B Does QM implicitly define an aether?

[Nocturnals]

I'm a newbie in all this, so I'm sure I'm wrong. :)

There are several schools of thought about quantum mechanics: Copenhagen, many worlds, pilot wave,... etc.. They all have, as far as I know, in common the Schrodinger equation. And here I could be wrong in my assumption: It doesn't matter if you believe the wave equation is real (ie. bohmian mechanics) or not (copenhagen). Is there not an assumption that the wave equation "runs" in the aether?

I thought the whole point of general relativity was that there isn't an aether?

 

[Orodruin]

There is no assumption of an aether in quantum mechanics.

 

[PeterDonis]

They all have, as far as I know, in common the Schrodinger equation.

Only as a non-relativistic approximation. Once you take relativity into account, you have to look at quantum field theory.

I thought the whole point of general relativity was that there isn't an aether?

Yes, that's correct. See above.

 

[bhobba]

Is there not an assumption that the wave equation "runs" in the aether?

Believe it or not its actually derivable from the Principle Of Relativity (POR) which specifically denies an aether. Here is why. The POR says the laws of physics are the same in all inertial frames. Now while usually accepted as part of the definition of an inertial frame it can actually be proven all inertial frames move at constant velocity relative to each other but I won't attempt a proof in a B level thread, but heuristically if they accelerated then the laws of physics would be different - we would have free particles moving about depending on the acceleration - a particle at rest would not stay at rest as Newtons Laws say.

Now let's suppose there is an aether. Then depending on the velocity of the inertial frame you would have a different 'aether wind' so the laws of physics are not the same.

Thanks
Bill

 

[PeterDonis]

it can actually be proven all inertial frames move at constant velocity relative to each other

I assume this proof would be limited to flat spacetime (or perhaps Newtonian, non-relativistic physics?), since the statement is false in curved spacetime.

 

[bhobba]

I assume this proof would be limited to flat spacetime (or perhaps Newtonian, non-relativistic physics?), since the statement is false in curved spacetime.

Absolutely.

Its simple actually. Define an inertial frame, as per Landau, as one where the laws of physics are the same at every point, direction and instant of time. Then its fairly easy to see the transformation from [x,t] to [x', t'] is linear from the homogeneity and a little calculus using Taylor's series for small intervals, so x' = ax + bt and y' = cx + dt. when it's set up so the origins coincide at t =0. Let x = 0 so x' = bt and t' = dt. x'/t' = bt/dt = b/d which is a constant. But of course since all points are equivalent any can be made the origin so all points move at the same constant velocity.

Thanks
Bill

 

[tomdaniels]

'Hydrodynamics of Superfluid Quantum Space: de Broglie interpretation of the quantum mechanics'
https://arxiv.org/pdf/1707.08508.pdf

Abstract: The ubiquitous ether coming from the ancient times up to middle of the twenty century is replaced by a superfluid quantum space. It represents by itself a Bose-Einstein condensate consisting of enormous amount of virtual particle-antiparticle pairs emerging and disappearing in an infinitely ongoing dance. Flowing of this medium in the non-relativistic limit is described by the modified Navier-Stokes equation along with the continuity equation. The first equation admits the splitting on to two coupled equations. They are the quantum Hamilton-Jacobi equation and the equation for vorticity. The quantum Hamilton-Jacoby equation paired with the continuity equation can be reduced to the Schr¨odinger equation. These two equations representing the kernel of the Bohmian mechanics give finding bundle of the Bohmian trajectories. Whereas the vorticity equation gives solutions for vortices moving along such trajectories. As the result we come to the de Broglie’s interpretation of quantum mechanics according to which there is a pilot-wave guiding the particle (in our case it is a vortex clot) from a source up to its detection along an optimal path that is the Bohmian trajectory.​

Robert B. Laughlin, Nobel Laureate in Physics, endowed chair in physics, Stanford University, had this to say:

the empty vacuum of space … is filled with 'stuff'. ... The modern concept of the vacuum of space, confirmed every day by experiment, is a relativistic ether.​

Einstein: Ether and Relativity

According to the general theory of relativity space without ether is unthinkable; for in such space there would be no propagation of light​

 

[PeterDonis]

Hydrodynamics of Superfluid Quantum Space: de Broglie interpretation of the quantum mechanics

This is a speculative proposal; it is not our best current theory.

Your other two quotes are not valid sources; they aren't textbooks or peer-reviewed papers. (And the people who made those statements would not have tried to get away with them in a textbook or peer-reviewed paper, because they know they would be called on it.)

 

[bhobba]

'the empty vacuum of space … is filled with 'stuff'. ... The modern concept of the vacuum of space, confirmed every day by experiment, is a relativistic ether

Your not kidding they will be called on it. That's simply NOT true.

Despite what you may read in populist material and even some textbooks the picture of the vacuum teeming with particles popping in and out of existence is a heuristic - its not what's going on at all. And even if it was true it would be relativistically invariant - nothing like the old concept of an aether.

It would be rejected during peer review by any of the professors that post here.

As far as we can tell today there is no aether - but we have some genuine speculations about it:
http://ilja-schmelzer.de/gravity/

When I posted a lot on sci.physics.relativirty many of the professors there thought the above was of publishable quality - but not all. So if Ilja tried to get it all published it would likely come down to the referees views on such things. However everyone agreed it was not junk like a lot of the stuff written about the aether - it was a genuine proposal - and some parts have passed peer review and were published.

Thanks
Bill

 

[bhobba]

Einstein: Ether and Relativity
According to the general theory of relativity space without ether is unthinkable; for in such space there would be no propagation of light

Well so the guy that rejected the aether thought it should be revived in the theory built on the theory that specifically rejected it - very interesting and actuality logically contradictory. Me-thinks context is important here and it is. He also states:
'Since according to our present conceptions the elementary particles of matter are also, in their essence, nothing else than condensations of the electromagnetic field, our present view of the universe presents two realities which are completely separated from each other conceptually, although connected causally, namely, gravitational ether and electromagnetic field, or - as they might also be called - space and matter.'

From the modern viewpoint the above is almost laughable - so we know the context of the statement - it was pure speculation in light of the physics known at the time - it is highly doubtful he would say it now.

But even if not just some speculation based on the physics of his time, it would be just one of a number of mistakes that great physicist made. The following book I am reading right now is very interesting:
https://www.amazon.com/dp/0393337685/?tag=pfamazon01-20

BTW as the book explains it in no way diminishes his genius - it simply reveals he is human like the rest of us. People used to sit in awe of the great polymath Von-Neumann - Poyla was genuinely scared how good he was - others said he was the only person fully awake, Feynman readily admitted he was above him. He could penetrate a problem with scary ease. When compared to Einstein his mathematical ability was in an entirely different league - in fact he is likely one of the 10 greatest mathematicians that ever lived. But Einstein is considered greater - why? The key area of scientific advancement is the ability to penetrate a problem, as great as Von-Neumann was in that, and he was great indeed, Einstein was even better, unparalleled at it. Feynman freely admitted based on what Einstein knew he could not have come up with relativity - somehow he was able to see to the core of the issue where even the other greats could not. He virtually created GR by himself - Hilbert helped a bit at the end - but freely admitted it was Einsteins physical ideas that were the key - he just did some math and always gave full credit for GR to Einstein. That ability to penetrate in fact is the essential area - not the dazzling technical expertise of a Von-Neumann or scary ability with the meaning behind the equations Landau and Feynman had (Einstein did as well - but that was not the key to his genius). That is what makes Einstein great, likely the greatest physicist ever. He made mistakes - but that's just being human and in no way diminishes his accomplishments - if anything it enhances them.

Thanks
Bill

 

[tomdaniels]

it is not our best current theory.

How is the particle always detected traveling through a single slit in a double slit experiment evidence the particle always travels through a single slit not our best theory?

In a boat double slit experiment does the boat travel through a single slit even when your eyes are closed? How do you deduce that it does? You deduce that it does because every time you physically detect the boat it was traveling through a single slit.

 

[tomdaniels]

And even if it was true it would be relativistically invariant - nothing like the old concept of an aether.

Hence, "relativistic ether".

It would be rejected during peer review by any of the professors that post here.

The quote you are referring to is from a Nobel Laureate.

 

[tomdaniels]

BTW as the book explains it in no way diminishes his genius - it simply reveals he is human like the rest of us.

Or, Einstein was correct as a teenager and moved back to that correct understanding late in his career.

http://www.straco.ch/papers/Einstein%20First%20Paper.pdf

The velocity of a wave is proportional to the square root of the elastic forces which cause [its] propagation, and inversely proportional to the mass of the aether moved by these forces.​

 

[bhobba]

The quote you are referring to is from a Nobel Laureate.

And they never make mistakes or speak in loose heuristics when not writing in journals that are peer reviewed? Any QFT text will repudiate the statement - hell even Wikipedia does:
https://en.wikipedia.org/wiki/Dyson_series

Virtual particles are just pictorial representations of terms in a series. Those 'pictures' are called virtual particles. They are not particles nor do they pop in and out of existence. Physicists just sometimes speak loosely as if they are.

As I carefully explained, even the greats like Einstein made mistakes, tons of them. But he was still able to penetrate often to the heart of things better than anyone else - but not always. Or do you actually believe:
'Since according to our present conceptions the elementary particles of matter are also, in their essence, nothing else than condensations of the electromagnetic field, our present view of the universe presents two realities which are completely separated from each other conceptually, although connected causally, namely, gravitational ether and electromagnetic field, or - as they might also be called - space and matter.'

If so your physics education is sadly lacking.

Thanks
Bill

 

[tomdaniels]

Virtual particles ...

I'm not referring to virtual particles. I'm referring to dark matter as consisting of SIMPs (https://en.wikipedia.org/wiki/Strongly_interacting_massive_particle) which fill 'empty' space and are what waves in a double slit experiment. Particles of ordinary move through and displace the space filling SIMPs, causing them to wave, analogous to a boat moving through and displacing the water, causing it to have a bow wave.

 

[bhobba]

The velocity of a wave is proportional to the square root of the elastic forces which cause [its] propagation, and inversely proportional to the mass of the aether moved by these forces.

Yes - your education is sadly lacking. EM waves don't behave like that as Maxwell's equations readily attest to.

Thanks
Bill

 

[tomdaniels]

Yes - your education is sadly lacking. EM waves don't behave like that as Maxwell's equations readily attest to.

You realize that's an Einstein quote, correct?

https://en.wikipedia.org/wiki/Aether_theories#Luminiferous_aether

James Clerk Maxwell said of the aether, "In several parts of this treatise an attempt has been made to explain electromagnetic phenomena by means of mechanical action transmitted from one body to another by means of a medium occupying the space between them. The undulatory theory of light also assumes the existence of a medium. We have now to show that the properties of the electromagnetic medium are identical with those of the luminiferous medium."​

 

[bhobba]

Iand are what waves in a double slit experiment. Particles of ordinary move through and displace the space filling SIMPs, causing them to wave, analogous to a boat moving through and displacing the water, causing it to have a bow wave.

Personal theories are not allowed.

The above it utter hogwash. Despite what popularizations say nothing waves in the double slit. Here is what is really happening:
https://arxiv.org/abs/quant-ph/0703126

Thanks
Bill

 

[bhobba]

You realize that's an Einstein quote, correct?

And you read the post about, and the book I linked to about the mistakes he made?

Thanks
Bill

 

[tomdaniels]

Personal theories are not allowed.

The above it utter hogwash. Despite what popularizations say nothing waves inn the double slit. Here is what is really happening:
https://arxiv.org/abs/quant-ph/0703126

In the following video the silicon bath represents the chaotic superfluid aether. In the video, in the double slit experiment example, the particle travels through a single slit and the associated wave in the aether passes through both.



In a double slit experiment the particle always travels through a single slit and the associated wave in the aether passes through both. As the wave exits the slits it creates wave interference which alters the direction the particle travels as it exits a single slit. Over time the particles form an interference pattern. Strongly detecting the particle exiting a single slit destroys the cohesion between the particle and its associated wave, the particle continues on the trajectory it was traveling and does not form an interference pattern.

 

[tomdaniels]

And you read the post about, and the book I linked to about the mistakes he made?

Thanks
Bill

The mistake Einstein made was moving away from the notion that the aether has mass. If he stuck with the correct notion he had as a teenager physics wouldn't be so ****ed up today.

 

[bhobba]

form an interference pattern.

That video is crank rubbish as has been discussed many times on this forum.

Thanks
Bill

 

[tomdaniels]

That video is crank rubbish as has been discussed many times on this forum.

Or, wave-particle duality is a moving particle and its associated wave in the aether.

 

[fresh_42]

This thread must not be a platform to debate ether theories and I have cut off this part of the discussion. Since @tomdaniels already has been quoted so often, I left the existing posts as they are. The OP was a valid question and this thread is still open in case @Nocturnals has further questions.

Edit: Since this doesn't seem to be the case, the thread will be closed.