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Muon G-2 Experiment at Fermilab Finds Hint of New Particles

quantamagazine.org

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Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#61

Post by whatshisface »

penteract wrote: post #60
whatshisface wrote: post #27

Earlier quoted context omitted.

The class of integrals that QCD solutions belong to is known to be NP-hard. It is not known specifically that QCD itself is NP-hard but it is suspected to be by many.

Would this mean that either the strong Church-Turing thesis(any model of computation based on physical reality gives the same class of problems solvable in polynomial time as a Turing machine) is wrong or P=NP?

If what is suspected is true, then yes, strong Church-Turing is false. If there's a symmetry in QCD that makes simulation possible in polynomial time, i.e. a helpful property that is true of QCD specifically but absent from the more general class of integrals its solutions belong to, then no.

If you're looking for something to raise your hair even farther, some suspect that gravity is outright uncomputable[0] due to the unclassifiability of 4-manifolds and the expectation that quantum gravity will require summing over possible spacetimes.

Since all of our computers are built with QED, it should come as no surprise that everything else made out of QED-obeying-matter, like Turing machines are imagined to be, is equally difficult to compute and equally powerful at computing. I don't see why you'd expect the other field theories to fall in to the same computational class.

[0]https://arxiv.org/pdf/gr-qc/0506019.pdf

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#63

Post by pochamago »

idolaspecus wrote: post #31
whimsicalism wrote: post #18

Earlier quoted context omitted.

It doesn't seem obvious that the fundamental models of reality would just happen to match up with the mathematical constructs that we humans have come up with.

On the flip side, it wouldn't be entirely surprising if mathematical constructs that we have thought of are in fact very good models of fundamental reality. We should remember that, after all, nothing exists outside of fundamental reality, and if certain basic patterns can be encoded such that the encoding is both high-fidelity and simple, that won't be shocking. It might be awe-inspiring, but not really surprising.

>nothing exists outside of fundamental reality

A bold assertion.

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#64

Post by Vitorystar »

willis936 wrote: post #47
whimsicalism wrote: post #45

Earlier quoted context omitted.

> Yes: testable predictions followed by experimental evidence. But there are an infinite number of theories matching the current evidence. Some predictions of the theories might not be testable, what do you do then?

Simple: you label them as fiction rather than science. The scientific method has experimental feedback built into the loop.

Well then you have to label everything as fiction rather than science because if you don't single out the simplest theory you can't say that general relativity is science and general relativity plus sun turns into cake tomorrow isn't science. And if someone tells you the sun will turn into cake tomorrow and claims that your theory where the sun doesn't turn into a cake tomorrow is fiction and unscientific cause it doesn't make predictions to distinguish it from their theory, you don't have any principled philosophical ground to disagree whith them .

And that's not so clearly bad there because they are obiously wrong, but then you get to complicated topics where everyone has hard to resolve disagreements about which theory should be the default from a big pool of theories that seem to agree whith the evidence.

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#65

Post by willis936 »

Vitorystar wrote: post #64
willis936 wrote: post #47

Earlier quoted context omitted.

Simple: you label them as fiction rather than science. The scientific method has experimental feedback built into the loop.

Well then you have to label everything as fiction rather than science because if you don't single out the simplest theory you can't say that general relativity is science and general relativity plus sun turns into cake tomorrow isn't science. And if someone tells you the sun will turn into cake tomorrow and claims that your theory where the sun doesn't turn into a cake tomorrow is fiction and unscientific cause it do…

Doing something clearly outside of empiricism then saying “why doesn’t empiricism cover this” is complete nonsense. What is the ontological explanation for your hypothesis that the sun will turn into cake? Misunderstanding the scientific method is not an issue with the scientific method.
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