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#1440
by
X_RaY
on 20 Apr, 2016 21:14
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@FL
This is the non scaled version of the Bread frustum with dilelectric @1.93GHz, it shows TM212. I am pretty sure the scaled version fits as well (compared to your scale factor). Believe it or not. I like to suggest you to install feko lite by your self and try it.
I am looking forward to future calculations from you.
Regards
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#1441
by
rfmwguy
on 20 Apr, 2016 21:14
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"gubrud 6 minutes ago...Why is the author of this post anonymous?"
Disingenuous question...it is obvious.
After seeing what happens to people in serious academia that is too friendly towards some fringe-y ideas, one doesn't have to wonder too much why anyone being at least open to the idea of Emdrive would publish an article anonymously.
There are ideas that are simply career poison, until they either prove themselves or fade away due to lack of proof.
Then everyone is in favor since the beginning.
No doubt, the emdrive is controversial...Reminds me of a TV show last night, it was about a Norwegian skydiver who video-taped a rock flying by his helmet cam at high velocity. He took it to researchers at a local university that spent a lot of time and effort determining it was likely a meteorite. Sometime afterwards NASA helped with software they had been developing for 10 years and concluded it was a smaller object (piece of gravel) released by the parachute after opening up. Much to the amazement of the Norwegian team, they were met with congratulations for their efforts and there was very little ridicule. Different culture...wish we had some of it.
http://norskmeteornettverk.no/wordpress/?p=1497
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#1442
by
Rodal
on 20 Apr, 2016 21:27
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@FL
This is the non scaled version of the Bread frustum with dilelectric @1.93GHz, it shows TM212. I am pretty sure the scaled version fits as well (compared to your scale factor). Believe it or not. I like to suggest you to install feko lite by your self and try it.
I am looking forward to future calculations from you.
Regards
Thank you for posting this information
Could you please also provide the value of relative permittivity you used for the dielectric for this latest run (dilelectric @1.93GHz, it shows TM212)?
PS: by the way, your screen captures are very clear, high resolution: one can actually read very clearly all the fields and numbers
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#1443
by
X_RaY
on 20 Apr, 2016 21:41
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#1444
by
demofsky
on 20 Apr, 2016 21:42
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MIT Technology Review, 4/20/2016, The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster:
http://tinyurl.com/hnf46q2
I can't remember if anyone made theoretical bridge between McCullough and the modelling approaches that we are currently using to optimize for a specific TM mode, for instance.
That is, would optimizing for Unruh's radiation result in different dimensions than are currently being considered??
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#1445
by
Rodal
on 20 Apr, 2016 22:21
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MIT Technology Review, 4/20/2016, The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster:
http://tinyurl.com/hnf46q2
I can't remember if anyone made theoretical bridge between McCullough and the modelling approaches that we are currently using to optimize for a specific TM mode, for instance.
That is, would optimizing for Unruh's radiation result in different dimensions than are currently being considered??
EXCELLENT question !
I am not aware of anyone making that connection. This would be one of the first questions I would ask Dr. McCulloch. His theory so far disregards mode shapes. Is this because his theory is approximate? What would a better approximation of McCulloch's theory reveal if mode shapes were taken into account?
Would TM or TE modes be better according to McCulloch's theory? Would low order modes be better? Would quadrupoles be better?
For comparison, Notsosureofit explicitly takes the mode shapes into account and makes a definite statement in this regard
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#1446
by
Rodal
on 21 Apr, 2016 02:33
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MIT Technology Review, 4/20/2016, The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster:
http://tinyurl.com/hnf46q2
My post: http://forum.nasaspaceflight.com/index.php?topic=39772.msg1510968#msg1510968
This is starting to be a lot clearer and is light-years ahead of my (weak) working theory about Cu+ and Cu++ inertia. I think this article from MIT is a significant moment for many of us who have been working with so much disparaging public commentary. Let hope they launch their own investigation and make it public.
...
I look forward to the COMMENTS section (at the bottom of the article), there are now 3 comments. Sometimes good comments are posted. It would be interesting if somebody comments with a clear identification to a University or research institution or Government Lab or from an aerospace company.
Interesting comments by Uncle Al on how to improve "the boojum"
:
#1 is a superconducting cavity
#2 is a better shape (reminiscent I think of the shape recommended by Todd DeSiato "WarpTech
at one point in time)
#3 optical wavelelengths: as per Monomorphic and Eusa
#4 study different mode shapes
#5 sub-wavelength optics; evanescent field emitters
UncleAl 6 hours ago
"The cone allows Unruh radiation of a certain size at the large end but only a smaller wavelength at the other end. So the inertia of photons inside the cavity must change as they bounce back and forth. And to conserve momentum, this must generate a thrust."
1) Given the Pioneer anomaly and Phong shading (arXiv:1103.5222, 1107.2886), fabricate the boojum of pure niobium, operate it below 9 kelvins, and observe what obtains.
2) Fabricate the boojum as a de Laval nozzle.
3) Reconfigure the boojum as a progressive etalon stack. At optical wavelengths,a progressive bandpass thin film stack.
4) What happens if the microwave feed is polarized linearly, circularly, or helically (orbital angular momentum)?
5) Extend the boojum - photonic effects and sub-wavelength optics; evanescent field emitters (and arXiv:1505.05414).
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#1447
by
coypu76
on 21 Apr, 2016 06:32
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I'm not a physicist, so please forgive me if this question proceeds from a basic misunderstanding. A couple of years ago I remember reading a couple of articles that hinted at a distinction between gravitational and intertial mass. The Technology Review article refers to intertial mass of the photons involved in Unruh radiation. Is there a relation between the distinction between gravitational and inertial mass, and the proposed mechanism by which the EM drive produces thrust?
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#1448
by
Mark7777777
on 21 Apr, 2016 10:17
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#1449
by
bunjatec
on 21 Apr, 2016 11:13
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I've just noticed this:
http://phys.org/news/2016-04-microworld-unity-strength.htmlThis seems to imply (to my limited understanding) that under certain conditions forces between particles don't add up linearly (at Casimir scales)
remembering back to previous discussions about casimir forces potentially being scaled up by the fustrum could this be relevant to our more theoretical physics oriented folks?
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#1450
by
Rodal
on 21 Apr, 2016 11:15
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I'm not a physicist, so please forgive me if this question proceeds from a basic misunderstanding. A couple of years ago I remember reading a couple of articles that hinted at a distinction between gravitational and intertial mass. The Technology Review article refers to intertial mass of the photons involved in Unruh radiation. Is there a relation between the distinction between gravitational and inertial mass, and the proposed mechanism by which the EM drive produces thrust?
See Einstein's principle of
equivalence of inertial and gravitational mass, one of the cornerstones of General Relativity:https://en.wikipedia.org/wiki/Equivalence_principleA little reflection will show that the law of the equality of the inertial and gravitational mass is equivalent to the assertion that the acceleration imparted to a body by a gravitational field is independent of the nature of the body.
If a distinction is suggested between gravitational and inertial mass, to explain a few hereto otherwise unexplained experimental results, this will have severe repercussions on its ability to explain the motion of bodies in the Cosmos. As all astrophysical measurements are consistent with General Relativity (in which inertial and gravitational mass are equivalent) up to now, any proposal of distinguishing between gravitational and inertial mass has a colossal task to reconcile all these astrophysical measurements with such a theory that flies in the face of Einstein's theory of equivalence.
Remember that a physical theory that tries to explain a single experiment on Earth, has to simultaneously be compatible with all the measurement knowledge we have accumulated of our entire Universe.
Hundreds of years ago, when mankind did not know much about the Cosmos, it was easy to come up with theories that were compatible with what was known at that time. The more knowledge we accumulate of the Universe, the more difficult is to come up with theories that are simultaneously compatible with the sum total of all those measurements.
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#1451
by
Rodal
on 21 Apr, 2016 13:03
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Lisa Randall has been pushing the concept of large extra hidden dimensions for some time:
http://www.math.columbia.edu/~woit/wordpress/?p=250However:
The search for hidden dimensions comes up empty againhttp://arstechnica.com/science/2016/04/the-search-for-hidden-dimensions-comes-up-empty-again/http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.131101what is interesting (besides the fact that it is shown that the inverse square law still holds for electrostatic charges to tiny dimensions, and hence the search for extra dimensions came up empty) is that this is shown experimentally using a
torsional pendulum with a sensitivity of the order of 10^-17 Nm (that's the torque on the pendulum, the actual force is on the order of 10^-19 N, but torque is what is actually measured). This is about the equivalent to the force of 10,000 water molecules falling onto a surface (a single millilitre of water has over 10^22).
The forces discussed in EM Drive experiments are of the order of microNewtons or greater. A microNewton is 10,000,000,000,000 times (that's a lot of zeros ! ) greater than the 10^-19 Newtons measured in this torsional pendulum experiment!
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#1452
by
Star One
on 21 Apr, 2016 13:17
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Lisa Randall has been pushing the concept of large extra hidden dimensions for some time: http://www.math.columbia.edu/~woit/wordpress/?p=250
However:
The search for hidden dimensions comes up empty again
http://arstechnica.com/science/2016/04/the-search-for-hidden-dimensions-comes-up-empty-again/
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.131101
what is interesting (besides the fact that it is shown that the inverse square law still holds for electrostatic charges to tiny dimensions, and hence the search for extra dimensions came up empty) is that this is shown experimentally using a torsional pendulum with a sensitivity of the order of 10^-17 Nm (that's the torque on the pendulum, the actual force is on the order of 10^-19 N, but torque is what is actually measured). This is about the equivalent to the force of 10,000 water molecules falling onto a surface (a single millilitre of water has over 10^22).
The forces discussed in EM Drive experiments are of the order of microNewtons or greater. A microNewton is 10,000,000,000,000 times (that's a lot of zeros ! ) greater than the 10^-19 Newtons measured in this torsional pendulum experiment!
I don't think that experiment quoted in the arts article is as foolproof or as definitive an answer as you seem to think it is. I'd rather wait for LHC work in the area of extra dimensions to be completed than a swinging pendulum.
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#1453
by
rfmwguy
on 21 Apr, 2016 13:35
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#1454
by
Rodal
on 21 Apr, 2016 13:36
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Lisa Randall has been pushing the concept of large extra hidden dimensions for some time: http://www.math.columbia.edu/~woit/wordpress/?p=250
However:
The search for hidden dimensions comes up empty again
http://arstechnica.com/science/2016/04/the-search-for-hidden-dimensions-comes-up-empty-again/
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.131101
what is interesting (besides the fact that it is shown that the inverse square law still holds for electrostatic charges to tiny dimensions, and hence the search for extra dimensions came up empty) is that this is shown experimentally using a torsional pendulum with a sensitivity of the order of 10^-17 Nm (that's the torque on the pendulum, the actual force is on the order of 10^-19 N, but torque is what is actually measured). This is about the equivalent to the force of 10,000 water molecules falling onto a surface (a single millilitre of water has over 10^22).
The forces discussed in EM Drive experiments are of the order of microNewtons or greater. A microNewton is 10,000,000,000,000 times (that's a lot of zeros ! ) greater than the 10^-19 Newtons measured in this torsional pendulum experiment!
I don't think that experiment quoted in the arts article is as foolproof or as definitive an answer as you seem to think it is. I'd rather wait for LHC work in the area of extra dimensions to be completed than a swinging pendulum.
Contrary to your misreading of my statement, the emphasis (in bold, besides bolding the title of the article) was actually in the accurate sensitivity provided by torsional pendulum experiments and the relevance of torsional pendulum experiments for the EM Drive (instead of teeter-totters, etc.). Gee, I am glad that I bothered to use bold, and even used blue color to highlight "torsional pendulum" and its sensitiivty.
I never stated that the torsional experiment was foolproof or that it provided definite answers concerning the search for extra dimensions.
This is an EM Drive thread: people are using torsional pendulums (NASA, Tajmar, etc.) to make measurements, as well as teeter-totters, scales, linear air bearings, inverted stiff pendulums, etc. Nobody has used LHC measurements to assess the EM Drive anomalous force.
Arguments about fool-proving extra-dimensions per se, unrelated to "EM Drive Developments - related to space flight applications" belong in other threads.
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#1455
by
rfmwguy
on 21 Apr, 2016 13:43
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Doc, speaking of a torsion experiment, have a question for you on my test stand modification...A pendulum torsion simply hangs on a wire, allowing Y axis deflection (though not the desired result). A torsion wire test has a wire connected at top and bottom with the beam mounted centrally (2 points on the beam about 10 inches vertically apart in my case). This configuration seems to make more sense since there will be some thermal lift in the Y axis and it would prevent this.
Your thoughts?
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#1456
by
Rodal
on 21 Apr, 2016 13:45
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Doc, speaking of a torsion experiment, have a question for you on my test stand modification...A pendulum torsion simply hangs on a wire, allowing Y axis deflection (though not the desired result). A torsion wire test has a wire connected at top and bottom with the beam mounted centrally (2 points on the beam about 10 inches vertically apart in my case). This configuration seems to make more sense since there will be some thermal lift in the Y axis and it would prevent this.
Your thoughts?
What is the orientation of the three cartesian axis, please (X, Y and Z). Thanks
(In principle, due to wobbling when hanging something having moments of inertia, you have the possibility of exciting pendulum displacement along all 3 axes, although it is meant to mainly rotate around its hanging axis).
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#1457
by
Star One
on 21 Apr, 2016 14:01
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Lisa Randall has been pushing the concept of large extra hidden dimensions for some time: http://www.math.columbia.edu/~woit/wordpress/?p=250
However:
The search for hidden dimensions comes up empty again
http://arstechnica.com/science/2016/04/the-search-for-hidden-dimensions-comes-up-empty-again/
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.131101
what is interesting (besides the fact that it is shown that the inverse square law still holds for electrostatic charges to tiny dimensions, and hence the search for extra dimensions came up empty) is that this is shown experimentally using a torsional pendulum with a sensitivity of the order of 10^-17 Nm (that's the torque on the pendulum, the actual force is on the order of 10^-19 N, but torque is what is actually measured). This is about the equivalent to the force of 10,000 water molecules falling onto a surface (a single millilitre of water has over 10^22).
The forces discussed in EM Drive experiments are of the order of microNewtons or greater. A microNewton is 10,000,000,000,000 times (that's a lot of zeros ! ) greater than the 10^-19 Newtons measured in this torsional pendulum experiment!
I don't think that experiment quoted in the arts article is as foolproof or as definitive an answer as you seem to think it is. I'd rather wait for LHC work in the area of extra dimensions to be completed than a swinging pendulum.
Contrary to your misreading of my statement, the emphasis (in bold, besides bolding the title of the article) was actually in the accurate sensitivity provided by torsional pendulum experiments and the relevance of torsional pendulum experiments for the EM Drive (instead of teeter-totters, etc.). Gee, I am glad that I bothered to use bold, and even used blue color to highlight "torsional pendulum" and its sensitiivty.
I never stated that the torsional experiment was foolproof or that it provided definite answers concerning the search for extra dimensions.
This is an EM Drive thread: people are using torsional pendulums (NASA, Tajmar, etc.) to make measurements. Nobody has used LHC measurements to assess the EM Drive anomalous force.
Which is not what I was saying in my OP which was talking purely in relation to proving or disapproving extra dimensions. Not about using the LHC to test the EM drive. Therefore, please do not add things I did not say just in an effort to prove some kind of point.
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#1458
by
francesco nicoli
on 21 Apr, 2016 14:28
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sorry for ruining your nice poll but...
you can't "release" a peer reviewed paper as long as the peer review process isn't over. Being it a dialogical process, it can takes months, years. My last peer-reviewed paper is in review (several stages of) sincefebruary 2015. I can't still say when, if ever, it will be published: it depends on the review's outcomes and on the amount of work you have to do to address the reviewers' concerns; there are no means to say it in advance.
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#1459
by
rfmwguy
on 21 Apr, 2016 14:29
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Doc, speaking of a torsion experiment, have a question for you on my test stand modification...A pendulum torsion simply hangs on a wire, allowing Y axis deflection (though not the desired result). A torsion wire test has a wire connected at top and bottom with the beam mounted centrally (2 points on the beam about 10 inches vertically apart in my case). This configuration seems to make more sense since there will be some thermal lift in the Y axis and it would prevent this.
Your thoughts?
What is the orientation of the three cartesian axis, please (X, Y and Z). Thanks
(In principle, due to wobbling when hanging something having moments of inertia, you have the possibility of exciting pendulum displacement along all 3 axes, although it is meant to mainly rotate around its hanging axis).
Can only give you rough estimates since I have not yet completed the emdrive assembly, but assuming 1 = 12 inches:
Bottom beam clamp to wire ~= (0,0)
Top mast clamp to wire ~= (1, 0)
Balance weight center of mass ~= (-3.5, -0.3)
EMDrive center of mass ~= (2, -1)
Torsion wire fixed mount points ~= (2,0) and -2,0)
LDS sensor (Z axis) ~= (3.5, 0)
The wire hasn't been selected yet, need about 15 lbs total weight support (don't know exactly yet). Rather than a torsion estimate, was planning on actual weight displacement calibration for horizontal deflections measured by the laser displacement sensor...40 MM +/- 10 MM range with micrometer level accuracy, so don't want too much Z axis (horizontal) displacement which would push LDS out of range.
My post: 