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Why Quantum Mechanics?

scottaaronson.blog

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Re: Why Quantum Mechanics?

#2
Q1: because that wouldn't be consistent with simulation.

Q2: because that's how the simulator works.

Joking aside, I wonder if there's some principle that: physics will always look like you'd expect it to look if it's a simulation. Perhaps that's what Yang-Mills Gauge Theory is about?

Re: Why Quantum Mechanics?

#3
The answer to these questions is one of those things that are beyond human understanding. It's like asking why does probability work? Why does predicate logic work?

They are axioms. We have never looked beyond these axioms nor will we ever in your lifetime.

I mean we may find a deeper mathematical model for quantum mechanics but the question of "why?" will never be answered. It may not even be the right question.

Re: Why Quantum Mechanics?

#4

The answer to these questions is one of those things that are beyond human understanding. It's like asking why does probability work? Why does predicate logic work? They are axioms. We have never looked beyond these axioms nor will we ever in your lifetime. I mean we may find a deeper mathematical model for quantum mechanics but the question of "why?" will never be answered. It may not even be the right question.

That is an assumption. We do not currently know of any process by which we might explain these axioms; but:

1. We may still glean insight by reflecting on them, and

2. There may be unknown processes by which we can explain these axioms

Re: Why Quantum Mechanics?

#6

I've always liked these kinds of questions. Myself, I always wondered why specifically three dimensions. (Please don't start telling me about string theory.)

I wondered that for a long time myself and recently stumbled on what I believe is (or at least is a good candidate for) the correct answer: planetary orbits are stable in three dimensions, but not any other dimensions. The anthropic principle therefore selects for three-dimensional slices/subsets of the wave function.

Re: Why Quantum Mechanics?

#7
Given the infinite number of ways the universe could have been, it seems kind of a mathematical truth that whatever it ended up being was incredibly improbable to begin with.

I would tend to say that unless it is logically necessary for the universe to be what it is, the question of why it is what it is necessarily lacks an answer. We should expect the universe to be improbable.

Re: Why Quantum Mechanics?

#8
> why complex values amplitudes?

If you multiply the left and right sides of schrodingers equation by its complex conjugate, do you still get an equation that the real valued square of the wave function solves? Can you do QM with just the real valued probability distribution? If you can, why not say that that’s the “real” thing, and factoring it is just a convenient way to solve it, same as imaginary solutions to quadratic equations.

Re: Why Quantum Mechanics?

#10

The answer to these questions is one of those things that are beyond human understanding. It's like asking why does probability work? Why does predicate logic work? They are axioms. We have never looked beyond these axioms nor will we ever in your lifetime. I mean we may find a deeper mathematical model for quantum mechanics but the question of "why?" will never be answered. It may not even be the right question.

We may not find the answer, but it seems really different than say predicate logic.

It seems easy to imagine a non-quantum world. I can't imagine a world where predicate logic doesn't work.

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