-
#2500
by
MazonDel
on 03 Feb, 2016 00:06
-
Pardon the interruption, would like to announced that my modest kickstarter funding campaign was successful! Special thanks to all backers who pledged to help me fund 2016 tests. While it isn't a big budget, I promise to share lots of data here. Thank you all again. There's about 22 hours left before it officially closes so last minute pledges can still be made. Makes all the long hours spent last year worth it!
Gah! Somehow I completely missed that you had started the kickstarter! Luckily there was plenty of time for me to kick in my two cents...or $25, whichever. Hehe.
-
#2501
by
rfmwguy
on 03 Feb, 2016 00:16
-
Pardon the interruption, would like to announced that my modest kickstarter funding campaign was successful! Special thanks to all backers who pledged to help me fund 2016 tests. While it isn't a big budget, I promise to share lots of data here. Thank you all again. There's about 22 hours left before it officially closes so last minute pledges can still be made. Makes all the long hours spent last year worth it!
Gah! Somehow I completely missed that you had started the kickstarter! Luckily there was plenty of time for me to kick in my two cents...or $25, whichever. Hehe.
I saw that, many thanks...yes a few hours left in the campaign, too. It will all go towards emdrive work this year. Yesterday, it looked bad for me continuing...today its a different story. Much appreciated!
-
#2502
by
SeeShells
on 03 Feb, 2016 02:20
-
Pardon the interruption, would like to announced that my modest kickstarter funding campaign was successful! Special thanks to all backers who pledged to help me fund 2016 tests. While it isn't a big budget, I promise to share lots of data here. Thank you all again. There's about 22 hours left before it officially closes so last minute pledges can still be made. Makes all the long hours spent last year worth it!
Gah! Somehow I completely missed that you had started the kickstarter! Luckily there was plenty of time for me to kick in my two cents...or $25, whichever. Hehe.
I saw that, many thanks...yes a few hours left in the campaign, too. It will all go towards emdrive work this year. Yesterday, it looked bad for me continuing...today its a different story. Much appreciated!
You know I even threw a little at you Dave. We can't let your test go without some equipment you need,
WE NEED DATA!!!Shell
-
#2503
by
rfmwguy
on 03 Feb, 2016 02:33
-
Yes shell, more than a little help came from you! I am honored and thankful for your help in getting the data out!
-
#2504
by
Prunesquallor
on 03 Feb, 2016 03:15
-
CONSERVATION OF RELATIVISTIC MOMENTUM FOR REACTION-LESS PROPULSION THROUGH VARIABLE INERTIAL MASS
Minotti states that the weak energy condition (the condition that demands that the mass should be positive) is violated for the EM Drive in Minotti's theory.
Lobo and Visser's paper also states that the condition requiring positive mass is also violated in other models of propellant-less (reaction-less) forms of proposed space-propulsion.
McCulloch, also proposes that the EM Drive self-accelerates because radio frequency photons at the larger end have higher inertial mass, and therefore to conserve momentum in its reference frame, the cavity must move towards the narrow end.
This motivated me to analyze conservation of momentum for the EM Drive (or any such resonant cavity proposed for reaction-less propulsion) analyzed as a lumped-mass that is able to change its inertial mass. Thus, conservation of momentum of the EM Drive under these theories, would be satisfied, when duly taking into consideration the change in mass.
In this post in another thread: http://forum.nasaspaceflight.com/index.php?topic=39214.msg1486645#msg1486645, I analyze conservation of momentum for the case of negative mass, and for the case of variable increasing and decreasing mass.
I define momentum, using the relativistic definition of momentum.
The analysis shows that such a mode of space propulsion (reaction-less propulsion by variable mass) is quite limited on the speeds and changes in speed that it would be able to achieve.
No warping of spacetime is considered in the analysis, only a reactionless variable mass is considered.
In this theory what happens if you turn the EMDrive on, then off, then on again?
-
#2505
by
SeeShells
on 03 Feb, 2016 03:16
-
Just noting that we now have reports of possible evanescent waves exiting the small end of the device and potentially anomalous interferometer readings in relation to the large end (mini-EM drive). If both of these can be confirmed it would seen to hint at something, but I'm not sure what.
Sometimes I wonder if what we're seeing is space-time buoyancy, of sorts, and that EM drive is a constant-displacement (perhaps fixed maximum velocity?) device relative to its initial state, and that the evanescent waves are part of, or a consequence of the working mechanism. But I have no firm grounding in general relativity, quantum field theory, electrodynamics, or even plain old RF engineering, so I have no idea what I should be looking for to prove or disprove that back-of-the-mind idea (or even if it's already been disproven).
I think many feel that the link of em and gravity is probably the way through this. We know mass then gravity warps spacetime in a macro sense, but what about in a micro sense? EWs interferometer hints that em could be warping spacetime on a very small scale...increasing the laser path as they indicated, about 40x that of thermal heating IIRC.
For the nondiyers with vacuum chambers, it seems clear that confined em in a cavity might well distort a laser interferometer. If I were a student or professor with access to the right equipment, I'd go after this hypothesis quickly.
Ditto rfmwguy. Run the laser interferometer through optical Quartz optics, one through the center of the EMDrive. I think you're right, this would be a great to do project for a university or students looking to do a thesis on. I'm sure TT would help with a TE013 frustum, if he doesn't I'll build one for them.
That would mean they wouldn't have to do one of the harder things by building a frustum, all the rest that's needed is simply OTS or exists in a lab already.
With a low power test they could use thinner fiber optic cables instead of the thicker one I'm using for tuning. If there is a spacetime distortion it will effect fiber optics too.
Shell
Added: I have some good contacts at the University of Michigan (Go Blue), I should email them.
I don't think fiber optic cables are generally used for interferometry because light travels by internal reflection inside them. The light exiting the fiber optic cable will not be collimated. Also the aperture is very tiny. This would seriously affect the throughput and thus the S/N. A quartz rod may have the same problems. This is just a guess, I have not done that. I have done gas cell calibration tests. The gas cell used in the optical path has two optically flat quartz windows and precision ground interfaces with O-rings so the windows are parallel. Judging from the picture, that is what EW used in their experiment. For the spectrometer resolution test I used to do the gas cell was filled with CO and pumped down to 10 Torr. I don't know how low they can be pumped down.
I've researched and found little on someone doing it this way.
http://www.sciencedirect.com/science/article/pii/0031916366902058 I've known quartz has some unique properties when subject to stresses that can be measured. Although if two identical Quarts rods were used, one inside of the chamber and one directly outside and using a splitter for the laser into each rod I wonder how much of a difference in the transmitted beams could be measured.
Any thought and ideas would be very welcome.
Shell
-
#2506
by
Mulletron
on 03 Feb, 2016 03:33
-
-
#2507
by
dustinthewind
on 03 Feb, 2016 04:41
-
I've researched and found little on someone doing it this way. http://www.sciencedirect.com/science/article/pii/0031916366902058
I've known quartz has some unique properties when subject to stresses that can be measured. Although if two identical Quarts rods were used, one inside of the chamber and one directly outside and using a splitter for the laser into each rod I wonder how much of a difference in the transmitted beams could be measured.
Any thought and ideas would be very welcome.
Shell
I googled, "collimating light from fiber" and got, "
https://www.rp-photonics.com/fiber_collimators.html" and "
http://www.edmundoptics.com/technical-resources-center/videos/?ytID=3JKRlEP7TGg" so maybe some interferometry could be done using fiber.
I know in school we did an experiment with a polarized laser through a crystal and measured the angle of polarization. The crystal was inside a solenoid and as we increased the magnetic field the polarization of the light would rotate and we could measure the rotation angle in the light with change in the B-field. We also did it with a AC B-field. It was just a straight crystal.
-
#2508
by
dustinthewind
on 03 Feb, 2016 05:20
-
Early morning Google-fu researching magnetic fields and gravity. Never heard of magnetocurvature before...
https://physics.aps.org/story/v7/st27
If magnetic fields tend to flatten space,
http://arxiv.org/abs/astro-ph/0012345
https://scholar.google.it/scholar?oe=utf-8&gws_rd=cr&um=1&ie=UTF-8&lr&cites=13528356710987714915
https://www.facebook.com/NatureMechanics/posts/1617925528471105?_fb_noscript=1
A couple of interesting anomalies thrown in for fun:
http://phys.org/news/2015-04-gravitational-constant-vary.html
https://www.newscientist.com/article/mg20327183-800-eclipse-sparks-hunt-for-gravity-oddity/
Concerning the top article. If the magnetic field has some drag on space-time so that it can force space time to relax so the B-field can relax then maybe, (grasping at straws), forming a B field under tension where it can relax, but isn't yet, and then letting the B-field relax could also drag space in the direction of the relaxing B field. I am not really sure this makes sense but what I am thinking of is the frustum and the conical walls and the large B-field at the tip.
It requires assuming the B-field formed at the tip is under stress and as it increases in power it pushed away from the tip, relaxing a bit and dragging space time with it. Power then dissipates from the B-field and the cycle starts over. Is this too much of a stretch?
Some part of me wants to think the magnetic field is formed in perfect equilibrium but the other part says it wants to push away from the conical walls. Of course if space time were to move in the direction of the back of the frustum I would think if it dragged on the matter in the frustum that the force would be towards the large plate. On the other hand if the space time was like a propellant then maybe it would be like a rocket pushing it forwards.
I guess the behavior might depend on the friction the magnetic field has on space-time, in comparison to the friction space time has on the frustum? Also any mass and net velocity attributed to space time. I really fell like I'm out there flapping as this is unexplored territory.
-
#2509
by
mwvp
on 03 Feb, 2016 06:10
-
...
A.A. Stahlhofen, G. Nimtz (2006). "Evanescent modes are virtual photons". Europhysics Letters 76 (2): 189–195. Bibcode:2006EL.....76..189S. doi:10.1209/epl/i2006-10271-9.
http://www.nature.com/ncomms/2014/140306/ncomms4300/full/ncomms4300.html
...
Extraordinary momentum and spin in evanescent waves
...
The indecent angle of a normal EM wave...composed of virtual photons and with the tunneling actions of the evanescent wave decaying into the walls of the frustum impart their extraordinary spin and momentum and therefore a thrust.
Maybe there is a connection here. I know I'm just a engineer playing with physics (as one dearly departed NSFer would say).
...
The red flag is still waving on the evanescent wave for me and looked at correctly it would provide a asymmetrical force to be generated in the copper of the drive walls
...
1. http://arxiv.org/ftp/arxiv/papers/0712/0712.0347.pdf
2. http://www.nature.com/ncomms/2014/140306/ncomms4300/full/ncomms4300.html
Interesting papers, and colorful too. I appreciate pictures and large-font, simple, familiar equations; I somehow find them easier to digest. One of several papers that have really helped me. Yet using the term "extraordinary" seems to imply new physics. AFAIK, Meep will be happy to give you the complex electric and magnetic fields, and complex Poynting vector (unless you tell it not to so you can run your simulation twice as fast with half the memory).
I understand the complex components of the EM fields and P vector contain the polarization/angular/orbital momentum and near/evanescent/(and, I suppose, if-you-will,) the virtual-photon field.
Doesn't seem like anything to get all excited about. I don't want to kill you buzz, dampen your spirits, disillusion you about the existence of Santa and a virtual, extraordinary, evanescent spin-fairy. But I really don't think anything is tunneling more than a micron or two in the waveguide before being almost entirely reflected, and just a smidgen dissipated as heat.
Yet, I do seem to vaguely recall reading somewhere that around waveguide bends, evanescent fields were responsible for increased current penetration into the waveguide and increased losses.
I will definitely pay attention to the complex components, the near/evanescent/virtual-photon fields in simulations. But I'm not expecting anything new over such well-trod ground because surely someone would have written about it already.
-
#2510
by
chad1
on 03 Feb, 2016 07:02
-
Hi All,
My name is chad I am a long time lurker, first time poster. I have been considering trying to replicate the interferometric experiment. I think I have all of the optics and laser stuff lying around. I also have a cnc machine shop and I am able to machine any optomechanics that I don't have. As well as any needed RF cavity.
I don't have a vibration isolation optics table but I do have a 600lb granite flat that I should be able to get quiet enough to experiment with. I have lots of laser experience and laser stuff around just no RF.
Where I come up short is:
1) Math, I suck at it.
2) I am pretty good at electronics, but RF is voodoo.
3) RF hardware. Short of sacrificing my microwave and blasting a KW of 2.4ghz around the shop I don't know where to begin.
4) I don't have lots of cash for said RF stuff, test gear.
Admittedly, you guys are all waaay smarter than I am, but, I am pretty good at designing and building things. If you can give me dimensions I can machine things to a high degree of precision and I am no stranger to optics and lasers.
If you guys have any suggestions I am all ears!
thanks,
chad
-
#2511
by
zen-in
on 03 Feb, 2016 07:25
-
...
I don't think fiber optic cables are generally used for interferometry because light travels by internal reflection inside them. The light exiting the fiber optic cable will not be collimated. Also the aperture is very tiny. This would seriously affect the throughput and thus the S/N. A quartz rod may have the same problems. This is just a guess, I have not done that. I have done gas cell calibration tests. The gas cell used in the optical path has two optically flat quartz windows and precision ground interfaces with O-rings so the windows are parallel. Judging from the picture, that is what EW used in their experiment. For the spectrometer resolution test I used to do the gas cell was filled with CO and pumped down to 10 Torr. I don't know how low they can be pumped down.
I've researched and found little on someone doing it this way. http://www.sciencedirect.com/science/article/pii/0031916366902058
I've known quartz has some unique properties when subject to stresses that can be measured. Although if two identical Quarts rods were used, one inside of the chamber and one directly outside and using a splitter for the laser into each rod I wonder how much of a difference in the transmitted beams could be measured.
Any thought and ideas would be very welcome.
Shell
Light is transmitted in a quartz rod by internal reflection and directly. How the laser light is coupled to the rod would determine how much of each transmission mode there is. It might be possible to eliminate transmission by internal reflections if the beam is narrow and aligned just right. For interferometry measurements there is an advantage to having a large aperture. Laser interferometers are used for distance measurement. An FTIR spectrometer uses a laser interferometer to clock the A/D and a white light interferometer for the start of scan reference. The movement of one mirror in a laser interferometer generates a sine wave while the white light interferogram is a sin(x)/x waveform. Those all have a small aperture. To measure phase shift through a medium you really need calibrated sampling, as provided by the white light and laser interferometers as well as an aperture of 1" or more, with collimated IR (longer wavelength than the laser light) I think the only accurate way to try to measure a phase shift or "warp effect" around an EM fustrum is to use an FTIR spectrometer with the software configured for phase shift measurement. There are dedicated instruments that do this. They have the accuracy needed and can co-add with precision. The DC measurement done by EW lab will always be subject to lots of drift and noise. There is no way of even knowing what the S/N is with that kind of measurement because there is no stability and every measurement is different.
-
#2512
by
Mulletron
on 03 Feb, 2016 08:47
-
Early morning Google-fu researching magnetic fields and gravity. Never heard of magnetocurvature before...
https://physics.aps.org/story/v7/st27
If magnetic fields tend to flatten space,
http://arxiv.org/abs/astro-ph/0012345
https://scholar.google.it/scholar?oe=utf-8&gws_rd=cr&um=1&ie=UTF-8&lr&cites=13528356710987714915
https://www.facebook.com/NatureMechanics/posts/1617925528471105?_fb_noscript=1
A couple of interesting anomalies thrown in for fun:
http://phys.org/news/2015-04-gravitational-constant-vary.html
https://www.newscientist.com/article/mg20327183-800-eclipse-sparks-hunt-for-gravity-oddity/
Concerning the top article. If the magnetic field has some drag on space-time so that it can force space time to relax so the B-field can relax then maybe, (grasping at straws), forming a B field under tension where it can relax, but isn't yet, and then letting the B-field relax could also drag space in the direction of the relaxing B field. I am not really sure this makes sense but what I am thinking of is the frustum and the conical walls and the large B-field at the tip.
It requires assuming the B-field formed at the tip is under stress and as it increases in power it pushed away from the tip, relaxing a bit and dragging space time with it. Power then dissipates from the B-field and the cycle starts over. Is this too much of a stretch?
Some part of me wants to think the magnetic field is formed in perfect equilibrium but the other part says it wants to push away from the conical walls. Of course if space time were to move in the direction of the back of the frustum I would think if it dragged on the matter in the frustum that the force would be towards the large plate. On the other hand if the space time was like a propellant then maybe it would be like a rocket pushing it forwards. I guess the behavior might depend on the friction the magnetic field has on space-time, in comparison to the friction space time has on the frustum? Also any mass and net velocity attributed to space time. I really fell like I'm out there flapping as this is unexplored territory.
Well for now it's just yet another chunk of information to store in memory. I don't see any application for it and I don't see any experimental proof. I'm curious about what @Notsosureofit and others think about it though. Thanks for your insightful reply too!
-
#2513
by
SeeShells
on 03 Feb, 2016 12:38
-
...
A.A. Stahlhofen, G. Nimtz (2006). "Evanescent modes are virtual photons". Europhysics Letters 76 (2): 189–195. Bibcode:2006EL.....76..189S. doi:10.1209/epl/i2006-10271-9.
http://www.nature.com/ncomms/2014/140306/ncomms4300/full/ncomms4300.html
...
Extraordinary momentum and spin in evanescent waves
...
The indecent angle of a normal EM wave...composed of virtual photons and with the tunneling actions of the evanescent wave decaying into the walls of the frustum impart their extraordinary spin and momentum and therefore a thrust.
Maybe there is a connection here. I know I'm just a engineer playing with physics (as one dearly departed NSFer would say).
...
The red flag is still waving on the evanescent wave for me and looked at correctly it would provide a asymmetrical force to be generated in the copper of the drive walls
...
1. http://arxiv.org/ftp/arxiv/papers/0712/0712.0347.pdf
2. http://www.nature.com/ncomms/2014/140306/ncomms4300/full/ncomms4300.html
Interesting papers, and colorful too. I appreciate pictures and large-font, simple, familiar equations; I somehow find them easier to digest. One of several papers that have really helped me. Yet using the term "extraordinary" seems to imply new physics. AFAIK, Meep will be happy to give you the complex electric and magnetic fields, and complex Poynting vector (unless you tell it not to so you can run your simulation twice as fast with half the memory).
I understand the complex components of the EM fields and P vector contain the polarization/angular/orbital momentum and near/evanescent/(and, I suppose, if-you-will,) the virtual-photon field.
Doesn't seem like anything to get all excited about. I don't want to kill you buzz, dampen your spirits, disillusion you about the existence of Santa and a virtual, extraordinary, evanescent spin-fairy. But I really don't think anything is tunneling more than a micron or two in the waveguide before being almost entirely reflected, and just a smidgen dissipated as heat.
Yet, I do seem to vaguely recall reading somewhere that around waveguide bends, evanescent fields were responsible for increased current penetration into the waveguide and increased losses.
I will definitely pay attention to the complex components, the near/evanescent/virtual-photon fields in simulations. But I'm not expecting anything new over such well-trod ground because surely someone would have written about it already.
Thank you for your very nice reply and no buzz kill at all. I enjoyed reading your reply.
I should be saying. Hey dude, you're right and trust me after decades of building using the fundamentals of our craft if it wasn't for a couple things that just bug the poo out of me I'd be off baking bread or sitting in my hot tub with something bubbly to drink.
Paul March summed it up a few hundred posts ago in when he said "And yet the anomalous thrust signals remain". I thought, it's NASA, it might be true, but Paul I have no idea of your build or how it's put together. Then I saw something in my build happen that I simply didn't understand. rfmwguy thinks there is something there in his tests and TT is over the top saying he has thrust. Shawyer seems to have something along with the Chinese and Tajmar even with the unique design was inclusive and RFPlumber got nothing. I've been accustom to building something to calculated design specs and having it work as our craft says it should. Sure, I've had a few surprises along the line but nothing that couldn't be discovered with a little sweat, trouble shooting and research. But, here it seems not only my craft and all the other fundamental crafts of science and physics that go into building this little can with microwaves in it still has us confounded and questions remain.
We have a wonderful grasp of the world and how it all fits together. When it doesn't work the way we think it should we throw all of our resources to discover why, and it truly is the finest quality we have. The resources we have have become incredibly powerful with meep, COMSOL, FEKO, ANSYS and a host of others all built from the fundamental building blocks of centuries of discovery, research and elbow grease. You have to wonder in what we might be seeing is something that those tools can't dig out and make that connection.
Whatever it is it's a darn sight more fun then sitting in my hot tub, well not always.
Shell
Added: Even in the electromagnetic spectrum I was surprised how little we use.
http://imgur.com/5DLgXpu
-
#2514
by
Rodal
on 03 Feb, 2016 12:43
-
CONSERVATION OF RELATIVISTIC MOMENTUM FOR REACTION-LESS PROPULSION THROUGH VARIABLE INERTIAL MASS
Minotti states that the weak energy condition (the condition that demands that the mass should be positive) is violated for the EM Drive in Minotti's theory.
Lobo and Visser's paper also states that the condition requiring positive mass is also violated in other models of propellant-less (reaction-less) forms of proposed space-propulsion.
McCulloch, also proposes that the EM Drive self-accelerates because radio frequency photons at the larger end have higher inertial mass, and therefore to conserve momentum in its reference frame, the cavity must move towards the narrow end.
This motivated me to analyze conservation of momentum for the EM Drive (or any such resonant cavity proposed for reaction-less propulsion) analyzed as a lumped-mass that is able to change its inertial mass. Thus, conservation of momentum of the EM Drive under these theories, would be satisfied, when duly taking into consideration the change in mass.
In this post in another thread: http://forum.nasaspaceflight.com/index.php?topic=39214.msg1486645#msg1486645, I analyze conservation of momentum for the case of negative mass, and for the case of variable increasing and decreasing mass.
I define momentum, using the relativistic definition of momentum.
The analysis shows that such a mode of space propulsion (reaction-less propulsion by variable mass) is quite limited on the speeds and changes in speed that it would be able to achieve.
No warping of spacetime is considered in the analysis, only a reactionless variable mass is considered.
In this theory what happens if you turn the EMDrive on, then off, then on again?
The equations presented were correct and frame-indifferent, but one of the variables chosen to present the results graphically, is not frame indifferent: deltaV/InitialVelocity.
It is better to express the solution solely in terms of frame-indifferent variables, which can readily be accomplished with the following change of variables, as follows:
deltaV/InitialVelocity =( deltaV/c ) *( 1/(InitialVelocity/c)
and then, when showing the results in completely frame-indifferent terms (*):
deltaMass/InitialMass = function (deltaV/c , InitialVelocity/c)
everything becomes more clear. The reason why there is a frontier becomes clear.
I will show all results in term of (deltaV/c , InitialVelocity/c) instead of (deltaV/InitialVelocity , InitialVelocity/c) this evening
Until then:
minimum requirement for negative mass occurs for very high relativistic speeds, intermediate between 0 and c. Maximum requirement for negative mass occurs for InitialVelocity/c close to zero and for InitialVelocity/c close to 1.___________
(*) deltaV is obviously frame-indifferent, being a difference of velocities. And the speed of light is clearly the only frame-indifferent speed to non-dimensionalize all variables
-
#2515
by
RERT
on 03 Feb, 2016 12:48
-
Mulletron -
Ref your recent posts, including a reference to Gravitational Waves carrying away momentum. This was mentioned a long while back. I dug into it over the last few days, and concluded, rather sadly, that gravitational waves have the same P=E/C characteristic as EM waves. At least, that's how I interpret equation 35.27 in Misner Thorne and Wheeler 'Gravitation' - with no little trepidation on account of the convention of setting c=1 and not including it in formulae! This is the case in the weak field/linearised gravity limit. So a colimated 'gravitational wave rocket' will be no more efficient than a Photon Rocket. It would be great if StrongGR or Notsureofit, or anyone else who is familiar with this stuff could confirm.
Another small problem is scale: the radiated power of gravitational waves is vanishingly small if the mass energy of the EM field is its source, even oscillating at 2.45Ghz. MTW later (36.5/6) give
Radiated Power = Internal Power flow^2/(c^5/G) (c^5!!! Argh!)
Again, a comment from someone who knows what they are talking about would be most welcome.
[So an explanation along these lines would need some additional coupling between EM and Gravitation/spacetime]
R.
[modified to add above parenthetical remark]
-
#2516
by
glennfish
on 03 Feb, 2016 12:50
-
Hi All,
My name is chad I am a long time lurker, first time poster. I have been considering trying to replicate the interferometric experiment. I think I have all of the optics and laser stuff lying around. I also have a cnc machine shop and I am able to machine any optomechanics that I don't have. As well as any needed RF cavity.
I don't have a vibration isolation optics table but I do have a 600lb granite flat that I should be able to get quiet enough to experiment with. I have lots of laser experience and laser stuff around just no RF.
Where I come up short is:
1) Math, I suck at it.
2) I am pretty good at electronics, but RF is voodoo.
3) RF hardware. Short of sacrificing my microwave and blasting a KW of 2.4ghz around the shop I don't know where to begin.
4) I don't have lots of cash for said RF stuff, test gear.
Admittedly, you guys are all waaay smarter than I am, but, I am pretty good at designing and building things. If you can give me dimensions I can machine things to a high degree of precision and I am no stranger to optics and lasers.
If you guys have any suggestions I am all ears!
thanks,
chad
Chad,
I have a suggestion that should be within your scope.
Thus far, all DIY folks have designs intended to create anomalous thrust. Most of the critiques that come back attribute what they are seeing to thermal effects.
To this point, no one has made a deliberate effort to characterize thermal effects by building something that shouldn't produce anomalous thrust, but which is basically a sealed can with microwaves pumped in.
If you went down that path, it would be a significant contribution to the knowledge base.
-
#2517
by
Rodal
on 03 Feb, 2016 13:27
-
CONSERVATION OF RELATIVISTIC MOMENTUM FOR REACTION-LESS PROPULSION THROUGH VARIABLE INERTIAL MASS
Minotti states that the weak energy condition (the condition that demands that the mass should be positive) is violated for the EM Drive in Minotti's theory.
Lobo and Visser's paper also states that the condition requiring positive mass is also violated in other models of propellant-less (reaction-less) forms of proposed space-propulsion.
McCulloch, also proposes that the EM Drive self-accelerates because radio frequency photons at the larger end have higher inertial mass, and therefore to conserve momentum in its reference frame, the cavity must move towards the narrow end.
This motivated me to analyze conservation of momentum for the EM Drive (or any such resonant cavity proposed for reaction-less propulsion) analyzed as a lumped-mass that is able to change its inertial mass. Thus, conservation of momentum of the EM Drive under these theories, would be satisfied, when duly taking into consideration the change in mass.
In this post in another thread: http://forum.nasaspaceflight.com/index.php?topic=39214.msg1486645#msg1486645, I analyze conservation of momentum for the case of negative mass, and for the case of variable increasing and decreasing mass.
I define momentum, using the relativistic definition of momentum.
The analysis shows that such a mode of space propulsion (reaction-less propulsion by variable mass) is quite limited on the speeds and changes in speed that it would be able to achieve.
No warping of spacetime is considered in the analysis, only a reactionless variable mass is considered.
In this theory what happens if you turn the EMDrive on, then off, then on again?
The equations presented were correct and frame-indifferent, but one of the variables chosen to present the results graphically, is not frame indifferent: deltaV/InitialVelocity.
It is better to express the solution solely in terms of frame-indifferent variables, which can readily be accomplished with the following change of variables, as follows:
deltaV/InitialVelocity =( deltaV/c ) *( 1/(InitialVelocity/c)
and then, when showing the results in completely frame-indifferent terms (*):
deltaMass/InitialMass = function (deltaV/c , InitialVelocity/c)
everything becomes more clear. The reason why there is a frontier becomes clear.
I will show all results in term of (deltaV/c , InitialVelocity/c) instead of (deltaV/InitialVelocity , InitialVelocity/c) this evening
Until then: minimum requirement for negative mass occurs for very high relativistic speeds, intermediate between 0 and c. Maximum requirement for negative mass occurs for InitialVelocity/c close to zero and for InitialVelocity/c close to 1.
___________
(*) deltaV is obviously frame-indifferent, being a difference of velocities. And the speed of light is clearly the only frame-indifferent speed to non-dimensionalize all variables
Variable mass, implying the need for negative mass to self-accelerate, addresses both conservation of momentum and it also addresses conservation of energy.
Energy is conserved, and such a propulsion device is not a free-energy machine, because the greater the speed, the lower the mass. More on that later...
(The practical problem of course is that up to now, nobody has found experimental evidence of negative mass
)
-
#2518
by
JasonAW3
on 03 Feb, 2016 13:41
-
Dr. Rodal,
I'm not quite sure I'm following this correctly, but, are you basically saying that you are producing a region of reduced mass at one end of the device while increasing the mass at the other end of the device, or are we talking about what could be a region of expanded space behind the device and a compressed area in front?
If this is a negative or educed mass situation, should there not be a pressure change in the immediate area of the actual negative mass? If so, this should be measurable in the pressure of the air column directly beneath the area of negative mass, should it not?
-
#2519
by
Rodal
on 03 Feb, 2016 13:57
-
Dr. Rodal,
I'm not quite sure I'm following this correctly, but, are you basically saying that you are producing a region of reduced mass at one end of the device while increasing the mass at the other end of the device, or are we talking about what could be a region of expanded space behind the device and a compressed area in front?
If this is a negative or educed mass situation, should there not be a pressure change in the immediate area of the actual negative mass? If so, this should be measurable in the pressure of the air column directly beneath the area of negative mass, should it not?
None of that is discussed. The relativistic equations for conservation of momentum are posed, treating the EM Drive as a lumped mass system, and then seeing what a change in speed implies for the change in mass in order to satisfy conservation of momentum. For conservation of momentum, it doesn't matter how the negative mass was produced, it is assumed that it can be produced somehow, and the consequences are explored. It is shown that the laws of physics are not violated, within the range of variables explored in the note.
As to how one can have negative mass:
1) there has not been experimental confirmation of negative mass occurring naturally in the Universe and no experiments exist that have conclusively shown that negative mass can be produced artificially, to my knowledge.
2) Negative mass is a consistent theoretical concept that has been discussed by many physicists, most prominently starting with Bondi. Negative mass is allowed by the laws of physics.
3) As pointed out in my note, Minotti states that self-acceleration of the EM Drive if due to General Relativity theory with the scalar coupling field, implies negative mass. Lobo has discussed a number of other reaction-less propulsion that imply negative mass, and McCulloch's theory implies variable mass. Prof. Woodward's Mach Effect theory also discusses how negative mass can be produced. Ditto for Dr. White's theory.
So, I don't discuss how negative mass can be produced, but Minotti's paper gives a consistent theory of how a General Relativity theory with the scalar coupling field can indeed result in effective negative mass for the EM Drive.
