Gerard 't Hooft on the incompleteness of quantum mechanics

[martinbn]

That's also true for determinism. The difference between determinism and superdeterminism is the following: Determinism postulates deterministic equations of motion, while superdeterminisim, in addition, postulates also a law for the initial conditions. In QM, the idea of superdeterminism (as opposed to mere determinism as in Bohmian mechanics) is to get rid of the need of nonlocal instantaneous action at a distance, by postulating a special law for initial conditions that can explain correlations violating Bell inequalities.

And those initial conditions have to contain nonlocal correlations, which are worse than what they try to explain!

 

[pines-demon]

Here's an analogy. Determinism would say that the outcome of every soccer match is predetermined. Or, at least, that the outcome follows deterministic laws. Two soccer matches in two countries, however, would be independent systems.

Superdeterminism additionally produces otherwise inexplicable correlations between soccer matches. For example, Glasgow Celtic's results in Scotland might be exactly correlated with Bayern Munich's in Germany.

This is the point that the superdeterminists try to sweep under the carpet. That the initial conditions conspire to produce otherwise inexplicable but experimentally repeatable correlations between seemingly independent events. And, not only that, but these correlations are precisely those that would convince some of us that QM is an appropriate theory of nature. Whereas, as Scott Aaronson points out, the superdeterminists believe that nature is leading us astray by making it look like QM is correct. And, equally critically, that these otherwise inexplicable correlations extend to nothing except those experiments that support QM.

Exactly. Superdeterminism is not much about determinism but about avoiding statistical independence. Under superdeterminism we are unable to REDUCE the correlations between systems no matter what we do.

 

[gen x]

You do not have interest in engaging in any other points I made? Only in showing me this YouTube video?

Yes I read your posts.
Do you think nature at all scales must be only random or only deterministic or it can be random in micro-world and deterministic in macro-world? If latter, where is border where random become deterministic?


I don't understand concept of randomness( absence of cause-effect), if nature is random why projectile with angle alpha and initial velocity v1, always land on same spot?

 

[PeterDonis]

randomness( absence of cause-effect)

These are not the same. An event that is random can still cause something else to happen.

 

[gen x]

These are not the same. An event that is random can still cause something else to happen.

But electron around nucleus don't follow any law, any pattern, nothing cause it that he behave like it is.. that is what randomness say.

 

[jeffn1]

But electron around nucleus don't follow any law, any pattern, nothing cause it that he behave like it is.. that is what randomness say.

Doesn't the Schrodinger equation apply to the electron like other quantum particles? We can only detect a location when when it is measured (but with the familiar tradeoff of location/momentum). So, we currently have "probabilities" (that, as I understand it, correspond to the shapes of orbitals we see in chemistry textbooks) . The question (at least as I see it it) is whether there is something going on we cannot measure that leads to these probabilities. (That's my understanding, but I'm not a physicist...or even a chemist!)

 

[PeterDonis]

electron around nucleus don't follow any law, any pattern, nothing cause it that he behave like it is

Um, what? It's like you don't even understand that QM itself is a set of such laws and patterns. Sure, they aren't laws and patterns that predict a single outcome with 100% confidence in every single experiment, but so what? They're still laws and patterns, and we can make predictions based on them, and those predictions get confirmed in experiments, sometimes to as many as 13 decimal places. That includes things like the energy levels of electrons in atoms, the spectra of radiation emitted or absorbed by electrons in atoms, etc. So your description here is simply wrong.

 

[Matterwave]

Do you think nature at all scales must be only random or only deterministic or it can be random in micro-world and deterministic in macro-world? If latter, where is border where random become deterministic?

I don't understand concept of randomness( absence of cause-effect), if nature is random why projectile with angle alpha and initial velocity v1, always land on same spot?

It seems that your mental model of "random" is different than the "random" relevant for the discussion here.

It appears that your usage is "completely random" meaning arbitrary and not following any physical law. However, as others have noted, that is not the kind of random that appears in Quantum Mechanics (or any physical theory, by definition).

In Quantum Mechanics there are events, for example "we will measure the particle to be here or there", which we can not predict with 100% certainty. But this does not mean that we can't predict anything, or that the event is arbitrary and not subject to physical laws and/or causality. We can calculate the probability distribution for said events.

 

[gen x]

It seems that your mental model of "random" is different than the "random" relevant for the discussion here.

It appears that your usage is "completely random" meaning arbitrary and not following any physical law. However, as others have noted, that is not the kind of random that appears in Quantum Mechanics (or any physical theory, by definition).

In Quantum Mechanics there are events, for example "we will measure the particle to be here or there", which we can not predict with 100% certainty. But this does not mean that we can't predict anything, or that the event is arbitrary and not subject to physical laws and/or causality. We can calculate the probability distribution for said events.

Um, what? It's like you don't even understand that QM itself is a set of such laws and patterns. Sure, they aren't laws and patterns that predict a single outcome with 100% confidence in every single experiment, but so what? They're still laws and patterns, and we can make predictions based on them, and those predictions get confirmed in experiments, sometimes to as many as 13 decimal places. That includes things like the energy levels of electrons in atoms, the spectra of radiation emitted or absorbed by electrons in atoms, etc. So your description here is simply wrong.

We don't have theory for path of single electron, we don't know what he do, so we say electron movement is random.

 

[Matterwave]

We don't have theory for path of single electron, we don't know what he do, so we say electron movement is random.

Wrong.

Why is left as an exercise to the reader.

 

[physika]

can be random in micro-world and deterministic in macro-world?

Who knows, maybe both.

...

 

[PeroK]

if nature is random why projectile with angle alpha and initial velocity v1, always land on same spot?

It doesn't. It depends on the wind.