Are determinism and MWI incompatible?

[ecoli]

This is probably why non-physicists shouldn't waste their time thinking about physics:

 

So by determinism, I'm talking about the concept that if you knew the state of every particle at the beginning of the big bang, you could recreate or model the universe perfectly as well as make perfect predictions about the future. I think the concept is rooted in chaos theory.

 

The Many worlds interpretation is, I think, considered correct by a consensus of physicists.

 

My question is, if you knew all the causes and effects starting from initial conditions, how could the wave function collapse on an alternative to our own universe?

 

Determinists claim that randomness is illusory even at the quantum level. If this is true, how could variations exist between universes?

 

Perhaps I've stumbled upon an argument for simulationism?

[Sisyphus]

But really, MWI is determinist. Heads or tails (not literally, but as an example) isn't random, because both will happen, necessarily. It's just determinism without the possibility of practical prediction. I can predict with certainty that I will be in the heads universe and I'll be in the tails universe, but since both of me will experience one or the other happening, that isn't a useful prediction.

[swansont]

 

So by determinism, I'm talking about the concept that if you knew the state of every particle at the beginning of the big bang, you could recreate or model the universe perfectly as well as make perfect predictions about the future.

 

But what if it takes more than the computing power of a proton to store and process the information about that proton? You can't use that proton anyway, because you are trying to predict its future, and not in some self-fulfilling way. I think the premise is fatally flawed.

[Mr Skeptic]

This is probably why non-physicists shouldn't waste their time thinking about physics:

 

So by determinism, I'm talking about the concept that if you knew the state of every particle at the beginning of the big bang, you could recreate or model the universe perfectly as well as make perfect predictions about the future.

 

So long as you don't use atoms nor energy from the universe to be modeled, nor leak matter nor energy into it.

 

I think the concept is rooted in chaos theory.

 

Deterministic chaos is a system that is annoyingly hard to predict despite being deterministic, and also highly sensitive to the tiniest changes in initial conditions.

 

The Many worlds interpretation is, I think, considered correct by a consensus of physicists.

 

I think all interpretations are equal if they make equal predictions. Just go for the one that makes the most sense to you.

 

My question is, if you knew all the causes and effects starting from initial conditions, how could the wave function collapse on an alternative to our own universe?

 

Determinists claim that randomness is illusory even at the quantum level. If this is true, how could variations exist between universes?

 

Perhaps I've stumbled upon an argument for simulationism?

 

For the multiple worlds interpretation, both events happen but you don't know ahead of time which universe you will be in. So for any practical purposes, there's still randomness.

[padren]

But what if it takes more than the computing power of a proton to store and process the information about that proton? You can't use that proton anyway, because you are trying to predict its future, and not in some self-fulfilling way. I think the premise is fatally flawed.

 

The premise is only viable if the calculation is occurring outside the universe where the data, processing, and results of that data could not impact the events in the universe being calculated.

Of course, it would also require acquiring all the initial state data without impacting the state of that data so to literally set up such a condition is impossible.

So even though it would be impossible to setup such an experiment, if the setup happened to pop into existence, there is no reason to believe it would not unfold as expected.

[vuquta]

The premise is only viable if the calculation is occurring outside the universe where the data, processing, and results of that data could not impact the events in the universe being calculated.

Of course, it would also require acquiring all the initial state data without impacting the state of that data so to literally set up such a condition is impossible.

So even though it would be impossible to setup such an experiment, if the setup happened to pop into existence, there is no reason to believe it would not unfold as expected.

 

Unfold implies determinism.