Superdeterminism could reconcile quantum and relativity

https://www.frontiersin.org/articles/10.3389/fphy.2020.00139/full

by billytetrud • 5 years ago

24 25 5 years ago

Sabine Hossenfelder rethinks Superdeterminism and explains in very accessible terms why Superdeterminism should be taken seriously and has been unfairly characterized in the past. She says that violating statistical independence is the only way to solve the measurement problem in a way that is compatible with relativity.

1980phipsi• 5 years ago

"very accessible" relative to what?

billytetrud6• 5 years ago

Relative to like 99% of writing by phycists.

nobodyandproud• 5 years ago

I like her analogies.

For laymen who has followed determinism vs non-determinism (I’m a fan of the latter camp; Bell never ruled out determinism), this article is on the cusp of comprehensible.

There are definitely paragraphs that aren’t, but it’s still a good read.

The exciting point, though, is that super determinism isn’t merely an interpretation of QM. Given time, one expects these theories to be testable.

johnklos• 5 years ago

She has some good videos, too:

https://www.youtube.com/c/SabineHossenfelder/videos

dia80• 5 years ago

Wouldn't it be funny if it were established no one had any free will, in a strict sense, all along. We'd still feel like we had it but know that we didn't.

From this layman's emotional point of view I never really liked "many worlds" and that sort of thing. I'd be quite accepting if the answer turns out to be super-determinism.

BeKindAndLearn3• 5 years ago

I would argue that it's pretty obvious nobody has free will in the sense that there's some kind of "soul" controlling your thoughts and actions.

Your brain is a biological computer. You zap parts and it makes you move. You give it some chemical inhibitors or promoters and your mood changes. You give it drugs and it hallucinates and thinks differently.

The brain isn't supernatural and there is zero evidence that supports the concept of spiritual will influencing it. Just like there's zero evidence of psychics, magic wands, or physics-violating miracles. It's all make believe.

teilo• 5 years ago

If you think it is that simple, then you do not quite understand superdeterminism and the hard problem of consciousness.

Also, your examples are not entirely accurate. It has been repeatedly demonstrated that zapping a part of the brain cannot consistently override the will, and the correlation to, for example, the motion of a limb to the activity of the brain does not stay consistent, but disappears after multiple attempts when the subject under experimentation resists. That doesn't prove that the will is independent from the brain, but so far, no one has found where the will expresses itself in the brain. Right now it is just taken on faith that it does so somehow.

And then there is perception. We can find general correlations for areas of the brain that respond to shape, color, smell, and kinesthetic sense, but nowhere where the various senses are assimilated and correlated into a cohesive perception.

We can alter mood, and induce hallucinations, but again, have no model as to how either translates to perception and self-awareness.

Before we can determine whether the will is free, we first need to define what the will and perception and self-awareness even is, and how it arises. And we don't have a clue where to start.

ithkuil• 5 years ago

Many worlds (by which I mean the Everett interpretation, not sure which you mean) is 100% deterministic.

The impact that apparent world branching has to domain of the free will question is purely due to the "amplification effects" that a complex control system like our brain can have in reaction to something perceived as a "measurement" result.

We cannot sense a superposition state directly. The moment we probe a particle, our instruments and us (the environment) becomes entangled with the observed particle. The instrument and later we the observers of the instrument are ourselves a quantum system with a well defined quantum stats, and a third observer not yet entangled with us can treat as still in a superposition state.

The idea is that everything evolves according to the Schrodinger equation. The wave function never really collapses. The illusion of wave function collapse springs out of the way that a control system like a brain or a mechanical automaton processes it's inputs while being in an entangled state with the thing they observe and thus react to it's state differently in the different superimposed states. This difference becomes amplified. A control system like a brain is not necessary; just pure macroscopic environments are enough to diverge the apparent state of the systems so that it's useful to think in terms of "world splitting"; but it's just a useful fiction; very useful because that's all we'll ever witness.

The amplification effect of control systems makes it easy to concoct extreme thought experiments. Let's imagine that spin up means you fire off a rocket and go to Mars and spin down means you stay put. All we did is that we managed to amplify the effect of this single superimposed state of one particle, into a macroscopic superposition of a rocket being on earth or on mars

meowface• 5 years ago

Superdeterminism is very different from determinism, and IMO would be a much more shocking revelation than Everettianism (or Sean Carroll's so-called "mad-dog Everettianism").

billytetrud6• 5 years ago

What is free will anyway? Isn't it free will if the decisions you make is a result of the structure of your brain built up by what you've learned in life? Isn't that the free will you're looking for? If not, what else could it be?

bArray• 5 years ago

I believe the Universe to be based on rules and therefore deterministic - the difference we're talking about is really just whether we can see inside the random number generator or not. A random number generator we can't peek inside doesn't make you any more free, you are still subject to making decisions based on variables outside of your control. There will always be far too much chaos to simulate large systems and make accurate/detailed long-term predictions.

In terms of free will, I believe it is really some manifestation of the human mind to fool ourselves into believing we are in control. This is useful of course, because if we act as if we have agency then we make better decisions as a result and the outcome is therefore better - despite it not being possible to have happened any other way.

lostmsu• 5 years ago

On retrocasuality: I find it interesting, that not only people tend to outright reject the notion that future events can be causes for present or past events, but they also are wrong about assuming they are doing it (e.g. rejecting) consistently.

For example, common sayings such as "nothing ventured, nothing gained" or "today's seed - tomorrow's harvest" are actually casually bidirectional, especially the second one.

dekhn4• 5 years ago

I would so love for this to be true, but it's far outside my area of expertise. The important thing, though, is there have to be useful experimental predictions. The only reason I could ever reconcile my understanding of reality with QM is that it's an extremely good theory for making predictions.

jfengel3• 5 years ago

QM interpretations don't really make predictions. They all use the same underlying math. They just rearrange the terms so that some of them correspond to something familiar, with the hopes of minimizing the confounding effects of the others.

They're all like trying to fold a map onto a globe: somewhere, something isn't going to fit. You just try to squeeze it into the parts you don't care as much about. Except somebody always cares.

It may be that somebody will discover one that's so effective that we declare it to be Correct. That's much like what we went through with heliocentrism. Geocentrism plus epicycles is also a perfectly valid interpretation, but it's vastly more complicated and less elegant. Even so it's incredibly useful and actually remains the dominant interpretation for a lot of activities.

It would be great if one such reformulation helped us reconcile with relativity, but I'll admit that I'm skeptical. I suspect that any unified theory will be so radically different in structure as to require a completely different interpretation, totally unrelated to any of the low-energy QM approximations.

I doubt any of them will be helpful -- especially superdeterminism, which I view as shoving the weirdness from "All events are decided randomly and then distributed FTL" to "All events were decided at the beginning but locked away so you can't know them until you get there". Neither one really gives us access to anything new -- which is to be expected.

dekhn4• 5 years ago

I didnt mean quantum interpretations (which are boring to me). I mean: transisitor theory is quantum theory and we wouldn't have developed the transistor to the point we have if QM wasn't a great model for solid state physics.

Nobody thinks event outcomes are distributed FTL, that's the whole point of QM.

Superdeterminism could reconcile quantum and relativity

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