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#2000 by Tellmeagain on 06 May, 2016 02:31
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The paper said at its footing area: received at:2014-10-09; revision time:2014-12-11。Dr. Rodal, the paper was published in Feb, 2016. It is that we got to know it just a few days ago. It was submitted in Oct, 2014.
Any info on why it took 1 year and 4 months to get published, wasn't it published in the Tuijin Jishu/Journal of Propulsion Technology with a relatively very low impact factor and very low citation index, it should have been easy for her to get published
Research Gate has horrible citation impact factor numbers for this Journal:
https://www.researchgate.net/journal/1001-4055_Tuijin_Jishu_Journal_of_Propulsion_Technology
Tuijin Jishu/Journal of Propulsion Technology
Current impact factor: 0.00
Impact Factor Rankings
Additional details
5-year impact 0.00
Cited half-life 0.00
Immediacy index 0.00
Eigenfactor 0.00
Article influence 0.00
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#2001 by SeeShells on 06 May, 2016 03:03
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To change this perception, the standards that have to be met have been raised: vacuum, batteries and torsional pendulum.[/b]
I am interested in EM Drive Developments - related to space flight applications
I am not interested in "penning a paper for posterity", instead I am interested in what would motivate funding so that we can use this for space flight applications , why the need to motivate funding? because it takes millions of dollars to put something in orbit.
I am interested in any and all propulsion schemes that may make such spaceflights to Mars and beyond a practical reality, the sooner the better. If there are other things better than the EM Drive, I'll be just as happy.
Let's see how did that phrase start out? One small step... Small steps Dr. Rodal, small steps.
Shell -
#2002 by Rodal on 06 May, 2016 03:10
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...
Well that is a death knell to the conspiracy theories: can you imagine, it doesn't make any sense whatsoever to release a paper for Public Relations Disinformation campaign and wait for almost a year and a half for its dissemination. One wouldn't wait a year and a half during a hot war or a cold war to release disinformation to the enemy, if that was the purpose.
The paper said at its footing area: received at:2014-10-09; revision time:2014-12-11。 -
#2003 by birchoff on 06 May, 2016 05:28
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...
(link please? are you referring to the Woodward thread?)
Since we are still waiting for new results here. Why not chime in on the Mach Effect Thread. Between the two new theory papers published towards the end of the year along with descriptions of their experimental setup should prove for some interesting reading
Yes I was referring to the Woodward Effect thread. I have posted links in that thread to Theory of Mach Effect Thruster I and Theory of Mach Effect Thruster II. But you can find those and other papers via Fearn's profile on research gate. There was also a link to a short paper from Woodward tackles the over unity argument made about MET's along with a long discussion about what woodward wrote in his short paper. -
#2004 by Eusa on 06 May, 2016 10:58
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When attached, do your spherical end plates have the common middle point of the curvature?My next build is in progress.
The flat & spherical end plate frustum is being manufactured to very high physical tolerance and polish standard as recommended by Roger Shawyer. It is being machined from a solid block of copper, highly polished, then silver and gold plated. Min sidewall and end plate thickness are 6mm. The frustum can be fitted with either flat or spherical end plates and can operate internally at high vac or be filled with various gases at adjustable pressure as the end plate to flange interface will form a high pressure & high vac rated seal. This frustum will basically look like a bigger Flight Thruster. Not cheap, expected final cost around $7k. I will visit the manufacturer to run tests before acceptance.
The 0.4N/kW rated S band thruster will be driven initially by a wide freq range 100W Rf amp that has the ability to control Rf output power over a 31dB range and provides real time forward & reflected power output. Work is also ongoing to develop an integral smart 250Wrf module that can be installed in multiples on the thruster, if higher than 100mN of reaction force generation is required. Max thruster power should be around 2.5kWrf or 1,000mN of reaction force generation.
Both static and dynamic reaction force generation will be monitored.
When a reaction force generation level of at least 20mN has been achieved and expected rotation of the rotary test table in a high vac has been achieved the data and video will be presented via YouTube.
Following that successful result, a business entity will be formed and potential customers will be invited to view, inspect & do their own tests on our in house test setup as part of their order process.
My next post here will be with the YouTube link and company contact details.
That's a very good price for the Copper machining. I'm sure the shop that quoted that price will be losing money. -
#2005 by sghill on 06 May, 2016 14:35
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May I respectfully suggest it is time for a new thread? With a nice little synopsis of what is going on lately? There has been a lot of cross chatter, and it's been hard to follow progress with all of the opining.
We are about 60% of the way based on customary views of over 400K per thread. As with T6, if Shell is ready to release data, that will kick it off early. Also, my data should hit in a few weeks plus monomorphics. Cannae is the latest per my post today. They are gathering special invite folks to witness testing this month. Plus yang refuted her old tests...no more from nwpu expected. EW remains silent on everything. Phd student offering from dresden specifically on emdrive. TT is going commercial. Shawyer is silent. McCulloughs new paper blends mihsc into a possible theory which includes flyby anomalies. Lot of new info about to break, fasten seat belts. Check into to hd webcast tmro.tv Saturday @ 4 pm cst for more general chat. Its a spaceflight focused weekly, I think with some support from spacex. They had lots of questions on emdrive past 2 weeks. They seem to be fun group but well grounded on technology. Might be their first dip into speculative propulsion. How's that for a brief synopsis?May I respectfully suggest it is time for a new thread? With a nice little synopsis of what is going on lately? There has been a lot of cross chatter, and it's been hard to follow progress with all of the opining.
The main thing that happened is that the scientist that had claimed the highest thrust/Input power (1 Newton per kiloWatt of power), Professor Yang in China, just published a couple of days ago new research that nullifies her previous tests. It shows that her prior EM Drive results were experimental artifacts (these are her own conclusions).
The main difference is that the new tests were performed with batteries powering the EM Drive. It turns out that the use of batteries is critical to prove whether this is real or not. The sensitivity of her tests is such that it may also nullify Shawyer Demonstrator and Boeing Flight Thruster Shawyer tests (who has never reported a single test with batteries or a single test in vacuum or a single test with a torsional pendulum).
NASA results are NOT nullified because NASA uses a different technology than Shawyer and Yang.
Therefore one hope for the EM Drive remains with NASA, who has only reported significant thrust by using polymer inserts inside the EM Drive (which neither Shawyer nor Yang ever did). Hope is that NASA is presently testing with a battery-powered unit in a John Hopkins Cavendish test setup.
There is also hope with Cannae (which has a new test unit meeting all conditions: torsional pendulum, vacuum and batteries, and uses polymer insert for copper and silver cavities) and Hackaday Aachen team in Germany who reports self-assessed-as-good results with battery operated tiny EM Drive in a rotating unit, when using polymer insert like NASA.
These are both superb updates! Thank you both!
I think these two blurbs together would make the beginnings of an excellent little update article for NSF of EMDrive developments (along with an update on worldwide lab and DIY tests).
I'm happy to tackle it with you both if you think there's value. We could go back over to the restricted EMDrive article development thread...
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#2006 by Rodal on 06 May, 2016 14:54
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Hi Dr. Notsosureofit,UPDATE: Looking for a reliable data point for illustration
The first (and only ?) good number I've come across is from: https://forum.nasaspaceflight.com/index.php?topic=39214.10;wap2 (@RODAL and @XRAY)
"Based on this measurement data I've got a look to my calculated frequency for this case and find:
Mode calculated(GHz) Comsol(GHz) measured NASA(GHz)
TE012 2.1653438127 2.1794 2.167138
"
and
"I think that NASA built the truncated cone cavity to within measurement tolerances of +/-0.01” , giving internal dimensions as follows
bigDiameter = (11.00") +/-0.01” ---> total % error = 0.18% = 1/550
smallDiameter = (6.25") +/-0.01”--->total % error = 0.32% = 1/313
axialLength = (9") +/-0.01” ---> total % error = 0.22% = 1/450
Therefore (taking the median total % error = 0.22% = 1/450) the dimensional tolerance of NASA's frustum is such that it is only for a Q<450 that one can hope to be within the resonant bandwidth, given the uncertainty due to dimensions ( 1/450)."
[Excuse my lousy editing]
To show what I'm trying to get at, the "0 entropy change from a cylindrical cavity" frequency should be 2.10575 GHz, 2.7% lower than the measured frequency and outside of the 0.22% error band.
The implication (or what I was hoping to illustrate w/ further data) is that this frustum cavity electromagnetic resonance shows a lower than expected entropy than the usual General Relativistic "constant volume" criteria.
Sorry if this isn't clearer but my time is severely limited at the moment.
QUESTIONS:
1) what is the support for the statement that "0 entropy change from a cylindrical cavity frequency should be 2.10575 GHz, 2.7% lower than the measured frequency". What equation(s) is(are) used to calculate this 2.10575 GHz frequency, which differs by 2.7% from the measured and calculated natural frequencies ?
2) Is the 2.7% difference between the 2.10575 GHz frequency and the measured and calculated natural frequencies for the truncated cone due to the fact that the 2.10575 GHz frequency is calculated for a cylindrical cavity while the actual cavity is instead a truncated cone?
PS: For reference, here are links to posts with data supporting the calculated natural frequencies and the experimental measurements, showing the very high quality of NASA's measurements, that fully support the fact that the experiment by NASA without a polymer insert was indeed in resonance at 2.16 GHz, although the measured anomalous force was insignificant, even at 10 times higher power input than the tests with the polymer insert:
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1469866#msg1469866
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1470390#msg1470390
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1470613#msg1470613
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1473238#msg1473238
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1473323#msg1473323
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1473726#msg1473726
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1473849#msg1473849
(and several other posts between them)
I have not heard from you in a while, I presume you are very busy, but I had a few more thoughts about entropy, photons and Gravitation, and look forward to your expert opinion and feedback.
In a photon gas having the gas concentrated in small regions of space represents low entropy.
In a photon gas having the gas spread uniformly represents high entropy.
In a photon gas the maximum entropy has the gas uniformly spread.
However, with gravity, the opposite occurs
With large gravitating bodies having a system of gravitating bodies spread uniformly represents low entropy.
With large gravitating bodies having a system of gravitating bodies concentrated together represents high entropy.
With large gravitating bodies the maximum entropy is achieved when the mass is concentrated in a black hole.
Unless the velocities of the bodies are enormously high and the bodies are very small (as in photons) so that the gravitational contributions become insignificant (for photons).
Therefore, to resolve this contradiction, using entropy arguments, it seems to me that the entropy states of a photon gas are the opposite of gravitating bodies, and this argues that based on entropy, gravitation should not have significant effects in the EM Drive (unless close to a singularity like the apex of a cone, but the prescription of Shawyer has prevented all EM Drives to get anywhere close to the apex of the cone (*), therefore the apex singularity effect should not be relevant).
___________
(*) Shawyer's prescription forbidding the small diameter of the EM Drive to be smaller than the cut-off wavelength for an open waveguide (when it is well-known that such cut-off condition does not apply to resonant microwave cavities)
(**) Credit for photon gas image: http://universe-review.ca/R15-30-stat.htm#BEQuotePhoton Gas in Cavity - Photon gas is the quantum version of electromagnetic wave when the particle-like behavior is dual to the wave property. It's main difference from the ideal gas is the way in reaching equilibrium. Whereas that state is attained by collisions in the latter case and the number of particle is conserved, the photon gas arrived at equilibrium by interacting with the matter in the cavity wall. The number of photons in a given state is not constant in the absorption and emission processes. However, the total energy remains the same at equilibrium, i.e., the total negative change of the chemical potential is balanced by the positive change.
(***) credit for black hole image: Wikipedia -
#2007 by D_Dom on 06 May, 2016 16:34
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These are both superb updates! Thank you both!
I think these two blurbs together would make the beginnings of an excellent little update article for NSF of EMDrive developments (along with an update on worldwide lab and DIY tests).
I'm happy to tackle it with you both if you think there's value. We could go back over to the restricted EMDrive article development thread...
Took the liberty if mashing together a few highlights which may or may not be a suitable start, hope that is helpful. -
#2008 by SeeShells on 06 May, 2016 17:10
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Maybe there is a light at the end of the tunnel. Interesting reading on the simple photon.
Shell
<Snip>
. Conclusions
Starting from Maxwell’s equations, the origin of an effective mass acquired by photons
propagating in a plasma or a rectangular waveguide has been analysed. We have discussed
how such constrained circumstances give the equations a form equivalent to those for
massive particles propagating in vacuum, with a mass that depends on the parameters of
the environment.
In the case of propagation through a tenuous neutral plasma, owing to the interaction with
the mobile electrons, light behaves as massive particles moving in vacuum with a velocity
lower than c. The acquired mass is proportional to the plasma frequency and for typical values of this parameter it may be as low as a fraction 10−10 of the rest mass of the electron.
https://www.researchgate.net/publication/258272518_Can_there_be_massive_photons_A_pedagogical_glance_at_the_origin_of_mass
AND
The momentum of light in media remains one of the most controversial topics in physics [1–6]. The debate has continued for more than a century since Minkowski and Abraham formulated 4 × 4 energy-momentum tensors in the early 1900s [7–9].
https://www.researchgate.net/publication/292342272_Kinetic-energy-momentum_tensor_in_electrodynamics -
#2009 by Rodal on 06 May, 2016 17:22
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Maybe there is a light at the end of the tunnel. Interesting reading on the simple photon.
Shell
<Snip>
. Conclusions
Starting from Maxwell’s equations, the origin of an effective mass acquired by photons
propagating in a plasma or a rectangular waveguide has been analysed. We have discussed
how such constrained circumstances give the equations a form equivalent to those for
massive particles propagating in vacuum, with a mass that depends on the parameters of
the environment.
In the case of propagation through a tenuous neutral plasma, owing to the interaction with
the mobile electrons, light behaves as massive particles moving in vacuum with a velocity
lower than c. The acquired mass is proportional to the plasma frequency and for typical values of this parameter it may be as low as a fraction 10−10 of the rest mass of the electron.
https://www.researchgate.net/publication/258272518_Can_there_be_massive_photons_A_pedagogical_glance_at_the_origin_of_mass
AND
The momentum of light in media remains one of the most controversial topics in physics [1–6]. The debate has continued for more than a century since Minkowski and Abraham formulated 4 × 4 energy-momentum tensors in the early 1900s [7–9].
https://www.researchgate.net/publication/292342272_Kinetic-energy-momentum_tensor_in_electrodynamics
The reference to Minkowski and Abraham is antithetical, and hence irrelevant to the ideas of anyone that insists in following Shawyer and Yang (who has now nullified her previous results) and have written that they are not interested in polymer inserts and dismiss the importance of the polymer insert in NASA's results.
As is well known, for a vacuum, the Mynkowski and Abraham theories agree 100%. The only difference between Mynkowski and Abraham are for a material very different from vacuum, for example a polymer insert as used by NASA. Thus, I would expect attention to the Abraham and Mynkowski controversy by those that do not dismiss the importance of the polymer insert (-> I don't think you have dismissed NASA's results with a polymer insert, SeeShells, so I hope that you will test following NASA's well detailed prescriptions for the polymer insert )
The Mynkowski and Abraham controversy is irrelevant to an EM Drive (as used by Yang and in Shawyer's Flight Thruster and Demonstrator) that does not use polymer inserts or other material inserts, as one can easily garner from their equations.
For a polymer insert, the Mynkowski and Abraham controversy is very interesting, because the Mynkowski formulation implies a stress-energy tensor that is NOT symmetric, which implies problems for the mass, and therefore implies an open system when using a polymer (or other material) insert. -
#2010 by SeeShells on 06 May, 2016 18:18
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...
Professor Melcher at MIT (and previously Prof. Chu and others at MIT's Radiation Laboratory) was already showing decades ago in MIT classes that the Einstein-Laub formulation of electrodynamics is invalid since it yields a stress-energy-momentum tensor that is not frame invariant. (It is an interesting historical vignette that Einstein did not realize this at the time he wrote the paper with Laub)
The momentum of light in media remains one of the most controversial topics in physics [1–6]. The debate has continued for more than a century since Minkowski and Abraham formulated 4 × 4 energy-momentum tensors in the early 1900s [7–9].
https://www.researchgate.net/publication/292342272_Kinetic-energy-momentum_tensor_in_electrodynamics
They do credit Prof. Chu with the correct invariance relations. But that is one of the reasons why Prof. Chu at MIT developed his formulation.
This was known by students that listened to the lectures of Prof. Chu and Melcher at MIT
Reference: Prof. Melcher's masterpiece "Continuum Electromechanics" which he wrote in 1972-1973 while he was in sabatical at Cambridge University working with Sir Taylor and G. Batchelor
Correct, although The Einstein-Laub formulation of electrodynamics does work in a real world lab. 1973, Ashkin and Dziedzic performed a experiment in which they focused a green laser beam on the surface of water and saw what they called "the toothpaste tube effect" where a bulge appeared in the surface of the water. Using a Lorentz formula the existence of expansive and compressing forces effectively cancel out, negating a possible bump forming on the water surface. The real world lab test showed where pure theoretical extraction detailing out why there are thrusts from a asymmetrical cavity are lacking. . .
This is why lab data is king right now.
Shell
Back to work... will be on later. Have company helping me move my new frame for the lab.
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#2011 by 1 on 06 May, 2016 18:43
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I had a few more thoughts about entropy, photons and Gravitation
A perturbation to your thoughts, as they appear to assume constant particle counts.
If one were to continue to shrink the region containing your photon gas, it would eventually cause enough of a rise in local energy density form a cavity-sized schwarzchild radius. In this instance, your first thought experiment transitions into your second! Suggest that there exists localized minima between the two situations; e.g. a large quantity of mass will try to stabilize as a neutron star until 'forced' into a singularity.
Should also note that the treatment of entropy within a singularity was often avoided and is still very much under theoretical debate; though general consensus agrees with you that singularities must be high-entropy constructs. -
#2012 by Rodal on 06 May, 2016 19:00
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I had a few more thoughts about entropy, photons and Gravitation
A perturbation to your thoughts, as they appear to assume constant particle counts.
If one were to continue to shrink the region containing your photon gas, it would eventually cause enough of a rise in local energy density form a cavity-sized schwarzchild radius. In this instance, your first thought experiment transitions into your second! Suggest that there exists localized minima between the two situations; e.g. a large quantity of mass will try to stabilize as a neutron star until 'forced' into a singularity.
Should also note that the treatment of entropy within a singularity was often avoided and is still very much under theoretical debate; though general consensus agrees with you that singularities must be high-entropy constructs.
As I said, however Shawyer's prescription (which has been followed so far by EM Drive experimenters) forbids that from happening. The rise in local energy density has been analyzed by Dr. Frasca (StrongGR) in these pages and his paper: it takes place near the apex of the cone. EM Drive experimenters truncate the cone far from the apex, hence their constructions don't allow that to happen. That is due to Shawyer's constraint on the small diameter. -
#2013 by SeeShells on 06 May, 2016 19:01
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I will not disagree, you reinforced what I was saying....
Professor Melcher at MIT (and previously Prof. Chu and others at MIT's Radiation Laboratory) was already showing decades ago in MIT classes that the Einstein-Laub formulation of electrodynamics is invalid since it yields a stress-energy-momentum tensor that is not frame invariant. (It is an interesting historical vignette that Einstein did not realize this at the time he wrote the paper with Laub)
The momentum of light in media remains one of the most controversial topics in physics [1–6]. The debate has continued for more than a century since Minkowski and Abraham formulated 4 × 4 energy-momentum tensors in the early 1900s [7–9].
https://www.researchgate.net/publication/292342272_Kinetic-energy-momentum_tensor_in_electrodynamics
They do credit Prof. Chu with the correct invariance relations. But that is one of the reasons why Prof. Chu at MIT developed his formulation.
This was known by students that listened to the lectures of Prof. Chu and Melcher at MIT
Reference: Prof. Melcher's masterpiece "Continuum Electromechanics" which he wrote in 1972-1973 while he was in sabatical at Cambridge University working with Sir Taylor and G. Batchelor
Correct, although The Einstein-Laub formulation of electrodynamics does work in a real world lab. 1973, Ashkin and Dziedzic performed a experiment in which they focused a green laser beam on the surface of water and saw what they called "the toothpaste tube effect" where a bulge appeared in the surface of the water. Using a Lorentz formula the existence of expansive and compressing forces effectively cancel out, negating a possible bump forming on the water surface. The real world lab test showed where pure theoretical extraction detailing out why there are thrusts from a asymmetrical cavity are lacking. . .
This is why lab data is king right now.
Shell
Back to work... will be on later. Have company helping me move my new frame for the lab.
The Chu formulation is not some theoretical stuff that sprung out without experiments. The opposite is the case, the Chu formulation sprung from very practical work at MIT's Radiation Laboratory, with many experiments that resulted in real world (Defense Department) applications. Lab data was king for Chu's formulation and its many applications.
Found where I read about the 1973 green laser experiment.
https://arxiv.org/ftp/arxiv/papers/1312/1312.3262.pdf
My Best,
Shell -
#2014 by Rodal on 06 May, 2016 19:07
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..
Also note that the Einstein-Laub formulation is irrelevant for any EM Drive that anyone may test that does not contain a polymer (or other material) insert. Without a material inserted in the cavity, it is the same as Chu's, Abraham's and Mynkowski's formulations: they are all the same. One does not need any lab data to verify that, the same way that one does not need lab data to verify 1+1=2, all these formulations become the same unless one has a material insert that has significantly different properties from a vacuum.
I will not disagree, you reinforced what I was saying.
Found where I read about the 1973 green laser experiment.
https://arxiv.org/ftp/arxiv/papers/1312/1312.3262.pdf
My Best,
Shell
Please notice the reference you are citing:Quote from: https://arxiv.org/ftp/arxiv/papers/1312/1312.3262.pdfIn 1973, Ashkin and Dziedzic performed a remarkable experiment in which they focused a green laser beam (λo=0.53μm) onto the surface of pure water
The diference occurs because of the water, which has very different properties from vacuum.
Relative electric permittivty:
Vacuum 1
Air ~ 1
Water 85
The important thing in all this is that the Abraham-Mynkowski controversy, and the Einstein-Laub and the Chu formulations are all irrelevant for any tests without a polymer (or other material) insert in the EM Drive.
QUESTION: SeeShells, have you been using a polymer insert, liquids, inorganics, etc., in your EM Drive tests? what material insert are you using as an insert in your tests? -
#2015 by X_RaY on 06 May, 2016 19:20
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The cutoff diameter of an open waveguide does not take place in in a truncated cone in the same manner / in the way as in a open waveguide(As shown in your paper). As shown by the feko simulations of Monomorphic (for TE01p) the position of highest energy density depends on the actual mode. The order of a mode (in this case the p value) and therefore the frequency must be huge to take place very close to the singularity of the apex(and infinite AT the apex/ ħ?).I had a few more thoughts about entropy, photons and Gravitation
A perturbation to your thoughts, as they appear to assume constant particle counts.
If one were to continue to shrink the region containing your photon gas, it would eventually cause enough of a rise in local energy density form a cavity-sized schwarzchild radius. In this instance, your first thought experiment transitions into your second! Suggest that there exists localized minima between the two situations; e.g. a large quantity of mass will try to stabilize as a neutron star until 'forced' into a singularity.
Should also note that the treatment of entropy within a singularity was often avoided and is still very much under theoretical debate; though general consensus agrees with you that singularities must be high-entropy constructs.
As I said, however Shawyer's prescription (which has been followed so far by EM Drive experimenters) forbids that from happening. The rise in local energy density has been analyzed by Dr. Frasca (StrongGR) in these pages and his paper: it takes place near the apex of the cone. EM Drive experimenters truncate the cone far from the apex, hence their constructions don't allow that to happen. That is due to Shawyer's bizarre constraint on the small diameter.
Even it's a spitz cone the actual em mode predicts the position of the highest energy density.
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#2016 by Rodal on 06 May, 2016 19:38
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The cutoff diameter for an open waveguide does not take place in in a truncated cone in the same manner / in the way as in a open waveguide(As shown in your paper). As shown by the feko simulations of Monomorphic (for TE01p) the position of highest energy density depends on the actual mode. The order of a mode (in this case the p value) and therefore the frequency must be huge to take place very close to the singularity of the apex.I had a few more thoughts about entropy, photons and Gravitation
A perturbation to your thoughts, as they appear to assume constant particle counts.
If one were to continue to shrink the region containing your photon gas, it would eventually cause enough of a rise in local energy density form a cavity-sized schwarzchild radius. In this instance, your first thought experiment transitions into your second! Suggest that there exists localized minima between the two situations; e.g. a large quantity of mass will try to stabilize as a neutron star until 'forced' into a singularity.
Should also note that the treatment of entropy within a singularity was often avoided and is still very much under theoretical debate; though general consensus agrees with you that singularities must be high-entropy constructs.
As I said, however Shawyer's prescription (which has been followed so far by EM Drive experimenters) forbids that from happening. The rise in local energy density has been analyzed by Dr. Frasca (StrongGR) in these pages and his paper: it takes place near the apex of the cone. EM Drive experimenters truncate the cone far from the apex, hence their constructions don't allow that to happen. That is due to Shawyer's bizarre constraint on the small diameter.
Even it's a spitz cone the actual em mode predicts the position of the highest energy density.
Thank you for reminding me of my report.
After all this time, I can see that when extending the truncated cone beyond the cut-off diameter, there are diminishing returns as to further push the energy density maximum towards the small end.
So, Shawyer's prescription can be interpreted as his way to make sense (since Shawyer probably did not deal with/understand the tensor formulations leading to the importance of energy density, so he explained this in his terms using waveguides) of the following:
the best EM Drive design is the one where the energy density is located closest to the small end, and a maximum smooth gradient is established for the energy density from one end to the other
*truncated cones that extend much beyond the cut-off end up (see my report) with an energy density located away from the small end
*very high order modes with "p" very high end up with a large portion of wasted mass where the energy density is not changing much (from the big end to the middle)
NOTE: Need a theory for "thrust" to justify this, that relies on energy density, for example Dr. White's QV theory, or Prof. Woodward's theory
Pictures of TE012 and TE013 close to cut-off (credit: the great Monomorphic )
Picture of TE013 in a cavity a little beyond cut-off (from Greg Egan):
Attachment: TE013 with small diameter way beyond cut-off: observe how energy density (here I am showing the Poynting vector field, but the energy density is also located there) stays away from end, the energy density cannot be pushed towards the small end, much beyond cut-off
We finally make some sense of Shawyer's prescription
!!!!!!
Reference: my post http://forum.nasaspaceflight.com/index.php?topic=39214.msg1526577#msg1526577
showing in detail the importance of the energy density (and in particular the magnetic energy density) for the stress in the EM Drive
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#2017 by SeeShells on 06 May, 2016 20:04
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Yes I have Dr. Rodal...
Also note that the Einstein-Laub formulation is irrelevant for any EM Drive that anyone may test that does not contain a polymer (or other material) insert. Without a material inserted in the cavity, it is the same as Chu's, Abraham's and Mynkowski's formulations: they are all the same. One does not need any lab data to verify that, the same way that one does not need lab data to verify 1+1=2, all these formulations become the same unless one has a material insert that has significantly different properties from a vacuum.
I will not disagree, you reinforced what I was saying.
Found where I read about the 1973 green laser experiment.
https://arxiv.org/ftp/arxiv/papers/1312/1312.3262.pdf
My Best,
Shell
Please notice the reference you are citing:
QUESTION: SeeShells, have you been using a polymer insert, liquids, inorganics, etc., in your EM Drive tests? what material insert are you using as an insert in your tests?
Not finished with the testing and not ready to let go of the secret sauce(s) yet
. Know I'm evaluating more than one insert at a time and a layering scheme which takes into account both the Mach Effect of Dr. Woodward and the QV VP of Dr. White and my own... with interesting results. Also since each component insert changes the resonate frequencies I've had to be creative in the tune-ability of the frustums. My funding hasn't allowed for me to go with the extra hardware in a variable sweep high power microwave generator.
I was doing this before you started talking about inserts....
Shell
PS: Sometimes it feels like finding the right filament for my light.
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#2018 by SeeShells on 06 May, 2016 20:18
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I mean recently you've been chatting about it....
I have been talking about inserts since EM Drive thread 1. We are now in thread 7. Main credit for immediately recognizing its significance go to 1) Paul March (first and foremost). Among NSF Members, credit goes to Mulletron.
I was doing this before you started talking about inserts....
Shell
When I joined NSF almost a year ago Mulletron and I were chatting about inserts. No taking anything away from Paul or Multron of NSF or Dr. Woodward or Dr. White or even you.
Shell
Added: No-one to my knowalage has tried multiple layered inserts. -
#2019 by Rodal on 06 May, 2016 20:59
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Interesting how things change, it feels like yesterday when others were arguing that inserts or other materials were not needed, that Shawyer said they were not needed, that Yang didn't use them.
That NASA now did not considered them useful (wrong ).
Having to prove in a separate thread (to make sure it did not get deleted: http://forum.nasaspaceflight.com/index.php?topic=39214.msg1470390#msg1470390) that NASA's test without a polymer, that resulted in no significant thrust , even when using 10 times higher power, did indeed resonate at the correct frequency, with a good quality of resonance Q.
That "dielectrics lower Q", that "they unnecessarily take real-estate", that "don't know what material or dimensions to use" (although Paul March specified the materials and dimensions very specifically while Shawyer and Yang never fully specified even the dimensions of their EM Drive).
Good , that's progress
!!!!!!
. Know I'm evaluating more than one insert at a time and a layering scheme which takes into account both the Mach Effect of Dr. Woodward and the QV VP of Dr. White and my own... with interesting results. Also since each component insert changes the resonate frequencies I've had to be creative in the tune-ability of the frustums. My funding hasn't allowed for me to go with the extra hardware in a variable sweep high power microwave generator.