Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Forgotten Solution: Superdeterminism

backreaction.blogspot.com

Post reply on HN
Print view View original

41–50 of 70 posts

Re: The Forgotten Solution: Superdeterminism

#41

Post by gus_massa »

In Superdeterminism each time a particle has to collapse, instead of rolling a dice it looks into a secret table of hidden variables that was calculated at the beginning of the universe. The table was calculated carefully so the apparent random choices follow all the laws of quantum mechanics, and the results are equivalent to what you would expect if any of the other interpretations where correct.

To calculate this secret table you must simulate all the interactions and path in the universe until it ends, because you must know which particles will be entangled, which result will have the "random" generator in the experiments, ...

So the universe is only a movie that follows the random choices made at the beginning of the universe. But the choices are not arbitrary, they have the correct values so when the events really happen they follow the laws of physics. For example, the random choices at the beginning of the universe make it look that you can't transmit information faster than light.

Physics study the laws of the real universe, but we can redefine Physics as the study of the laws that study the random number generator. Both real-Physics and initial-rng-Physics follow special relativity. Bot agree about QM. Both agree about the Bell inequality.

So with Superdeterminism we solve the problem of QM in the real word, because everything we is already determined. Now the problem is how the RNG at the beginning of the universe work to simulate QM and all the other effects. Let's call the study of the RNG Physics. Now the problem is as hard as before Superdeterminism.

Re: The Forgotten Solution: Superdeterminism

#42

Post by mjevans »

whatshisface wrote: post #4

"The Facts" basically say that among the statements, "Your experiment design isn't predestined by the universe to make it accidentally seem like quantum mechanics is true," "the state of the universe today is all you need to know to predict the state of the universe tomorrow," and "an experiment only has one outcome," there is at least one lie. If the first one is a lie that's superdeterminism, the second one the Cop…

My issue with the second statement, about knowing the exact state of the universe at any given reference time is that by definition the information within that state would require the entire space of the universe to store with sufficient detail to make an accurate prediction of future states. (One might also assume it would require a real universe's worth of processing power to compute a new state as well.)

I believe it's impossible to completely isolate any segment of that universe (E.G. to make it smaller and thus predictable within the capability bounds of a larger universe) without literally removing it from that universe. That no matter what every part of an existing universe interacts with every other part, even if very, very, indirectly.

As for the question of free will: I believe the biology is largely deterministic. For me, that leaves the main set of questions in the direction of all of the elements that might happen between, outside, or otherwise beyond our current understanding of how the universe works. I feel that if there is any actual freedom in free will that is where it comes from; otherwise it's just the RNG being too complex to understand completely masking the lack of actual choice.

Re: The Forgotten Solution: Superdeterminism

#43

Post by chr1 »

whatshisface wrote: post #4

"The Facts" basically say that among the statements, "Your experiment design isn't predestined by the universe to make it accidentally seem like quantum mechanics is true," "the state of the universe today is all you need to know to predict the state of the universe tomorrow," and "an experiment only has one outcome," there is at least one lie. If the first one is a lie that's superdeterminism, the second one the Cop…

There is also the fourth possibility that the physical space is not similar to euclidean space at short distances, and locality in euclidean space is not physical. In this case the entangled particles are actually linked with one another, and can transmit the information about the filter they are interacting with, but because particles prefer to be linked to closeby particles, the long range links easily break not allowing to pass much information.

Re: The Forgotten Solution: Superdeterminism

#44

Post by marcosdumay »

IX-103 wrote: post #36
klodolph wrote: post #17

Earlier quoted context omitted.

My understanding is that it is possible to conduct an experiment which would invalidate pilot wave theory or confirm it, to the extent that theories are invalidated or confirmed--we just haven't figured out how to conduct the experiment. The article mentions that Bell's inequality was in a similar position in the past.

Why does pilot wave theory violate locality -- does it assume that the pilot waves travel faster than light? And if so, is it necessary for the pilot waves to travel faster than light or can they be limited to the speed of light and preserve locality?

Pilot wave theory is based on the assumption that every particle is interacting with the entire Universe all the time.

Re: The Forgotten Solution: Superdeterminism

#45

Post by cbkeller »

whatshisface wrote: post #4

"The Facts" basically say that among the statements, "Your experiment design isn't predestined by the universe to make it accidentally seem like quantum mechanics is true," "the state of the universe today is all you need to know to predict the state of the universe tomorrow," and "an experiment only has one outcome," there is at least one lie. If the first one is a lie that's superdeterminism, the second one the Cop…

I think you forgot one: "The principle of locality always applies" / "no spooky action at a distance" -- while local hidden variable interpretations have been ruled out, nonlocal ones are still very much on the table.

Re: The Forgotten Solution: Superdeterminism

#46

Post by cybersnowflake »

coldtea wrote: post #23
teilo wrote: post #21

Superdeterminism is a self-defeating philosophy. In essence, it cedes everything to random chance, and makes all scientific inquiry meaningless. There is no longer any "why" or "how." There is merely, "That's just the way it is." Any apparent order or structure which might be observed is exactly that: merely apparent. Therefore any attempt to understand the universe is vain. It is little better than the presumption t…

> In essence, it cedes everything to random chance, and makes all scientific inquiry meaningless. There is no longer any "why" or "how." There is merely, "That's just the way it is." Which doesn't make it wrong...

Bearded Intellectual: Superdeterminism did it. 'Intelligentsia': YAY two minutes later... Evangelist: God did it... 'Intelligentsia': REEEEEEEEEEEEEEEEEEEEEEEEEEEE

Re: The Forgotten Solution: Superdeterminism

#48

Post by IX-103 »

pdonis wrote: post #39
IX-103 wrote: post #38

I'm not fond of superdeterminism since it's not that useful for making predictions. Any purely deterministic model has implications for free will, so that doesn't seem to be a legitimate criticism. Actually I would like to know more about provable violations if Bell's theorem as I am somewhat attached to local determinism and haven't seen an experiment that I would consider convincing. I mean the theories behind the…

> In such an equilibrium the system state effectively becomes a standing wave so you risk measuring an effect that was actually a result of a previous cycle and mistakenly interpret it as being a result of the current cycle I don't know where you're getting this from, but it doesn't describe quantum systems on which Bell inequality violations have been experimentally confirmed (such as photon pairs from parametric do…

In short the problem I'm addressing is that the interpretation of the experiment assumes that the system is memoryless, so that the only thing being measured is the interaction with the particles being measured.

In the experiments generating the photon pairs from parametric downconversion, for example, does the entire system start up, send 1 photon which gets split into the entangled photon pairs which then go to the detectors -- with no other photons generated?

If there is a warm-up period for the equipment or other photons are emitted or absorbed then there is the potential for memory effects that could interfere with the measurements.

For instance if we treat light as a wave then the cosine correlation with angle we see in the basic "two entangled photons with polarizing lenses experiment" is exactly what we would expect to see. The difficulty is simply resolving this with the particle nature of photons. If the experimental system has memory then it could easily have the phase of the effective wave or some other function of the history of photons encoded in the state of the system.

There are probably some ways to compensate for these memory effects and demonstrate their (non)existence, but I am not a physicist.

Re: The Forgotten Solution: Superdeterminism

#49

Post by IX-103 »

marcosdumay wrote: post #44
IX-103 wrote: post #36

Earlier quoted context omitted.

Why does pilot wave theory violate locality -- does it assume that the pilot waves travel faster than light? And if so, is it necessary for the pilot waves to travel faster than light or can they be limited to the speed of light and preserve locality?

Pilot wave theory is based on the assumption that every particle is interacting with the entire Universe all the time.

Does it have to be the simultaneous version of the current universe or can it be the universe as it was distance/c ago?

Actually with relativity and all I'm not exactly sure there is a just a single correct definition of the instantaneous state of the universe.

Re: The Forgotten Solution: Superdeterminism

#50

Post by pdonis »

IX-103 wrote: post #48
pdonis wrote: post #39

Earlier quoted context omitted.

> In such an equilibrium the system state effectively becomes a standing wave so you risk measuring an effect that was actually a result of a previous cycle and mistakenly interpret it as being a result of the current cycle I don't know where you're getting this from, but it doesn't describe quantum systems on which Bell inequality violations have been experimentally confirmed (such as photon pairs from parametric do…

In short the problem I'm addressing is that the interpretation of the experiment assumes that the system is memoryless, so that the only thing being measured is the interaction with the particles being measured. In the experiments generating the photon pairs from parametric downconversion, for example, does the entire system start up, send 1 photon which gets split into the entangled photon pairs which then go to the…

> the problem I'm addressing is that the interpretation of the experiment assumes that the system is memoryless

That's easy to verify by testing the various components--parametric down conversion, prisms, beam splitters, etc.--and showing that if you shine repeated photons on them from the same source, prepared in the same state, they all come out in the same state, or more generally give the same results. All of the optical components involved in these experiments have been tested in this way: if they had failed such tests, they wouldn't be used in experiments because we wouldn't be able to be confident in their behavior.

> n the experiments generating the photon pairs from parametric downconversion, for example, does the entire system start up, send 1 photon which gets split into the entangled photon pairs which then go to the detectors -- with no other photons generated?

For current photon sources, it's impossible to control exactly when they emit a photon. The sources are so inefficient (in terms of converting input energy into photons that are useful for the experiment) that they end up emitting photons slowly enough that only one at a time is inside the apparatus. However, a typical experiment does not use just one photon. It has to take data from many photons because the results are statistical, so you need enough runs to do statistics.

> If the experimental system has memory then it could easily have the phase of the effective wave or some other function of the history of photons encoded in the state of the system.

We know how to design systems that do this: they're called "detectors" and "computers that store data". But such systems have to be carefully designed to do those jobs. Optical components like prisms and beam splitters are not designed to do that: they're designed to do exactly the opposite, to act the same way on every photon that comes into them in the same input state. As I noted above, those components have been extensively tested to make sure they do in fact do that; if they didn't, they wouldn't be used in experiments.

Post reply on HN