Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2169236 times)

Offline Prunesquallor

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These seem to be depressive, defeatist, Kafkaesque responses. I am going to wait to see what people who actually work at Eagleworks say. $25M (just picking a reasonable but arbitrary amount here) might to a lot of money Eagleworks, but for the federal government, that's pin money. Even in a word where governments are overrun by corruption, pettiness, and mismanagement, that doesn't mean that all parts are, all the time.

Maybe, but the risk of unintended consequences is high, IMHO. Given the type of publicity this effort garners, would the following headline be unrealistic?:
"President asks Congress to fund Warp Drive development".
I expect the response could be unfortunate.
« Last Edit: 05/02/2015 11:56 AM by Prunesquallor »
Retired, yet... not

Offline Mulletron

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"Dean Drive" mechanics can offer an insight to EM Drive function.

-snip-


http://www.npl.washington.edu/AV/altvw83.html

Quote
Later more detailed studies showed that the Dean Drive developed no net time- averaged force and that Newton's 3rd Law remained intact.
« Last Edit: 05/02/2015 12:27 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Jim

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This is a question for Eagleworks people:
It seems as though you are short of resources of various types. I propose an online petition, utilizing the "we the people" facility of whitehouse.gov, to ask for more resources to be given to NASA, earmarked for Eagleworks, for the projects of the EM-drive/ME-drive/Q-thruster, and its application to the Alcubierre drive. If you could come up with a proposal, perhaps more focused than I've indicated, this would be the meat of the petition.

I don't mean to over the heads of the NASA Administration, and force them to take money away from other programs for this one. This would be additional, federal money. In my experience, being given more resources than you can use raises expectations beyond what is achievable. Most often, you can't get a project done twice as fast by spending twice as much money on it.


That is completely the wrong way to go at it.   Why should they be singled out?  what says they are worthy of it?  If anything, it should be a competition for the resources. 

Offline rgreen

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Following on what jknuble said about the multipactor-like effect as a possible cause of thrust. http://en.wikipedia.org/wiki/Multipactor_effect  I can't help but wonder about what's going on with the copper surface of the frustum. A quick back of the envelope (well, python) calculation shows that there's certainly enough energy in these devices to somehow atomize a small amount of copper , and propel them with enough momentum to produce a small amount of thrust.

For example, a 30 watt emdrive where 0.001% of the energy went towards atomization and 1% went toward addtional momentum of the particles... You'd have a device with 91uN thrust, propelling 1.4ng of copper a second at 65500m/s.

I can think of 3 ways to debunk this. 1) perhaps that amount of particles going that fast would be noticeable with the naked eye, so this isn't really a valid explanation. 2) stick a detector behind the thruster (are they ionized?). 3) SEM of the surface compared to scraps from the same batch of copper not used in the thrustum.

Offline Mulletron

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Just want to run this by the group.

I am a believer that thrust doesn't scale ONLY with Q. We even can see that in the data. See the original Nasa paper.
http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

I think I have a good idea for once. I think the "Where is the balanced gain and loss?" thing from the other day is addressed by creating an unstable cavity, aka not high Q, not low Q either.

The balanced gain and loss stuff came up here. 4th-6th links from top.
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1357829#msg1357829

I think the trick is to get energy in, put it to work a few thousand times (doing all that quantum wizardry I posted papers on :) ), then let it go as heat, which will inevitably happen as photons are red shifted and fall out of resonance. High Q is a baddie. Low Q is a baddie.

What's the point of having all that accumulated energy sitting in there static, doing nothing?

We need this thing to ride the razor's edge between gain and loss.

Also, what made this kinda click with me is what Mr. Shawyer said below. The Cullen paper he mentioned is shared here:
https://drive.google.com/folderview?id=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM&usp=sharing

So if this passes the smell test, how is the next question. Seems like not having the dielectric covering the entire small end (vs just a small patch) might be a good thing to try. I'm sure there's a ton of ways to do this.

There's a lot we can learn from that whispering-gallery research cited.
http://revolution-green.com/optics-breakthrough-demonstrates-new-behaviors-physics/
http://www.researchgate.net/publication/262451086_Paritytime-symmetric_whispering-gallery_microcavities
http://arxiv.org/ftp/arxiv/papers/1308/1308.4564.pdf

I'm openly brainstorming here. Would like some feedback.
« Last Edit: 05/02/2015 06:09 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline inquisitive-j

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I am new to this forum and hesitant to post since my expertise is not in a relevant field of science, but I am excited about this research and have read all pages of comments since page 80 though most were admittedly over my head. Please forgive me if my ignorance shows too much in comments to come. But right now I'm just curious about this article.

I received an article last night via google alert that said that the interferometer test, not the thrust tests, had now been replicated in a vacuum. Is this true? I've seen no mention of it here though perhaps I just missed it. Here is the link: http://www.escapistmagazine.com/news/view/140670-NASA-Confirms-The-EMDrive-Warp-Field-Still-Generates-Works-In-A-Vacuum.
« Last Edit: 05/02/2015 04:06 PM by inquisitive-j »

Offline richardcampos

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Let's say this all works as claimed by Shawyer, and there is indeed scability and improved performance in high Qs.

Theoretically, what would be the smallest size possible for a Q-thrust device?

Rick

Online Stormbringer

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the limit would probably be the soft to medium X-ray range? because the smaller the frustrum the higher the frequency required to obtain resonance.
When antigravity is outlawed only outlaws will have antigravity.

Offline richardcampos

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So we're talking about something on the intracellular level...

Online Stormbringer

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I know there also has to be room inside the frustrum to establish various resonant modes and that x rays begin to heat metal particularly the higher energy ones. I do not know the actual minimal dimensions needed to establish the resonant modes or that won't be melted or compromised by the x rays so I am just going to use the force and say you probably cannot go down to IC chip level though because of the one or both of the above issues.
When antigravity is outlawed only outlaws will have antigravity.

Offline Thutmose

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Let's say this all works as claimed by Shawyer, and there is indeed scability and improved performance in high Qs.

Theoretically, what would be the smallest size possible for a Q-thrust device?

Rick

the physical size should be directly related to the wavelength of the microwaves used, so it can theoretically be scaled down as small as you want, until you start hitting engineering limits of precisely manufacturing the correctly shaped cavity, and generating high power microwaves of very high frequencies

Offline LasJayhawk

Star-Drive, is your current test setup the same as shown in figure 17 of the AIAA paper from July last year, but with the RG-8 cable? If so, you might have issues with the cable. Most high quality RG-8 has a  manufacturers minimum bend radius of 4" and can develop some "entertaining" behavior in short order if bent beyond that. You might want to check the cable in its current shape on a network analyzer to verify performance.

If the cable is degrading, you might want to look at something like Gore phaseflex cable in that spot. It would give you the flexibility of the RG-142 with the RF performance of the RG-8, and better repeatablity to boot.

Offline Dmytry

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Star-Drive, is your current test setup the same as shown in figure 17 of the AIAA paper from July last year, but with the RG-8 cable? If so, you might have issues with the cable. Most high quality RG-8 has a  manufacturers minimum bend radius of 4" and can develop some "entertaining" behavior in short order if bent beyond that. You might want to check the cable in its current shape on a network analyzer to verify performance.

If the cable is degrading, you might want to look at something like Gore phaseflex cable in that spot. It would give you the flexibility of the RG-142 with the RF performance of the RG-8, and better repeatablity to boot.
A very high frequency microwave resonant cavity is commonly known as a "laser".

Offline Dmytry

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Following on what jknuble said about the multipactor-like effect as a possible cause of thrust. http://en.wikipedia.org/wiki/Multipactor_effect  I can't help but wonder about what's going on with the copper surface of the frustum. A quick back of the envelope (well, python) calculation shows that there's certainly enough energy in these devices to somehow atomize a small amount of copper , and propel them with enough momentum to produce a small amount of thrust.

For example, a 30 watt emdrive where 0.001% of the energy went towards atomization and 1% went toward addtional momentum of the particles... You'd have a device with 91uN thrust, propelling 1.4ng of copper a second at 65500m/s.

I can think of 3 ways to debunk this. 1) perhaps that amount of particles going that fast would be noticeable with the naked eye, so this isn't really a valid explanation. 2) stick a detector behind the thruster (are they ionized?). 3) SEM of the surface compared to scraps from the same batch of copper not used in the thrustum.
4: enclose the device (complete with the microwave source and, preferably, batteries, provided the pendulum is not too sensitive to shifts in CoM) in a sealed box. Then you can even run your microwave cavity in pressurized SF4 if that helps.
« Last Edit: 05/02/2015 06:04 PM by Dmytry »

Offline Rodal

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This thread is for EM Drive DEVELOPMENT, related to space flight applications.

THERE ARE A NUMBER OF INQUIRING POSTS HERE LATELY that instead belong on this thread:

http://forum.nasaspaceflight.com/index.php?topic=37438.280




Offline squid

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Just want to run this by the group.

I am a believer that thrust doesn't scale ONLY with Q. We even can see that in the data. See the original Nasa paper.
http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

I think I have a good idea for once. I think the "Where is the balanced gain and loss?" thing from the other day is addressed by creating an unstable cavity, aka not high Q, not low Q either.

The balanced gain and loss stuff came up here. 4th-6th links from top.
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1357829#msg1357829

I think the trick is to get energy in, put it to work a few thousand times (doing all that quantum wizardry I posted papers on :) ), then let it go as heat, which will inevitably happen as photons are red shifted and fall out of resonance. High Q is a baddie. Low Q is a baddie.

What's the point of having all that accumulated energy sitting in there static, doing nothing?

We need this thing to ride the razor's edge between gain and loss.

Also, what made this kinda click with me is what Mr. Shawyer said below. The Cullen paper he mentioned is shared here:
https://drive.google.com/folderview?id=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM&usp=sharing

So if this passes the smell test, how is the next question. Seems like not having the dielectric covering the entire small end (vs just a small patch) might be a good thing to try. I'm sure there's a ton of ways to do this.

There's a lot we can learn from that whispering-gallery research cited.
http://revolution-green.com/optics-breakthrough-demonstrates-new-behaviors-physics/
http://www.researchgate.net/publication/262451086_Paritytime-symmetric_whispering-gallery_microcavities
http://arxiv.org/ftp/arxiv/papers/1308/1308.4564.pdf

I'm openly brainstorming here. Would like some feedback.

Shawyer's explanation does not pass the smell test, and is not adressed by the Cullen paper you linked. Look for example at figure 5. There is a movable piston at the end of the waveguide T-junction, which is subject to radiation pressure. The piston will exert a (Newton's 3rd law) reaction force, and so momentum is conserved.

The EM drive is a fully enclosed cavity. The radiation inside will reflect off the walls and create some strain in the copper, but the net force integrated by the surface (given by the integral of the Poynting vector) has a time average of 0, as has been demonstrated mathematically many many times.

It is absolutely true that one can view standing waves as linear superpositions of traveling waves. This is just a different way of saying that Maxwell's equations are linear. Rodal's analysis is true whether one thinks of the fields as standing or superpositions of traveling waves. There is nothing besides the stress-energy tensor in the classical theory of electromagnetism.

To be clear: there is NO explanation for any increase in momentum of the drive to be found in classical theory (including Special Relativity through Maxwell's equations).

If there is an actual effect, then it must be caused by the coupling of electromagnetic fields to some other heretofore unobserved field. Even if such a coupling could be made in a way that is Lorentz invariant, it should have been detectable very easily at particle colliders. So again I ask:

If there is some effect here, why has it not been observed in far more precise experiments that probe the exact same physics?






Offline zellerium

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Hey everyone!


My name is Kurt Zeller, my colleague Bran Kraft and I are undergraduate Aerospace Engineering students at California Polytechnic State University, San Luis Obispo. (authors of this review: http://www.slideshare.net/KurtZeller/investigation-and-analysis-of-anomalous-electromagnetic-propulsion-devices-41315-46946953 )

We are currently designing an experiment to test a resonant cavity. We have made considerable progress on our own and would like to share our methodology with the forum to gain insight and suggestions before we start purchasing materials. Our primary objective is to demonstrate thrust using a counterbalanced lever. Our secondary objective is to quantify the thrust and make changes to the geometry of the dielectric.

We have recently received funding for a copper cavity, PTFE plate, and aluminum beam. This aluminum beam will have a sharp fulcrum welded to the bottom and the ends will be recessed lower than the fulcrum to put the center of mass closer to the balance point. We anticipate the thrust will be larger than the fulcrum's friction but this is still a concern in our experiment. An additional concern is the tension force from the cables that supply power. We plan to fix these cables above the fulcrum with enough slack to negate this issue. We acknowledge the difficulties in accurately obtaining thrust measurements but are mainly attempting to demonstrate thrust before quantifying it. 

The cavity will be made of C10100 Copper alloy tube with two C11000 copper end plates. A symmetric shape was chosen to minimize complications and cost as well as provide a different cavity geometry for comparison. A PTFE plate will machined into discs of varying thickness that fit adequately at the end of the cylinder. We have access to a VNA from our EE department and will use it to determine the resonant frequencies.

We are still awaiting approval for our latest proposal to the Cal Poly committee where we requested $3,500 to rent a 2-3 GHz signal generator, a 50W amplifier, and a spectrum analyzer. We are also planning to implement a matched load to absorb reflected power but are still working with professors to design it.   

Because these devices are incredibly expensive, we have been researching how to engineer a microwave oven magnetron into the power source. Unfortunately, the relatively constant frequency will limit the number of resonant modes that can be excited unless our cavity length is adjustable. Furthermore, thermal expansion may be a much greater issue at higher power and resonance may be more difficult to maintain.

In the event that we are approved funding for the rental equipment we will most likely attempt both setups.
We are happy to address questions or concerns and we look forward to any suggestions you may have. We understand Eagleworks is planning a similar experiment and we are hoping to gain more insight into their power delivery system.

We would like to thank all the contributors to this forum who have been a great help and inspiration for us throughout this project.

Offline cfs

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Just want to run this by the group.

I am a believer that thrust doesn't scale ONLY with Q. We even can see that in the data. See the original Nasa paper.
http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

I think I have a good idea for once. I think the "Where is the balanced gain and loss?" thing from the other day is addressed by creating an unstable cavity, aka not high Q, not low Q either.

The balanced gain and loss stuff came up here. 4th-6th links from top.
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1357829#msg1357829

I think the trick is to get energy in, put it to work a few thousand times (doing all that quantum wizardry I posted papers on :) ), then let it go as heat, which will inevitably happen as photons are red shifted and fall out of resonance. High Q is a baddie. Low Q is a baddie.

What's the point of having all that accumulated energy sitting in there static, doing nothing?

We need this thing to ride the razor's edge between gain and loss.

Also, what made this kinda click with me is what Mr. Shawyer said below. The Cullen paper he mentioned is shared here:
https://drive.google.com/folderview?id=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM&usp=sharing

So if this passes the smell test, how is the next question. Seems like not having the dielectric covering the entire small end (vs just a small patch) might be a good thing to try. I'm sure there's a ton of ways to do this.

There's a lot we can learn from that whispering-gallery research cited.
http://revolution-green.com/optics-breakthrough-demonstrates-new-behaviors-physics/
http://www.researchgate.net/publication/262451086_Paritytime-symmetric_whispering-gallery_microcavities
http://arxiv.org/ftp/arxiv/papers/1308/1308.4564.pdf

I'm openly brainstorming here. Would like some feedback.

Shawyer's explanation does not pass the smell test, and is not adressed by the Cullen paper you linked. Look for example at figure 5. There is a movable piston at the end of the waveguide T-junction, which is subject to radiation pressure. The piston will exert a (Newton's 3rd law) reaction force, and so momentum is conserved.

The EM drive is a fully enclosed cavity. The radiation inside will reflect off the walls and create some strain in the copper, but the net force integrated by the surface (given by the integral of the Poynting vector) has a time average of 0, as has been demonstrated mathematically many many times.

It is absolutely true that one can view standing waves as linear superpositions of traveling waves. This is just a different way of saying that Maxwell's equations are linear. Rodal's analysis is true whether one thinks of the fields as standing or superpositions of traveling waves. There is nothing besides the stress-energy tensor in the classical theory of electromagnetism.

To be clear: there is NO explanation for any increase in momentum of the drive to be found in classical theory (including Special Relativity through Maxwell's equations).

If there is an actual effect, then it must be caused by the coupling of electromagnetic fields to some other heretofore unobserved field. Even if such a coupling could be made in a way that is Lorentz invariant, it should have been detectable very easily at particle colliders. So again I ask:

If there is some effect here, why has it not been observed in far more precise experiments that probe the exact same physics?

This is why I'm saying there should be more of an effort to actually quantify the radiation emanating from the EMDrive.  If there really are e+/e- pairs popping out of the vacuum then we should be able to see them with appropriate detection mechanism (e.g. if NASA is like a standard physics department they should have some PMTs and scintillation crystals lying around somewhere).
« Last Edit: 05/02/2015 07:22 PM by cfs »

Offline Mulletron

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Just want to run this by the group.

I am a believer that thrust doesn't scale ONLY with Q. We even can see that in the data. See the original Nasa paper.
http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf

I think I have a good idea for once. I think the "Where is the balanced gain and loss?" thing from the other day is addressed by creating an unstable cavity, aka not high Q, not low Q either.

The balanced gain and loss stuff came up here. 4th-6th links from top.
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1357829#msg1357829

I think the trick is to get energy in, put it to work a few thousand times (doing all that quantum wizardry I posted papers on :) ), then let it go as heat, which will inevitably happen as photons are red shifted and fall out of resonance. High Q is a baddie. Low Q is a baddie.

What's the point of having all that accumulated energy sitting in there static, doing nothing?

We need this thing to ride the razor's edge between gain and loss.

Also, what made this kinda click with me is what Mr. Shawyer said below. The Cullen paper he mentioned is shared here:
https://drive.google.com/folderview?id=0B4PCfHCM1KYoTXhSUTd5ZDN2WnM&usp=sharing

So if this passes the smell test, how is the next question. Seems like not having the dielectric covering the entire small end (vs just a small patch) might be a good thing to try. I'm sure there's a ton of ways to do this.

There's a lot we can learn from that whispering-gallery research cited.
http://revolution-green.com/optics-breakthrough-demonstrates-new-behaviors-physics/
http://www.researchgate.net/publication/262451086_Paritytime-symmetric_whispering-gallery_microcavities
http://arxiv.org/ftp/arxiv/papers/1308/1308.4564.pdf

I'm openly brainstorming here. Would like some feedback.

Shawyer's explanation does not pass the smell test, and is not adressed by the Cullen paper you linked. Look for example at figure 5. There is a movable piston at the end of the waveguide T-junction, which is subject to radiation pressure. The piston will exert a (Newton's 3rd law) reaction force, and so momentum is conserved.

The EM drive is a fully enclosed cavity. The radiation inside will reflect off the walls and create some strain in the copper, but the net force integrated by the surface (given by the integral of the Poynting vector) has a time average of 0, as has been demonstrated mathematically many many times.

It is absolutely true that one can view standing waves as linear superpositions of traveling waves. This is just a different way of saying that Maxwell's equations are linear. Rodal's analysis is true whether one thinks of the fields as standing or superpositions of traveling waves. There is nothing besides the stress-energy tensor in the classical theory of electromagnetism.

To be clear: there is NO explanation for any increase in momentum of the drive to be found in classical theory (including Special Relativity through Maxwell's equations).

If there is an actual effect, then it must be caused by the coupling of electromagnetic fields to some other heretofore unobserved field. Even if such a coupling could be made in a way that is Lorentz invariant, it should have been detectable very easily at particle colliders. So again I ask:

If there is some effect here, why has it not been observed in far more precise experiments that probe the exact same physics?

Thank you for that thoughtful response and yes I agree with you that there is no way to explain this with classical theory:
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1367355#msg1367355
Quoting myself:
Quote
What I mean is that any attempt to formulate a theory of where the anomalous thrust is coming from which is based on classical electrodynamics will fail. A fully quantum approach is required. What I mean by "other than usual symmetry conditions" is that based off what I've been reading (aka not my own original research), simultaneous breaking of P & T symmetries is required.

On the flipside, the Q-thruster theory out there doesn't resonate  ;) with me either. That's why I've been trying to find other science out there that is accepted and makes sense. Do you think that is a worthy endeavor?
« Last Edit: 05/02/2015 08:07 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline dustinthewind

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Following on what jknuble said about the multipactor-like effect as a possible cause of thrust. http://en.wikipedia.org/wiki/Multipactor_effect  I can't help but wonder about what's going on with the copper surface of the frustum. A quick back of the envelope (well, python) calculation shows that there's certainly enough energy in these devices to somehow atomize a small amount of copper , and propel them with enough momentum to produce a small amount of thrust.

For example, a 30 watt emdrive where 0.001% of the energy went towards atomization and 1% went toward addtional momentum of the particles... You'd have a device with 91uN thrust, propelling 1.4ng of copper a second at 65500m/s.

I can think of 3 ways to debunk this. 1) perhaps that amount of particles going that fast would be noticeable with the naked eye, so this isn't really a valid explanation. 2) stick a detector behind the thruster (are they ionized?). 3) SEM of the surface compared to scraps from the same batch of copper not used in the thrustum.

Just how would we get a net-thrust from a closed cavity with atomization.  Even if atoms are being ioniozed inside the cavity I don't see how that could result in a net thrust.  Atomization results in immediate thrust but then that creates impact on the other side of the cavity canceling out the propulsion. 

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