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#1600 by rfmwguy on 25 Apr, 2016 14:36
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Hackaday tiny EM Drive V. 4 with ABS polymer insert shows test with cavity reversed ( the cavity is turned in the opposite direction.).. but know what?
Perhaps a note to them would be in order as well as sending them the Insert...builders do appreciate donations of materials, etc. That way they won't have to scour the internet for the right piece. You'd need their small diameter dimensions, tho.
It shows reverse direction
Aachen team writes: "test looking good" with ABS polymer insert
results appear better than without polymer insert
https://hackaday.io/project/5596-em-drive/log/36758-test-with-dielectric-cavity-reversed
Hope that they eventually try:
1) polymer insert at small end instead of big end
2) semi-crystalline HDPE extruded insert instead of amorphous spaghetti 3D printed ABS
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#1601 by Rodal on 25 Apr, 2016 14:38
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A couple of things:
A) That estimate is for a single molecule of the fatty alcohol 2-Octanol
1) On a post Dr.Rodal made at or close to the point where he introduced the research on magnetochiral molecules/QV, I couldn't help noticing the scaling "1 nm/s at B=10T" in the picture of a slide. It seems like this would be negligible in any DIY experiment. Happy to be shown wrong, but that's as it appears at first blush.
2) I'm very encouraged by DaChuna's news that TU Dresden is handing out PhD studentships to optimize EM-drive resonances. Sounds like some serious work is going on there.
R.
with molecular mass of 130 u, which compares with the experiments of Rikken and van Tiggelen of 2011 and 2012:
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.107.170401
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.230402
See this http://arxiv.org/pdf/1204.6617
B) At 8.72 kHz eigenfrequency, 10^7 V/m, 16 T they calculate much larger delta V = 3.7 µm/s (that is 3700 times greater than 1 nm/s) for 10 µg of chiral molecular mass
C) van Tiggelen states that there is a linear dependence of the force on the frequency of the electric field. The higher the frequency, the higher the force. They present no estimates at GHz frequency, which is clearly orders of magnitude higher frequency than their estimates you are discussing
Need to perform delta V calculations for the intensity field of the EM Drive, at 2.4 GHz, and for hypothetical amount of chiral mass inside the cavity, as p ~ intensity
They also suggest it may be a good idea to use lasers.
Admittedly, this is a long way away from showing that the claims of EM Drive experimenters (orders of magnitude greater force/InputPower of a photon rocket) can be supported. -
#1602 by Rodal on 25 Apr, 2016 14:43
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...
Perhaps:
Perhaps a note to them would be in order as well as sending them the Insert...builders do appreciate donations of materials, etc. That way they won't have to scour the internet for the right piece. You'd need their small diameter dimensions, tho.
1) The Aachen team can join NSF and have a dialog at NSF EM Drive thread, as there is a huge amount of knowledge accumulated at the NSF threads with a number of knowledgeable people in the field, including NASA members (including DIY and several members active for several threads read by hundreds of thousands of viewers).
2) Material and source of material has been previously reported at NSF EM Drive thread by a NASA member: it is available from McMasterCarr and quite inexpensive. Definitely this is not an issue of availability or cost. McMasterCarr readily ships to Aachen, and Aachen Germany has several sources of extruded HDPE providers , as Germany is one of the main producers of HDPE in the world. HDPE is a commodity plastic used for myriads of applications. It is one of the most common plastic materials in Germany. It is not too difficult to get an extuded rod with their diameter and simply cut it . If they insist in using 3D printing plastic, HDPE is also readily available in Germany for 3D printing machines.
3) I tried previously to communicate suggestions concerning using Ammonia since it would considerably amplify their results since they are operating at 24 GHz, which coincides with the emission of Ammonia, as known from the Ammonia Maser since the work of Savage and Townes in 1953. I find it to be a very difficult experience to communicate with them through Hackaday. Definitely not as good a medium of communication as NSF. NSF much better !
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#1603 by Monomorphic on 25 Apr, 2016 14:55
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Adding a dialectric insert definitely adds to the complexity! The position and geometry of the insert matters greatly.
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#1604 by Rodal on 25 Apr, 2016 15:01
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Adding a dialectric insert definitely adds to the complexity! The position and geometry of the insert matters greatly.
As previously discussed the function of the polymer insert is not to be a dielectric. The relative electric permittitivity of the materials involved (~2) is much closer to the one of air and vacuum (~1) than the relative electric permittivity of dielectrics as used by Shawyer and for other dielectric applications in typical applications (~38).
The function of the polymer is not one of being a dielectric, it is to increase the anomalous force for a Q-Thruster. The position and dimensions were given by NASA. The location is the small end. Therefore everything has been precisely given:
1) material
2) material processing method
3) material source (McMaster Carr)
4) material location (small end)
5) material dimensions
This stands in complete and utter contrast to the Shawyer and Yang's EM Drive:
A) neither Shawyer or Yang ever provide complete dimensions for any of their EM Drives (DIY making EM Drives based on Shaywer or Yang have to make estimates from photographs, or from reports)
B) NASA has provided ALL information required for their EM Drive, including the polymer insert (no estimates needed)
For the Aachen tiny EM Drive all they have to do is to linearly scale the dimensions provided by NASA.
What is missing from here?
One would only wish that DIY would have as much explicit, numerical, detailed information from Shawyer or Yang as NASA has provided for the NASA tests -
#1605 by Rodal on 25 Apr, 2016 15:18
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Also thanks to Monomorphic and X-Ray for running FEKO with dielectrics !
Monomorphic and X-Ray FEKO computer runs confirm that the function of the polymer insert cannot be to serve as a dielectric.
These FEKO computer runs show that the narrative that the polymer insert serves as a dielectric is incorrect.
This actually agrees with Shawyer's prescription: one should not place a material with high electric permittivity in the EM Drive: the imaginary part of the permittivity will decrease the Q. It is counterproductive.
This is NOT what NASA has been doing, as NASA's test also show that they got poor performance from running dielectrics with high electric permittiivty dielectrics.
The narrative that the polymer inserts in NASA's EM Drive purpose is to be a dielectric (thus a function of just the permittivity) is misguided and misinformed. Star-Drive himself wrote that the action had nothing to do with the electric permittivity. And that was not the reason why he had the idea to insert them in the EM Drive. Instead he was motivated by Woodward's Mach Effect https://en.wikipedia.org/wiki/Woodward_effect , and he repeatedly stated that he saw Woodward's Mach effect as one side of the same coin having the White's QV theory on the other side.
Where:
m_0 is the proper mass of the dielectric
G is the gravitational constant
c is the speed of light in vacuum
\rho_0 is the proper density of the dielectric
V is the volume of the dielectric
P is the instantaneous power delivered to the system
The material density appears explicitly. Notice that the electric permittivity does not appear explicitly in this equation. Electric permittivity is not the guiding choice in the selection of material. The polymer insert is submitted to a varying electric power and thus the Woodward Mach effect. -
#1606 by Tellmeagain on 25 Apr, 2016 15:23
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Hackaday tiny EM Drive V. 4 with ABS polymer insert shows test with cavity reversed ( the cavity is turned in the opposite direction.).. but know what?
It shows reverse direction
...
...
Can somebody enlighten me how we tell from this plot that the thrust was reversed? -
#1607 by JaimeZX on 25 Apr, 2016 16:14
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All - I really enjoy keeping up with this thread. Thank you for the tremendous effort everyone is putting forth! Excited to see what Shells (on lockdown) comes up with!
General question: since Dr. McCoulloch's theory suggests a maximum acceleration with a given drive, is it then evident how to scale up the effect?
As in:
I guessed A and B might be different based on the way the drive interacts with <the aether>; C would be a scaled-up frustum tuned to the appropriate mode...
...or is it too soon to hypothesize?
Thanks again! Hope everyone is having a great day. Also thinking of making "Rodal" the middle name of some future child of mine... you are amazing, sir.
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#1608 by Rodal on 25 Apr, 2016 16:22
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All - I really enjoy keeping up with this thread. Thank you for the tremendous effort everyone is putting forth! Excited to see what Shells (on lockdown) comes up with!
General question: since Dr. McCoulloch's theory suggests a maximum acceleration with a given drive, is it then evident how to scale up the effect?
As in:
I guessed A and B might be different based on the way the drive interacts with <the aether>; C would be a scaled-up frustum tuned to the appropriate mode...
...or is it too soon to hypothesize?
Thanks again! Hope everyone is having a great day. Also thinking of making "Rodal" the middle name of some future child of mine... you are amazing, sir.
Based on my analysis of McCulloch's (as well as Shawyer's and Notsosureofit's) equations here:
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347
the conclusion is clear: the best thing is to scale up as big as possible, like "C" in your picture, because that will have the highest Q, and will allow the highest power density
Small dimensions limit the Q, and severely limit the power density you can run. All 3 theories (McCulloch, Shawyer and Notsosureofit) are linearly dependent on power and on Q.
In Cannae's latest attempt I see he has realized this. He is going with lower eigenfrequency (hence larger dimensions). He may be limited on how big he can go, so after achieving the highest dimension, the next thing to try is several of them of course, perhaps stacked, since one cannot make them any larger.
For stacking, take a look at Monomorphic FEKO runs It is not trivial to stack them, but it is possible. This will result (if well designed) in greater acceleration of charged particles along the longitudinal axis, like in a particle accelerator.
_____________________________________________________
PS: suggest not to handicap your future child with such a name, you may consider the following suggestions as better names
* Paul (after Paul March)
* Michelle (after SeeShells)
* Sonny (after Dr. Sonny White)
* Roger (after Roger Shawyer)
* James (after Prof. James Woodward)
* Yang (after Prof. Yang)
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#1609 by tchernik on 25 Apr, 2016 19:58
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All - I really enjoy keeping up with this thread. Thank you for the tremendous effort everyone is putting forth! Excited to see what Shells (on lockdown) comes up with!
General question: since Dr. McCoulloch's theory suggests a maximum acceleration with a given drive, is it then evident how to scale up the effect?
As in:
I guessed A and B might be different based on the way the drive interacts with <the aether>; C would be a scaled-up frustum tuned to the appropriate mode...
...or is it too soon to hypothesize?
Thanks again! Hope everyone is having a great day. Also thinking of making "Rodal" the middle name of some future child of mine... you are amazing, sir.
Based on my analysis of McCulloch's (as well as Shawyer's and Notsosureofit's) equations here:
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347
the conclusion is clear: the best thing is to scale up as big as possible, like "C" in your picture, because that will have the highest Q, and will allow the highest power density
Small dimensions limit the Q, and severely limit the power density you can run. All 3 theories (McCulloch, Shawyer and Notsosureofit) are linearly dependent on power and on Q.
In Cannae's latest attempt I see he has realized this. He is going with lower eigenfrequency (hence larger dimensions). He may be limited on how big he can go, so after achieving the highest dimension, the next thing to try is several of them of course, perhaps stacked, since one cannot make them any larger.
For stacking, take a look at Monomorphic FEKO runs It is not trivial to stack them, but it is possible. This will result (if well designed) in greater acceleration of charged particles along the longitudinal axis, like in a particle accelerator.
_____________________________________________________
PS: suggest not to handicap your future child with such a name, you may consider the following suggestions as better names
* Paul (after Paul March)
* Michelle (after SeeShells)
* Sonny (after Dr. Sonny White)
* Roger (after Roger Shawyer)
* James (after Prof. James Woodward)
* Yang (after Prof. Yang)
Seems like the choice of parameters to explore is finally getting narrower.
To the list of overall attributes that would probably end up being fortunate or desirable as well, I'd add the judicious choice (IMO) of superconducting cavities cooled by radiative cooling made by Cannae, where the microwave input power never exceeds the radiative cooling required for keeping the cavities superconductive.
Superconductors are really at home in deep space, just by ensuring they are safe and hidden from solar thermal radiation (easier said than done, but much easier to do in the outer Solar System and farther), or by keeping them well cooled.
Nevertheless a passive cooling method is much better, given its lack of moving parts that break. This joined with power sources like RTGs can give us a glance of things that may come.
A fully solid state deep space probe/ship would be like a science fiction dream come true, because those kinds of systems can last for decades, allowing us to plan many missions simply unthinkable today.
But first things first: let's prove if this works or not. The best dreams are those based on the composition of reality and facts into something new. -
#1610 by Monomorphic on 25 Apr, 2016 20:44
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Just got back from a field trip to onlinemetal.com's new fulfillment center here in Atlanta. I can now order copper and aluminum for pickup on the same day! Picked up some more .5mm copper sheet today.
This place is huge, with everything imaginable. The last image is their copper scrap bin. It's sold by the pound at a great price. For $20 one could easily find enough copper to build a frustum. Most DIYers are purchasing new copper, so we are paying a premium of ~$140+ per frustum for the copper.
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#1611 by Eusa on 25 Apr, 2016 21:21
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http://arxiv.org/abs/1506.04248
A resonant cone-shaped standing wave warping momentum got empirical evidence? -
#1612 by Rodal on 25 Apr, 2016 21:27
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http://arxiv.org/abs/1506.04248
This is extremely interesting, and I very much appreciate it that you took your valuable time to post this at NSF:
A resonant cone-shaped standing wave warping momentum got empirical evidence?QuoteHere we report the direct observation of an extraordinary optical momentum and force directed perpendicular to the wavevector, and proportional to the optical spin (i.e., degree of circular polarization). This transverse spin-dependent optical force, a few orders of magnitude weaker than the usual radiation pressure, was recently predicted for evanescent waves [10] and other structured fields
A force, perpendicular to the longitudinal axis, has been measured and reported by several EM Drive experimenters, including at these Universities in Germany and in the USA:
* Prof. Tajmar et.al at TU Dresden
* Zeller, Kraft, Echols at California Polytechnic State Univ., San Luis Obispo, USA
These measured forces have been up to now dismissed as experimental artifacts by others not personally involved in the experiments, but the above information should be also considered as an alternative, in assessing what is their true nature.
The experimental artifact explanation as a Lorentz force due to the cables still merits first consideration because this report explicitly states that the measured perpendicular force is a few orders of magnitude weaker than the usual radiation pressure, while the perpendicular forces measured at TU Dresden and CalPoly are of the same order of magnitude (actually in the CalPoly case, it was the only significant force measured). -
#1613 by RotoSequence on 25 Apr, 2016 21:55
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The experimental artifact explanation as a Lorentz force due to the cables still merits first consideration because this report explicitly states that the measured perpendicular force is a few orders of magnitude weaker than the usual radiation pressure, while the perpendicular forces measured at TU Dresden and CalPoly are of the same order of magnitude (actually in the CalPoly case, it was the only significant force measured).
A few orders of magnitude weaker, but perhaps amenable to amplification? -
#1614 by rfmwguy on 25 Apr, 2016 22:59
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Hi Mr Li, busy with my build, sorry you did not get a reply. It has been difficult for me to follow the charts and the test procedure so I cannot be of any help here. The noisy graph appears to show reverse thrust when they change their orientation, but that's about all I can gather...their general commentary. No idea on differences between the 2 tests so I guess we'll have to wait for more details.Hackaday tiny EM Drive V. 4 with ABS polymer insert shows test with cavity reversed ( the cavity is turned in the opposite direction.).. but know what?
It shows reverse direction
...
...
Can somebody enlighten me how we tell from this plot that the thrust was reversed?
p.s. Probably be ready to send you some pics via PM of my test stand in a couple of weeks for you commentary on Lorentz force minimization. -
#1615 by rfmwguy on 25 Apr, 2016 23:32
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EMDrive Theory Alert - Have been focused on Cu++ (Ion and Electron) interactions in self-sputtering systems. So have a few others:
"Rotating structures in low temperature magnetized plasma devices: spokes, electron vortices and others"
"In low temperature magnetized plasma sources, electrons are often strongly magnetized and confined by the magnetic field while ions are not. These sources are generally cylindrically symmetric and operate in a crossed electric field E and magnetic field B configuration where EB is in the azimuthal direction. Various devices such as Hall thrusters for satellite propulsion, End-Hall ion sources, magnetrons for sputtering applications, Penning discharges, etc… operate in such configuration."
(snip)
"High power pulsed magnetrons for sputtering-deposition applications (High Power Impulse Magnetron Sputtering, HiPIMS), have been the subject of numerous publications in the last ten years. One of the topics discussed in these papers is the presence in the plasma of these E B discharge devices of rotating structures, termed as “rotating spokes” and described as rotating regions of enhanced ionization associated with an electric potential structure with an azimuthally directed electric field. Due to the large and pulsed power used in these devices, the analysis of the physical processes responsible for the presence of spokes is difficult and different mechanisms are invoked to explain these structures and their dynamics (e.g. neutral depletion, secondary electron emission)."
http://www.icpig2015.net/Content/Papers/General_Invited_Speakers/GL6.pdf
Where this seems to be heading (in my lay-person theoretical musings) is this...Magnetic fields (B H) will extend outside the emdrive as they are not inhibited by the copper. The vortices or rotating spokes as this white paper suggests might be the "propeller" some have been suggesting. I still have my reservations, but E field interactions are probably trapped within the device. B H are not when using copper. Regardless, that's the update on my working theory musings. I have an H field meter and will try and map it to the best of my ability. I will have to separate the mag pulses from the "spokes" this paper talks about. May take me some time after the data dump I'll provide in mid-May. -
#1616 by Rodal on 25 Apr, 2016 23:56
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...Where this seems to be heading (in my lay-person theoretical musings) is this...Magnetic fields (B H) will extend outside the emdrive as they are not inhibited by the copper. ...
Dave,
The magnetic fields in the EM Drive are at microwave frequencies. In your case, using a magnetron this frequency is around 2.45 GHz +/- .03 GHz.
Why do you think that the magnetic fields in a microwave cavity like the EM Drive will extend outside the EM Drive? (*)
Why do you think that they are not inhibited by copper 1 mm thick or thicker?
Please recall the concept of skin depth for the electromagnetic field, the skin depth at these frequencies is only about 1 micrometer.
Since the skin depth is only about a micrometer, and the copper is thousands time thicker: a mm thick, the copper EMF shielding works well for both the electric and magnetic components of higher-frequency RF and microwave fields.
Do you have a permanent magnet in your EM Drive or are you referring to a 60 Hz magnetic component? If so this needs to be stated explicitly as others (for example NASA) are not running their EM Drive with permanent magnets or low frequency 60Hz magnetic components. The purpose by many EM Drive experimenters is to deliver the power at the microwave natural frequency in order to have maximum Q.
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(*) If so, microwave ovens sold for home kitchens would also leak the magnetic field, since they also have magnetrons operating at 2.45 GHz. That they are not leaking the magnetic field can be verified by turning on the microwave oven and inspecting the magnetic field outside the oven. -
#1617 by A_M_Swallow on 26 Apr, 2016 00:33
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{snip}
The magnetic fields in the EM Drive are at microwave frequencies. In your case, using a magnetron this frequency is around 2.45 GHz +/- 2GHz.
{snip}
Is that +/- 2GHz right? It is very big. -
#1618 by rfmwguy on 26 Apr, 2016 00:39
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I made a video of H field leakage outside the aluminum and stainless steel kitchen microwave which one would think is well shielded from the factory...not.
I am assuming copper will also pulse radiate (rotate?) the H field. The difficulty is separating out the 60 hz pulse from any rotating "spokes" which I already alluded to. I'll simply have a ~10% relative meter accuracy and not capable of analyzing any overall fields beyond a few points. I am far from CE/EMC lab capabilities. There are 2 permanent ring magnets that are part of the magnetron assembly. -
#1619 by Rodal on 26 Apr, 2016 00:41
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{snip}
The magnetic fields in the EM Drive are at microwave frequencies. In your case, using a magnetron this frequency is around 2.45 GHz +/- 2GHz.
{snip}
Is that +/- 2GHz right? It is very big.
Sorry forgot the period and a zero, meant +/- .02GHz but it is more like 2.45 GHz +/- .03GHz, typically between 2.42GHz to 2.48Ghz, see below:
Thanks for pointing it out (still not noticing that I had forgotten to type the period I even went through the trouble of getting the images to show that there is a bandwidth.) 
