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It’s time to admit quantum theory has reached a dead end

nautil.us

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Re: It’s time to admit quantum theory has reached a dead end

#101

Post by exdsq »

mellosouls wrote: post #69
fennecs wrote: post #64

Amusing to see all the pessimistic comments form programmers who have zero understanding beyond high school maths thinking somehow there is a magic solution to all the problems in physics like you can just refactor everything. Quantum field theory is definitely not stuck in the 1920s. Modern physics has a lot more going on than 19th century mathematics. We understand quite a lot about the mathematical structure under…

Don’t use your intuition developed from grinding out web crap to try and reason about the forefront of human knowledge. Have you tried front end web frameworks recently? String theory has nothing on them.

100%

My friends a pretty decent physicist at Oxford and the hardest part of his research? Makefiles.

Re: It’s time to admit quantum theory has reached a dead end

#102

Post by [deleted] »

agumonkey wrote: post #75
mellosouls wrote: post #69

Earlier quoted context omitted.

Don’t use your intuition developed from grinding out web crap to try and reason about the forefront of human knowledge. Have you tried front end web frameworks recently? String theory has nothing on them.

C String > String

[deleted]

Re: It’s time to admit quantum theory has reached a dead end

#103

Post by scythe »

>Another alternative is to suppose there are hidden factors that we can’t quite access. David Bohm influentially suggested that a particle is accompanied by a “pilot wave” that guides its trajectory through the double-slit experiment and creates the interference pattern. Most physicists will tell you that this kind of “hidden variable” interpretation of quantum theory has been ruled out by a combination of experimental results and mathematical proofs.

This isn't the problem with Bohmian mechanics at all. Bohmian mechanics "solves" the EPR experiment by letting hidden variables jump around across spacelike separations. This cannot be disproven by Bell tests.

The problem with Bohmian mechanics (which I have always heard called "Bohmian mechanics", and not "pilot-wave theory") is that it isn't truly relativistic; it doesn't happen in Minkowski space and nobody has to my knowledge extended it to Minkowski space in a way that is widely considered acceptable. If the author likes Bohm's approach so much, he should learn about the ongoing developments:

http://en.wikipedia.org/wiki/de_Broglie-Bohm_theory#Relativi...

Re: It’s time to admit quantum theory has reached a dead end

#104

Post by astrange »

tus666 wrote: post #26
blueprint wrote: post #18

Earlier quoted context omitted.

aiui, professional physicists don't think particles are "real" but a phenomenon that appears as a result of attempting to localize a wavefunction through a measurement

Professional physicists are so lost in the mathematics of wave functions they have lost touch with reality.

You seem to be arguing an old version of pilot-wave theory, which has a version that's wrong (because it predicts real life incorrectly) or isn't known to be wrong but isn't falsifiable either (because it predicts real life exactly the same as QM). It also doesn't work well with special relativity, so it's less correct than QFT.

Re: It’s time to admit quantum theory has reached a dead end

#106

Post by astrange »

not1ofU wrote: post #23
wpietri wrote: post #9

Earlier quoted context omitted.

Could you point to some articles on this? It's way outside of my field, but it sounds very interesting.

This is cool IMO (2016): https://www.youtube.com/watch?v=nRSBaq3vAeY Apologies if its considered off topic - I see double slit experiment and I always think of this. It blew my mind.

Of course "consciousness is special" is what you'd expect someone with a consciousness to say, so we shouldn't trust it unless we can prove the video was made by a p-zombie.

Re: It’s time to admit quantum theory has reached a dead end

#107

Post by adriand »

fennecfoxen wrote: post #98
sidlls wrote: post #87

Earlier quoted context omitted.

I hope that's a misunderstanding or miscommunication. It might be useful in some limited contexts, but it would point to gaps in the theory (at minimum).

There are 19 free parameters in the Standard Model. These include such values as the mass of various particles (electron, muon, tau, six quarks, Higgs), Higgs vacuum expectation value, the strength of several interactions, and the mixing angles and phases for certain interactions. You can rearrange some of the parameters so that they're not free, and redefine each of these in terms of some other related parameter — y…

One theory, which I find quite plausible, is that there are many universes, all of which have variations on these constants. And the reason our universe is the way it is, is because we are here to observe it - given that most other configurations of these constants wouldn’t support life (the strong anthropic principle).

Re: It’s time to admit quantum theory has reached a dead end

#108

Post by astrange »

blueprint wrote: post #30
tus666 wrote: post #26

Earlier quoted context omitted.

Professional physicists are so lost in the mathematics of wave functions they have lost touch with reality.

what is the reality then? when you get down to those scales, there really does seem to be uncertainty when you try to localize parameters. on one hand it's troubling but it's also lovely because we get stuff like the casimir effect, and who knows what other futuristic technology we might end up making, which we all want

There's a viable alternative to this called "superdeterminism", but it makes everyone in the world except Sabine Hossenfelder unhappy if you bring it up because it's even worse than telling them they don't have free will.

Re: It’s time to admit quantum theory has reached a dead end

#109

Post by astrange »

mrfusion wrote: post #79

Anyone can explain superdeterminism in a simple way? That sounds interesting.

Explanation 0: QM, unlike classical physics, says quantum effects are truly random and unpredictable and we can only know their probability distribution. (Or something like that.)

Explanation 1: The universe is not random and doesn't have cause and effect. All scientific experiments appear to work because the whole universe is actually a movie playing out where each new frame has been edited to produce the results we see, but for some reason the author decided to never violate QM.

Explanation 2: Unlike what QM predicts (true randomness) there's a finite amount of randomness added at the beginning of the universe, enough that our experiments appear to follow QM, but eventually if we looked hard enough there would be a predictable result with finite entropy. So it's actually regular determinism.

A few people claim #2 is true and doesn't imply #1. Everyone else thinks they're the same and doesn't like it for philosophical reasons.

https://www.youtube.com/watch?v=ytyjgIyegDI

Re: It’s time to admit quantum theory has reached a dead end

#110

Post by akomtu »

8bitsrule wrote: post #28

Even on the macro level there are lots of tricky questions. A bar magnet is surrounded by magnetic flux lines. Apparently it takes no energy to maintain that magnetic field. If I heat the bar in boiling water for long enough, it becomes demagnetized. On the macro level there's no visible/measureable change in the bar. We need a lot of magnification to see that the 'particles are no longer aligned'. On the other hand,…

I've been bothering myself with the same question. This rabbit hole in the wikipedia has led me to a dead-end explanation: those iron filings are pulled by virtual photons created by the magnet, those virtual photons are completely virtual and cannot be observed, except for the fact that they somehow pull the filings despite being virtual (this must be a small incursion of the purely mathematical world into reality). I've concluded that magnetism is an unexplained phenomenon, just like gravity: we have accurate formulas, but nobody knows what those formulas describe. For intuitive understanding, I see a magnet as a well, except that this well can be moved around and has two poles. Just like a regular well, things fall into it at no expense to the well, because the well isn't really a "thing" that pulls other things by force.
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