[Valen (OP)]

Does true randomness exist? Imagine an omniscient being, who does know all variables of all particles, it even knows all variables of particles that humans can't measure without changing those particles. This being has a perfect understanding of everything and infinite calculating power. Can this being predict the future or does true randomness exist?

[evan_au]

A similar question about true randomness in computers was answered here:
https://www.thenakedscientists.com/forum/index.php?topic=71507.0

But your question is more like the philosophical debate about whether free will really exists?
https://en.wikipedia.org/wiki/Free_will_in_theology

[alancalverd]

The question is absurd. You have asked whether A exists, then stated it  could not if B were to exist.

Let's simplify the argument: Is the light on? It can't be if the switch is off.

Philosophers get paid to waste their students' time worrying about this sort of thing. Priests get paid for asserting that B exists, with no evidence or requirement.  Politicians get paid for not answering questions.

[Valen (OP)]

Let me rephrase the question, because it was misunderstood: If the multiverse is changed to the EXACT state it was just before the first double slit experiment, will the first foton then always traverse the same slit?   

[Kryptid]

I think Bell's inequality has something to say about this, but for the life of me I can't understand it.

[Halc]

Let me rephrase the question, because it was misunderstood: If the multiverse is changed to the EXACT state it was just before the first double slit experiment, will the first foton then always traverse the same slit?

Definitely a philosophical question.

You call it a multiverse, which already answers the question.  In the sort of multiverse that comes from this line of questioning, all measurements take place.  The cat is dead in the universe where it is dead, and alive in the one where it lives.  Even an omniscient god cannot predict both answers since both occur.  So all the super-being can do is change your memory to a history where the correct prediction was made before the experiment took place.

Anyway, none of that is true randomness (and the photon goes through both slits, not just one of them).  True randomness is more one universe (one outcome), unpredictable: It would not necessarily happen the same way if it were done again.

Nobody gets to try twice, so of course there is no scientific distinction between that and determinism.

[Valen (OP)]

Multiverse does not necessary refer to the many worlds theory, I used that term because we are not 100% certain that other universes couldn't influence events in this universe.

But I think that the true issue is that no measurement can differentiate between an unpredictable event and a true random one, those 2 will generate similar data. While off course unpredictability does not prove true randomness.

It is similar in how no measurement could differentiate between randomness and free will, they will generate similar data.

[alancalverd]

You can go on adding untestable hypotheses ad lib, until you end up with a religion. This will give you an excuse to kill people, so I won't encourage it by continuing an otherwise pointless discussion.

[Valen (OP)]

You can go on adding untestable hypotheses ad lib, until you end up with a religion. This will give you an excuse to kill people, so I won't encourage it by continuing an otherwise pointless discussion.

What has anything here to do with religion ? Most religions would hate the idea of true randomness.

But the religious and you in this thread have one thing in common: They react hatefull and emotional to a question they can't answer, why not simply aswer that you can't answer it right now. Only religious people would object to that idea.

But thanks to the others in this thread who actually tried to answer the question, who actually ARE interessed in discovering how reality works(free of any taboo questions). askamathematician also has a good discusion of this issue.

Many great scientist have discussed this issue, are all of them religious fanatics? Even while some of them did not believe at all?

I don't see anything religious about asking questions like: "Was in 1900 WWI a possible or a certain outcome?" "Is the universe probabilistic or deterministic" OR "Does true randomness exist"

I just want to know how the universe works, what is religious about that?

[Valen (OP)]

Found the best answer until now:

"To say that the randomness of quantum phenomena is coming from somewhere/something is to assert what physicists call a hidden variable theory. In such a theory, there would be apparent randomness, but there are hidden variables we are not yet aware of (for lack of better knowledge of physics, lack of better measurement equipment, etc...) which if known would provide a deterministic explanation of the apparent randomness. John Bell proved in his 1964 paper (Bell's theorem) that no local hidden variable theory can reproduce the results of quantum mechanics. His theorem was experimentally validated by Aspect et al in 1981 (and many subsequent teams), in the sense that the experimental results indicate that Quantum Mechanics holds.

The key terms here are "local" and "hidden variable". "hidden variable" was already explained above. "local" theory means any theory that precludes instantaneous interaction at a distance.

It is still possible for a non local hidden variable theory to reproduce the results of quantum mechanics. We would eliminate the quantum randomness, but at the cost of removing locality as well.

You might say "well fine, locality is not essential". But the consequences of non locality for causality are seen by some as even more disturbing than quantum randomness. Keep in mind that what is meant by non-local here is fully instantaneous interaction, not just faster than the speed of light. This means that it would be possible in theory for you to push a button on earth and cause a cat to die on the other side of the galaxy without any signal having to travel from here to there. The implications of this spooky action at a distance for causality are significant, especially given the results of relativity (which are much more intuitive than people think they are)."

My conclusion is that true randomness probably exists.

The many worlds theory does not remove true randomness, the paths of an observer are still randomly selected.

[Bored chemist]

What has anything here to do with religion ?

It asks a poorly phrased question, then pretends that there is something mystical about the lack of a clear answer.

[Valen (OP)]

What has anything here to do with religion ?

It asks a poorly phrased question, then pretends that there is something mystical about the lack of a clear answer.

Were did I pretend that there is something mystical about the lack of a clear answer? I even later quoted a clear answer!

EDIT: English is not my native language and somethings may have been misunderstood as a result but that is no reason to be passive aggresive.

[Halc]

Multiverse does not necessary refer to the many worlds theory, I used that term because we are not 100% certain that other universes couldn't influence events in this universe.

If it influences stuff here, it isn't a separate universe, pretty much by any definition.  Dark matter for instance is barely detectable, and yet is not posited as an influence from some other universe.

But I think that the true issue is that no measurement can differentiate between an unpredictable event and a true random one, those 2 will generate similar data. While off course unpredictability does not prove true randomness.

Kind of.  There can be self-unpredictable systems that have no randomness, and random systems that are fully predictable.  The words really do mean different things, but much of it is interpretation dependent.
Anyway, my comment was mostly about your claiming that a multiverse could be set 'to the same state', but a multiverse doesn't really have a state.  It has a bunch of them, none of which are 'the state'.  That's what makes it a multiverse, be it the MWI kind or one of several other types.

It is similar in how no measurement could differentiate between randomness and free will, they will generate similar data.

I could tell the difference between those two, but perhaps not determinism and free will.  I don't cross the street at a random moment .  I use my will (free or otherwise) to do it at a safe time.  Randomness (lack of choice about it) would quickly kill me.

Found the best answer until now:

"To say that the randomness of quantum phenomena is coming from somewhere/something is to assert what physicists call a hidden variable theory.

Where did you find this?  Hidden variable theory (Bohmian mechanics, or de Broglie–Bohm interpretation) is an interpretation designed around single-world hard determinism.  Those variables cause the same thing to happen every time, totally eliminating randomness.
So maybe this comment refers to a different interpretation with hidden random variables, the throwing of dice that Einstein so abhorred, but no:

" ... In such a theory, there would be apparent randomness, but there are hidden variables we are not yet aware of (for lack of better knowledge of physics, lack of better measurement equipment, etc...) which if known would provide a deterministic explanation of the apparent randomness.

OK, they're definitely talking about apparent but not true randomness.  That's Bohmian mechanics, the exact opposite of randomness.

" ... John Bell proved in his 1964 paper (Bell's theorem) that no local hidden variable theory can reproduce the results of quantum mechanics.

To clarify this a little, his theorem proved that you can't have an interpretation with both locality and counterfactual definiteness.  The hidden variable theory is one of counterfactual definiteness, so it cannot be a local theory.  It seems to be the only mainstream interpretation that holds to this principle.  Other interpretations hold to the principle of locality, and thus cannot have an unmeasured 'state of the system'.

" ... You might say "well fine, locality is not essential". But the consequences of non locality for causality are seen by some as even more disturbing than quantum randomness.

For the record, I am one of those people.  The alternative is not necessarily randomness, unless that is the label applied to lack of counterfactual definiteness (that there is a factual state of an unmeasured system).  The ability for things to be in superposition pretty much makes it clear that such factual states are probably fiction.

The many worlds theory does not remove true randomness, the paths of an observer are still randomly selected.

You misrepresent MWI here.  There is no random selecting going on.
I'm a quantum relativist myself, not an MWI guy, but I understand it well enough.  There is no randomness in that one either.  I think an ontological (as opposed to epistemological) version of Copenhagen has actual randomness going on.

[guest45734]

Does true randomness exist? Imagine an omniscient being, who does know all variables of all particles, it even knows all variables of particles that humans can't measure without changing those particles. This being has a perfect understanding of everything and infinite calculating power. Can this being predict the future or does true randomness exist?

Given a set of inputs the probable outcome for anything can be worked out, so NO true randomness does not exist. The probability of something happening doesn't have to be 0 or 1, it can be any value in between.

https://en.wikipedia.org/wiki/Probability_theory

[yor_on]

It definitely exist. Whenever you fail to find a answer instead citing the 'probability' of it you admit it to exist. We can't even predict orbits looking too far ahead in time.
=

But if you're talking about a God, nothing is set in stone, except possibly the seventh commandments that is. Knowing it all means seeing every probability there can be, and then also defining which one it will be, before. That is presuming God having a arrow of time, like us.
==

Then again, if you by it wonder whether there can be 'true randomness' that we can't define probabilities too?
I don't know. But I have a hard time imagining it.

Actually I think of that as 'magic'

==

It might become clearer if you consider that mathematics and physics goes hand in hand, and are built from logic and observation. So far I don't know of any scientific fact that doesn't fit this. Physics are presumed to work everywhere you are and at any time. To have randomness refuting probability would mean that physics no longer can give you a prediction of 'probabilities', no matter how long time we took upon us to observe whatever we observed. That would really be interesting :)

[guest46746]

If randomness can be expressed as a non repeating number, the sqrt of 2 and pi, would qualify! lol

[alancalverd]

A phenomenon is random if there is no way of predicting its next state or value from its present or previous states. This excludes the next digit of pi since it is entirely calculable, as was every preceding digit.

It is worth considering whether the position of an electron in a hydrogen atom is predictable. The atom's diameter is determined by Heisenberg's indeterminacy relationship ΔpΔx ≥ h : it is sometimes clumsly expressed as"you cannot know the position and momentum of an object simultaneously to an indefinite degree of precision", but it's more fundamental than that, and has nothing to do with the existence of an observer. If either the position or momentum of the electron were not "truly random", the atom would collapse and we would not exist.

[guest46746]

"you cannot know the position and momentum of an object simultaneously to an indefinite degree of precision",

As with 2 squared , Pi never end and never repeats, as such it extends to infinity. Now it may be calculated out to a large 10th power but the last number on it's chain remains indeterminate. lol

It can be liken to the uncertainity principle in that a location can be calculated but the next value remains unknown! lol

[alancalverd]

You need to understand the difference between "unknown" and "unknowable". There is nothing random or unknowable about any digit of an irrational number for which we can write an equation.

And I think you will find that 2² = 4 with absolute certainty.

[guest46746]

And I think you will find that 22 = 4 with absolute certainty.

I'm holding up a single finger with absolute certainty which one is it? lol