Sean Carroll

You take the majority rules, and that works very, very well classically.

But quantum mechanically, if you mess up one of those bits, it's entangled with the others, and it ruins everything.

So you need to have a – you need to invent a new kind of quantum redundancy, which I'm not going to explain right now.

But it turns out that that idea of quantum redundancy might be crucial to understanding the origin of space and time.

So it's the universe kind of doing maintenance on itself.

Well, the first thing you need to do is some theory.

You need to decide how can you encode a quantum entangled set of qubits in such a way that there is an algorithm for doing the equivalent of voting, right?

You know, picking the majority rule.

And so people have done that.

And then you need to build into your quantum computer algorithms.

um, steps in the algorithm that along the way, uh, massage the qubits to make sure that they have not been, uh, have not been subject to noise.

So you're going to have to build, it's going to be an important step if you want to build quantum computers that can do commercially useful applications.

I do, I do.

It's going to be trickier than we thought to build large quantum computers.

They're very, very fragile.

And so the theory is there, the technology for building qubits is there, but keeping them all decohered, et cetera, or coherent, I suppose I should say, is going to be tricky.

So, yeah.

Absolutely.

Yeah.

I mean, he was one of the people who invented the idea of quantum computing.