How Randomness Can Arise from Determinism • Hacker News Board

Re: How Randomness Can Arise from Determinism

#21

Post by n4r9 » Thu, Oct 17, 2019, 4:56 PM UTC

computerex wrote: post #18

kerkeslager wrote: post #12

Earlier quoted context omitted.

> This article seems to be starting from a conclusion and then working its way up to an explanation. That's not how science works. No, it's starting from a phenomena and providing a possible hypothesis for why that phenomena is occurring. This is explaining an existing, untested hypothesis. > There is lots of experimental evidence that on a quantum scale there is inherent randomness. No, there isn't, at least not as…

Also: https://en.wikipedia.org/wiki/Bell%27s_theorem In conjunction with https://en.wikipedia.org/wiki/Lorentz_covariance Lorentz invariance has not shown to be violated despite many tries experimentally and from observation.

Bell's Theorem is really about locality rather than randomness. It's possible to define quantum theory in terms of deterministic but non-local random variables. In fact, this is a pretty apt description of the de Broglie-Bohm interpretation.

Re: How Randomness Can Arise from Determinism

#22

Post by criddell » Thu, Oct 17, 2019, 4:59 PM UTC

bonoboTP wrote: post #19

criddell wrote: post #11

Earlier quoted context omitted.

> Anyone can claim that there are deterministic causal factors leading to what appears to be randomness. What are those factors? What's the alternative? That something happens without a cause?

I mean, things could be that way. It's not so hard to imagine a universe where some events just happen without any causation or correlation with past events. The astonishing thing is that there is any causation at all! That events at different times are related to each other.

You think a billiard ball that just starts moving for reasons of randomness is less astonishing than a billiard ball that moves because it was struck by another ball?

Re: How Randomness Can Arise from Determinism

#23

Post by kerkeslager » Thu, Oct 17, 2019, 5:04 PM UTC

computerex wrote: post #16

kerkeslager wrote: post #12

Earlier quoted context omitted.

> This article seems to be starting from a conclusion and then working its way up to an explanation. That's not how science works. No, it's starting from a phenomena and providing a possible hypothesis for why that phenomena is occurring. This is explaining an existing, untested hypothesis. > There is lots of experimental evidence that on a quantum scale there is inherent randomness. No, there isn't, at least not as…

> No, it's starting from a phenomena and providing a possible hypothesis for why that phenomena is occurring. This is explaining an existing, untested hypothesis. There is no hypothesis presented, merely that there are deterministic factors that we don't know of. That's not a hypothesis. > No, there isn't, at least not as far as I know. The experimental evidence I'm aware of shows that we cannot, with current measure…

> There is no hypothesis presented, merely that there are deterministic factors that we don't know of. That's not a hypothesis.

How is that not a hypothesis?

How is it any less valid a hypothesis than "it occurs randomly"?

> Science doesn't work backwards from conclusions.

And neither does the article.

> If you think that there is determinism, there needs to be a testable theory that explains what these deterministic factors are.

If you think that there is randomness, that is inherently not a testable hypothesis (nor is it a theory: please do not use "hypothesis" and "theory" as if they are interchangeable--in scientific discussion they are not interchangeable terms).

I don't think that there is determinism: that would be a conclusion.

I think it's possible that there is determinism. That's a hypothesis.

I also think it's possible that there is not determinism. That's also a hypothesis.

Given current technology, I don't think we have the means to test either hypothesis. I'll also point out that randomness is inherently untestable.

> Like I said, we can simply attribute this supposed determinism to invisible unicorns and it'd be an equally valid explanation.

This is also a valid argument against inherent randomness.

As an atheist with a good amount of atheist reading under my belt, I am quite familiar with this argument, and in general agree with it when applied to i.e. God. The problem in this case is that BOTH hypotheses are untestable: you cannot test whether the underlying mechanism is random OR deterministic.

Here's a thought experiment for you: I've generated the following sequence of numbers:

    2385355152251270793561664145629697283988594371684899475531490573
    2823786386194927922215110087335052193747272459669030480603069080
    8421209646110735430316730270075597685536122026199316753888263136
    8982777911253921734120343767097551341142139450682090146370225695

I generated this sequence of numbers via a widely-used secure pseudorandom generator, so they are not random. But if I didn't tell you that, you'd have no idea, and these pseudorandom generators are time-tested to be very hard to distinguish from random numbers if you don't know the seed (otherwise you'd be able to break a lot of modern encryption). So by your logic, since you can't tell me what the deterministic factors are, you can only conclude that the numbers are truly random. But that's wrong, the numbers aren't random.

EDIT: This was downvoted faster than anyone can read, I'd wager.

Re: How Randomness Can Arise from Determinism

#24

Post by jayd16 » Thu, Oct 17, 2019, 5:06 PM UTC

computerex wrote: post #10

jayd16 wrote: post #9

Earlier quoted context omitted.

Assuming it lands perfectly in the center, it rests, perfectly balanced on the peg.

What if the size of the peg is really tiny, let's say a few atoms and what if the marble was also very tiny, a single atom? What would happen then?

I can assure you I don't know. That moves the problem from platonic shapes to real interactions of quantum particles. Atoms are not equivalent to perfect spheres.

Re: How Randomness Can Arise from Determinism

#25

Post by dragonwriter » Thu, Oct 17, 2019, 5:07 PM UTC

kerkeslager wrote: post #23

computerex wrote: post #16

Earlier quoted context omitted.

> No, it's starting from a phenomena and providing a possible hypothesis for why that phenomena is occurring. This is explaining an existing, untested hypothesis. There is no hypothesis presented, merely that there are deterministic factors that we don't know of. That's not a hypothesis. > No, there isn't, at least not as far as I know. The experimental evidence I'm aware of shows that we cannot, with current measure…

> There is no hypothesis presented, merely that there are deterministic factors that we don't know of. That's not a hypothesis. How is that not a hypothesis? How is it any less valid a hypothesis than "it occurs randomly"? > Science doesn't work backwards from conclusions. And neither does the article. > If you think that there is determinism, there needs to be a testable theory that explains what these deterministic…

> How is that not a hypothesis?

It makes no falsifiable predictions, therefore, it's speculation, not a hypothesis.

Re: How Randomness Can Arise from Determinism

#26

Post by computerex » Thu, Oct 17, 2019, 5:07 PM UTC

n4r9 wrote: post #21

computerex wrote: post #18

Earlier quoted context omitted.

Also: https://en.wikipedia.org/wiki/Bell%27s_theorem In conjunction with https://en.wikipedia.org/wiki/Lorentz_covariance Lorentz invariance has not shown to be violated despite many tries experimentally and from observation.

Bell's Theorem is really about locality rather than randomness. It's possible to define quantum theory in terms of deterministic but non-local random variables. In fact, this is a pretty apt description of the de Broglie-Bohm interpretation.

You are right, but any non-local variable theory cannot be lorentz invariant.

Re: How Randomness Can Arise from Determinism

#27

Post by kerkeslager » Thu, Oct 17, 2019, 5:14 PM UTC

dragonwriter wrote: post #25

kerkeslager wrote: post #23

Earlier quoted context omitted.

> There is no hypothesis presented, merely that there are deterministic factors that we don't know of. That's not a hypothesis. How is that not a hypothesis? How is it any less valid a hypothesis than "it occurs randomly"? > Science doesn't work backwards from conclusions. And neither does the article. > If you think that there is determinism, there needs to be a testable theory that explains what these deterministic…

> How is that not a hypothesis? It makes no falsifiable predictions, therefore, it's speculation, not a hypothesis.

Would you care to answer the question directly after the one you answered?

Attributing quantum phenomena to randomness also makes no falsifiable predictions.

In fact, asserting quantum phenomena are caused by pure randomness is equivalent the assertion that no prediction is possible.

Re: How Randomness Can Arise from Determinism

#28

Post by n4r9 » Thu, Oct 17, 2019, 5:14 PM UTC

computerex wrote: post #26

n4r9 wrote: post #21

Earlier quoted context omitted.

Bell's Theorem is really about locality rather than randomness. It's possible to define quantum theory in terms of deterministic but non-local random variables. In fact, this is a pretty apt description of the de Broglie-Bohm interpretation.

You are right, but any non-local variable theory cannot be lorentz invariant.

I don't think it's that simple. A fair amount of work has been done on relativistic extensions of de Broglie-Bohm type theories, e.g. https://arxiv.org/pdf/quant-ph/0406173.pdf

Re: How Randomness Can Arise from Determinism

#29

Post by dragonwriter » Thu, Oct 17, 2019, 5:35 PM UTC

kerkeslager wrote: post #27

dragonwriter wrote: post #25

Earlier quoted context omitted.

> How is that not a hypothesis? It makes no falsifiable predictions, therefore, it's speculation, not a hypothesis.

Would you care to answer the question directly after the one you answered? Attributing quantum phenomena to randomness also makes no falsifiable predictions. In fact, asserting quantum phenomena are caused by pure randomness is equivalent the assertion that no prediction is possible.

> Attributing quantum phenomena to randomness also makes no falsifiable predictions.

“Any research effort will find no deterministic explanation” is, I suppose, falsifiable, but mostly I agree; randomness as explanation is the absence of an explanatory hypothesis, not a substantial hypothesis.

Re: How Randomness Can Arise from Determinism

#30

Post by kerkeslager » Thu, Oct 17, 2019, 5:56 PM UTC

dragonwriter wrote: post #29

kerkeslager wrote: post #27

Earlier quoted context omitted.

Would you care to answer the question directly after the one you answered? Attributing quantum phenomena to randomness also makes no falsifiable predictions. In fact, asserting quantum phenomena are caused by pure randomness is equivalent the assertion that no prediction is possible.

> Attributing quantum phenomena to randomness also makes no falsifiable predictions. “Any research effort will find no deterministic explanation” is, I suppose, falsifiable, but mostly I agree; randomness as explanation is the absence of an explanatory hypothesis, not a substantial hypothesis.

My thinking on this is basically, hypotheses don't have to be falsifiable, but they aren't very useful if they aren't, because you can't design an experiment to test them.

Neither the determinism nor nondeterminism hypotheses are falsifiable, so there's no reason to prefer one over the other right now.

However, non-determinism will never be falsifiable, whereas determinism is only currently non-falsifiable because a plausible, testable mechanism has not yet been hypothesized. So while there's no reason to favor determinism as something we believe, there's reason to favor it in research, because research has the potential to yield further information.