Is the Universe Deterministic or Not?

[Ken G]

The problem with that argument is, when Newton's deterministic laws were found to work well, people said "the universe is fundamentally deterministic." Then, when the probabilistic equations of quantum mechanics were found to work well, people said "the universe is fundamentally probabilistic." Then Bohm comes along and says "there is a pilot wave that makes a fundamentally deterministic universe look probabilistic." At what point do we just clue in, and stop thinking that the latest flavor of our current best model is the way the universe "fundamentally is"? That's not the kind of question science answers, it just tries to learn lessons about what kinds of models work well in what situations.

 

[AgentSmith]

Hello everyone!

There's this one question that keeps bothering my mind, but I'm not sure if this is the right section. So if not I apologise and ask for a moderator to move it for me.

If there was somehow a way to 'reproduce' the universe we exist with ALL the trillions of constants there are. Would I be questioning this question on this forum at this time on the second Universe? Did I mix the scales too much? That would be either the whole Universe is deterministic or it's not. Do we know which one is it? Is that even graspable?

Have a good day :)

 

[AgentSmith]

The universe is deterministic. You had no choice about posting your question. I had no choice about posting this reply. I made my coffee this morning thinking I would like some coffee but it was predetermined in the initial singularity. You will have a good day.

 

[Ken G]

Yet there would be no point in defining the word "choice" to mean something that nothing has. The real question is not do we have a choice, it is what is choice in the first place. It is certainly possible to have choice in a deterministic universe-- choice can just mean attention to where the determination came from.

 

[OCR]

The universe is deterministic.

Well, you can say that ... or ... Well, you can not say that.

Lol...

 

[OCR]

I made my coffee this morning thinking I would like some coffee but it was predetermined...

And damned determined... no choice about it... lol

 

[AgentSmith]

I was being a bit sarcastic, folks. There are things that are predetermined and things that aren't; things we have no choice about, and things we do. This viewing the question as either-or is simply wrong.
I just had to say that.

 

[Ken G]

Human choice, and determinism in physics, are two quite different things, and best not confused. For humans, "choice" has more to do with where the determination came from (the person or their environment), whereas in physics, it is a property of the mathematical structure of some given theory. We really have no idea how those two things intersect, or do not intersect, because we are nowhere close to a theory of the mind. Most likely, when we do have a theory of the mind, it may involve both deterministic and probabilistic elements, but you can see that neither saying that your choices were determined at the start of the universe, nor saying that they are completely random, has much to do with what you mean by making a choice. Various possibilities, therefore, are that what we regard as a choice is a kind of internal illusion, or it is something real but will require a new kind of physical model to address-- perhaps one that is less reductionist than what physics now does. Either is certainly relevant to the question, "is the universe deterministic", since our minds must be considered part of the universe, but it's not an area where we seem particularly close to the necessary breakthroughs.

 

[Quds Akbar]

If you are with Quantum Mechanics, and it appears to be, then everything is based on uncertainty, probability, and chance. So according to quantum mechanics then the answer is no but in other ideologies then maybe.

 

[Robin]

It seems to me people confuse two words
A] Deterministic
B] Prediction
Quantum mechanics does not prove the universe is indeterministic.
It simply proves there are certain things we are unable to predict

 

[eachus]

There are three real zingers that have been left out of the discussion. The first comes from Gödel's Proofs (there are two). No mathematics can be complete and consistent. Inconsistency in this context allows anything to be proven true in that mathematics. So is QM incomplete or inconsistent? Hmm...

Another is time travel and/or faster than light travel may be possible in our universe. Even if humans can't do either, one photon squeezing through a wormhole makes this discussion almost irrelevant. Even if the universe as a whole is deterministic, any subset, like the visible universe, is non-deterministic. What if you can hop into a super FTL ship and visit every part of the universe in a day--or a million years? There can still be event chains that you have no knowledge of.

Finally, at any point in time, most, if not all, particles in the universe, plus the vacuum are in superpositions of states. An observer can look back in time and see a deterministic view of events, but that is history. In the instant of now, you cannot say anything about the state of the universe. At best you can say that the universe will have been in a state consistent with its historical states.

 

[Ken G]

Nothing could prove the universe is deterministic, and nothing could prove that it is not deterministic. Those are not provable attributes of the universe, those are demonstrable attributes of physical theories we can choose to invoke to understand the universe. And the current theory that is quantum mechanics is not a deterministic theory, because although the wavefunction evolves deterministically, the outcomes of observations are predicted only statistically by the Born rule.

 

[Ken G]

Idiots doesn't have an apostrophe.

 

[Chronos]

I assume you meant dark energy as opposed to dark matter with respect to 'the impossible, expanding universe'.

 

[nikkkom]

Yes, but that's all philosophy. As far as physics is concerned, the universe cannot be deterministic, it is probabilistic.

Experiments did not prove that yet.
Bell inequalities prove that no local deterministic theory can explain experiments. They did not prove that a NON-local deterministic theory can't explain experiments. Bohmian mechanic is one example of a non-local, deterministic QM theory.

 

[phinds]

Experiments did not prove that yet.
Bell inequalities prove that no local deterministic theory can explain experiments. They did not prove that a NON-local deterministic theory can't explain experiments. Bohmian mechanic is one example of a non-local, deterministic QM theory.

Interesting. Thanks. I was not aware of that.

 

[nikkkom]

Nothing could prove the universe is deterministic, and nothing could prove that it is not deterministic.

Bell inequalities did rule out a large class of deterministic theories. Why do you think some future experiment can't possibly prove that ALL possible deterministic theories can't match observations?