Direct measurement of quantum fluctuations

[PB666]

http://phys.org/news/2015-10-team-sampled-electric-field-vacuum-fluctuations.html

[sgt_flyer]

Mmh - if they manage to determine that they really are observing quantum fluctuations in vacuum (and devellop the corresponding theories about their detectors)

If it works, their detector could be used to check if the EMdrives theory that it's pushing against quantum particles is correct or not. (If their detector works and don't detect quantum fluctuations in a working EMdrive, then it'll simply mean that EMdrives use something else

Lots of ifs, but well

Edited October 2, 2015 by sgt_flyer

[monstah]

Ah, sigh, not the EMdrives again...

[Hcube]

Ah, sigh, not the EMdrives again...

What's an EM drive ?

[monstah]

A few topics back, people were discussing that someone discovered a magical engine that propelled by pushing against quantum fluctuations, and this forum went ablaze with people who actually have PhDs in physics and people who think they have, bashing heads over wether this was actual science or just the usual press BS.

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Oh, just for the record, there's no way for me to actually know which of the people had PhDs, but it's clear from the content of this forum that some people are gonna have one.

[Darnok]

So they have found aether in micro scale and they are calling it quantum fluctuations... [face palm]

[PB666]

Mmh - if they manage to determine that they really are observing quantum fluctuations in vacuum (and develop the corresponding theories about their detectors)

If it works, their detector could be used to check if the EMdrives theory that it's pushing against quantum particles is correct or not. (If their detector works and don't detect quantum fluctuations in a working EMdrive, then it'll simply mean that EMdrives use something else

Lots of ifs, but well

The problem is that it would appear energy is conserved, only the polarization appears to shift.

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A few topics back, people were discussing that someone discovered a magical engine that propelled by pushing against quantum fluctuations, and this forum went ablaze with people who actually have PhDs in physics and people who think they have, bashing heads over wether this was actual science or just the usual press BS.

- - - Updated - - -

Oh, just for the record, there's no way for me to actually know which of the people had PhDs, but it's clear from the content of this forum that some people are gonna have one.

Doesn't matter who has the Ph.D. what only matters is who was right!

My point in those post many many topics back (maybe 1000?) is that we should not be so quick to shut the door on new ideas.

Let me put it more carefully

Camp one, quantum fluctuations occur all the time, but they only have meaning when other known fields interact with them.

Camp two, quantum fluctuations occur all the time, but they only have meaning when known fields and potentially unknown fields interact with them. *unknown fields may not actually exist, but if they did this can explain the RF resonator.

Camp three, no in the argument, if space gets empty enough then quantum fluctuations may have the ultimate meaning, initiating the next new universe.

There is, in light of camp three, a hair shaves difference between camp one and camp two. But more to the point, any person with a historical perspective of science realizes that strongly held theories get overturned, and even really good theories get tweeked. Newton could not fully withstand the test of time, neither could Einstein, and there are some particle physicist out there that are not entirely convinced that the standard model works the way we think. So even if I was convinced that camp one is correct, I would not lay all my eggs in that basket.

So that if you read this page the first thing that you see is "In theoretical physics, Feynman diagrams . . . . . " IOW these interactions are not observed. Nor do these interactions exclude other interactions.

However certain limitations apply listed below the diagram, such as fermions interact via bosonic fields (wavey line). There is a general position about spatial proximity, which of course has flexibility according to uncertainty.

This equation basically argues that any transition in space can be explained by the diagram or a superposition of several of these diagrams.

The diagrams are drawn according to the Feynman rules, which depend upon the interaction Lagrangian. For the QED interaction Lagrangian, , describing the interaction of a fermionic field with a bosonic gauge field , the Feynman rules can be formulated in coordinate space as follows:

1. Each integration coordinate is represented by a point (sometimes called a vertex);
   
2. A bosonic propagator is represented by a wiggly line connecting two points;
   
3. A fermionic propagator is represented by a solid line connecting two points;
   
4. A bosonic field is represented by a wiggly line attached to the point ;
   
5. A fermionic field is represented by a solid line attached to the point with an arrow toward the point;
   
6. A fermionic field is represented by a solid line attached to the point with an arrow from the point;
   

However if you read down the page you will find that there can be a substantive random or spontaneous contributions

Randomly pick the real and imaginary parts of each Fourier mode at wavenumber k to be a gaussian random variable with variance . This generates a configuration at random, and the Fourier transform gives . For real scalar fields, the algorithm must generate only one of each pair , and make the second the complex conjugate of the first.

You can think of me as the inverse of K2. Something required in order to keep fixated universe a little bit unpredictable.

^better summary. Argue on.

[K^2]

Because long explanation involves a lot of math and concepts from field theory, let me just say that there is a very good reason why this experiment was carried out in a crystal, and not vacuum. The fact that crystal lattice can absorb excess momentum is the key factor in allowing these fluctuations to be detectable. EMDrive, supposedly, works in vacuum, where none of this applies.

superposition of several of these diagrams

Minor correction. Infinitely many such diagrams. Always. Locations of vertices alone have infinitely many possibilities. But you also have two, three, four... photon exchanges that contribute to the same interaction. In fact, in low-energy collisions, the many-photon interactions dominate.

[PB666]

Because long explanation involves a lot of math and concepts from field theory, let me just say that there is a very good reason why this experiment was carried out in a crystal, and not vacuum. The fact that crystal lattice can absorb excess momentum is the key factor in allowing these fluctuations to be detectable. EMDrive, supposedly, works in vacuum, where none of this applies.

Minor correction. Infinitely many such diagrams. Always. Locations of vertices alone have infinitely many possibilities. But you also have two, three, four... photon exchanges that contribute to the same interaction. In fact, in low-energy collisions, the many-photon interactions dominate.

lol. I was hoping you would go there! Is there any space at any time were that is not true, if we go to very longest wavelengths, hv that comes from the very edges of the visible universe but are so low energy its not possible to detect them and have extremely high penetrance. I mean one hypothetical explanation is that the hv resonance is interacting with other low energy magnifying simple EM momentum by redirecting these low frequency waves when they approach from certain directions. This is what i mean by uncertainty, at least oneof the devises it does not appear possible that it could be producing a reaction mass at ST. If it was equilibrated in a vacuum then that could be extended to STVac.

This is one of the reasons that doing the calcs now is futile, there is no sense in wasting good theory on bad data. Aside from the space experiment, they should place a whole feild of graphene circuited probes inside the fulstrum using fractal geometry to survey the em feild intensites over many wavelengths. The problem is that the longest wavelenths would not interact with probes of the shortest curvature. The only way to deal with this is to vary external frequencies across a wide frequeny range or block them across all ranges.

In turns of the crystal experiment, yes, but it also creates other artefacts, for examples transitions in the crystal can also alter the observed c. How many directions did the example the polarization shift and did the break the shift down into distance from beam center and look for increases in variance. I will DL the paper next week.

im off.

[monstah]

lol. I was hoping you would go there!

Aaaaaaand it's popcorn munching time!!

[K^2]

Is there any space at any time were that is not true

That would produce very noticeable symmetry violations, which would be detectable in one of hundreds of finely tuned experiments designed specifically to probe these symmetries. You aren't going to generate measurable thrust with a microwave magnetron, when no deviation was detected in far, far more precise experiments, both ones that are set at far greater energies and these set at far greater ranges.

We can safely discard any possibility of violations of momentum conservation in EM case, for same exact reason why we can safely discard any possibility that the guy on YouTube who claims to have built a perpetual motion machine with magnets. In fact, EMDrive was "invented" by an equally crazy person.

[YNM]

On EM Drive: You don't need to argue about it. Just tell them make a probe with fine corrections powered by the drive and look who's right.

On measuring fluctuations : I hope it's not in the detector itself instead. That'd be sucks.

[andrewas]

There's no question that EMDrive produces thrust, but we don't know how. It is not violating conservation of momentum, or physics is broken, so where is the momentum going? We can't really stick one on a probe till we answer that. We could put up a technology demonstrator and verify that it works in orbit, but that still wouldn't tell us what it's using as reaction mass which we need to know to put it in a real spacecraft.

[YNM]

A probe is supposedly solving problems. So lets stick a problem on a problem solver - sounds correct isn't it ?

I mean, you can deduce what happens once it's out there. Is it leaking radiation ? Is it pushed by solar photons ? I mean, you don't need to know first how it works - usage will tell you, just like how they made LHC first then try answer about higgs boson. Going to orbit to solve why the drive works doesn't sound complicated... CubeSats anyone ?

[K^2]

There is no experiment that we can't do in a vacuum chamber that we can do in orbit. The simplest way we could test this is by running the drive for a long time and seeing if thrust diminishes. Trouble is, nobody has yet built one out of components that can survive vacuum long enough.

So if nobody has made a test unit that can even perform equivalent operation in a vacuum on the ground, with no radiation to worry about, what makes you think that it'd be easier to make a unit that can operate in actual orbit and launching it there. We don't have enough people who think it's a worthwhile investment to even do the full rante of testing that needs to be done on the ground before putting it in orbit.

[YNM]

So if nobody has made a test unit that can even perform equivalent operation in a vacuum on the ground, with no radiation to worry about, what makes you think that it'd be easier to make a unit that can operate in actual orbit and launching it there.

If it were to fail, it'll fail spectacularly. If it were to succeed that'd be a successful amazement. The only reason why you need to put something up so it's important.

For who will do it... This forum have users who are in support of EM drive. There's also a group of guys who want to send cubesats to orbit in the name of the game (and forum). Maybe we can make this huge ? Who knows some large agency with similar curiosity will cover the cost or anything. Additionally, it'll be cool, if it's successful, that we literally have equivalent to ion-powered probe.

[PB666]

That would produce very noticeable symmetry violations, which would be detectable in one of hundreds of finely tuned experiments designed specifically to probe these symmetries. You aren't going to generate measurable thrust with a microwave magnetron, when no deviation was detected in far, far more precise experiments, both ones that are set at far greater energies and these set at far greater ranges.

We can safely discard any possibility of violations of momentum conservation in EM case, for same exact reason why we can safely discard any possibility that the guy on YouTube who claims to have built a perpetual motion machine with magnets. In fact, EMDrive was "invented" by an equally crazy person.

[vger]

A few topics back, people were discussing that someone discovered a magical engine that propelled by pushing against quantum fluctuations, and this forum went ablaze with people who actually have PhDs in physics and people who think they have, bashing heads over wether this was actual science or just the usual press BS.

I think pretty much every forum that cares at all about science did.

And a few that don't care about science at all as well.

[YNM]

suit yourself, the evidence appears, in this specific context to be leaning to a contrary. I would say specific that it is leaning in disfavor of mass ejection without running over conservation of momentum, yet.

I think we are looking at this the wrong way, why RF and why this shape, what is the guass feild strenght, is this exception in any way?

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All, K2 denies the possibility that the device could be pushing off mass at a distance. If you beliveve that this is a no ejection mass device but may be pushing off at a distance then space is the best place to test it. If you rely solely upon beleif that existing theories are perfect then space is equivilent to vacuum.

Second, see artcile posted a couple weeks back space on a 50kg max sat will cost 1/2 million dollars.

So, why not make that our first CubeSats ? Couple a few cams, a kerbal figure (with cams !), and the EM drive. And a separator / decoupler in case it didn't work or it did too much work. Simple.

[PB666]

So, why not make that our first CubeSats ? Couple a few cams, a kerbal figure (with cams !), and the EM drive. And a separator / decoupler in case it didn't work or it did too much work. Simple.

it needs a couple of telescoping panels, a guidance system, as far as i know noone has precisely measured the thrust vectors on the device so that the thruster itself needs to be gimbled. IOW it needs weight. it needs an antenna, kerbals are a bad choice of bling. When it reaches lunar orbit I would recommended frankies 'I did it my way song' , also it activates a KSP patch that adds a massless drive to the stock engine parts. . . . . . :^)

OTOH. Has noone asked about why RF frequency?

1. for a given sized device do we know the optimal frequency.

2. If we know the optimal frequency, can we not shrink the device and use higher hv

3. if we can shrink the device we can make it smaller double the frequency means 1/8 th size means one eighth the weight.

if you can shrink the weight you can have a device pointin each of 6 directions and 4 for attitude control. Or you could have a large device and 5 smaller devices for attitude control.