What do you think? It has a nice wide rim I can drill holes in to add a flat base plate to it. 
https://www.amazon.com/dp/B004NG9FFI/ref=psdc_289696_t2_B002X3MUV4
I like it!
So I made a sphere of radius 2749/240 inches and cut it at 7.5 inches (did I do the math right? It looks pretty close...)
I put a copper plate on it and left the bowl stainless steel.
Here are the first 12 Eigenmodes starting from 2.4 GHz (I'm guessing you want to use a microwave oven magnetron?)
2400644080
2400846805
2439096216
2439343994
2445869115
2446058467
2458632429
2467518727
2467539775
2485758762
2488443199
2493716505
HFSS finds unique orthogonal modes at slightly different frequencies because of slight solver error, hence the duplicates.
I like the bolded one because its perfectly aligned with a typical magnetron frequency and you could electrically couple through the center of either end.
That's a pretty high mode. TE or TM? V/m up the middle, I assume it's TM?
Yes, TM... well atleast TM in the center. Sorry I forgot to put the vectors on 
Thanks! With the 22" diameter, I was shooting for ~ 1 GHz TE012 mode. My theory expects a higher thrust from a lower frequency, because the amount of energy stored "is" the counter mass it is pushing against. Energy is Power/frequency so lower frequency is higher energy and mass.
The definition of an open system is one that interacts with something else. The emDrive as described by Shawyer does not do this, so it is a closed system. Saying "it is an open system" does not magically make it one.
...
Actually, the copper frustum is interacting with "something else". It is interacting with the EM field inside it. This field is NOT trapped inside, it escapes through dissipation. So by definition, it is an open system. It could only be considered a closed system if the energy inside could not escape. Meaning, once stored, it would stay there indefinitely without decaying. That is not the case.
The definition of an open system is one that interacts with something else. The emDrive as described by Shawyer does not do this, so it is a closed system. Saying "it is an open system" does not magically make it one.
...
Actually, the copper frustum is interacting with "something else". It is interacting with the EM field inside it. This field is NOT trapped inside, it escapes through dissipation. So by definition, it is an open system. It could only be considered a closed system if the energy inside could not escape. Meaning, once stored, it would stay there indefinitely without decaying. That is not the case.
I was talking about Shawyer's theory, not yours. Yours relies on general relativity, and I need some more time before I can respond to it properly.
For the case I was talking about (Shawyer's theory) the EM field is not "something else" it is part of the system and must be included. The dissipation of the EM field is into the metal of the cavity, so that is not it escaping.
Thermal radiation does escape, but that is less than ideal photon rocket thrust.
Again
as described by Shawyer the emDrive is a closed system.
The definition of an open system is one that interacts with something else. The emDrive as described by Shawyer does not do this, so it is a closed system. Saying "it is an open system" does not magically make it one.
...
Actually, the copper frustum is interacting with "something else". It is interacting with the EM field inside it. This field is NOT trapped inside, it escapes through dissipation. So by definition, it is an open system. It could only be considered a closed system if the energy inside could not escape. Meaning, once stored, it would stay there indefinitely without decaying. That is not the case.
Give you a little hint. E fields exist at night levels externally. I originally thought it was propagation through the wire harness and now am not so certain. Will be trying to map this next year and not prepared to make a definitive statement...but I registered full deflection switching from H field to RF detection on 3 occasions on my old school meter.
My friend made the argument that Eagleworks' results are invalid because they did not account for error sources in their own apparatus by swapping out the test frustum and replace it with a cylinder that resonates at the same frequency with the same mode. Is this a reasonable argument against the validity of the scientific results?
My friend made the argument that Eagleworks' results are invalid because they did not account for error sources in their own apparatus by swapping out the test frustum and replace it with a cylinder that resonates at the same frequency with the same mode. Is this a reasonable argument?
Seems like that argument has made the rounds with the exception of maintaining mode. In a perfect world, dozens of equal mass cavities all resonating at TM212 would likely not satisfy skeptics. RF loads are a classic RF termination and thermal absorption component. In effect, energy and heat are contained in a relatively small space.
The slippery slope of standard cavities involves more than shape, it's mass, material, thermal and electrical properties all needing to be identical to the original test article. Not as simple as one might think.
The definition of an open system is one that interacts with something else. The emDrive as described by Shawyer does not do this, so it is a closed system. Saying "it is an open system" does not magically make it one.
...
Actually, the copper frustum is interacting with "something else". It is interacting with the EM field inside it. This field is NOT trapped inside, it escapes through dissipation. So by definition, it is an open system. It could only be considered a closed system if the energy inside could not escape. Meaning, once stored, it would stay there indefinitely without decaying. That is not the case.
Heat escapes, which is very different to an interaction imparting the thrust levels being measured.
My friend made the argument that Eagleworks' results are invalid because they did not account for error sources in their own apparatus by swapping out the test frustum and replace it with a cylinder that resonates at the same frequency with the same mode. Is this a reasonable argument?
Seems like that argument has made the rounds with the exception of maintaining mode. In a perfect world, dozens of equal mass cavities all resonating at TM212 would likely not satisfy skeptics. RF loads are a classic RF termination and thermal absorption component. In effect, energy and heat are contained in a relatively small space.
The slippery slope of standard cavities involves more than shape, it's mass, material, thermal and electrical properties all needing to be identical to the original test article. Not as simple as one might think.
They're rather adamant that it just needs to replicate TM212 and be comparable in mass, otherwise Eagleworks has no adequate control on the apparatus itself, with the 50 ohm load being an insufficient test to demonstrate a divergent result. What do our resident experimental physicists (not necessarily, and perhaps even preferably not EM drive builders) think of this outlook? Are the Eagleworks experiments insufficiently rigorous to prove that the drive works by not including a TM212 resonant control cavity?
My friend made the argument that Eagleworks' results are invalid because they did not account for error sources in their own apparatus by swapping out the test frustum and replace it with a cylinder that resonates at the same frequency with the same mode. Is this a reasonable argument?
Seems like that argument has made the rounds with the exception of maintaining mode. In a perfect world, dozens of equal mass cavities all resonating at TM212 would likely not satisfy skeptics. RF loads are a classic RF termination and thermal absorption component. In effect, energy and heat are contained in a relatively small space.
The slippery slope of standard cavities involves more than shape, it's mass, material, thermal and electrical properties all needing to be identical to the original test article. Not as simple as one might think.
They're rather adamant that it just needs to replicate TM212 and be comparable in mass, otherwise Eagleworks has no adequate control on the apparatus itself, with the 50 ohm load being an insufficient test to demonstrate a divergent result.
Ideally, a round, cylindrical, square or rectangular cavity or any combination of the aforementioned could satisfy some, but not all skeptics I would assume. But we know there would be those asking for additional mechanical variations. I look at this as one paper with strong enough evidence that it should encourage further research, pro or con. Evidence comes from mulletron and zellerium that rectangular and/or circular cavities provided no measurable thrust. I could see a limited budget curtailing multi-cavity construction. Just don't think this is a deal breaker. Force was measured.
My friend made the argument that Eagleworks' results are invalid because they did not account for error sources in their own apparatus by swapping out the test frustum and replace it with a cylinder that resonates at the same frequency with the same mode. Is this a reasonable argument?
Seems like that argument has made the rounds with the exception of maintaining mode. In a perfect world, dozens of equal mass cavities all resonating at TM212 would likely not satisfy skeptics. RF loads are a classic RF termination and thermal absorption component. In effect, energy and heat are contained in a relatively small space.
The slippery slope of standard cavities involves more than shape, it's mass, material, thermal and electrical properties all needing to be identical to the original test article. Not as simple as one might think.
They're rather adamant that it just needs to replicate TM212 and be comparable in mass, otherwise Eagleworks has no adequate control on the apparatus itself, with the 50 ohm load being an insufficient test to demonstrate a divergent result.
Ideally, a round, cylindrical, square or rectangular cavity or any combination of the aforementioned could satisfy some, but not all skeptics I would assume. But we know there would be those asking for additional mechanical variations. I look at this as one paper with strong enough evidence that it should encourage further research, pro or con. Evidence comes from mulletron and zellerium that rectangular and/or circular cavities provided no measurable thrust. I could see a limited budget curtailing multi-cavity construction. Just don't think this is a deal breaker. Force was measured.
The problem isn't satisfying skeptics. The criticism is that it's an insufficiently rigorous test to be considered a fundamentally valid scientific experiment. It doesn't matter that force was measured, because they haven't shown divergence through a different, but likewise TM212 resonant geometry - which means they haven't proven that the conical cavity geometry uniquely affects more than the resonance mode, frequency, etc in their experiment.
My friend made the argument that Eagleworks' results are invalid because they did not account for error sources in their own apparatus by swapping out the test frustum and replace it with a cylinder that resonates at the same frequency with the same mode. Is this a reasonable argument?
Seems like that argument has made the rounds with the exception of maintaining mode. In a perfect world, dozens of equal mass cavities all resonating at TM212 would likely not satisfy skeptics. RF loads are a classic RF termination and thermal absorption component. In effect, energy and heat are contained in a relatively small space.
The slippery slope of standard cavities involves more than shape, it's mass, material, thermal and electrical properties all needing to be identical to the original test article. Not as simple as one might think.
They're rather adamant that it just needs to replicate TM212 and be comparable in mass, otherwise Eagleworks has no adequate control on the apparatus itself, with the 50 ohm load being an insufficient test to demonstrate a divergent result.
Ideally, a round, cylindrical, square or rectangular cavity or any combination of the aforementioned could satisfy some, but not all skeptics I would assume. But we know there would be those asking for additional mechanical variations. I look at this as one paper with strong enough evidence that it should encourage further research, pro or con. Evidence comes from mulletron and zellerium that rectangular and/or circular cavities provided no measurable thrust. I could see a limited budget curtailing multi-cavity construction. Just don't think this is a deal breaker. Force was measured.
The problem isn't satisfying skeptics. The criticism is that it's an insufficiently rigorous test to be considered a fundamentally valid scientific experiment. It doesn't matter that force was measured, because they haven't proven divergence through a different, but likewise TM212 resonant geometry.
So you're saying a tm212 cavity in comparison to an RF load is invalid? I suppose the next critique could be multimodal comparisons across other shapes, which then drives the cost up significantly. I have no clue to their budget but everything I've read indicates a very modest resource. Giving them the benefit of the doubt, I assume they've worked within their means. A tm212 cavity moved and an RF load didn't is my takeaway. This is enough to stimulate further research and I'm glad this peer reviewed journal has it published. Does it answer every possible question? No. Is it a good start? I'd say yes.
The definition of an open system is one that interacts with something else. The emDrive as described by Shawyer does not do this, so it is a closed system. Saying "it is an open system" does not magically make it one.
...
Actually, the copper frustum is interacting with "something else". It is interacting with the EM field inside it. This field is NOT trapped inside, it escapes through dissipation. So by definition, it is an open system. It could only be considered a closed system if the energy inside could not escape. Meaning, once stored, it would stay there indefinitely without decaying. That is not the case.
Heat escapes, which is very different to an interaction imparting the thrust levels being measured.
I never said that heat convection causes the thrust. I've said in numerous posts, it is the gradient in the internal effective potential that gives it a thrust greater than a photon rocket. The fact that internal energy is not stored indefinitely and that heat escapes means, it is not a closed system. The possibility that the dissipation is asymmetrical, allows there to be a gradient in the potential, with which to attract the internal stored equivalent mass to "pull against",
before it is dissipated as heat.
So you're saying a tm212 cavity in comparison to an RF load is invalid? I suppose the next critique could be multimodal comparisons across other shapes, which then drives the cost up significantly. I have no clue to their budget but everything I've read indicates a very modest resource. Giving them the benefit of the doubt, I assume they've worked within their means. A tm212 cavity moved and an RF load didn't is my takeaway. This is enough to stimulate further research and I'm glad this peer reviewed journal has it published. Does it answer every possible question? No. Is it a good start? I'd say yes.
Right now, I'm playing devil's advocate, and I've made the same points to my critical friend. I am, have been, and continue to give Eagleworks (and everyone else whose been working on this for years now) the benefit of the doubt. The concern isn't that Eagleworks has failed to produce thrust, but that they've failed to include any cavity geometry control in the experiment, leaving it insufficiently rigorous to prove that the effect is real.
Unfortunately, I haven't seen a good rebuttal of that criticism yet.
My friend made the argument that Eagleworks' results are invalid because they did not account for error sources in their own apparatus by swapping out the test frustum and replace it with a cylinder that resonates at the same frequency with the same mode. Is this a reasonable argument?
Seems like that argument has made the rounds with the exception of maintaining mode. In a perfect world, dozens of equal mass cavities all resonating at TM212 would likely not satisfy skeptics. RF loads are a classic RF termination and thermal absorption component. In effect, energy and heat are contained in a relatively small space.
The slippery slope of standard cavities involves more than shape, it's mass, material, thermal and electrical properties all needing to be identical to the original test article. Not as simple as one might think.
They're rather adamant that it just needs to replicate TM212 and be comparable in mass, otherwise Eagleworks has no adequate control on the apparatus itself, with the 50 ohm load being an insufficient test to demonstrate a divergent result.
Ideally, a round, cylindrical, square or rectangular cavity or any combination of the aforementioned could satisfy some, but not all skeptics I would assume. But we know there would be those asking for additional mechanical variations. I look at this as one paper with strong enough evidence that it should encourage further research, pro or con. Evidence comes from mulletron and zellerium that rectangular and/or circular cavities provided no measurable thrust. I could see a limited budget curtailing multi-cavity construction. Just don't think this is a deal breaker. Force was measured.
The problem isn't satisfying skeptics. The criticism is that it's an insufficiently rigorous test to be considered a fundamentally valid scientific experiment. It doesn't matter that force was measured, because they haven't shown divergence through a different, but likewise TM212 resonant geometry - which means they haven't proven that the conical cavity geometry uniquely affects more than the resonance mode, frequency, etc in their experiment.
IMO, the criticism is completely irrelevant. They showed there "is" a repeatable, measurable force, in a vacuum, where there should not be any force given "their" current understanding of physics. What shape the cavity is, is completely irrelevant. It moved, and to the best of their ability, it wasn't random or noise. That's what's relevant.
My friend made the argument that Eagleworks' results are invalid because they did not account for error sources in their own apparatus by swapping out the test frustum and replace it with a cylinder that resonates at the same frequency with the same mode. Is this a reasonable argument?
Seems like that argument has made the rounds with the exception of maintaining mode. In a perfect world, dozens of equal mass cavities all resonating at TM212 would likely not satisfy skeptics. RF loads are a classic RF termination and thermal absorption component. In effect, energy and heat are contained in a relatively small space.
The slippery slope of standard cavities involves more than shape, it's mass, material, thermal and electrical properties all needing to be identical to the original test article. Not as simple as one might think.
They're rather adamant that it just needs to replicate TM212 and be comparable in mass, otherwise Eagleworks has no adequate control on the apparatus itself, with the 50 ohm load being an insufficient test to demonstrate a divergent result.
Ideally, a round, cylindrical, square or rectangular cavity or any combination of the aforementioned could satisfy some, but not all skeptics I would assume. But we know there would be those asking for additional mechanical variations. I look at this as one paper with strong enough evidence that it should encourage further research, pro or con. Evidence comes from mulletron and zellerium that rectangular and/or circular cavities provided no measurable thrust. I could see a limited budget curtailing multi-cavity construction. Just don't think this is a deal breaker. Force was measured.
The problem isn't satisfying skeptics. The criticism is that it's an insufficiently rigorous test to be considered a fundamentally valid scientific experiment. It doesn't matter that force was measured, because they haven't shown divergence through a different, but likewise TM212 resonant geometry - which means they haven't proven that the conical cavity geometry uniquely affects more than the resonance mode, frequency, etc in their experiment.
IMO, the criticism is completely irrelevant. They showed there "is" a repeatable, measurable force, in a vacuum, where there should not be any force given "their" current understanding of physics. What shape the cavity is, is completely irrelevant. It moved, and to the best of their ability, it wasn't random or noise. That's what's relevant.
Yes, you are right - barring (again, playing devil's advocate) an unexpected and un-characterized error stemming from the particular experimental setup in the paper. Is this plausible? If this is not an unreasonable concern, they've left a gap in variable control will still leave the collective public in the dark on whether or not these things actually work, instead of absolutely certain of their functionality.
Meberb's critique is not invalid. The experimental signal is still smaller than the noise component, and Egleworks has not wholly characterized 100% of the potential error sources.
Eagleworks has not proven beyond a shadow of a doubt that the effect is real. However, they have substantially raised the bar on what would be required to disprove the effect.
I think it is impossible to characterize 100% of the potential error sources.. Only to test it in space..
I was wander how they tested HAL effect when they first discovered it which is 300 times weaker than of this EM drive according to the:
http://www.nextbigfuture.com/2016/11/final-version-of-nasa-emdrive-paper.html
The definition of an open system is one that interacts with something else. The emDrive as described by Shawyer does not do this, so it is a closed system. Saying "it is an open system" does not magically make it one.
...
Actually, the copper frustum is interacting with "something else". It is interacting with the EM field inside it. This field is NOT trapped inside, it escapes through dissipation. So by definition, it is an open system. It could only be considered a closed system if the energy inside could not escape. Meaning, once stored, it would stay there indefinitely without decaying. That is not the case.
Heat escapes, which is very different to an interaction imparting the thrust levels being measured.
I never said that heat convection causes the thrust. I've said in numerous posts, it is the gradient in the internal effective potential that gives it a thrust greater than a photon rocket. The fact that internal energy is not stored indefinitely and that heat escapes means, it is not a closed system. The possibility that the dissipation is asymmetrical, allows there to be a gradient in the potential, with which to attract the internal stored equivalent mass to "pull against", before it is dissipated as heat.
This chain of posts is about Shawyer's theory not yours, if your theory works (I need some more time to work though some details), it involves special GR effects that make it an open system. Shawyer's theory does not include those.
Please stop pulling this out of context and changing the subject.
*trim long nested quote tree*
Yes, you are right - barring (again, playing devil's advocate) an unexpected and un-characterized error stemming from the particular experimental setup in the paper. Is this plausible? If this is not an unreasonable concern, they've left a gap in variable control will still leave the collective public in the dark on whether or not these things actually work, instead of absolutely certain of their functionality.
Asking for the specific setup of the cylindrical cavity is not the most useful of control tests, it would answer some questions, but not all. There are other concerns that would be easier to put to rest. Using no RF, and just heaters to replicate thermal effects would be much more useful for example. The main issue is the cylindrical cavity idea doesn't actually have a specific error source it is targeting, and it changes too many things. If the goal was just have a control test, they did one, although I have no idea why they thought it would be a helpful one.
Meberb's critique is not invalid. The experimental signal is still smaller than the noise component, and Egleworks has not wholly characterized 100% of the potential error sources.
Eagleworks has not proven beyond a shadow of a doubt that the effect is real. However, they have substantially raised the bar on what would be required to disprove the effect.
I think it is impossible to characterize 100% of the potential error sources.. Only to test it in space..
Yes, 100% is not a reasonable goal, but getting rid of or doing detailed characterization of error sources that are within an order of magnitude of the signal does not seem like too much to ask for, especially in a case like this.
The definition of an open system is one that interacts with something else. The emDrive as described by Shawyer does not do this, so it is a closed system. Saying "it is an open system" does not magically make it one.
...
Actually, the copper frustum is interacting with "something else". It is interacting with the EM field inside it. This field is NOT trapped inside, it escapes through dissipation. So by definition, it is an open system. It could only be considered a closed system if the energy inside could not escape. Meaning, once stored, it would stay there indefinitely without decaying. That is not the case.
Heat escapes, which is very different to an interaction imparting the thrust levels being measured.
I never said that heat convection causes the thrust. I've said in numerous posts, it is the gradient in the internal effective potential that gives it a thrust greater than a photon rocket. The fact that internal energy is not stored indefinitely and that heat escapes means, it is not a closed system. The possibility that the dissipation is asymmetrical, allows there to be a gradient in the potential, with which to attract the internal stored equivalent mass to "pull against", before it is dissipated as heat.
This chain of posts is about Shawyer's theory not yours, if your theory works (I need some more time to work though some details), it involves special GR effects that make it an open system. Shawyer's theory does not include those.
Please stop pulling this out of context and changing the subject.
I was responding to a different user who replied to me. However, I don't recall reading anywhere that Shawyer said it is a closed system. I do recall reading where he said that the energy stored inside as the Q, decreases as the energy is converted into thrust. This is not a closed system. In a closed system, the energy could not escape at all, and I think he's said it is an open system, for which he is correct. His math is flawed, his words are confusing, and he has confounded experimental data, but when "I" read between the lines of what he really means by those words, he is describing my theory. The mass inside accelerates toward the rear, and the frustum moves forward to conserve momentum. That is what he's saying, as best he knows how.
It seems bassackwards but it's not, once you realize it's not a closed system and there is a potential difference between the frustum and the energy inside it, because that energy is leaving the cavity and heating the copper asymmetrically forming a potential gradient.
Personally, I feel sorry for the guy. It's a complicated problem, unlike anything anyone has ever seen before since Newton, whose mind wasn't clouded with preconceptions. Shawyer has proposed an incorrect mathematical theory, but his intuition is correct. He understands how it works, he just doesn't know how to do the math.
Is new talk of interstellar drive too good to be true?
https://www.newscientist.com/article/2113253-is-new-talk-of-interstellar-drive-too-good-to-be-true/
Final NASA Eagleworks Paper Confirms Promising EMDrive Results, Proposes Theoretical Model
https://hacked.com/final-nasa-eagleworks-paper-confirms-promising-emdrive-results-proposes-theoretical-model/
Final version of NASA EMdrive paper confirms 1.2 millinewtons per kw of thrust which is 300 times better than other zero propellent propulsion
http://www.nextbigfuture.com/2016/11/final-version-of-nasa-emdrive-paper.html?m=1
The second story is mine, thanks for sharing.
The first story (New Scientist) ends with: "In truth, until there is real scientific evidence on the table for others to pore over, critique, test and reproduce, the vast majority care little about the claims of interstellar revolutions. And for those who are not scientists, but who dream of interstellar flight and galactic colonisation, and wonder what to make of all of this, remember the old adage: 'If it sounds too good to be true, it probably is.'"
The thing is, real scientific evidence that EmDrive works IS on the table, and has been there for quite some time. The NS writer is making, perhaps intentionally, some confusion between EmDrive and "warp-drives," FTL and all that. But even if we are talking of "magic" FTL propulsion, the conclusion is defeatist. I would add a few words to the conclusion:
If it sounds too good to be true, it probably is, but we should do our f## best to find out.
