Is Quantum Mechanics Indeterministic?

Question

Traditionally, quantum calculations were structured in terms of statistical probability, ie. the notion of subatomic processes being indeterministic. Some people such as Einstein and Hooft have proposed or believed in the idea of "hidden variables", ie. the idea that if we believe quantum processes are indeterministic, we must have forgotten to take something into account. They believe that a future theory, or observations, will one day demonstrate determinism.

My questions are
A) What is the latest scientific consensus on this?
B) If most scientists believe in quantum indeterminism (or aren't sure), how are philosophers such as Daniel Dennett (for example, in "Freedom Evolves") arguing against free will? What rational cases are being made for saying that free will is an illusion?

I'm guessing a case can be made, but if quantum indeterminism is still generally accepted, I don't see how such cases could be rooted in empirical evidence.

Please cite sources if possible. Thanks.

Answer 1

A) The consensus is that quantum mechanics works. Quantum mechanics often has results that indicate only the relative probablity of different outcomes (E.g. we know an average value if it were to happen many times.) "Bell's inequality" showed that no local hidden variable theory can ever reproduce all of the predictions of quantum mechanics.

B) Don't know. Any argument for or against free will can eventuallly be shown to be circular.

Any quantum textbook will explain this as the "Copenhagen interpretation" of quantum mechanics.

Answer 2

There was such a thing called Bell's Inequality which states that no physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics. However, this one far from free of loopholes because this theorem assumed a lot of things such as the computability of certain things.

Answer 3

Modern science recognizes that the Heisenberg Uncertainty Principle requires processes to be fundamentally nondeterministic at the quantum scale. For most, perhaps all, of his life, Einstein was not willing to concede this. If any modern scientist disagrees with this, he's keeping it a secret.

The connection between quantum uncertainty and free will, if it exists at all, is extremely weak. I haven't read the book, but I'd be surprised if Mr. Dennett bases any of his arguments on quantum considerations. Your first step should probably be to read his book.