lobo on spacetime, on topic http://arxiv.org/pdf/gr-qc/0406083v2.pdf
I took another look at the paper by Minotti. I had forgotten a number of great points about it:
1) It calculates that if Yang would have run the dominant TM mode shape instead of TE012, the force would have been several times greater, and in the completely opposite direction, directed towards the big base instead of being directed towards the small base. This should be something that could be tested!
2) He considers a skin depth much smaller than the cavity walls. Under this condition, the force he calculates is proportional to the thickness and density of the metal wall. In other words: Minotti calculates that
the force due to General Relativity is greater, the greater the thickness and the density of the metal employed !!! This should be tested !
A paper from Francisco Lobo on spacetime, on topic http://arxiv.org/pdf/gr-qc/0406083v2.pdf
I took another look at the paper by Minotti. I had forgotten a number of great points about it:
1) It calculates that if Yang would have run the dominant TM mode shape instead of TE012, the force would have been several times greater, and in the completely opposite direction, directed towards the big base instead of being directed towards the small base. This should be something that could be tested!
2) He considers a skin depth much smaller than the cavity walls. Under this condition, the force he calculates is proportional to the thickness and density of the metal wall. In other words: Minotti calculates that the force due to General Relativity is greater, the greater the thickness and the density of the metal employed !!! This should be tested !
This reminds me of my attempt at using Frame Dragging to propel a ship, if frame dragging could be increased in effect to some degree.
http://forum.nasaspaceflight.com/index.php?topic=39464.msg1484673#msg1484673The mention of negative energy made me think of the analogy that Dark matter could maybe be Negative energy matter in another dimension pulling in our time space (anti gravity). The idea then being to get some of that negative energy matter in our dimension and it would expel their space instead of pull ours in. We then put some behind our ship with some positive energy matter in front of the ship. The result is a flow of space time and we accelerate. That we could get our hands on negative energy matter seems slim to none as far as I know and of course it is only my fanciful speculating that such matter could exist. (or that matter really pulls in/expels space.)
The other option is to swim through space and hence using the frame dragging effect but in the shape of a torus around the ship. The ship inside then experiences drag from the space inside the torus. The only problem is actually getting any circulation of space that is significant. Hence, my contemplation if light could possibly have any drag on space time. I guess the big question is what has a significant drag on space time. I am reminded of that one experiment with the superconducting electrodes called a "gravity impulse generator".
https://en.wikipedia.org/wiki/Eugene_Podkletnov or (
http://www.americanantigravity.com/news/space/eugene-podkletnov-on-antigravity.html) or (
http://www.superconductors.org/gravity.htm) I can't vouch for its legitimacy
and I admit I am sceptical but hope it could be true.
...
What motivated the writing of my paper was the news that people at EW shot a laser beam through a cavity filled with an e.m. field and observed a change in the interference pattern. This is somewhat a different way from the original use of the White-Juday interferometer and far removed from the criticisms by Zen-in. This idea by EW people is really original and worth to be analysed further. Nobody else, as far as I can tell, just did this before. The point of view of general relativity, as I have shown, is that they are right as already the simplest plane wave, as stated in the classical textbook "Gravitation", generates a deformation of space-time. So, if I fill a cavity with an e.m. field this effect should be observable and EW people seems to have shown that this is indeed the case.
...
I am awaiting, as most people in this forum, the official publication of results of people at EW. I think they are onto something. Then, NASA should assume an official position and it will be a great moment for everybody I believe.
I would be interested in reading a report on this research. However, right now it doesn't look to me like it is any different than the experiment I commented on earlier. In that experiment EW used a Michelson interferometer which they for some unknown reason decided to call a White-Juday interferometer. In this new research they are again looking at an interference pattern of laser light. So in this new case they are again using a Michelson interferometer. Earlier I explained how difficult it is to get a good S/N with optical systems that are not differential, because of DC drift, etc. This is why interference measurements are usually done with a 2 channel system and the interferometer has a moving mirror. A Michelson interferometer is very sensitive to the smallest change in one of the optical paths. I believe this is the principle used by schlieren photography; of which I know almost nothing. The slightest temperature differential in one of the optical paths through air will produce interesting interference patterns. There may also be some interaction between the microwave energy and the laser light. This is an area I know very little about. Without seeing anything they have written on this subject I can't comment any further.
A paper from Francisco Lobo on spacetime, on topic http://arxiv.org/pdf/gr-qc/0406083v2.pdf
I took another look at the paper by Minotti. I had forgotten a number of great points about it:
1) It calculates that if Yang would have run the dominant TM mode shape instead of TE012, the force would have been several times greater, and in the completely opposite direction, directed towards the big base instead of being directed towards the small base. This should be something that could be tested!
2) He considers a skin depth much smaller than the cavity walls. Under this condition, the force he calculates is proportional to the thickness and density of the metal wall. In other words: Minotti calculates that the force due to General Relativity is greater, the greater the thickness and the density of the metal employed !!! This should be tested !
Another remarkable statement in Minotti's paper, showing that the anomalous force of the EM Drive is due to General Relativity (of the scalar-tensor theory type) effects is:
it is worth noting that the weak energy condition (WEC) is violated for the cavity, as is the case in other models of propellant-less drive
In plain English, what Prof. Minotti is stating is that
the EM Drive anomalous force due to General Relativity, implies negative energy , since violation of the weak energy condition implies negative energy (see
https://en.wikipedia.org/wiki/Energy_condition#Weak_energy_condition for example).
So, Minotti, just like Dr. White when discussing the Quantum Vacuum explanation (and like Dr. White in his interferometer experiment using a resonant cavity), brings up the issue that EM Drive anomalous force implies negative energy, and when discussing negative energy being typical of propellant-less drives, he quotes the same paper by Lobo and Visser that you quote above:
http://arxiv.org/abs/gr-qc/0406083However, caution must be exercised: the General Relativity theory this is based on is by Mbelek. Mebelek also proposes that the Pioneer anomaly is related to his General Relativity theory: see
http://arxiv.org/pdf/gr-qc/0407023.pdf. Also, caution, because the paper by Lobo and Visser on the violation of the weak energy condition implying negative energy is meant as a cautionary statement against the reality of such mechanism:
in plain English meaning that propellant-less propulsion implies negative energy and therefore it may be a non-physically possible solution (although allowed by General Relativity).
The comment on the strong energy condition here
https://en.wikipedia.org/wiki/Energy_condition#Strong_energy_condition raises a couple of interesting, maybe related thoughts with regards to inflationary cosmology. The potential expansion of space time through resonating cavities, and the 750 GeV diphoton excess, which seems to have no other particles in the decay, is easiest to explain as a product of gluon-gluon fusion, and is rumored to be leaning towards Spin 2... I wonder if there's some light being shed on an existing, dire misunderstanding of gravity. On the other hand, no one does impenetrable jargon like particle physicists, so who knows?
A paper from Francisco Lobo on spacetime, on topic http://arxiv.org/pdf/gr-qc/0406083v2.pdf
I took another look at the paper by Minotti. I had forgotten a number of great points about it:
1) It calculates that if Yang would have run the dominant TM mode shape instead of TE012, the force would have been several times greater, and in the completely opposite direction, directed towards the big base instead of being directed towards the small base. This should be something that could be tested!
2) He considers a skin depth much smaller than the cavity walls. Under this condition, the force he calculates is proportional to the thickness and density of the metal wall. In other words: Minotti calculates that the force due to General Relativity is greater, the greater the thickness and the density of the metal employed !!! This should be tested !
This reminds me of my attempt at using Frame Dragging to propel a ship, if frame dragging could be increased in effect to some degree. http://forum.nasaspaceflight.com/index.php?topic=39464.msg1484673#msg1484673
The mention of negative energy made me think of the analogy that Dark matter could maybe be Negative energy matter in another dimension pulling in our time space (anti gravity). The idea then being to get some of that negative energy matter in our dimension and it would expel their space instead of pull ours in. We then put some behind our ship with some positive energy matter in front of the ship. The result is a flow of space time and we accelerate. That we could get our hands on negative energy matter seems slim to none as far as I know and of course it is only my fanciful speculating that such matter could exist. (or that matter really pulls in/expels space.)
The other option is to swim through space and hence using the frame dragging effect but in the shape of a torus around the ship. The ship inside then experiences drag from the space inside the torus. The only problem is actually getting any circulation of space that is significant. Hence, my contemplation if light could possibly have any drag on space time. I guess the big question is what has a significant drag on space time. I am reminded of that one experiment with the superconducting electrodes called a "gravity impulse generator". https://en.wikipedia.org/wiki/Eugene_Podkletnov or (http://www.americanantigravity.com/news/space/eugene-podkletnov-on-antigravity.html) or (http://www.superconductors.org/gravity.htm) I can't vouch for its legitimacy and I admit I am sceptical but hope it could be true.
White claims that the "permitivity" of space can be modulated with an AC field. if this is true then frame dragging or at least frame dragging like effects should be modulable too. since the permitivity he was referring to is the succeptibility of space(/time) to deformation (AKA warping.)
so if White's assertion is true then space (which is what he was shooting for) is artificially deformable.
parenthetically: and presumably time should be too.
and if you can modulate the permitivity one way; why not in the other direction such that the effect of negative energy mass is produced? inducing the opposite curvature of space from what is expected from regular energy and mass?
