I'm Steve Strogatz and this is the joy of why.

A podcast from Quantum Magazine that takes you into some of the biggest unanswered questions in math and science today.

In this episode, we're going to be talking about time crystals.

What are they?

Well, have you ever heard of a perpetual motion machine?

And have you heard that they're impossible?

Yeah, well, they are impossible in the world that we live in because of friction.

But in the quantum world, all bets are off.

So is there any way to play with quantum phenomena to make a state of matter that will keep changing back and forth, back and forth forever?

Well, my guest today is a member of a team that theoretically discovered the time crystal and helped realize it experimentally on a quantum computer.

Theoretical physicist Vedica Kamani is an assistant professor of physics

at Stanford University. In 2021, she received the New Horizons in Physics Prize from the

Breakthrough Prize Foundation for her work on non-equilibrium quantum matter, including time crystals.

She joins me to explain what time crystals are, how they're

expanding our understanding of what's possible in the quantum sandbox, and whether all of this

is consistent with the second law of thermodynamics. Welcome, Professor Vedica Kamani.

Thank you, Steve. It's great to be here and thank you for having me.

You're very welcome.

I'm super excited to be talking with you.

I think your work is spectacular and I'm really curious to hear more about it.

So, you know, mentioning perpetual motion machines, that's an invitation to disaster on any science show since there really

are all kinds of reasons not to believe in them. So maybe before we start talking about

...