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Does quantum theory imply the universe is preordained?

nature.com

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Re: Does quantum theory imply the universe is preordained?

#11

Post by digging »

sim7c00 wrote: post #4
gavinray wrote: post #2

When I was a teenager I had an idea: If you rolled marbles down a hill, assuming that identical starting conditions were applied each time, then the marbles' paths and final position would be the same each time. This also implies that if you know the starting conditions, you could calculate the state of any point in time from there. It made me curious whether you could apply this same logic to our universe -- though…

i think for physical systems this might hold true in some way, though, i am not a physics person at all. it just 'feels' that way to me. however, life is also there, and life doesnt nessesarily follow such rules, as actually most of (intelligent?) life is not physical. (emotions, thought etc.) but does have impact / effect on the physical. i dont think non physical things are so determenistic. (maybe they are, but it…

For classical physics it's basically true[1]; see Laplace's demon. I recall also independently inventing determinism as a kid after I realized how easily I'd been swayed by external factors into buying one toy over another.

For non-physical things, such as emotions and thought... well, we have no actual proof they're anything but physical. We just don't have proof that they're entirely physical, either. But the simplest explanation is actually that they are completely physical processes and just as deterministic as everything else (which is to say, possibly not at all, depending on how QM is resolved).

[1] "Basically true" here means it's not strictly true (by that I mean it's not true in all possible cases) - but classical physics itself is not strictly true, thus relativity and QM... which are themselves not strictly true. We're still trying to find the theory that accurately describes all of physics.

Re: Does quantum theory imply the universe is preordained?

#12

Post by digging »

__turbobrew__ wrote: post #10

I have yet to see a subscriber of superdeterminism not look both ways before crossing the road.

A good quip, lol. But of course they would, because they must, because the feeling of control (that is: the unconscious belief in control) is just as intrinsic as the actual absence of control.

Re: Does quantum theory imply the universe is preordained?

#13

Post by variadix »

elromulous wrote: post #5

This does make me wonder: how do we know that random quantum processes are truly random? This gets philosophical very quickly. But for our purposes: independent, uniform, etc. But how do we know there isn't another (earlier) way to observe the result in some fashion.

I think Bell’s inequality implies the state can’t be deterministic but hidden. I’m not sure how you could evaluate the “quality” of the randomness, or if there are existing results analyzing this.

Re: Does quantum theory imply the universe is preordained?

#14

Post by voxl »

digging wrote: post #12
__turbobrew__ wrote: post #10

I have yet to see a subscriber of superdeterminism not look both ways before crossing the road.

A good quip, lol. But of course they would, because they must, because the feeling of control (that is: the unconscious belief in control) is just as intrinsic as the actual absence of control.

which in other words makes superdeterminism unfalsifiable, because any attempt to do so can be met with "it must have been that way"

Re: Does quantum theory imply the universe is preordained?

#15

Post by PheonixPharts »

"Random" is a property of your mind, not of the world.

If I shuffle a deck of cards in a way that you don't know about, then the next card I pull is "random" to you even though, obviously, if one were to turn the cards face up nothing would have changed about the order of the cards, but now the next card would be fully deterministic.

I could likewise sort the deck with an algorithm completely unknown to you. I could perfectly predict the next card pulled because I know the algorithm, and yet the next card would still be random for you.

Heisenberg uncertainty principle is more a statement about the limits of knowledge than about "God throwing dice". Randomness often has a supernatural property in the popular mind, but is really just a statement about how much information we have about an event.

The famous Bayesian philosopher ET Jaynes refereed to this tendency to confuse the randomness as a property of the world rather than our mind as the "Mind Projection Fallacy" [0]

0. https://en.wikipedia.org/wiki/Mind_projection_fallacy

Re: Does quantum theory imply the universe is preordained?

#16

Post by qarl »

__turbobrew__ wrote: post #10

I have yet to see a subscriber of superdeterminism not look both ways before crossing the road.

That's because superdeterminism doesn't imply you shouldn't.

Superdeterminism implies that you don't really have a choice as to whether you look both ways.

Re: Does quantum theory imply the universe is preordained?

#19

Post by tedivm »

sheepdestroyer wrote: post #8
sim7c00 wrote: post #4

Earlier quoted context omitted.

i think for physical systems this might hold true in some way, though, i am not a physics person at all. it just 'feels' that way to me. however, life is also there, and life doesnt nessesarily follow such rules, as actually most of (intelligent?) life is not physical. (emotions, thought etc.) but does have impact / effect on the physical. i dont think non physical things are so determenistic. (maybe they are, but it…

What makes you say that life is not physical? There seems to be no reason to believe that it's not. On the contrary it seems most plausible that everything, including emotions, thoughts, decisions, are just chemical and electrophysical reactions. Thus deterministic.

If those physical reactions occur at or are influenced by the quantum level then they stop being deterministic. Hence the article.

Re: Does quantum theory imply the universe is preordained?

#20

Post by gpderetta »

gavinray wrote: post #2

When I was a teenager I had an idea: If you rolled marbles down a hill, assuming that identical starting conditions were applied each time, then the marbles' paths and final position would be the same each time. This also implies that if you know the starting conditions, you could calculate the state of any point in time from there. It made me curious whether you could apply this same logic to our universe -- though…

If the path of the marbles were to be determined by some sort of gate in the path that would open or close depending, via a Geiger detector, on whether some uranium atom had decayed, then, as far as we know, the path would be truly unpredictable.
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