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#740
by
krsears
on 14 Dec, 2018 16:38
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Enjoy the latest www.emdrive.com news
December 2018
A short Technical Note on Thrust performance versus Load conditions of EmDrive Thrusters is given here.
The note explains why EmDrive complies with both the Law of Conservation of Momentum, as well as the Law of Conservation of Energy.
Technical Note on Emdrive Thrust v Load
http://www.emdrive.com/thrustvload.pdf
TT,
Most of your argument just doesn’t make sense. Still a single sentence from early in the link above seems to suggest I have missed something very important... These have been repeatedly observed during experimental work extending over many years, and under many different test conditions, including reports of in orbit tests.
Where is the data from these, “…in orbit tests.”?
Why not follow the advice on the site and contact
[email protected] instead of asking here?
Kendall
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#741
by
Monomorphic
on 14 Dec, 2018 21:09
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including reports of in orbit tests.[/b]
Where is the data from these, “…in orbit tests.”?
The key word here is "reports." As in media reports that as far as we can tell have not been independently substantiated.
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#742
by
flux_capacitor
on 18 Dec, 2018 13:50
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#743
by
meberbs
on 18 Dec, 2018 17:47
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Mike McCulloch's article on "propellantless horizon drives" (including hypotheses about the EmDrive and Mach Effect thrusters) has been recently accepted for publication in the Journal of Space Exploration. Here is the preprint:
https://www.researchgate.net/publication/329754104_Propellant-less_Propulsion_from_Quantised_Inertia
The good news is that this paper has numerical predictions.
The bad news is that there are major problems with the comparisons to experimental data, which seem to be severely cherry picked.
The emDrive thrust values are based on early measurements from Shawyer that have long since been shown to not be real. More recent experiments clearly show that if there is any thrust, it is much smaller. This mismatch with experiment alone is possibly enough to invalidate the entire theory.
Possibly a worse infraction from the standpoint of academic behavior is an inaccurate citation of Tajmar. The cited paper is a purely theoretical one, and the value of the supposedly observed measurement is apparently taken from the theoretical model that is the worst fit to the experimental data from Fearn et al referenced by Tajmar. This complete misrepresentation is made worse by the fact that Tajmar has in fact taken experimental data, but there was no real measured force. (The actual report from Tajmar identifies an error in the setup, (refining the setup was the main point) and if there was any real signal, the expectation was that it was too small to detect due to the error present.)
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#744
by
Ricvil
on 19 Dec, 2018 19:46
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The flat spacetime has conformal symmetries, including the called special conformal transformations.
The classical electrodynamics presents conformal invariance too.
The file attached presents the use of conformal invariance to calculate the fields generated by a constantly accelerating charged particle, starting from a static charged particle before the special conformal transformation.
A interesting comment about causality and the special conformal transformation on page two.
"Transformations such as (2.2) or (2.3) do not in general preserve the time ordering of even time-like separated points."
Basically, at page 5, the expressions defining frontiers between causal and not causal regions by signal changes of a conformal factor.
The final discussion ( page 18) has an interesting pointing about quantum electrodynamic:
"At a mundane level there are immediate problems of introducing gauge fixing while maintaining conformal invariance [13]. More significantly attempts to impose exact conformal invariance on quantum electrodynamics have led to the condition that current Jµ = 0 as an operator equation, which leads to a trivial theory."
Looking at page six, one can note the gauge invariance between advanced and retarded potentials depends on a gradient of a function wich can becomes complex and non analytic.
Curiously, similar situation of a additive imaginary vector potential arises when one tries to find a path integral representation of klein gordon propagator in non harmonic coordinate systens.
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#745
by
JohnFornaro
on 20 Dec, 2018 13:48
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From the abstract:
https://www.researchgate.net/publication/329754104_Propellant-less_Propulsion_from_Quantised_Inertia"A new model for inertial mass, quantised inertia, that predicts galaxy rotation without dark matter, also predicts that a highly-accelerated system surrounded by an asymmetric conductor will feel thrust in a new way, without having to store and expel propellant."
Here is the definition of an "asymmetric conductor" that I am familiar with:
"A conductor which exerts different conductivity depending on the direction of the current flowing through it. A diode is an example of an asymmetric conductor."
http://thesciencedictionary.org/asymmetric-conductor/Is this paper using the term "asymmetric conductor" as per this definition? If not, what is the difference between an asymmetric conductor as is widely known, and an asymmetric conductor as used in this paper?
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#746
by
Notsosureofit
on 20 Dec, 2018 13:58
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Pretty sure he means "conductor of asymmetric geometry".
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#747
by
R.W. Keyes
on 21 Dec, 2018 18:03
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Pretty sure he means "conductor of asymmetric geometry".
Regarding McCulloch's pre-print of Dec 2018,
That is how I interpreted it. I asked him, and he said yes that's what he means.
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#748
by
flux_capacitor
on 21 Dec, 2018 18:25
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Mike McCulloch's article on "propellantless horizon drives" (including hypotheses about the EmDrive and Mach Effect thrusters) has been recently accepted for publication in the Journal of Space Exploration. Here is the preprint:
https://www.researchgate.net/publication/329754104_Propellant-less_Propulsion_from_Quantised_Inertia
[…]
Possibly a worse infraction from the standpoint of academic behavior is an inaccurate citation of Tajmar. The cited paper is a purely theoretical one, and the value of the supposedly observed measurement is apparently taken from the theoretical model that is the worst fit to the experimental data from Fearn et al referenced by Tajmar. This complete misrepresentation is made worse by the fact that Tajmar has in fact taken experimental data, but there was no real measured force. (The actual report from Tajmar identifies an error in the setup, (refining the setup was the main point) and if there was any real signal, the expectation was that it was too small to detect due to the error present.)
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#749
by
R.W. Keyes
on 21 Dec, 2018 20:01
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Here's what Mike McCulloch said to me in email, posted here with permission:
"1. I did not cherry pick. The publications in this area are usually non very
comprehensive and those were the only papers I could find with all the information I
needed in them.
2. The early data of Shawyer has not be falsified at all. Tajmar's emdrive results
appear to be about 10 times smaller than what were expected and seem to be due to a
thermal deformation. According to Shawyer, he has no resonance in his cavity.
3. By asymmetric conductor, I simply mean any conductor that has an asymmetric
shape. This fits the emdrive, MET and asymmetric capacitor.
4. The last criticism is a good one and it seems I have made a mistake somehow in
misinterpreting Tajmar's paper. In my rush I may have confused that one with his
later one. Very embarrassing, but what can you do? I will be changing the paper as
soon as I can."
He also asked me to thank the fellow who originally pointed it out, and that's you, meberbs.
If anyone feels as though there is data that he left out, that he should have included, please cite the data.
I have found Prof. McCulloch to be very approachable, responsive, and committed to good science.
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#750
by
meberbs
on 21 Dec, 2018 22:02
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Here's what Mike McCulloch said to me in email, posted here with permission:
"1. I did not cherry pick. The publications in this area are usually non very
comprehensive and those were the only papers I could find with all the information I
needed in them.
2. The early data of Shawyer has not be falsified at all. Tajmar's emdrive results
appear to be about 10 times smaller than what were expected and seem to be due to a
thermal deformation. According to Shawyer, he has no resonance in his cavity.
3. By asymmetric conductor, I simply mean any conductor that has an asymmetric
shape. This fits the emdrive, MET and asymmetric capacitor.
4. The last criticism is a good one and it seems I have made a mistake somehow in
misinterpreting Tajmar's paper. In my rush I may have confused that one with his
later one. Very embarrassing, but what can you do? I will be changing the paper as
soon as I can."
He also asked me to thank the fellow who originally pointed it out, and that's you, meeberbs.
If anyone feels as though there is data that he left out, that he should have included, please cite the data.
I have found Prof. McCulloch to be very approachable, responsive, and committed to good science.
McCulloch's response to this is very good. I can't overstate how important being willing to own a mistake like this is in having confidence in someone's integrity. I initially had a good impression of him, but after reading some of his blog posts, that had begun to sour, but this rights that and then some.
I still think those blog posts I mentioned are wrong (I think I was specific in a past post on here, but specifics aren't important right now), and I do not believe that the full available experimental data actually supports the theory. I am not sure I really want to get into many details right now, since the most important concern was addressed, and the rest falls into the category of standard academic discussion. I'll at least make a few comments now though.
For the emDrive, I would expect at least Eaglework's results to be included, unfortunately many emDrive results, particularly null results, are not published, and if they are reported at all, they are from DIYers (even if some have extremely excellent setups.) Tajmar's recent testing, while an inconclusive null result due to errors present, provides an upper limit that McCulloch could potentially use (not the original emDrive from Tajmar, which I think we can all agree should be excluded.) Shawyer's results would be in doubt simply from questions about how he can measure a force, when he has repeatedly published papers that demonstrate a lack of understanding of what a force is.
I refrain from further comment on the MET data until seeing which of the available data sets get referenced in McCulloch's update (the data from Fearn that Tajmar referenced, presumably, since Tajmar's most recent results are just a very weak upper bound due to the setup issues.) Possibly someone else here knows of a recent publication from Woodward that could be used.
...and as usual that was longer than what I intended. The important point is McCulloch should be applauded for this kind of response.
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#751
by
Notsosureofit
on 22 Dec, 2018 18:20
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FYI:
https://scitechdaily.com/new-equations-go-beyond-einsteins-theory-of-general-relativity/Quantum extension of the Kruskal spacetime
Abhay Ashtekar, Javier Olmedo, and Parampreet Singh
Phys. Rev. D 98, 126003 – Published 10 December 2018
ABSTRACT
A new description of macroscopic Kruskal black holes that incorporates the quantum geometry corrections of loop quantum gravity is presented. It encompasses both the “interior” region that contains classical singularities and the “exterior” asymptotic region. Singularities are naturally resolved by the quantum geometry effects of loop quantum gravity. The resulting quantum extension of spacetime has the following features: (i) It admits an infinite number of trapped, anti-trapped and asymptotic regions; (ii) All curvature scalars have uniform (i.e., mass independent) upper bounds; (iii) In the large mass limit, all asymptotic regions of the extension have the same ADM mass; (iv) In the low curvature region (e.g., near horizons) quantum effects are negligible, as one would physically expect; and (v) Final results are insensitive to the fiducial structures that have to be introduced to construct the classical phase space description (as they must be). Previous effective theories shared some but not all of these features. We compare and contrast our results with those of these effective theories and also with expectations based on the AdS/CFT conjecture. We conclude with a discussion of limitations of our framework, especially for the analysis of evaporating black holes.
Quantum Transfiguration of Kruskal Black Holes
Abhay Ashtekar, Javier Olmedo, and Parampreet Singh
Phys. Rev. Lett. 121, 241301 – Published 10 December 2018
ABSTRACT
We present a new effective description of macroscopic Kruskal black holes that incorporates corrections due to quantum geometry effects of loop quantum gravity. It encompasses both the “interior” region that contains classical singularities and the “exterior” asymptotic region. Singularities are naturally resolved by the quantum geometry effects of loop quantum gravity, and the resulting quantum extension of the full Kruskal space-time is free of all the known limitations of previous investigations of the Schwarzschild interior. We compare and contrast our results with these investigations and also with the expectations based on the AdS/CFT duality.
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#752
by
Ricvil
on 26 Dec, 2018 11:40
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A very subtle final comment about some space time axisymmetric solutions called Bondi-Sachs metrics, where the accelerated source mass time variation may not be in balance with emmited null dust radiation.
AND
For the called Petrov Type D spacetimes appears to exist an analog of holographic principle, linking full 4d space time to 2d null boundary conditions.
PS: The conical cavity with flat end plates presents two impulsive rings of intrinsic curvature originated by the shape of boundary conditions, and by mirror symmetry at end plates, these rings of curvature has different signals, and the electromagnetic wavefronts, under optical approximation of conformal invariant eikonal equation, feels and interact with these rings of curvature.
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#753
by
Ricvil
on 28 Dec, 2018 15:11
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Just a curiosity.
There is a classe of Type D spacetimes related to "twisted gravitational waves".
AND...
There is the "holographic principle" for Type D spacetimes.
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#754
by
Flyby
on 29 Dec, 2018 08:33
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#755
by
Star One
on 29 Dec, 2018 10:13
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Here's what Mike McCulloch said to me in email, posted here with permission:
"1. I did not cherry pick. The publications in this area are usually non very
comprehensive and those were the only papers I could find with all the information I
needed in them.
2. The early data of Shawyer has not be falsified at all. Tajmar's emdrive results
appear to be about 10 times smaller than what were expected and seem to be due to a
thermal deformation. According to Shawyer, he has no resonance in his cavity.
3. By asymmetric conductor, I simply mean any conductor that has an asymmetric
shape. This fits the emdrive, MET and asymmetric capacitor.
4. The last criticism is a good one and it seems I have made a mistake somehow in
misinterpreting Tajmar's paper. In my rush I may have confused that one with his
later one. Very embarrassing, but what can you do? I will be changing the paper as
soon as I can."
He also asked me to thank the fellow who originally pointed it out, and that's you, meberbs.
If anyone feels as though there is data that he left out, that he should have included, please cite the data.
I have found Prof. McCulloch to be very approachable, responsive, and committed to good science.
Thanks for this. At least you did it the right way by approaching him privately rather than certain alternatives.
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#756
by
MadMarx
on 30 Dec, 2018 19:58
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Hi, all!
First post, won't bother you too much.
But I've been following this story for years, coming from bioscience, can someone please explain to me why people are still arguing about stuff that won't ever get any closure.
Everybody is trying to build a truncated cone with a resonating EM field inside all other parameters being at the discretion of the experimenter.
Last year I saw Sonny White presenting not vague ideas, not theoretical paper, but a full blown computer simulation of what he thinks in going inside the device.
This simulation shows how inefficient the current geometry is and seems perfectly able to be the virtual test bed for potential huge increase in the thrust efficiency or at least to test the theory.
But Mr White tells us he sees the humongous inefficiency (like 2-3 orders of magnitude on the animation), but is not interested in decreasing it right now...
Would the numerical optimization of the EMdrive not be a more direct path to clear science that the current fumbling with non linearities of torsion pendulum and ultra tiny weird interaction with earth magnetic field etc
Is the simulation code available? Could it explain the discrepancies between current experiments? Can it lead to a big improvement in efficiency yielding clear and indisputable measurements?
Isn't the pinnacle of science to be able to design a simulation that fit the experiments? :-)
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#757
by
aero
on 30 Dec, 2018 23:28
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Welcome to the forum.
I took a shot at such a thing using meep software, unfortunately, meep is pure classical electrodynamics and gives pure classical results. Meep does provide source code and some contributors to this thread are sufficiently skilled to modify it, but it requires they have a theoretical path to follow. Maybe Sonny White's theory gives a direction but It doesn't seem to have gained much traction on this thread. As for myself, I can run meep as it exists but I can't even get it to compile, let alone code and integrate new modules so I have passed the baton.
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#758
by
meberbs
on 31 Dec, 2018 07:00
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Hi, all!
First post, won't bother you too much.
But I've been following this story for years, coming from bioscience, can someone please explain to me why people are still arguing about stuff that won't ever get any closure.
A theme of several of my recent posts has been that if anyone has any remaining interest in looking into the emDrive, they should come up with something falsifiable so that it is possible to call an end to it.
Last year I saw Sonny White presenting not vague ideas, not theoretical paper, but a full blown computer simulation of what he thinks in going inside the device.
You seem to be confused, you reference "theoretical paper" and "computer simulation" as separate things with the second being implied as better somehow. A computer simulation is just a single method that can be used for working out a theory. Many papers are based on such models, but depending on the context sometimes they are more useful than working out the math directly, and sometimes they are less. A simulation is useless if it doesn't accurately represent the theory, and a theory is useless if it disagrees with experiment in the relevant regimes.
This simulation shows how inefficient the current geometry is and seems perfectly able to be the virtual test bed for potential huge increase in the thrust efficiency or at least to test the theory.
Except there is no generally accepted theory for the emDrive, in fact I haven't seen one that was even slightly plausible. No matter how many times you run a simulation that doesn't actually plausibly describe reality in the regimes you are testing, the results aren't going to be useful. I don't know specifically what theory the presentation you saw was based on, but the old quantum vacuum proposal never made any sense to begin with since it required the quantum vacuum to have contradictory properties.
Would the numerical optimization of the EMdrive not be a more direct path to clear science that the current fumbling with non linearities of torsion pendulum and ultra tiny weird interaction with earth magnetic field etc
No, because no one has any clue what to optimize it for. Without some real data to back up, simulations prove nothing other than to answer "what if we lived in a universe with an alternate set of laws of physics?"
Isn't the pinnacle of science to be able to design a simulation that fit the experiments? :-)
The best experiments that have been done have have shown null results to within their sensitivities, or have had probable error sources comparable to any signal. The best model to fit these results is therefore the standard electrodynamics that has been around for over a century. This is an unsurprising result, because the field strengths and other aspects of the emDrive are well within realms that have been thoroughly tested before.
edit:typo
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#759
by
dustinthewind
on 01 Jan, 2019 02:37
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If I wanted the emdrive to work I think I would probably replicate the podkletnov gravity impulse experiments inside a cavity. My hypothesis is that by introducing a serries of frequencies in a cavity you can make a Mach Effect of extreme acceleration on the electrons in one direction with much less acceleration on the electrons in the other direction. My guess is that podkletnov's experiments may be verification of a Mach Effect.
The combined electric field inside a cavity of the frequency serries at Max electron acceleration in the desired direction would create the voltage or electron acceleration podkletnov expects. My guess is that when the electrons are in their ground state in the vacuum electron cloud in a superconductor that it enhances interaction with the vacuum.
He claims to now be generating gravity impulses with enough force to dent inch thick plates of some metal I think it was. Problem is his isn't on a cycle. I think the Mach effect is the same thing but on a cycle. In the end you end up pushing the vacuum in a direction like a rocket but there is another effect that begins to modify the effective mass (the worm hole effect). Even if the Mach effect is bogus we know black holes can exhaust real momentum into the vacuum. That the vacuum is even dragged around plants and rotating black holes almost like a fluid as in the lens thirring effect. If podkletnov's experiments are real then I think it's the next step.
I also think the gravity wave podkletnov is generating is a negative gravity. Stretched space. That's why his experiments seem to show it traveling faster than c and deflecting laser pulses. WarpTech used to also talk about adding energy to the vacuum also. Where gravity was a depeltion of energy from the vacuum leading to lorentz contraction. Enhancing the vacuum with energy stretches it. podkletnov's wave pushes objects away as it passes through them.
