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#1600
by
RERT
on 04 Sep, 2015 09:38
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Aero -
The Q value for rfmwguy's mesh frustrum seems to be of interest at the moment.
It was a while back, but if I recall correctly, you said that creating a MEEP control file for a mesh frustrum would be way too much effort.
It occurred to me yesterday that I may be able to compute and output a complex file using Excel if I knew the syntax required and it was reasonably tractable (and I could compute the position data for the holes!). Doubtless there are other ways, but this is one I'm familiar with.
I know the Q values from MEEP are somewhat controversial, but with the correct control files we might see how MEEP thinks Q would change when holes are added.
Anyway, I'm volunteering to help if this is something you want to have a look at.
R.
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#1601
by
Prunesquallor
on 04 Sep, 2015 09:39
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Everyone read this? From Eagle Works
http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Yes, this paper was pre-announced by Paul March (who is one of the co-authors) pre-publication, who also shared it at publication time (as a NASA report), and discussed in previous threads with Paul March and others in the forum 
I see that it has now been published in:
Journal of Modern Physics, 2015, 6, 1308-1320
One of the main purposes is to discuss Dr. White's hypothesis that there are different sub-levels to the Quantum Vacuum, and hence formally address the objection from some people that if the QV is the zero-point energy (as originally postulated by Einstein) then one should not be able to extract any energy from it. The paper intends to address the issue of inmutability and undegredability of the QV. In Dr. White's hypothesis the QV needs to be mutable and degradable if his explanation for EM Drive thrust is to hold.
**************************************************
This is an open access peer-reviewed journal that has a
Google h5-index=13 h5-median =19
https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=phy
(https://scholar.google.com/citations?hl=en&view_op=search_venues&vq=Journal+of+Modern+Physics)
Got to give them credit they are definitely trying to chip away at the QV immutability.
Thanks for the reply, I had not seen it.
Shell
Those comparisons toward the end between the pressure waves in a ringing basketball and the hydrogen electron orbitals are...quite interesting.
I'm not quite sure if I follow what he is trying to say and I think I see it but I want to read it again. I do know new evidence is showing that the QV isn't as non-mutable as it was once seemed and can be something lower than zero.
(warning Clickbait) http://phys.org/news/2015-08-scientists-particle.html
I think the point is that wave-like behavior of the quantum vacuum could potentially explain things in the quantum world just as well as blind adherence to Schroedinger's equation. And therefore could also give the EM-Drive something to "push against". It's basically the Copenhagen vs the deBroglie-Bohm interpretations.
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#1602
by
graybeardsyseng
on 04 Sep, 2015 11:36
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I finally finished the loop antenna modeling exercise. Not sure if this is still useful but I will post here. Likely the patterns are the most useful part - as they should give some idea of what modes can be stimulated.
These models and results are made using a version of the NEC codes (specifically EZNEC). NEC antenna modeling is not perfect but if you stay within the constraints it can produce qualitatively useful results. As with all such models, quantitative results are highly dependent on many factors including geometry, signal quality, and many more. Hopefully these will be of use - particularly if the loops are in a spherical chicken in a vacuum.
I modeled three sizes of antenna 1/2, 1, and 2 wavelength circumference, at three different heights - 1/4, 1/2 and 1 wavelength. Also modeled each of these configurations for loops both parallel to and normal to their ground plane.
Sorry for how long this took - as some of you know I have been in the process of retiring and unfortunately this exercise mostly had to take place late in evening after all other boring but necessary stuff had been done. I am now free and hope to start detailed planning for my own DIY experiments soon.
Herman
Herman,
Here's a 4NEC2 file of a small loop, I ran cases for .36 inch dia and am posting the NASA 0.55 inch loop. They serve as an approximate starting point in free space, in a cavity the impedance will be reduced by the mirroring of the walls. Impedance is 133-j60 and SWR 3.28. You will have to rename the NEC file, replace dot with a period and delete txt. The images are bmp files, replace dot with a period and remove txt.
Cee - THANKS! I will get to converting these and running ASAP - hopefully today or tomorrow. This saves a bunch of time.
Herman
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#1603
by
SeeShells
on 04 Sep, 2015 12:50
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Everyone read this? From Eagle Works
http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Yes, this paper was pre-announced by Paul March (who is one of the co-authors) pre-publication, who also shared it at publication time (as a NASA report), and discussed in previous threads with Paul March and others in the forum
I see that it has now been published in:
Journal of Modern Physics, 2015, 6, 1308-1320
One of the main purposes is to discuss Dr. White's hypothesis that there are different sub-levels to the Quantum Vacuum, and hence formally address the objection from some people that if the QV is the zero-point energy (as originally postulated by Einstein) then one should not be able to extract any energy from it. The paper intends to address the issue of inmutability and undegredability of the QV. In Dr. White's hypothesis the QV needs to be mutable and degradable if his explanation for EM Drive thrust is to hold.
**************************************************
This is an open access peer-reviewed journal that has a
Google h5-index=13 h5-median =19
https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=phy
(https://scholar.google.com/citations?hl=en&view_op=search_venues&vq=Journal+of+Modern+Physics)
Got to give them credit they are definitely trying to chip away at the QV immutability.
Thanks for the reply, I had not seen it.
Shell
Those comparisons toward the end between the pressure waves in a ringing basketball and the hydrogen electron orbitals are...quite interesting.
I'm not quite sure if I follow what he is trying to say and I think I see it but I want to read it again. I do know new evidence is showing that the QV isn't as non-mutable as it was once seemed and can be something lower than zero.
(warning Clickbait) http://phys.org/news/2015-08-scientists-particle.html
I think the point is that wave-like behavior of the quantum vacuum could potentially explain things in the quantum world just as well as blind adherence to Schroedinger's equation. And therefore could also give the EM-Drive something to "push against". It's basically the Copenhagen vs the deBroglie-Bohm interpretations.
You know what they say? Don't piss off the cat.
As simple as make a bump in the QV and push against it, somehow it seems too simple and in other ways not so much. I wish I had more hardcore data to attach to it.
Shell
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#1604
by
Rodal
on 04 Sep, 2015 14:37
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Prof. Dr. James Woodward, it is my understanding, is of the opinion that the only way that any propulsion out of the EM Drive could be justified using his Machian theory is if the EM Drive contains a dielectric insert as used by NASA in their experiments.
Therefore, the experiments performed by RFMWGUY, as well as the latest experiments and designs of Shaywer, and the experiments of Yang and Tajmar, for example cannot result in space propulsion according to Prof. Woodward's theory since all these experiments do not include any dielectric insert. Prof. Woodward, as I understand it, maintains that an EM Drive tested without a dielectric insert cannot obtain any thrust whatsoever for space propulsion because such thrust is precluded by what Prof. Woodward calls "THE LAW" in capital letters: the law of conservation of momentum. You are welcome to contact Prof. Woodward to find out whether my understanding is up to date (and if so, whether your understanding of his theory is being properly applied to an EM Drive without any dielectric insert).
The principle explored by Dr Woodward to induce Machian mass fluctuation must be distinguished from his particular engineering implementation which uses dielectric capacity to put the highest possible energy on accelerated matter. Woodward could well have used magnetic energy put in high permeability material. Moreover Woodward does not exclude the use of polarizable vacuum to play with this Machian mass fluctuation as he explains it in the following excerpt of his article "RAPID SPACETIME TRANSPORT AND MACHIAN MASS FLUCTUATIONS: THEORY AND EXPERIMENT "
"Should the relative phase of the mass fluctuation and the magnetic part of the Lorentz force be auspicious, a stationary force should result. But such a force, if present, is a result of the mass fluctuation that arises from the inertial coupling of the constituents of the dielectric to the rest of the universe. It is not due to a local violation of the conservation of momentum in a purely electrodynamical system. It is worth remarking that a stationary force in a system of this sort may be expected even if the “substance” between the plates of the capacitor is the vacuum. If the charged particle pair production in the vacuum of quantum lore actually takes place, the pairs should experience the same effects as material dielectric media. So exploration of this sort of arrangement of circuit elements has scientific value (as a test of the “polarizable vacuum” conjecture), as well as potential technological implications."
The importance of harmonics generation is outlined in this other excerpt of the same article :
" For example, generation of the effect seems to depend quite critically on the production of higher harmonics in the PZT stacks, for sinking a lot of power into a stack at a mechanical resonance of the stack is not, itself, sufficient to yield an effect. "
I give in the attachment the article of Woodward I refer to.
Prof. Woodward, has been familiar with Shawyer's EM Drive for several years, as well as familiar with NASA Eagleworks experiments. You are welcome to contact Prof. Woodward directly and verify Prof. Woodward's opinion, on whether he agrees with you that Woodward's theory can be used to justify any thrust as a means of space propulsion from Shawyer's closed cavity EM Drive
without a dielectric insert:
http://physics.fullerton.edu/component/zoo/item/dr-james-f-woodwardTo the extent that your interpretation of Woodward's theory differs from Woodward's conclusions regarding the ability of Shawyer's EM Drive
without a dielectric insert, then the theory becomes your theory and not Woodward's theory. To the extent that your interpretation of Woodward's theory differs from Woodward's, it may be interesting to discuss in this thread: will you change Woodward's opinion regarding Shawyer's EM Drive
without a dielectric insert? will Woodward change your opinion?
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#1605
by
Gravity
on 04 Sep, 2015 15:00
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#1606
by
Rodal
on 04 Sep, 2015 15:07
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hello everybody!
do you know this work of Chris Hardeman in 2001 with microwaves
http://jnaudin.free.fr/html/gravshld.htm
best regards
The experiment is performed in a garage and not in a vacuum. As discussed numerous times in this thread and lately regarding RFMWGUY's experiments, magnetrons get hot and therefore produce lifting thermal currents due to natural convection. Any such test should either be conducted in a vacuum or otherwise the thermal lifting forces should be properly accounted for and not ignored when claiming "lifting effects".
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#1607
by
cee
on 04 Sep, 2015 15:52
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hello everybody!
do you know this work of Chris Hardeman in 2001 with microwaves
http://jnaudin.free.fr/html/gravshld.htm
best regards
Don't know about antigravity but sure admire the shop mechanics and workmanship. The wave generator appears to be a modified waveguide log spiral cavity that transitions the TE10 to a three way TE11 circular splitter that feeds three paralleled spherical resonators. A modeler's nightmare in any EM sim. Amazing what can be done with fiberglass,sheet metal and aluminum foil, wonder how much more copper would have cost.
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#1608
by
aero
on 04 Sep, 2015 16:10
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Aero -
The Q value for rfmwguy's mesh frustrum seems to be of interest at the moment.
It was a while back, but if I recall correctly, you said that creating a MEEP control file for a mesh frustrum would be way too much effort.
It occurred to me yesterday that I may be able to compute and output a complex file using Excel if I knew the syntax required and it was reasonably tractable (and I could compute the position data for the holes!). Doubtless there are other ways, but this is one I'm familiar with.
I know the Q values from MEEP are somewhat controversial, but with the correct control files we might see how MEEP thinks Q would change when holes are added.
Anyway, I'm volunteering to help if this is something you want to have a look at.
R.
That's a generous offer but I'm not sure how it could work. The syntax for meep geometry is here:
http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#geometric-objectAs you can see, meep expects input geometry to be defined in the Scheme programming language. (Python and C++ interfaces are also available, but not on my system)
You can also load data into meep that has been saved in HDF5 format but that requires identical dimensions to the meep lattice and, well basically, the data file to have been generated by a prior meep run. Meep does not deal well with anything that is different than what it expects.
I think it would be more productive to learn to code control file geometry in Scheme. You could use the control file from the emdrive wiki and focus on coding the mesh into the existing geometry.
aero
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#1609
by
Rodal
on 04 Sep, 2015 16:20
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hello everybody!
do you know this work of Chris Hardeman in 2001 with microwaves
http://jnaudin.free.fr/html/gravshld.htm
best regards
Don't know about antigravity but sure admire the shop mechanics and workmanship. The wave generator appears to be a modified waveguide log spiral cavity that transitions the TE10 to a three way TE11 circular splitter that feeds three paralleled spherical resonators. A modeler's nightmare in any EM sim. Amazing what can be done with fiberglass,sheet metal and aluminum foil, wonder how much more copper would have cost.
I also note that while the author of the experiment wrote:
Buoyancy and thermal interference's can be ruled out as the cause of the effects as the device never gets hot.
He did not report measurements of the magnetron's temperature, unlike RFMWGUY who carefully measured and reported the magnetron's temperature.
Furthermore I note that none of the links to the author in
http://nexusilluminati.blogspot.com/2011/11/gravity-shielding-experiment.html are still active. All these links are no longer active:
http://users.icnet.net/~chrish/Post_tests.htmetc.
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#1610
by
aero
on 04 Sep, 2015 16:51
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Would someone please make a movie of this loop antenna?
https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharingThe drive frequency is 2.47 GHz, loop circumference is 1 wave length and the run is for 3 cycles with 20 png's output per cycle.
It looks good to me. That doesn't mean that it will do what we expect but it is a start.
Now, if SeeShells will only tell me, in English, what it is that she is measuring with 1/4, 1/2 and 1/3 wavelength then I would make some test runs.
But I think I will go this way.
All DYI'ers. Acceptable loop antenna specification is "circumference of the loop" in wave lengths of the drive center frequency. The drive center frequency must also be specified. The x, y and z coordinate location of the center of the loop must also be specified in wavelengths and referenced to either the 0, 0, 0 point at the mid-point of the axis of rotation of the cavity, or to one or the other of the inside face of the big or small end and the side wall.
This requirement for sound specification also holds for dipole and stub antennas, just substitute length for circumference and dipole or stub for loop and add axial or lateral orientation.
Again, all dimensions must be specified in wave lengths, or a fraction of, or a rational fraction of wavelengths. OK - This specification requirement to use wavelength is NULL AND VOID. Use meters instead. See my post on page 84. Problem is that wavelength changes with frequency, so the geometry changes and like a dog chasing his tail, that doesn't work when making resonance runs to find the frequency of resonance.
The loop can be tipped off horizontal up to 90 degrees rotation about the y axis. Tipping the loop about the x axis is not implemented.
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#1611
by
VAXHeadroom
on 04 Sep, 2015 16:55
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#1612
by
X_RaY
on 04 Sep, 2015 17:04
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Would someone please make a movie of this loop antenna?
https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing
The drive frequency is 2.47 GHz, loop circumference is 1 wave length and the run is for 3 cycles with 20 png's output per cycle.
It looks good to me. That doesn't mean that it will do what we expect but it is a start.
Now, if SeeShells will only tell me, in English, what it is that she is measuring with 1/4, 1/2 and 1/3 wavelength then I would make some test runs.
But I think I will go this way.
All DYI'ers. Acceptable loop antenna specification is "circumference of the loop" in wave lengths of the drive center frequency. The drive center frequency must also be specified. The x, y and z coordinate location of the center of the loop must also be specified in wavelengths and referenced to either the 0, 0, 0 point at the mid-point of the axis of rotation of the cavity, or to one or the other of the inside face of the big or small end and the side wall.
This requirement for sound specification also holds for dipole and stub antennas, just substitute length for circumference and dipole or stub for loop and add axial or lateral orientation.
Again, all dimensions must be specified in wave lengths, or a fraction of, or a rational fraction of wavelengths.
The loop can be tipped off horizontal up to 90 degrees rotation about the y axis. Tipping the loop about the x axis is not implemented.
Whatever you have changed this looks much more natural than the last try.
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#1613
by
SteveD
on 04 Sep, 2015 17:10
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Stupid question but, is there anything in a magnetron housing that might provide some current to the magnetron from a themoelectric effect after power off?
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#1614
by
SeeShells
on 04 Sep, 2015 17:14
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I'll do a detailed spec after I get back from an errand.
Shell
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#1615
by
X_RaY
on 04 Sep, 2015 18:07
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Would someone please make a movie of this loop antenna?
https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing
The drive frequency is 2.47 GHz, loop circumference is 1 wave length and the run is for 3 cycles with 20 png's output per cycle.
It looks good to me. That doesn't mean that it will do what we expect but it is a start.
Now, if SeeShells will only tell me, in English, what it is that she is measuring with 1/4, 1/2 and 1/3 wavelength then I would make some test runs.
But I think I will go this way.
All DYI'ers. Acceptable loop antenna specification is "circumference of the loop" in wave lengths of the drive center frequency. The drive center frequency must also be specified. The x, y and z coordinate location of the center of the loop must also be specified in wavelengths and referenced to either the 0, 0, 0 point at the mid-point of the axis of rotation of the cavity, or to one or the other of the inside face of the big or small end and the side wall.
This requirement for sound specification also holds for dipole and stub antennas, just substitute length for circumference and dipole or stub for loop and add axial or lateral orientation.
Again, all dimensions must be specified in wave lengths, or a fraction of, or a rational fraction of wavelengths.
The loop can be tipped off horizontal up to 90 degrees rotation about the y axis. Tipping the loop about the x axis is not implemented.
Whatever you have changed this looks much more natural than the last try.
@aero
Can you try either a run with the same frequency but 2 times the actual circumference, or two times the frequency of the last run?
The background is that in such a test there has to be two more nodes along the circumference. That would be a simple way to test your code.
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#1616
by
aero
on 04 Sep, 2015 19:26
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... snip ...
Whatever you have changed this looks much more natural than the last try.
@aero
Can you try either a run with the same frequency but 2 times the actual circumference, or two times the frequency of the last run?
The background is that in such a test there has to be two more nodes along the circumference. That would be a simple way to test your code.
Yes, I made that run - see attached. I did run it with circumference of 3 wave lengths also but I neglected to save that data set. It looked right though with 6 nodes along the circumference.
These are point sources distributed around in a loop and turned on in sequence synchronized with meep-time. Sequencing the turn-on, as lmbfan pointed out, maintains the phasing around the loop. Thanks lmbfan. So I don't need to fool with manually phasing the source with amplitude. It is much less complex.
It seems that meep will not do a dipole source at arbitrary angles to the primary axis so I'm forced to use point sources. There are no sequenced dipoles, and seemingly no support in meep for that except parallel to primary axis.
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#1617
by
flux_capacitor
on 04 Sep, 2015 19:33
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Prof. Dr. James Woodward, it is my understanding, is of the opinion that the only way that any propulsion out of the EM Drive could be justified using his Machian theory is if the EM Drive contains a dielectric insert as used by NASA in their experiments.
Therefore, the experiments performed by RFMWGUY, as well as the latest experiments and designs of Shaywer, and the experiments of Yang and Tajmar, for example cannot result in space propulsion according to Prof. Woodward's theory since all these experiments do not include any dielectric insert. Prof. Woodward, as I understand it, maintains that an EM Drive tested without a dielectric insert cannot obtain any thrust whatsoever for space propulsion because such thrust is precluded by what Prof. Woodward calls "THE LAW" in capital letters: the law of conservation of momentum. You are welcome to contact Prof. Woodward to find out whether my understanding is up to date (and if so, whether your understanding of his theory is being properly applied to an EM Drive without any dielectric insert).
The principle explored by Dr Woodward to induce Machian mass fluctuation must be distinguished from his particular engineering implementation which uses dielectric capacity to put the highest possible energy on accelerated matter. Woodward could well have used magnetic energy put in high permeability material. Moreover Woodward does not exclude the use of polarizable vacuum to play with this Machian mass fluctuation as he explains it in the following excerpt of his article "RAPID SPACETIME TRANSPORT AND MACHIAN MASS FLUCTUATIONS: THEORY AND EXPERIMENT "
"Should the relative phase of the mass fluctuation and the magnetic part of the Lorentz force be auspicious, a stationary force should result. But such a force, if present, is a result of the mass fluctuation that arises from the inertial coupling of the constituents of the dielectric to the rest of the universe. It is not due to a local violation of the conservation of momentum in a purely electrodynamical system. It is worth remarking that a stationary force in a system of this sort may be expected even if the “substance” between the plates of the capacitor is the vacuum. If the charged particle pair production in the vacuum of quantum lore actually takes place, the pairs should experience the same effects as material dielectric media. So exploration of this sort of arrangement of circuit elements has scientific value (as a test of the “polarizable vacuum” conjecture), as well as potential technological implications."
The importance of harmonics generation is outlined in this other excerpt of the same article :
" For example, generation of the effect seems to depend quite critically on the production of higher harmonics in the PZT stacks, for sinking a lot of power into a stack at a mechanical resonance of the stack is not, itself, sufficient to yield an effect. "
I give in the attachment the article of Woodward I refer to.
The text by Woodward you refer to was cowritten with Paul March:
Woodward, James F.; Mahood, Thomas L.; March, Paul (July 2001).
"Rapid Spacetime Transport and Machian Mass Fluctuations: Theory and Experiment".
JPC 2001 Proceedings. 37th AIAA/ASME Joint Propulsion Conference, Salt Lake City, Utah. American Institute of Aeronautics and Astronautics. doi:10.2514/6.2001-3907
Most importantly, it was written in
2001, while Puthof's Polarizable Vacuum theory was only a few months old. Nowadays Woodward does not think PV is realistic anymore, nor any ZPF theory (including McCulloch's MiHsC or White's QVF conjecture) to explain Mach effects. He is very clear about that when asked on that matter.
Woodward is even currently writing a paper demonstrating why virtual particles of the vacuum can
not be used for propulsion.
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#1618
by
X_RaY
on 04 Sep, 2015 19:53
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... snip ...
Whatever you have changed this looks much more natural than the last try.
@aero
Can you try either a run with the same frequency but 2 times the actual circumference, or two times the frequency of the last run?
The background is that in such a test there has to be two more nodes along the circumference. That would be a simple way to test your code.
Yes, I made that run - see attached. I did run it with circumference of 3 wave lengths also but I neglected to save that data set. It looked right though with 6 nodes along the circumference.
These are point sources distributed around in a loop and turned on in sequence synchronized with meep-time. Sequencing the turn-on, as lmbfan pointed out, maintains the phasing around the loop. Thanks lmbfan. So I don't need to fool with manually phasing the source with amplitude. It is much less complex.
It seems that meep will not do a dipole source at arbitrary angles to the primary axis so I'm forced to use point sources. There are no sequenced dipoles, and seemingly no support in meep for that except parallel to primary axis.
Go on this way, it looks right
The smaller antenna with lambda/4 for Shell will excite the TE012 for sure if you place it symmetrically around the middle axis. Dont ask me at what hight/ distance to the end plate ( ~Lambda/4 could work?*). The loop will be verry small but first don't worry about that (Rodal pointed this out some pages ago...).
Good luck for your next runs!
* Why lambda/4 ? : The wave will travel that way(90°) to the plate, than while the reflection the wave undergoes and shifts 180°, after that the wave travels back in the antenna direction(90°).
All that together gives one full wavelength and there will be constructive interference at the antenna location in the direction to the other plate.
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#1619
by
aero
on 04 Sep, 2015 20:12
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The smaller antenna
Are you referring to the antenna with circumference of 1 wavelength?
