-
#2860 by spupeng7 on 15 Feb, 2016 00:03
-
Hope a nsf user team here might agree to tackle this together...cannot open it also
If the author is now living in Toronto maybe he has translated his paper to english. His translation, if it exists, would have more meaning than the Google robot translation. A good way to get a splitting headache is trying to make sense of the Google translation. Almost as bad as an OCR of a microfiche printout.
Sorry folks, I will not attach anything again without checking it all the way through
-
#2861 by spupeng7 on 15 Feb, 2016 00:11
-
Reading back into thread 6 there are questions about buoyancy which may not have been resolved. Hot air inside and above the waveguides may cause a decrease in measured weight. It is also possible that heated air surrounding the waveguides may cause an increase in measured weight, for the same reason that a surfer sinks in highly aerated turbulent white-water, because buoyancy is a consequence of the mass displaced as well as the mass within the displacement.
No aerodynamic equation set can help us model this because the turbulence overrides all other factors and is completely random in development over time and in response to initial conditions. I have no wish to be the bearer of bad news but the only solution I can see for thrust measurement at atmospheric pressure is to make generous allowance for these effects according to the temperatures of the test equipment.
The density of free air changes in proportion to its temperature in degrees Kelvin and volume in cubic meters,
V1 / T1 = V2 / T2
where one cubic meter at standard pressure and temperature has a mass of 1.225 KG.
The density of trapped air depends also upon its pressure in Newtons per square meter,
P1 x V1 / T1 = P2 x V2 / T2
A little play with these relationships will reveal how much your measurements can be distorted.
-
#2862 by rfmwguy on 15 Feb, 2016 00:35
-
Yang-Mills lecture, worth a look beyond the laborious speaker introduction
-
#2863 by aero on 15 Feb, 2016 05:00
-
A quick question. How accurate is this statement?Quote
Q values are generally on the order of magnitude of the volume - to - surface ratio divided by the skin depth
Addressing the quality factor of a resonator of course. -
#2864 by Chrochne on 15 Feb, 2016 06:34
-
Hackday Baby EmDrive posted an interesting update.
https://hackaday.io/project/5596-em-drive/log/31857-results
"Just finished an acoustic test of the EMDrive V3 and got interesting results:"
-
#2865 by Prunesquallor on 15 Feb, 2016 11:06
-
...
One cannot move a spacecraft's center of mass by banging on the wall of the spacecraft, moving the furniture to one corner or emitting waves inside one end of the spacecraft. One must actually eject mass or energy out of the spacecraft to move the center of mass.
...
I think one needs to be careful how this is stated to avoid confusion. It certainly IS possible to move a spacecraft or aircraft center of mass with respect to a body-fixed frame. The Concorde shifted fuel amongst various internal tanks to move the center of mass, and any cargo master would be happy to tell stories about the effects of shifting cargo on aircraft center of mass. I believe what you are referring to is the positionn of the center of mass with respect to some external frame. -
#2866 by Rodal on 15 Feb, 2016 11:36
-
What we are discussing in these EM Drive threads is whether the EM Drive can be used for spaceflight propulsion: the title of the thread is "EM Drive Developments - related to space flight applications "...
One cannot move a spacecraft's center of mass by banging on the wall of the spacecraft, moving the furniture to one corner or emitting waves inside one end of the spacecraft. One must actually eject mass or energy out of the spacecraft to move the center of mass.
...
I think one needs to be careful how this is stated to avoid confusion. It certainly IS possible to move a spacecraft or aircraft center of mass with respect to a body-fixed frame. The Concorde shifted fuel amongst various internal tanks to move the center of mass, and any cargo master would be happy to tell stories about the effects of shifting cargo on aircraft center of mass. I believe what you are referring to is the positionn of the center of mass with respect to some external frame.
Emphasis is on flight: for spaceflight propulsion what matters is to move the center of mass of a spaceship with respect to an external frame of reference. The point of these threads is to examine whether the EM Drive can be used to move from point A in space to point B in space (for example, from Earth to Mars).
It would be worthless for spaceflight propulsion (for example, to be able to go from the Earth to Europa) to move the center of mass of a spacecraft with respect to an intrinsic body-fixed coordinate system without moving the center of mass of the spacecraft with respect to an external frame of reference. The spacecraft would not be able to reach its destination solely by shifting the furniture inside the spacecraft or solely by shifting fuel between tanks: that is not spaceflight propulsion.
That's why I gave the example of moving the furniture inside the spaceship to one corner of the spaceship: this makes it obvious that one is talking about moving the center of mass of the spacecraft with respect to an external frame of reference.
Since the context of this forum is space flight propulsion: moving the center of mass with respect to an external frame and the purpose of this thread is not moving things inside a spacecraft (moving the center of mass with respect to body-fixed coordinates that does not result in moving the center of mass with respect to an external frame), it seems that one should not need to have to belabor this point too much for the purposes of this thread. I think that one doesn't risk too much in assuming that the readers understand that.
_________
On the other hand, regarding experimental artifacts , it has been accepted by Star-Drive (Paul) that NASA's earlier tests presented a problem of shifting the center of mass because of asymmetric thermal expansion that resulted in erroneous assessment of the magnitude of the anomalous force being measured. They realized that of course, shifting the center of mass with respect to intrinsic geometrical coordinates is worthless for spaceflight propulsion and they embarked on a program to address this experimental artifact: 1) by re-arranging the test equipment to minimize the asymmetry in thermal expansion and 2) by developing a software model to quantify the asymmetric thermal expansion responsible for the shifting of the center of mass with respect to geometry and subtract this effect when displaying the anomalous force magnitude.
Also, if somebody tests an EM Drive in a teeter-totter balance, makes sure that it is perfectly balanced prior to testing the EM Drive, with equal moments:
WeigthLeft*InitialLengthLeft = WeigthRight*InitialLengthRight
and upon exciting the magnetron at one end of the teeter-totter balance that end thermally expands due to induction heating asymmetrically, such that the moment-arm on the EM Drive end becomes longer, and therefore the teeter-totter balance rotates with the EM Drive end going down,
WeigthLeft*InitialLengthLeft < WeigthRight*(InitialLengthRight + deltaLength)
where deltaLength = asymmetric thermal expansion of right end
that is another example of how asymmetric thermal expansion can result in shifting of the center of mass, and hence measuring a force that is just an experimental artifact. -
#2867 by Rodal on 15 Feb, 2016 12:06
-
A quick question. How accurate is this statement?
This explains it: http://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347QuoteQ values are generally on the order of magnitude of the volume - to - surface ratio divided by the skin depth
Addressing the quality factor of a resonator of course.
Q=(2/SkinDepth)( ∫Electromagnetic Energy Density dV/ ∫ Electromagnetic Energy Density dA) -
#2868 by Rodal on 15 Feb, 2016 13:37
-
Somebody else, that like Trunev, is looking at a unified theory of quantum gravity by combining General Relativity with Yang-Mills
http://www.scirp.org/journal/PaperInformation.aspx?PaperID=40152
From Yang-Mills Photon in Curved Spacetime to Dark Energy Density
Mohamed S. El Naschie
Journal of Quantum Information Science, 2013, 3, 121-126
CAUTION: This journal has an impact factor of zero in ResearchGate:
https://www.researchgate.net/journal/2162-5751_Journal_of_Quantum_Information_Science
Current impact factor: 0.00
This Journal's IMPACT FACTOR RANKINGS as per ResearchGate
5-year impact 0.00
Cited half-life 0.00
Immediacy index 0.00
Eigenfactor 0.00
Article influence 0.00
This Journal's Google-based Impact Factor: 1.19
This is the Editorial Board: http://www.scirp.org/journal/EditorialBoard.aspx?JournalID=591#.VsHlIPk4FD8
The author reasons that the measured energy density is the energy of the quantum particle in 5D Kaluza-Klein spacetime. (For connections with other arguments, it is interesting that Dr. White uses other 5D spacetime theories in some of his arguments for his EM Drive theory and that Minotti used a scalar tensor theory based on a 4D Kaluza Klein spacetime).
Still, it may be of interest to look at the Venn diagrams below to understand what these authors have in mind (which is a unified theory of quantum gravity):
-
#2869 by Rodal on 15 Feb, 2016 13:52
-
Here is a list of Quantum Gravity researchers: https://en.wikipedia.org/wiki/List_of_quantum_gravity_researchers
The list includes:
John Baez: who has written articles in his blog that the EM Drive must be an experimental artifact and can serve no purpose for spaceflight applications (see for example: https://plus.google.com/117663015413546257905/posts/C7vx2G85kr4)
David Finkelstein: Physicist who has contributed much quantum relativity and the logical foundations of QR, mentioned by the above author (El Naschie) among his references for unifying General Relativity with Yang Mills
Bill Unruh: who was a Ph.D. student under Wheeler, and is responsible for the discovery of the so-called Unruh effect, used by McCulloch in his EM Drive explanation
Brian Greene: string theorist known for Popular Science
Michio Kaku: known for Popular Science.
James Hartle: Physicist who helped develop the Hartle-Hawking wavefunction for the universe.
Stephen Hawking: Leading physicist, expert on black holes and discoverer of Hawking radiation who helped develop the Hartle-Hawking wavefunction for the universe.
Roger Penrose: Mathematical physicist who invented spin networks and twistor theory.
Lee Smolin: One of the founders and major contributors to loop quantum gravity.
Robert Wald: Leading physicist in the field of quantum field theory in curved spacetime.
Edward Witten: Leading mathematical physicist, famous for string theory and M-theory.
Leonard Susskind: Leading physicist, who is considered to be one of the three fathers of String theory
----------------------------
The list is conspicuous for missing famous people
like Juan Martín Maldacena who zoomed to being a full Professor of Physics at Harvard, and then quickly became a professor at the Institute for Advanced Study in Princeton, New Jersey (famous for Einstein, Goedel, Weyl and so many others).
Among his many discoveries, the most famous one is the most reliable realization of the holographic principle and he co-authored an analysis of the 2012 black hole firewall paradox with Leonard Susskind, arguing that the paradox can be resolved if entangled particles are connected by minor wormholes. -
#2870 by rfmwguy on 15 Feb, 2016 14:07
-
Somebody else, that like Trunev, is looking at a unified theory of quantum gravity by combining General Relativity with Yang Mill
I also watched an interview with Yang from Stony Brook. He spoke with Einstein, Oppenheimer and other brilliant thinkers when he was younger. He seems to present himself as a theoretical physicist and not a mathematician. In fact, he spoke at length about the deep divide between mathematics and theoretical physics at Princeton, only now starting to heal.
http://www.scirp.org/journal/PaperInformation.aspx?PaperID=40152
From Yang-Mills Photon in Curved Spacetime to Dark Energy Density
Mohamed S. El Naschie
Journal of Quantum Information Science, 2013, 3, 121-126
CAUTION: This journal has an impact factor of zero in ResearchGate:
https://www.researchgate.net/journal/2162-5751_Journal_of_Quantum_Information_Science
The Millenium Prize
http://www.claymath.org/millennium-problems/yang%E2%80%93mills-and-mass-gap
is still out there for anyone able to solve the yang-mills theorem, so perhaps it will be looked at more rigorously. Regarding Trunev, his paper appears to attempt to try and bridge the mass gap. In my simplistic view, it boils down to "no mass", high speed, long distance forces versus near-field atomic forces with mass; like you say, a unification theory revolving around quantum gravity.
Seems to me not enough experiments are being conducted to bridge the gap. Perhaps there are, but can't recall reading anything recently. There is enough uncertainty that an experiment like the EMDrive might be useful in this academic pursuit, provided there is not experimental bias that it cannot possibly work according to classical electromagnetic theory. -
#2871 by rfmwguy on 15 Feb, 2016 15:29
-
EMDRive tangential alert -
OK, so its just fan art, but fun anyway...
-
#2872 by aero on 15 Feb, 2016 16:21
-
A quick question. How accurate is this statement?
This explains it: http://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347QuoteQ values are generally on the order of magnitude of the volume - to - surface ratio divided by the skin depth
Addressing the quality factor of a resonator of course.
Q=(2/SkinDepth)( ∫Electromagnetic Energy Density dV/ ∫ Electromagnetic Energy Density dA)
Thank you Dr. Rodal. I believe that confirms the rule of thumb as quoted. Missing the factor of 2, but still the same order. -
#2873 by rfmwguy on 15 Feb, 2016 17:53
-
EMDrive experimenter hardware(?) - Anyone thinking of building on-board or light-weight data recording (temp, humidity, motion, accereration, signal strength, etc) or control (tuning, pulse output) should take a look at:
http://getchip.com
Not an endorsement, but seems it may be a cost-effective component for emdrive experiments. -
#2874 by flux_capacitor on 15 Feb, 2016 18:02
-
Hot from the Reddit online library.
The paper's contribution is that it allows evanescent wave solutions to occur inside the EM Drive cavity, apparently even under Shawyer's prescription forbidding small end diameters smaller than the one for cutoff of a cylindrical waveguide of the same diameter.
http://arxiv.org/pdf/1509.02603v1.pdf
However, assuming that such evanescent waves inside the EM Drive would indeed be possible, the Lorentz force that the author addresses cannot by itself result in self-acceleration of the EM Drive:
1) One cannot move a spacecraft's center of mass by banging on the wall of the spacecraft, moving the furniture to one corner or emitting waves inside one end of the spacecraft. One must actually eject mass or energy out of the spacecraft to move the center of mass.
2) The author's Lorentz force equation is written for a particle of electric charge q. Even if there would be such particles with charge q inside the EM Drive cavity (which the author never justifies), if they are inside, and they are not emitted outside the cavity, this cannot result in moving the spacecraft center of mass. For his Lorentz force equation to allow self-acceleration, there would need to be an outside field interaction, a field that would penetrate the copper walls of the EM Drive. What field would that be? The author does not begin to address this problem.
Hence, unless mass or energy is emitted out of the EM Drive or somehow it couples with an external field (in which case it would become an open system), internal evanescent waves would not allow self-acceleration of the EM Drive, and such solution (although interesting for other applications) does not seem to advance the state of discourse on the EM Drive conundrum.
Yesterday I emailed your remarks to Dr. Montillet, translated in French for more convenience. Clearly he understood these questions were asked constructively, from people that are genuinely trying to understand whether the anomalous force in the EmDrive can be used for space propulsion. Dr. Montillet kindly answered the following directly in English, telling I could post his message in this forum. Here it is:Quote from: Jean-Philippe MontilletFirst of all, the last section of my paper entitled "Multiplicity of Solutions for Linear Partial Differential Equations Using (Generalized) Energy Operators" is dedicated on the application of the mathematical model developed in the Section 2. That is why there are many assumptions which can be seen as "jumping the gun".
Thus, I assume the possibility of Evanescent waves propagating inside the cavity. The evanescent waves are common solutions in the application of wave guides. This assumption is based on the idea that 1/ planar waves are just an ideal model and could potentially being reflected many times on the walls/ends of the EMD cavity; 2/ my mathematical model predicts additional solutions for the wave equation (and more generally linear and non-linear PDEs, but with restrictions – see also http://arxiv.org/abs/1308.0874), with these solutions classified in "Energy Spaces" subspaces of the Schwartz Space S^-(R). The planar waves do not fulfill mathematically the first rule to be part of S^-(R) – stated in Equation 1. Evanescent waves were chosen as a good possibility justified in the last Section of my previous paper http://arxiv.org/abs/1308.0874
In my model, I show that with the assumption of a slight increase of energy (see Taylor Series of energy function in equations 34 , 35 and 36), new solutions (or waves in our case) should be considered, because they are not negligible anymore (Definition of the negligibility is given in equation 35). Now, my work lacks of "physical meaning". I am aware of it (and in my free time, I am trying to develop the next step but this is very slow process). One possibility to give some meaning to the slight increase of energy, could be the reflections of the waves on the cavity's walls. However, the evanescent waves should vanish quickly after the reflection, hence the new solutions/waves would appear close to the reflector. If that is true, the phenomenon is local and should appear on both ends of the cavity with a different intensity.
About your statement 1), I agree with you and my work does not show anything against this principle. If it does, please do not hesitate to show it to me.
2/ That is tricky. The justification of the Lorentz force inside the cavity is one of the big criticism of Shawyer's work. I use the assumptions of Shawyer's early paper (IAC 2008 paper available on emdrive.com). My assumptions are very reductive, because I only consider the electric field to simplify the application. However, the additional waves predicted with my model could generate this additional Lorentz force as discussed at the end of my article. The origin of the additional charge could be discussed via simulations. Would it be possible that additional charges are created via collisions of particles inside the cavity?
Beyond the use of evanescent waves, the idea of my work is based on a local phenomenon created via multiple reflections of the waves inside the cavity which produces this additional thrust. My model is only one attempt to explain this phenomenon.
I will follow with great interest your discussion on your forum. Perhaps, I can contribute further.
Best Regards,
Jean-Philippe -
#2875 by Rodal on 15 Feb, 2016 19:03
-
...
Thank you so much for your initiative and thanks to Dr. Montillet for the great, very helpful response !
Yesterday I emailed your remarks to Dr. Montillet, translated in French for more convenience. Clearly he understood these questions were asked constructively, from people that are genuinely trying to understand whether the anomalous force in the EmDrive can be used for space propulsion. Dr. Montillet kindly answered the following directly in English, telling I could post his message in this forum. Here it is:
...
-
#2876 by rfmwguy on 15 Feb, 2016 19:57
-
Prof Jeff Lee of Baylor addresses students at the Queens Space Conference a couple of weekends ago in Toronto. This conference follows the Canadian Smallsat Conference and is in its 4th year. If you recall, this Professor was an advisor NASA's blue ribbon panel evaluating their QV Thruster project.
http://forum.nasaspaceflight.com/index.php?topic=39004.msg1475651;topicseen#msg1475651
It is interesting to note the Prof Lee wrote a paper on how the Eagleworks interferometer would not be capable of resolving space-time distortions:
http://tinyurl.com/z6aqafx
My (only) speculation is he might have been an advisor to the panel specifically because of his 2014 paper IF interferometry was part of the EW paper.
Photo courtesy QSC's public facebook page. -
#2877 by ThinkerX on 15 Feb, 2016 20:30
-
Ok...
Considerable hesitation here because the items listed are way beyond my level to evaluate. From the titles, though, a few might be relevant to this topic, so:
http://physicsgirl.com/
-
#2878 by flux_capacitor on 15 Feb, 2016 20:59
-
Cannae LLC has a new international patent application, published 7 January 2016:
WO application 2016004044, Fetta, Guido P., "Electromagnetic thrusting system", published 2016-01-07, assigned to Cannae LLC
Attached below.
-
#2879 by masterharper1082 on 16 Feb, 2016 01:40
-
Cannae LLC has a new international patent application, published 7 January 2016:
WO application 2016004044, Fetta, Guido P., "Electromagnetic thrusting system", published 2016-01-07, assigned to Cannae LLC
Attached below.
LOL, this is the one I just got. I beat him by 5 days. Mine doesn't produce thrust. 
https://patents.google.com/patent/US9255900B2/en
Hello,
Just introducing myself to the forum, and trying to get used to the strange features of the NSF message editor. I've been lurking for quite a while - I read all of Thread 6, but haven't gone back any further.
As a Mechanical Engineer specializing in control algorithms and physics-based simulation, I may be able to offer some assistance on topics relevant to EMDrive - especially with respect to thermal effects, cooling, or writing/modifying simulation codes in C++, C, or Matlab/Simulink. Finally, I may have some mechanisms to get access to ANSYS CFX and computation time as long as we are last in the scheduler - I can inquire if there is interest.
Yeah, my most recent patent doesn't make thrust either - it just makes a heat pump work better:
Receiver Fill Valve and Control Method
Here's more info on me courtesy of my
LinkedIn Profile.
Best wishes to all,
masterharper1082
like Juan Martín Maldacena