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#2000 by Rodal on 20 Jan, 2016 12:20
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@RFPLUMBER
Did you see the post in which notsosureofit predicted ~5 uN given your power levels and quality factor?
In my opinion your only option is to increase quality factor or noise to a suitable level to disprove his hypothesis, which I find to be the best mathematical formulation of the general effect Shawyer mistakenly describes.
As we all know, the momentum of a photon through dialectics and such, as well as relativistic effects at higher energies, are not perfectly yet described by math. Shawyer's idea is not really anything new (as far as abusing Minkowski-related phenomena to gain momentum, which the government has previously investigsted) but I think we can all agree to be skeptical about his math. In this regard we may as well operate on the best mathematical approach if we are attempting to address the phenomena itself that has been observed and postulated (rather than Shawyer's theory itself).
There are other ways to check these theories besides the obvious one of increasing Power and Q.
Look at the equations that have been proposed.
***EDIT: LOOK AT FOOTNOTE BELOW, "c" in Notsosureofit's expression is not the speed of light in vacuum****
EM Drive theories, like the Notsosureofit Hypothesis http://emdrive.wiki/@notsosureofit_Hypothesis predict (everything else being the same) a larger force if the medium inside the EM Drive would have a higher (μr * εr), value. For example, the force should be higher if the medium inside the EM Drive would be ammonia instead of being air (or vacuum)
Notsosureofit's Hypothesis predicts a force/(Q*PowerInput) proportional to (μr * εr)^(1.5) (*) so that, if instead of filling the cavity with air, the cavity would be filled with:
Ammonia, εr=17 then force/(Q*PowerInput) should be 70 times greater
A number of other gases and fluids can be explored.
Notsosureofit predicted 6.56 μN for RFPlumber's test using air. Using Ammonia, the prediction would be 460 uN, which is 2.3 times his detection limit of 200 μN
If the cavity could be filled with water, εr=80.1 then force/(Q*PowerInput) should be 717 times greater
Using Water, the prediction would be >4700 μN, which is more than 23 times his detection limit of 200 μN] Of course, water conductivity would be a big problem and also water would attenuate the microwaves, so water is only indicated here to show the multiplier effect that increasing permittivity has on the predicted force.
It is perplexing that, although it is obvious that Masers have used ammonia (for the additional reason that Ammonia emits at 24 GHz) for 60 years, nobody testing EM Drives has bothered to test with Ammonia filling the cavity.
I pointed this out several threads ago.
McCulloch pointed out the advantage of increasing (μr * εr) in his paper (although the effect predicted by McCulloch is smaller than the one predicted by Notsosureofit, McCulloch predicts an effect proportional to (μr * εr)^0.5 while Notsosureofit predicts an effect proportional to (μr * εr)^1.5).
NASA increased (μr * εr) asymmetrically, by using a HDPE asymmetrically placed in the cavity, at the small end.
De Aquino proposed to increase (μr * εr) asymmetrically, by using a ferromagnetic end with high μr.
No EM Drive researcher has tried any of this yet.
Instead EM Drive researchers worry about non-existing laws like worrying about the cut-off frequency for open waveguides (which we learnt at school does not apply to closed resonant cavities like the EM Drive)
____________
(*) Here I assumed that "c" in Notsosureofit's expression is the speed of light in vacuum.
Notsosureofit's Force=(2PQ/(L(2πf)^3))((cX)^2)(1/Ds^2−1/Db^2)
If "c" in Notsosureofit's expression is the speed of light in the medium, then the Force/(InputPower*Q) in his expression goes like c^2/(f^3) and hence it would increase by a factor of (μr * εr)^0.5 instead of (μr * εr)^1.5. The behavior for Notsosureofit would be like McCuloch's.
because
is the expression for frequency for TE modes, for example, applicable to his cylindrical approximation.
So for
Ammonia, εr=17 then force/(Q*PowerInput) instead of 17^1.5=70 times greater
it would be
17^0.5 = 4.1 times greater, so for RFPlumber's test the force would be 27 microNewtons instead of 6.56 which is still way below the threshold detection of 200 microNewtons, but a factor of 4 increase is not bad, if in addition the Q could be increased by a factor of 10
_____________
(**)
The U. S. Occupational Safety and Health Administration (OSHA) has set a 15-minute exposure limit for gaseous ammonia of 35 ppm by volume in the environmental air and an 8-hour exposure limit of 25 ppm by volume. NIOSH recently reduced the IDLH from 500 to 300 based on recent more conservative interpretations of original research in 1943. IDLH (Immediately Dangerous to Life and Health) is the level to which a healthy worker can be exposed for 30 minutes without suffering irreversible health effects. Other organizations have varying exposure levels. U.S. Navy Standards [U.S. Bureau of Ships 1962] maximum allowable concentrations (MACs):continuous exposure (60 days): 25 ppm / 1 hour: 400 ppm[52] Ammonia vapour has a sharp, irritating, pungent odour that acts as a warning of potentially dangerous exposure. The average odour threshold is 5 ppm, well below any danger or damage. Exposure to very high concentrations of gaseous ammonia can result in lung damage and death.[51] Although ammonia is regulated in the United States as a non-flammable gas, it still meets the definition of a material that is toxic by inhalation and requires a hazardous safety permit when transported in quantities greater than 13,248 L (3,500 gallons).[53]
Toxicity
The toxicity of ammonia solutions does not usually cause problems for humans and other mammals, as a specific mechanism exists to prevent its build-up in the bloodstream. Ammonia is converted to carbamoyl phosphate by the enzyme carbamoyl phosphate synthetase, and then enters the urea cycle to be either incorporated into amino acids or excreted in the urine[citation needed]. Fish and amphibians lack this mechanism, as they can usually eliminate ammonia from their bodies by direct excretion. Ammonia even at dilute concentrations is highly toxic to aquatic animals, and for this reason it is classified as dangerous for the environment. -
#2001 by Notsosureofit on 20 Jan, 2016 12:46
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Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question. -
#2002 by SeeShells on 20 Jan, 2016 13:56
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Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Days you feel just like this.
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#2003 by Rodal on 20 Jan, 2016 14:07
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Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
So, from this I take it that c in your equation is the speed of light in the medium, not in the vacuum, so that the effect goes like the square root of the relative permitivity and permeability.
That makes sense because checking your formulation on this link: http://emdrive.wiki/@notsosureofit_Hypothesis the first equation there is missing the denominator for c, so that means that your "c" instead of being the speed of light, it is c/√[ (μr * εr)]
So, the effect for Notsosureofit, turns out similar to McCulloch's, the force/(Power*Q) increasing with √[ (μr * εr)] .
That still means that Ammonia will increase the force by a factor of more than 4, purely based on the medium properties. Ammonia has been used in Masers for over 60 years because it emits at 24 GHz, which is another benefit.
And it is a fact that NASA only measured a force when using a dielectric insert (which increases (μr * εr)), as their measurement without a dielectric insert gave a resounding zero force.
I still don't understand the reluctance of EM Drive researchers to explore dielectrics and other mediums inside the cavity, since Ammonia has been used for over 60 years in Masers and since NASA only measured a force when using a dielectric. Instead EM Drive researchers pay homage to non-existent laws like the cut-off frequency for open waveguides, which goes against everything we learnt at school, instead of looking at how Masers operate...or at NASA's experiments -
#2004 by Notsosureofit on 20 Jan, 2016 14:14
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Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
So, from this I take it that c in your equation is the speed of light in the medium, not in the vacuum, so that the effect goes like the square root of the relative permitivity and permeability.
That makes sense because checking your formulation on this link: http://emdrive.wiki/@notsosureofit_Hypothesis the first equation there is missing the denominator for c, so that means that your "c" instead of being the speed of light, it is c/√[ (μr * εr)]
So, the effect for Notsosureofit, turns out similar to McCulloch's.
That still means that Ammonia will increase the force by a factor of more than 4, purely based on the medium properties. Ammonia has been used in Masers for over 60 years because it emits at 24 GHz, which is another benefit.
And it is a fact that NASA only measured a force when using a dielectric insert (which increases (μr * εr)), as their measurement without a dielectric insert gave a resounding zero force.
I still don't understand the reluctance of EM Drive researchers to explore dielectrics and other mediums inside the cavity, since Ammonia has been used for over 60 years in Masers and since NASA only measured a force when using a dielectric.
Assuming no losses, and also the possibility of gain (anomalous dispersion) !
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#2005 by SeeShells on 20 Jan, 2016 14:21
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Dr. Rodel, there is no such reluctance here in my testing schedule.Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
So, from this I take it that c in your equation is the speed of light in the medium, not in the vacuum, so that the effect goes like the square root of the relative permitivity and permeability.
That makes sense because checking your formulation on this link: http://emdrive.wiki/@notsosureofit_Hypothesis the first equation there is missing the denominator for c, so that means that your "c" instead of being the speed of light, it is c/√[ (μr * εr)]
So, the effect for Notsosureofit, turns out similar to McCulloch's.
That still means that Ammonia will increase the force by a factor of more than 4, purely based on the medium properties. Ammonia has been used in Masers for over 60 years because it emits at 24 GHz, which is another benefit.
And it is a fact that NASA only measured a force when using a dielectric insert (which increases (μr * εr)), as their measurement without a dielectric insert gave a resounding zero force.
I still don't understand the reluctance of EM Drive researchers to explore dielectrics and other mediums inside the cavity, since Ammonia has been used for over 60 years in Masers and since NASA only measured a force when using a dielectric. Instead EM Drive researchers pay homage to non-existent laws like the cut-off frequency for open waveguides, which goes everything we learnt at school, instead of looking at how Masers operate...or at NASA's experiments
I already have the 1 inch thick insert of Polytetrafluoroethylene PTFE to tight fit into the tune chamber. I have a rebuild going on right now so some time is needed, but it will happen.
Shell -
#2006 by Rodal on 20 Jan, 2016 14:22
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Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
So, from this I take it that c in your equation is the speed of light in the medium, not in the vacuum, so that the effect goes like the square root of the relative permitivity and permeability.
That makes sense because checking your formulation on this link: http://emdrive.wiki/@notsosureofit_Hypothesis the first equation there is missing the denominator for c, so that means that your "c" instead of being the speed of light, it is c/√[ (μr * εr)]
So, the effect for Notsosureofit, turns out similar to McCulloch's.
That still means that Ammonia will increase the force by a factor of more than 4, purely based on the medium properties. Ammonia has been used in Masers for over 60 years because it emits at 24 GHz, which is another benefit.
And it is a fact that NASA only measured a force when using a dielectric insert (which increases (μr * εr)), as their measurement without a dielectric insert gave a resounding zero force.
I still don't understand the reluctance of EM Drive researchers to explore dielectrics and other mediums inside the cavity, since Ammonia has been used for over 60 years in Masers and since NASA only measured a force when using a dielectric.
Assuming no losses, and also the possibility of gain (anomalous dispersion) !
Well yes, while water would increase the effect by Sqrt[80.1] = 9 times, we know that water will attenuate the microwaves at these GHz frequencies. But Ammonia's attenuation we know is much less than water, it actually emits at 24 GHz.
Concerning dielectrics, we know that there is a tan delta effect which will decrease Q, but the tan delta is miniscule: the decrease is not that much. Tan Delta for HDPE is only 0.00031 @ 3 GHz
Ditto for other media (very tiny tan delta).
We have the fact that NASA was still able to obtain Q=18,100 for TM212 and Q=22,000 for TE012 with dielectric HDPE insert, and that NASA obtained a force with dielectrics and measured NO force without a dielectric. -
#2007 by Rodal on 20 Jan, 2016 14:57
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Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Although, looking at the first equation in http://emdrive.wiki/@notsosureofit_Hypothesis, it does say that "c" is not the constant speed of light in vacuum, it would be helpful to change the nomenclature accordingly throughout the article, replacing "c" by "cmedium" for example, or even better to replace c by c/√[ (μr * εr)] everywhere.
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
As rapid reading, looking only at the final equations, one may miss the fact that c is not the conventional meaning of speed of light in vacuum in the article, as one normally associates c with 299,792,458 m / s -
#2008 by SeeShells on 20 Jan, 2016 15:13
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As reported so far from EagleWorks Dr. Rodal. I still am waiting for the papers from EagleWorks and I'm curious if they still are needing the dielectric inserts.Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
So, from this I take it that c in your equation is the speed of light in the medium, not in the vacuum, so that the effect goes like the square root of the relative permitivity and permeability.
That makes sense because checking your formulation on this link: http://emdrive.wiki/@notsosureofit_Hypothesis the first equation there is missing the denominator for c, so that means that your "c" instead of being the speed of light, it is c/√[ (μr * εr)]
So, the effect for Notsosureofit, turns out similar to McCulloch's.
That still means that Ammonia will increase the force by a factor of more than 4, purely based on the medium properties. Ammonia has been used in Masers for over 60 years because it emits at 24 GHz, which is another benefit.
And it is a fact that NASA only measured a force when using a dielectric insert (which increases (μr * εr)), as their measurement without a dielectric insert gave a resounding zero force.
I still don't understand the reluctance of EM Drive researchers to explore dielectrics and other mediums inside the cavity, since Ammonia has been used for over 60 years in Masers and since NASA only measured a force when using a dielectric.
Assuming no losses, and also the possibility of gain (anomalous dispersion) !
Well yes, while water would increase the effect by Sqrt[80.1] = 9 times, we know that water will attenuate the microwaves at these GHz frequencies. But Ammonia's attenuation we know is much less than water, it actually emits at 24 GHz.
Concerning dielectrics, we know that there is a tan delta effect which will decrease Q, but the tan delta is miniscule: the decrease is not that much. Tan Delta for HDPE is only 0.00031 @ 3 GHz
Ditto for other media (very tiny tan delta).
We have the fact that NASA was still able to obtain Q=18,100 for TM212 and Q=22,000 for TE012 with dielectric HDPE insert, and that NASA obtained a force with dielectrics and measured NO force without a dielectric.
It would put some theories to rest if it was needed or wasn't needed. You could be correct in it being a pivotal point as why it should be investigated.
Shell -
#2009 by SeeShells on 20 Jan, 2016 15:15
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It's also called called Multi-wavelength anomalous dispersion, abbreviation ... MAD.Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
So, from this I take it that c in your equation is the speed of light in the medium, not in the vacuum, so that the effect goes like the square root of the relative permitivity and permeability.
That makes sense because checking your formulation on this link: http://emdrive.wiki/@notsosureofit_Hypothesis the first equation there is missing the denominator for c, so that means that your "c" instead of being the speed of light, it is c/√[ (μr * εr)]
So, the effect for Notsosureofit, turns out similar to McCulloch's.
That still means that Ammonia will increase the force by a factor of more than 4, purely based on the medium properties. Ammonia has been used in Masers for over 60 years because it emits at 24 GHz, which is another benefit.
And it is a fact that NASA only measured a force when using a dielectric insert (which increases (μr * εr)), as their measurement without a dielectric insert gave a resounding zero force.
I still don't understand the reluctance of EM Drive researchers to explore dielectrics and other mediums inside the cavity, since Ammonia has been used for over 60 years in Masers and since NASA only measured a force when using a dielectric.
Assuming no losses, and also the possibility of gain (anomalous dispersion) ! -
#2010 by Notsosureofit on 20 Jan, 2016 15:18
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Good review:
http://nvlpubs.nist.gov/nistpubs/jres/117/jres.117.001.pdf
See p.51 in particular
Ref. 108 concerns tables, but there were a lot of experimental measurements in the 50's and 60's on these parameters. Where are those tables ? -
#2011 by SeeShells on 20 Jan, 2016 15:39
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Update on FEKO.
Lite will not run my frustum and I've heard others telling me the same thing.
Also: (quote) Full FEKO evaluation license valid for 45 days is no longer available. Only the FEKO LITE version which is a restricted version is available to download for free.(end quote)
Nice user interface and I was able to model my frustum and the change I wanted quite quickly but that's where it stopped. They want you to buy the full version and I'm waiting for some pricing.
Shell -
#2012 by TheTraveller on 20 Jan, 2016 15:46
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Update on FEKO.
Lite will not run my frustum and I've heard others telling me the same thing.
Also: (quote) Full FEKO evaluation license valid for 45 days is no longer available. Only the FEKO LITE version which is a restricted version is available to download for free.(end quote)
Nice user interface and I was able to model my frustum and the change I wanted quite quickly but that's where it stopped. They want you to buy the full version and I'm waiting for some pricing.
Shell
If a 45 day full evaluation is not available, how is one to know FEKO can deliver the goods?
Seems a strange policy decision? -
#2013 by Tellmeagain on 20 Jan, 2016 15:47
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Silly me. I only now realized that the EW results described in their original "Anomalous Thrust Production..." paper have not been performed in vacuum. Duh.
...And I kept wondering how most of this paper thrust plots (including one from a dummy load) which I thought had all been performed in vacuum were having all the same now very familiar long post-RF tails I have just got in my garage! Now I understand. ... Also, in this paper there is not a single plot of thrust in the opposite direction?
Anyway, it turns out the only remaining vacuum test today with "thrust" is EW 10 uN from 35W? Detected with the same setup where they have previously seen null Lorentz forces of 9 uN?
This was interesting. Obviously there is no point for me trying to test this further with HDPE disks as 10 uN is way below anything I could reasonably expect to detect (and/or be excited about).
Yes you can detect sub 10uN forces with your setup if you install a pyramidal frame, air flow blocker and an oil damper. I did that with my setup. But if you are not interested in sub 10uN forces that's another story.
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#2014 by Rodal on 20 Jan, 2016 15:58
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As reported so far from EagleWorks Dr. Rodal. I still am waiting for the papers from EagleWorks and I'm curious if they still are needing the dielectric inserts.Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
So, from this I take it that c in your equation is the speed of light in the medium, not in the vacuum, so that the effect goes like the square root of the relative permitivity and permeability.
That makes sense because checking your formulation on this link: http://emdrive.wiki/@notsosureofit_Hypothesis the first equation there is missing the denominator for c, so that means that your "c" instead of being the speed of light, it is c/√[ (μr * εr)]
So, the effect for Notsosureofit, turns out similar to McCulloch's.
That still means that Ammonia will increase the force by a factor of more than 4, purely based on the medium properties. Ammonia has been used in Masers for over 60 years because it emits at 24 GHz, which is another benefit.
And it is a fact that NASA only measured a force when using a dielectric insert (which increases (μr * εr)), as their measurement without a dielectric insert gave a resounding zero force.
I still don't understand the reluctance of EM Drive researchers to explore dielectrics and other mediums inside the cavity, since Ammonia has been used for over 60 years in Masers and since NASA only measured a force when using a dielectric.
Assuming no losses, and also the possibility of gain (anomalous dispersion) !
Well yes, while water would increase the effect by Sqrt[80.1] = 9 times, we know that water will attenuate the microwaves at these GHz frequencies. But Ammonia's attenuation we know is much less than water, it actually emits at 24 GHz.
Concerning dielectrics, we know that there is a tan delta effect which will decrease Q, but the tan delta is miniscule: the decrease is not that much. Tan Delta for HDPE is only 0.00031 @ 3 GHz
Ditto for other media (very tiny tan delta).
We have the fact that NASA was still able to obtain Q=18,100 for TM212 and Q=22,000 for TE012 with dielectric HDPE insert, and that NASA obtained a force with dielectrics and measured NO force without a dielectric.
It would put some theories to rest if it was needed or wasn't needed. You could be correct in it being a pivotal point as why it should be investigated.
Shell
Actually, several threads ago, Notsosureofit and I discussed an equation for a cylinder with perfectly constant cross-section with an asymmetrically placed dielectric. I came up with an equation for the dependence on frequency with an aysmmetrically placed dielectric and Notsosureofit came out with an anomalous force even for a cylinder with constant cross-section if you insert a dielectric.
It follows that according to the Notsosureofit hypothesis the force for a tapered cavity with a dielectric asymmetrically placed on it should be even higher. The issue is by how much precisely (given a reduction in Q due to tan delta, hence one needs a dielectric with low tan delta at the frequency of operation, etc.)
Given the fact that NASA conclusively measured no force without a dielectric insert, and the fact that they were still using a dielectric insert the last time we heard from them, there is no NASA evidence that things should be better without them. On the contrary, the attempt to measure a force without a dielectric was made in a teeter-totter balance, which as user TellMeAgain has stated, (and he is very correct) is less sensitive than a torque pendulum used by NASA and by Tajmar in vacuum. Not only that, but the attempt to measure a force with a teeter-totter arrangement by NASA was reported as inconclusive, last time we heard.
Not only NASA reported no force for the truncated cone without a dielectric, but it also reported no force without a dielectric for the Cannae drive, and NASA falsified Cannae's hypothesis on the effect of those grooves.
So, all the NASA evidence points, summarily to the advantage of using an asymmetrically placed dielectric, and so appears the Notsosureofit hypothesis.
Also, Professor Woodward is emphatic on his dismissal of the EM Drive without a dielectric as being impossible to generate a force, and Professor Woodward thinks that the anomalous force measured by NASA may be due to the dielectric producing a Mach Effect.
Prof. Woodward's theory is much more consistent with General Relativity and known physics than Roger Shawyer's attempt at explaining a force based on classical physics (employing Maxwell's equations and Special Relativity).
EM Drive fans should be happy that when Paul March measured no force for the Cannae and for the truncated-cone Shawyer drives without dielectrics, he didn't just quit, but March came up with the idea to place a dielectric, because otherwise the only report from NASA would have been that they measured no force with both of them when testing them without a dielectric
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#2015 by SeeShells on 20 Jan, 2016 16:11
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Good review:
http://nvlpubs.nist.gov/nistpubs/jres/117/jres.117.001.pdf
See p.51 in particular
Ref. 108 concerns tables, but there were a lot of experimental measurements in the 50's and 60's on these parameters. Where are those tables ?
Waiting for some glue to dry. (Didn't see your tables.) I'm surfing over this. One thing jumped out at me.
4.2 Material Response to Applied Fields
When a field is suddenly applied to a material, the charges, spins, currents, and dipoles in a medium respond to the local fields to form an average field. If an EM field is suddenly applied to a semi-infinite material, the total field will include the effects of both the applied field, transients, and the particle backreaction fields from charge, spin, and current rearrangement that causes depolarization fields. This will cause the system to be in nonequilibrium for a period of time.
I have a section of HDPE in the small end that not only will the high energy modes react with in this fashion but if done correctly you can also cause the generation of evanescent waves then I have ...
http://www.nature.com/ncomms/2014/140306/ncomms4300/full/ncomms4300.html
<snip... in summary>
Thus, we have shown that evanescent electromagnetic waves can carry four distinct momenta and three distinct spin angular momenta. This is in sharp contrast with the single momentum and single spin for a propagating plane wave (photons). Each of these momenta and spins has a clear physical meaning and result in a corresponding directly-observable force or torque...
Just a thought...
Shell -
#2016 by rfmwguy on 20 Jan, 2016 16:12
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Good suggestions Mr Li. With such low RF power it seems to be only possible to do a few micronewtons, well into the Lorentz force and other systemic noise sources.Silly me. I only now realized that the EW results described in their original "Anomalous Thrust Production..." paper have not been performed in vacuum. Duh.
...And I kept wondering how most of this paper thrust plots (including one from a dummy load) which I thought had all been performed in vacuum were having all the same now very familiar long post-RF tails I have just got in my garage! Now I understand. ... Also, in this paper there is not a single plot of thrust in the opposite direction?
Anyway, it turns out the only remaining vacuum test today with "thrust" is EW 10 uN from 35W? Detected with the same setup where they have previously seen null Lorentz forces of 9 uN?
This was interesting. Obviously there is no point for me trying to test this further with HDPE disks as 10 uN is way below anything I could reasonably expect to detect (and/or be excited about).
Yes you can detect sub 10uN forces with your setup if you install a pyramidal frame, air flow blocker and an oil damper. I did that with my setup. But if you are not interested in sub 10uN forces that's another story. -
#2017 by Rodal on 20 Jan, 2016 16:20
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Update on FEKO.
Lite will not run my frustum and I've heard others telling me the same thing.
Also: (quote) Full FEKO evaluation license valid for 45 days is no longer available. Only the FEKO LITE version which is a restricted version is available to download for free.(end quote)
Nice user interface and I was able to model my frustum and the change I wanted quite quickly but that's where it stopped. They want you to buy the full version and I'm waiting for some pricing.
Shell
There are other programs beside FEKO.
RFPlumber has access to COMSOL and has used it effectively. COMSOL can readily calculate the natural frequencies and mode shapes of cavities with asymmetrically placed dielectrics. Also COMSOL can readily display numerical values of the electromagnetic fields in SI units for a 3-D truncated cone that is readily digested and understood. -
#2018 by Tellmeagain on 20 Jan, 2016 16:23
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It is fair not to build it. Here is just some explanation. The purpose is not to produce thrust, but to reduce error bar, so you can say "if there is any thrust, it would be below 1uN" instead of "it would be below 50uN".
Your ceiling may introduce much of the "minor excitation" you see, that's why I suggest a frame. It is easy to build anyway, just four wood sticks tied together to form the pyramid shape.
But since we are on the opposite side of EmDrive, and my purpose is improve "no thrust" claim and your purpose is to find under what condition there is thrust, it is fair for you not to take my suggestion.
Thinking about this more, there would still be air convection inside this enclosure caused by the RF amp hot plate...
My conclusion at this point is that chasing anything below 100 uN is better be done in vacuum.
Soaking your heat sink into a ice-water mix will fix this problem. That's what we did to our experiment. We used thin plastic bag around a heat-generating transistor and between the transistor and heat sink. The heat sink makes contact to the ice-water mix directly.
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#2019 by TheTraveller on 20 Jan, 2016 16:25
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Soaking your heat sink into a ice-water mix will fix this problem. That's what we did to our experiment. We used thin plastic bag around a heat-generating transistor and between the transistor and heat sink. The heat sink makes contact to the ice-water mix directly.
Phase change heat sink. Nice!
