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Fluid Tests Hint at Concrete Quantum Reality

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Re: Fluid Tests Hint at Concrete Quantum Reality

#101

Post by msane »

sriku wrote: post #91

If you try to create a classical situation that obeys similar mathematics to a quantum situation, you're bound to get "quantum-like behaviour" isn't it? Wouldn't this be some kind of an analog computer for simulating the two-slit experiment in the classical realm? If so, what would this offer to the interpretation of quantum mechanics that cannot be gleaned from the mathematics itself?

The significance is that this is a model of a special, alternate formulation of quantum mechanics called Pilot-wave Theory.

Re: Fluid Tests Hint at Concrete Quantum Reality

#102

Post by sriku »

msane wrote: post #101
sriku wrote: post #91

If you try to create a classical situation that obeys similar mathematics to a quantum situation, you're bound to get "quantum-like behaviour" isn't it? Wouldn't this be some kind of an analog computer for simulating the two-slit experiment in the classical realm? If so, what would this offer to the interpretation of quantum mechanics that cannot be gleaned from the mathematics itself?

The significance is that this is a model of a special, alternate formulation of quantum mechanics called Pilot-wave Theory.

pwt is an interpretation. All interpretations of QM share the same mathematics .. or effectively the same maths. Different "interpretations" cannot produce different predictions in experiments. So using an experiment designed to emulate pwt (which afaik violates special relativity) can only say one thing possibly - that if we find it convenient to think in this way in some limited cases of quantum mechanics, we may do so. In other words, it may at best serve as a heuristic to teach children, that they can later grow out of.

Re: Fluid Tests Hint at Concrete Quantum Reality

#103

Post by sriku »

sriku wrote: post #92
acqq wrote: post #21

Earlier quoted context omitted.

So please explain in a few sentences what is that that Yudkowski writes, did he make any new contribution to the standard model or made something else or do you agree that the standard model is the most researched and most usable model up to now, and he just made a lot of posts where he just writes a lot of text? I see a lot of links in the article you gave, but I don't understand what we're supposed to discover in Y…

Yudkowsky's contribution is pedagogical rather than anything fundamentally new. He explains quite well in short the process of "decoherence" and links it well to the many worlds interpretation. He makes a case for why the "many worlds interpretation" is not really an "interpretation", but is just stating what the mathematics says on its face anyway .. and hence is the one we should adopt. In particular, he does a goo…

edit: Sorry! Tongue of the slip. I was referring to the "Wheeler-DeWitt equation" [1] and not the "Weyl equation" [2].

[1] http://en.wikipedia.org/wiki/Wheeler%E2%80%93DeWitt_equation

[2] http://en.wikipedia.org/wiki/Weyl_equation

Re: Fluid Tests Hint at Concrete Quantum Reality

#104

Post by DavidPlumpton »

acqq wrote: post #21
spacehome wrote: post #18

Yes! But the best theory is not Copenhagen or Pilot Wave. Eliezer Yudkowski has a brilliant treatise on the Many Worlds interpretation here: http://lesswrong.com/lw/r5/the_quantum_physics_sequence/ that really should be required reading for anyone that wants to talk intelligently on the subject. Edit: seriously, don't even bother reading the article. It (like most science journalism) is garbage. Take the time to work…

So please explain in a few sentences what is that that Yudkowski writes, did he make any new contribution to the standard model or made something else or do you agree that the standard model is the most researched and most usable model up to now, and he just made a lot of posts where he just writes a lot of text? I see a lot of links in the article you gave, but I don't understand what we're supposed to discover in Y…

Yudkowsky is more of an expert in reasoning than in Physics. For example, imagine you are a world class expert in Quantum Mechanics and you are asked to give a talk at a science club. You cover a lot of stuff and think "that was great". But somebody else tells you "that was terrible, you mumbled, you wrote illegible stuff on the board etc." and you realise it wasn't about QM, it was about public speaking.

Similarly physicists have done amazing work over the decades, and now it's time to draw conclusions from all that evidence. But it turns out that physicists are not domain experts in drawing conclusions from evidence. That kind of skill is a separate domain in its own right.

Re: Fluid Tests Hint at Concrete Quantum Reality

#106

Post by ars »

im3w1l wrote: post #98
spacehome wrote: post #18

Yes! But the best theory is not Copenhagen or Pilot Wave. Eliezer Yudkowski has a brilliant treatise on the Many Worlds interpretation here: http://lesswrong.com/lw/r5/the_quantum_physics_sequence/ that really should be required reading for anyone that wants to talk intelligently on the subject. Edit: seriously, don't even bother reading the article. It (like most science journalism) is garbage. Take the time to work…

I'd like to propose a thought experiment that in my opinion speaks for a many world interpretation. Imagine Schrödingers Cat. Only we have a physicist in the box instead! Also inside the box is a photon emitter programmed to send a photon after 30 seconds. Our dear physicist has been instructed to, if he is still alive after 20 seconds (adjusted to have 50% prob) to move the emitter just a tiny little bit to the left…

https://en.wikipedia.org/wiki/Quantum_suicide

Re: Fluid Tests Hint at Concrete Quantum Reality

#107

Post by Ono-Sendai »

trhway wrote: post #9
adocracy wrote: post #3

Liquid dynamics sounds like an interesting hypothesis, but I agree with the critics that entanglement presents a tough analogy. If Pilot Wave theory suggests that the particle-wave duality is actually two distinct actors - a wave and a particle riding the wave - then 1) each particle has an independently generated wave? and 2) it's difficult to see how that wave could be exactly preserved for both particles over the…

In interpretation of dual slit experiment people do the main mistake of mixing up the 2 waves - one is wave like quantization of position and another is de Broglie wave-equivalent of the particle. The mix up is caused by photon where both have the same wavelength. They are different in the case of all other particles. Hitachi experiment shows its the best - it clearly shows interference of the positional waves of dif…

Do you have any more information or references about this, in particular your claim that there are two different wavelengths in play?

Re: Fluid Tests Hint at Concrete Quantum Reality

#108

Post by ars »

DavidPlumpton wrote: post #105

I was unable to figure out one key thing about this article. Are they claiming that if the droplet is observed while going through one of the slits that the interference pattern will vanish? If not can we really claim a strong analogy with QM?

Yes.

"And just as measuring the trajectories of particles seems to “collapse” their simultaneous realities, disturbing the pilot wave in the bouncing-droplet experiment destroys the interference pattern."

Re: Fluid Tests Hint at Concrete Quantum Reality

#110

Post by DanielBMarkham »

GregBuchholz wrote: post #4

I've liked: Clearing up Mysteries - The Original Goal http://bayes.wustl.edu/etj/articles/cmystery.pdf " ...we must keep in mind that Einstein's thinking is always on the ontological level; the purpose of the EPR argument was to show that the QM state vector cannot be a representation of the "real physical situation" of a system. Bohr had never claimed that it was, although his strange way of expressing himself often…

This goes back a long ways before QM. Even Newton, observing gravity, concluded that he had no idea why it worked, he could only describe how to numerically model the results of it working.

We've been modeling ever since, hoping that enough pieces of the puzzle come together for a cogent picture to emerge.

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