Sean Carroll

Yeah, it is.

I have to relate an anecdote that I think I've probably told on the podcast before.

But there is this field called quantum error correction.

in the study of quantum computers.

I know.

You should, you should.

Well, all I want to say about it is John Preskill, who's a good friend of mine and a great physicist, former podcast guest here, he was a pioneer in quantum error correction.

If you have a quantum computer and you have these qubits, they're entangled.

What do you do if one of the qubits gets messed up?

It turns out to be much, much harder than for a classical computer because of the entanglement between different qubits.

And when I first heard the term, I was like, that sounds like the most boring thing in the world, quantum error correction.

But I was super wrong.

It turns out to be absolutely central, not just to building quantum computers, but to many ideas in theoretical physics.

So hopefully I've learned my lesson.

Yeah.

Well, if you send a classical message, so let's say you send a single bit, right?

A zero or a one.

There's a very simple strategy, which is just to send three copies of it, right?

And if there's some noise and there's some chance that one of the bits gets flipped, but it's a small chance,

Then at the end, you get your three copies, and if one of them is wrong, you just discard it.