Science

Superdeterminism isn't just the idea that if you know the initial state of everything you can predict the outcome with certainty. It's more bizarre than that. Superdeterminism suggests that particles have pre-existing correlations created at the Big Bang that would allow you to predict the behavior of a system that the particle never interacted with without knowing anything about it, at least in contrived cases.

For example, you can imagine setting up an experiment whereby the particles will be measured by an experimenter and the experimenter can freely choose the measurement basis as a personal conscious decision. Superdeterminism would suggest that if you could measure the hidden variables on the particles before using them in the experiment, just from the particles alone, even if they have never interacted with the experimenter since the Big Bang, would be sufficient to predict the experimenter's conscious decision of the choice in measurement basis.

Indeed, if you knew that one singular variable from the particles, you would know the experimenter's decision ahead of time with certainty, even if you know nothing about the experimenter and never met them before yourself. You could even go up to the experimenter and insist they should use a different measurement basis, but you shouldn't be able to ever change their mind, because it's absolutely predetermined they would make that decision, and that decision is also correlated with the hidden variable of the particle, so knowing the hidden variable of the particle alone is equivalent to knowing what their decision will be ahead of time.

Nothing is logically impossible about it, it is just a bit strange.