Author Topic: EM Drive Developments Thread 1  (Read 1473052 times)

Offline Raj2014

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Re: EM Drive Developments
« Reply #160 on: 08/03/2014 11:07 pm »
Has there been any new news on what NASA will do now?

Offline Elmar Moelzer

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Re: EM Drive Developments
« Reply #161 on: 08/04/2014 02:31 pm »
Why are there now two threads for this nonsense?
I reported it to mods earlier, when it was only 5 posts long...
Posted another point over the in the other thread (well one of many on the subject): Where is the electricity coming from? Is it from a battery or capacitor on the thruster or a wall outlet. If it is the latter, then this could be an explanation for the thrust and it would also make the device irrelevant as a thruster.
I think that this mistake was made at least with the Cannae thruster experiment. I am not sure about Shawyers later experiments, though (his setups are pretty big and the power source might be on it).
Another problem is that the Cannae experiments were not done in a vacuum. We might just see ionized air flowing over the device, creating thrust.
Finally, we have the previously mentioned problem that the Null device also created thrust.
All this makes me highly skeptical, though I am more than willing to be positive surprised (would be cool if it worked).
« Last Edit: 08/04/2014 02:38 pm by Elmar Moelzer »

Offline IslandPlaya

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Re: EM Drive Developments
« Reply #162 on: 08/04/2014 02:52 pm »
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.

Offline Cinder

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Re: EM Drive Developments
« Reply #163 on: 08/04/2014 03:39 pm »
It seems much confusion has arisen here. I have been reading on the Polywell forums that firstly the business with the Null article is not a concern, what you are seeing is an ill chosen abstract. Please see the quote below for more detail.
If the experiments were actually done at atmospheric pressure none of that matters. It's clear from the paper that at least some of the tests were (see fig 22). That fact that it isn't clearly stated for each test is a major flaw in the paper regardless of the results, and strongly suggests the paper wasn't rigerously reviewed.

I don't understand why you think the quoted post would "clear up confusion", it looks like a hand wavy rationalization to me. To most scientists, a "null" that produces the predicted effect would be a strong hint to look for experimental error, not new physics.

My overall view is this is going to have wait for the further round of tests in the fall of this year, it looks like at this time there are just too many possible issues with this as it stands. It sounds like what they are planning next is either going to make or break this whole thing.

Nothing will ever break it.  The tests will fail to show convincing evidence of anomalous thrust, and the proponents of the various reactionless drives will come up with rationalizations for it and explain how they're working on new versions that will fix the problems.  It will continue without end.

What is "it"?  Yes it can be broken, with good enough experimental setup.  That is what science is.  If this thing (Cannae or whatever White used and/or renamed) is non-functional, and so simply non-functional, why doesn't someone else demonstrate that?

If that happened, would "they" have any credence (ie employment) at NASA? 
NEC ULTIMA SI PRIOR

Offline Elmar Moelzer

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Re: EM Drive Developments
« Reply #164 on: 08/04/2014 03:57 pm »
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.
The power is provided from a physically connected source, but the source is not accelerated with the device. This means that you are feeding a current from a static system into a moving frame of reference and that could appear as a thrust. And I might be wrong with this, but I am pretty sure that this could be a potential problem, especially when we are dealing with very small amounts of thrust here.

Offline frobnicat

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Re: EM Drive Developments
« Reply #165 on: 08/04/2014 04:15 pm »
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.

Don't know the exact setup but it's not trivial to exchange power from laboratory frame to device frame without exchanging momentum down to µN. The thrust of the device is measured as a displacement against a spring. With a torsion pendulum the device should be completely free to rotate about a vertical axis save for a very weak spring restoring force. The torsion wire(s) should be the only mechanical link(s) between lab frame and device frame. If you go current through them they are heating (changing stiffness). If you have other "soft" bent wires they will exert spurious forces. Also 10 cm of straight wire passing only 200mA of current will get about a µN of lateral thrust in the earth magnetic field alone. A curved wire will tend to straighten up a little bit from interaction with its own generated magnetic field. Going wireless would probably be worse as it's basically coupling electromagnets across the two frames. Even optical power transmission has some radiation pressure (not sure how much). All effects that go on when power on and off when power off (like the effect to be measured). I'm sure all that can be mitigated, but it's really far from trivial. Better have the power source on the suspended test bed (though not perfect as it can still electromagnetically interfere with lab/earth frame even in a vacuum)
Edited : 200mA not 20mA
« Last Edit: 08/04/2014 05:52 pm by frobnicat »

Offline CW

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Re: EM Drive Developments
« Reply #166 on: 08/04/2014 05:14 pm »
I don't get it in my head, why each and every one of these experiments seems unable to just put the local power supply on the would-be drive and start the damn thing. It should be an easy task to put the test article in a non-functional mode and record possible forces, while energy is supplied for an exact duration of time. Do this a statistically relevant number of times and e.g. average the recorded data, then make the test article functional (we all wish for that, don't we) and do your real recordings, for the same time duration as for calibrating. Then do a friggin' delta, and you should pretty much know if Scotty farted in the lab or if there is some real stuff going on :) .
Reality is weirder than fiction

Offline sghill

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Re: EM Drive Developments
« Reply #167 on: 08/04/2014 05:41 pm »
Hello all,

I think there is one elephant in the room that nobody seems to notice. If the drive is supposed to gain impulse by interaction with virtual particles of the quantum vacuum, then these particles obviously have to be accelerated in the opposed direction in which the drive is accelerated.

Here comes now the elephant: When those accelerated virtual particles (which pop in an out of existence spontaneously) disappear again to who-knows-where, what happens to the impulse that these particles previously gained.. is it gone? I can hardly imagine that this should be the case. So.. where would the imparted impulse on the virtual particles go? Ideas? On the other hand.. please correct me if I'm wrong.. I seem to remember some knowledge that virtual particles were not subject to impulse conservation?

Regards

Welcome to the forum!

[sophomoric speculation] Perhaps the impulse goes to wherever the virtual particles came "from" when they pop out of existence again.  Conservation of momentum only matters in a closed system right? [/sophomoric speculation]
Bring the thunder!

Offline DanielW

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Re: EM Drive Developments
« Reply #168 on: 08/04/2014 05:55 pm »
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.

Don't know the exact setup but it's not trivial to exchange power from laboratory frame to device frame without exchanging momentum down to µN. The thrust of the device is measured as a displacement against a spring. With a torsion pendulum the device should be completely free to rotate about a vertical axis save for a very weak spring restoring force. The torsion wire(s) should be the only mechanical link(s) between lab frame and device frame. If you go current through them they are heating (changing stiffness). If you have other "soft" bent wires they will exert spurious forces. Also 10 cm of straight wire passing only 20mA of current will get about a µN of lateral thrust in the earth magnetic field alone. A curved wire will tend to straighten up a little bit from interaction with its own generated magnetic field. Going wireless would probably be worse as it's basically coupling electromagnets across the two frames. Even optical power transmission has some radiation pressure (not sure how much). All effects that go on when power on and off when power off (like the effect to be measured). I'm sure all that can be mitigated, but it's really far from trivial. Better have the power source on the suspended test bed (though not perfect as it can still electromagnetically interfere with lab/earth frame even in a vacuum)

I would like to know more about the experimental set up. But what they have just sounds prone to error. They are not measuring force directly, they are measuring torque. We know that they are passing electrons through wires, but not how those wires are shaped. In a stainless steel container. I can easily think of cases that would create a small torque. induced eddy currents for example. Maybe they just got unlucky that whatever weird EM effects are going on happened to create a net torque in the same direction that they expected a force for the plane of measurement.

Offline IslandPlaya

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Re: EM Drive Developments
« Reply #169 on: 08/04/2014 07:08 pm »
I think they did the test with an RF load also.
They reported no force in this case. That must go someway to eliminating systemic errors in their setup.

Offline RanulfC

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Re: EM Drive Developments
« Reply #170 on: 08/04/2014 07:13 pm »
Too important to be public. Military knows to release crappy results.
What do you think X34 is for?

Sure you want to go with that example there? The X-34 never flew and so provided NO data. Just an FYI :)

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline ChrisWilson68

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Re: EM Drive Developments
« Reply #171 on: 08/04/2014 07:14 pm »
I think they did the test with an RF load also.
They reported no force in this case. That must go someway to eliminating systemic errors in their setup.

No, they reported there was some thrust detected from the RF load, also, but not as much, and they subtracted that from the measured thrust for the other two devices.

Offline IslandPlaya

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Re: EM Drive Developments
« Reply #172 on: 08/04/2014 07:15 pm »
Too important to be public. Military knows to release crappy results.
What do you think X34 is for?

Sure you want to go with that example there? The X-34 never flew and so provided NO data. Just an FYI :)

Randy
Lol. Fair cop RanulfC!
I 'of course' meant to say the X-37
 :-[

Offline RanulfC

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Re: EM Drive Developments
« Reply #173 on: 08/04/2014 07:20 pm »
Too important to be public. Military knows to release crappy results.
What do you think X34 is for?

Sure you want to go with that example there? The X-34 never flew and so provided NO data. Just an FYI :)

Randy
Lol. Fair cop RanulfC!
I 'of course' meant to say the X-37
 :-[

Of course you did, :) Don't forget "we" are watching you... No, really we are, now turn the light back on and open the curtain so we can get a better view...
(Did I ever mention I once had a hobby of "tweeking" the conspiricy theory boards? Loads of fun... The the Illuminatia contacted me... Yes that was a Weird Al reference! :) )

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline CW

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Re: EM Drive Developments
« Reply #174 on: 08/04/2014 07:57 pm »
Welcome to the forum!

[sophomoric speculation] Perhaps the impulse goes to wherever the virtual particles came "from" when they pop out of existence again.  Conservation of momentum only matters in a closed system right? [/sophomoric speculation]

Thanks for your welcome, sghill.

If you put it like that, it seems to me that 'existence' should comprise some weird form of (in lack of a better word) event horizon that is perhaps comparable to a mirror surface. Maybe physical reality actually takes the form of a mirrored state, while the sum of all vectors over both sides of the mirror half spaces is perfectly zero? If so, then you could even produce BS like 'free energy', because device A then existed on both sides of the mirror with exactly diametral vectors, and everything still nulls out at all times.. NASA, you can do it ::) !
Reality is weirder than fiction

Offline IslandPlaya

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Re: EM Drive Developments
« Reply #175 on: 08/04/2014 08:16 pm »
I think they did the test with an RF load also.
They reported no force in this case. That must go someway to eliminating systemic errors in their setup.

No, they reported there was some thrust detected from the RF load, also, but not as much, and they subtracted that from the measured thrust for the other two devices.
They did? Going back over the abstract they mention the RF load, but nothing about testing of such.
Did I just overlook it or do you have extra info?

Offline JasonAW3

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Re: EM Drive Developments
« Reply #176 on: 08/04/2014 08:41 pm »
I'm hoping that they find that this gizmo actually works, but if it doesn't, I don't think that they can accuse anyone of fraud this time.  It may be a set of honest mistakes.

I just find it danged interesting that preliminary testing shows a success, even on the rigged device that wasn't supposed to work.

It makes me wonder just what the heck have they found here anyway?
My God!  It's full of universes!

Offline brokndodge

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Re: EM Drive Developments
« Reply #177 on: 08/04/2014 08:50 pm »
IANAS - But, I have read the report and it seems to me that they are only reporting on experimental results that they could not explain and honestly didn't expect to see.  The first set of experiments and the "null" (they should have chosen a better word) device indicated results that were unexpected and invalidated 1 theory as to why results were seen.  The so called "null" device was not really such a device. Rather, the engineer that made it had a theory that placing groves in one end of the device would create thrust and that not having the grooves would not create thrust.  He was proven wrong in that the device appeared to create thrust irregardless of the groves. 

The second set of experiments conducted with a different device of a type more closely related to the EMDrive also yielded results.  They were able to take lessons learned about their first experimental setup and apply them to the second set of tests.  As such they were able to test at much higher frequencies. 

Among all of the tests, time available to test has been an issue. They stated in the opening brief about the setup of their vacuum chamber and pendulum that it takes "days" to pull an appropriate vacuum.  Later in the paper they stated that one of the devices used had electrical components that were not vacuum friendly.  I don't recall a specific mention of the second set of tests being performed in a vacuum. 

The paper did not make any conclusions as to what is causing the effect that they are seeing.  It does state that the effect is worth investigating and that they are planning to test a more powerful 1GHz version at other facilities with better equipment.  I believe that at this time such an advanced concept lab as this is doing the right thing in further researching the results that they measured.  I also believe that they are confident to a high enough degree to warrant larger scale testing at facilities that are better equipped for such tests. 

I look forward to the results of such testing whether they be positive or negative.

Offline Star One

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Re: EM Drive Developments
« Reply #178 on: 08/04/2014 08:53 pm »
Am not sure I understand the objection to power being provided from a source not physically connected to the device.

I understand that it would no longer be a closed system, but considering the scope of the mechanism of which these things are supposed to work then it is a moot point.
Why would it matter? Honest question.
The power is provided from a physically connected source, but the source is not accelerated with the device. This means that you are feeding a current from a static system into a moving frame of reference and that could appear as a thrust. And I might be wrong with this, but I am pretty sure that this could be a potential problem, especially when we are dealing with very small amounts of thrust here.

I assume that's why they are building a more powerful setup to test.

From what I have gathered it mentions somewhere this net setup being sent out to places like the JPL to test, can anyone confirm this?
« Last Edit: 08/04/2014 08:57 pm by Star One »

Offline IslandPlaya

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Re: EM Drive Developments
« Reply #179 on: 08/04/2014 08:57 pm »
IANAS - But, I have read the report and it seems to me that they are only reporting on experimental results that they could not explain and honestly didn't expect to see.  The first set of experiments and the "null" (they should have chosen a better word) device indicated results that were unexpected and invalidated 1 theory as to why results were seen.  The so called "null" device was not really such a device. Rather, the engineer that made it had a theory that placing groves in one end of the device would create thrust and that not having the grooves would not create thrust.  He was proven wrong in that the device appeared to create thrust irregardless of the groves. 

The second set of experiments conducted with a different device of a type more closely related to the EMDrive also yielded results.  They were able to take lessons learned about their first experimental setup and apply them to the second set of tests.  As such they were able to test at much higher frequencies. 

Among all of the tests, time available to test has been an issue. They stated in the opening brief about the setup of their vacuum chamber and pendulum that it takes "days" to pull an appropriate vacuum.  Later in the paper they stated that one of the devices used had electrical components that were not vacuum friendly.  I don't recall a specific mention of the second set of tests being performed in a vacuum. 

The paper did not make any conclusions as to what is causing the effect that they are seeing.  It does state that the effect is worth investigating and that they are planning to test a more powerful 1GHz version at other facilities with better equipment.  I believe that at this time such an advanced concept lab as this is doing the right thing in further researching the results that they measured.  I also believe that they are confident to a high enough degree to warrant larger scale testing at facilities that are better equipped for such tests. 

I look forward to the results of such testing whether they be positive or negative.
Great post.
I may be slow today, but could you supply a link to the paper please?
Cheers mate.

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