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Edwin's avatar

According to quantum physics, no matter how much information

we obtain or how powerful our computing abilities, the outcomes

of physical processes cannot be predicted with certainty

because they are not determined with certainty. Instead, given the

initial state of a system, nature determines its future state through

a process that is fundamentally uncertain. In other words, nature

does not dictate the outcome of any process or experiment, even

in the simplest of situations. Rather, it allows a number of different

eventualities, each with a certain likelihood of being realized.

It is, to paraphrase Einstein, as if God throws the dice before deciding

the result of every physical process. That idea bothered

Einstein, and so even though hè was one of the fathers of quantum

physics, hè later became critical of it.

Quantum physics might seem to undermine the idea that nature

is governed by laws, but that is not the case. Instead it leads

us to accept a new form of determinism: Given the state of a system

at some time, the laws of nature determine the probabilities of

various futures and pasts rather than determining the future and

past with certainty. Though that is distasteful to some, scientists

must accept theories that agree with experiment, not their own

preconceived notions.

What science does demand of a theory is that it be testable. If

the probabilistic nature of the predictions of quantum physics

ALTERNATIVE HISTORIES

meant it was impossible to confirm those predictions, then quantum

theories would not qualify as valid theories. But despite the

probabilistic nature of their predictions, we can still test quantum

theories. For instance, we can repeat an experiment many times

and confirm that the frequency of various outcomes conforms to

the probabilities predicted. Consider the buckyball experiment.

Quantum physics tells us that nothing is ever located at a dcfinite

point because if it were, the uncertainty in momentum would

have to be infinite. In fact, according to quantum physics, each

partiële has some probability of being found anywhere in the universe.

So even if the chances of finding a given electron within the

double-slit apparatus are very high, there will always be some

chance that it could be found instead on the far side of the star

Alpha Centauri, or in the shepherd's pie at your office cafeteria. As

a result, if you kick a quantum buckyball and let it fly, no amount

of skill or knowledge will allow you to say in advance exactly

where it will land. But if you repeat that experiment many times,

the data you obtain will reflect the probability of finding the ball

at various locations, and experimenters have confirmed that the

results of such experiments agree with the theory's predictions.

It is important to realize that probabilities in quantum physics

are not like probabilities in Newtonian physics, or in everyday life.

https://en.wikipedia.org/wiki/Uncertainty_principle

Edwin's avatar

They we cannot know argument was also used to put aside the QM proof that determinism cant exist. The argument was for hidden variables we didn't know about. In the end also that was proven not possible.

https://en.wikipedia.org/wiki/Bell%27s_theorem

In 1982, Alain Aspect performed a series of groundbreaking experiments that tested these Bell inequalities using entangled photons. His results showed a clear violation of the inequalities, confirming the predictions of quantum mechanics and ruling out local hidden variable theories. This means that the behavior of quantum particles cannot be explained by any deterministic theory with hidden variables that respect locality. Instead, the results imply that the quantum world is inherently probabilistic and that entanglement leads to correlations that cannot be explained by any classical deterministic mechanism

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