Sean Carroll

There's like two locations, two boxes it could be in.

It could be in box A or box B. And the proton could be in box A or box B, okay?

But they're absolutely not in the same box.

So there is some wave function, some part of the superposition is electron is in box A, proton is in box B. There's also some part of the wave function that says proton is in box A, electron is in box B. But there's no part of the wave function that says the electron and proton are both in box A or both in box B.

Totally new.

That's entanglement.

Nothing like this happens in classical mechanics.

But if you think of the wave function as a superposition of every possible measurement outcome...

it kind of makes sense, right?

Because when you look to see where's the electron and where's the proton, you're going to see them somewhere.

And the example I gave of electrons and protons being in different boxes, that's just one possible wave function.

That's not necessarily built into the idea of a wave function.

You could have a different wave function which says they're both in the same box, okay?

Or they're both definitely in box A. Like there's all different possible wave functions, but you've opened up a new possibility.

because of entanglement in quantum mechanics, that you don't know which box the electron's in, but you know it's not in the same box as the proton.

Or even better, just to be very, very precise about it, because I know that you people are sticklers and you're listening closely, it is a superposition of both of those possibilities, and there's no such thing in that wave function as where the electron is.

This is a crucial feature of quantum mechanics, that the wave function appears as a real thing.

This is precisely what the Copenhagen interpretation denies, but there's all sorts of good reasons not to deny it, and that's one of the reasons why the more you think about the foundations of quantum mechanics, the less you like the Copenhagen interpretation.

So again, not everyone agrees, but I'm giving my views here, and this is a solo podcast, no guest that I have to put up with, you're just listening to me.

So in my view, the wave function is the real thing, and if that wave function says the electron has some possibility of being in box A and some possibility of being in box B, then there's no such thing as where the electron is, really.