2 ms·

I'm assuming you're referring to Bell's inequality, but that has little to do with determinism. Bell's inequality says "locality or hidden variables, pick one".

I'm assuming you're referring to Bell's inequality, but that has little to do with determinism. Bell's inequality says "locality or hidden variables, pick one". In fact, "superdeterminism" can actually render Bell's inequality moot. That is, you can have locality + hidden variables + superdeterminism. You can't have locality + hidden variables + [statistical independence between the measurement settings and the state you are trying to measure]. The existence of hidden variables is also sometimes called "realism" or "counterfactual definiteness" - since if there are no hidden variables, it means that the question "what would another measurement have shown" or, equivalently, "what state were the particles in before the measurement" doesn't make sense. Indeed, in the Copenhagen Interpretation, particles don't have any meaningful classical "state" before a measurement. For example, if you chose to measure their position, they will have a position, but can have any spin; if instead you measure their spin, they will have a spin, but no definite position. You can't then ask "but what spin would they have had if I had measured their spin instead of their position" - there is no answer to that question according to CI (or, there is an infinity of answers according to MWI). Note that superdeterminism simply means "the measurement settings on the apparatus depend on the real state of the particles". That is, the particle actually has a property lambda such that if, say, lambda=0, when the particle hits the apparatus and the apparatus is set to measure position, it will show a definite position; whereas is the the particle hits the apparatus when it is set to measure spin it will have a spin. For a different lambda, a different pair of <apparatus settings, apparatus results> will be expected.

Retric 5y ago
Superdeterminism also gets rid of the need for photons etc. If you’re instruments are running a predetermined script they can just as easily be playing back a movie as having an actual detector. Really though it’s just another flavor of non-localism that gets around FTL.
- tsimionescu 5y ago
  Not necessarily, superdeterminism is a concept, not a specific theory/model. You have specific models that can basically explain anything at all as a "grand conspiracy", but you can also have models that don't. There are no useful, testable "superdeterministic" models yet, to be fair. But they can, in principle, exist. Again, all that this requires is a model where the measurement settings depend on the hidden variables themselves.
  - Retric 5y ago
    That’s the problem, we aren’t talking about a specific theory so you need to toss in all the suddenly possible models under stuff super determinism allows. Excluding the ultimate “grand conspiracy” stuff that only applies to scientific instruments it posits that basically every interaction between any particle is following a predetermined script. You can of course still have photons etc, but like two actors in a play such particles don’t need to be having a conversation. The idea also extends into all sorts of strange and untestable territories such as our universe being a copy of a prior one that operated on different principles. Of course none of that means such an idea is false, just that it’s currently as unproductive as saying god did it.

Retric 5y ago

Superdeterminism also gets rid of the need for photons etc. If you’re instruments are running a predetermined script they can just as easily be playing back a movie as having an actual detector. Really though it’s just another flavor of non-localism that gets around FTL.

tsimionescu 5y ago
Not necessarily, superdeterminism is a concept, not a specific theory/model. You have specific models that can basically explain anything at all as a "grand conspiracy", but you can also have models that don't. There are no useful, testable "superdeterministic" models yet, to be fair. But they can, in principle, exist. Again, all that this requires is a model where the measurement settings depend on the hidden variables themselves.
- Retric 5y ago
  That’s the problem, we aren’t talking about a specific theory so you need to toss in all the suddenly possible models under stuff super determinism allows. Excluding the ultimate “grand conspiracy” stuff that only applies to scientific instruments it posits that basically every interaction between any particle is following a predetermined script. You can of course still have photons etc, but like two actors in a play such particles don’t need to be having a conversation. The idea also extends into all sorts of strange and untestable territories such as our universe being a copy of a prior one that operated on different principles. Of course none of that means such an idea is false, just that it’s currently as unproductive as saying god did it.