Those objections to super determinism seem weak, or more along the lines of “I don’t like the implications, so I won’t consider it.”
Genuine question: Would quantum computers work in any deterministic framework?
Genuine question: Would quantum computers work in any deterministic framework?
First, the logical flow: Bell’s theorem proves that no local, realistic theory can reproduce the predictions of quantum mechanics. It does so by considering a very specific situation of entangled particles being measured by spin detectors set at different angles. Critically, the angles of these spin detectors are assumed to be set independently from one another. ...
Experimenters have tried to ensure independence for all practical purposes with elaborate techniques: independent quasi-random number generators running with different algorithms on different computers are one very basic example. On more advanced experiments, they use quantum sources of randomness, and try to make sure that the choice is only made once the particles are in flight.
The trouble is that in principle, there will always be a point in the past at which mechanism used for the angle choice, and the mechanism used to produce the entangled particles were in causal contact with one another. (If all else fails, then the early universe will provide such a point.) The super-determination thesis says that any past causal contact can in principle provide correlation between the settings of the two detectors (or the detectors and the properties of the particles), and is the source of the violation of Bell’s inequality.
Here’s a deliberately ridiculous example. Once the particles are in flight, I throw in the air a box of Newton’s notes on alchemy. I select the one that falls closest to my feet. I roll two dice, and use them to select a random word from that page. I match the word with its closest equivalent in Caesar’s commentary on the Gallic wars, or the Iliad, or the complete works of Dickens, my choice of work depending on the orientation of the Crab pulsar at the moment of measurement. I use the word position in these works to select a number in this book A Million Random Digits (take the time to read the customer reviews). And I use this number to set my detectors. I repeat this for my other measurement runs, but I substitute in Dan Brown’s Da Vinci Code for Dickens every third go.
Superdetermination advocates would tell me that there is in principle a causal connection between my throwing the papers in the air, Newton, Caesar, Dickens as they sat down to write 300, 2000, and 150 years ago, the Crab pulsar and the RAND corporation’s random digit selection. And that it’s possible that these things have conspired (unknowingly) to make sure that my detector settings and a particle’s spin measurement is correlated in a particular way in my lab in a law-like way.
I can only reply that yes, it’s possible. I cannot prove it wrong. But I can find it unreasonable. And I would be tempted to call these people philosophically desperate.
https://www.quora.com/Why-do-some-crackpot-scientists-go-aft...
e.g Anything could be predicted with absolute knowledge of the starting state of the universe, and infinite computing power, but in most practical cases the causal connections between seemingly unrelated objects is irrelevant and as good as random?
I'm not a physicist though, so I might have something wrong here.
Wouldn't it be equally valid to say that the Quora commenter is philosophically desperate to avoid the natural conclusion that there is an entity that is able to influence the actions of Newton and Caesar etc. and the commenter themselves?
I'd be tempted to call those people closet theists who are in denial, but maybe you're more polite than I am.
What I mean is that they have something in their system that is playing a god-like role, but they're "scientific", so it can't be God.
By the way, I would say the same about the "universe is a simulation" people.
Yes exactly, which is to say that your instrument calibration dicated by that elaborate randomization process, just ensures that the particle will arrive in a specific configuration, which is a purely local, realistic phenomenon.
Sabine and Palmer recently explained how superdeterminism can be understood easily as future input dependence:
https://www.frontiersin.org/articles/10.3389/fphy.2020.00139...
Edit: despite superdeterminism annoying you so much, I bet you're perfectly fine with general relativity in which time is just another space-like coordinate, and the correlation you describe is a perfectly well-defined path along a closed timelike curve. An interesting inconsistency if true.