This is 60-Second Science. I'm Tuleka Bose.

You probably already know what a black hole is, but have you ever heard of the black hole

information paradox? I'm here with Clara Mosquitz, our space and physics editor, who just

edited a big special issue for Scientific American on black holes. Hey Clara.

Hi. Thanks for having me. So Clara, what are we here to talk about today?

We're here to talk about the black hole information paradox, which has been a problem in physics

for a long time. Basically, black holes seem to break the rules of physics. And part of

the reason why is because we have to use two different theories to describe them, and

the two theories do not get along. On the one hand, we have quantum mechanics, which describes

the world of the very small, atoms and particles. On the other hand, we have general relativity,

which describes things that are very big, very massive, very large. And most things in

the world don't require both theories. They're either big or they're small. Black holes

are both. Black holes are the densest things in the entire universe, and they take up very

little space, but they have so much mass. You really need both theories. And yet, when

you try to combine quantum mechanics and general relativity, everything goes crazy. How can

two rules of physics not apply? Each one works perfectly in its own realm. So quantum

mechanics does very well describing everything that's subatomic, everything that we can't

see that's very small. And general relativity works perfectly to describe very big things

like the motions of planets. But we almost never have to combine them in one example, except

for black holes. Black holes take up very little space, but they have so much mass that general

relativity and quantum mechanics equally apply. And yet, when you try to combine the two

theories, they don't work together. But how exactly do they not work together? Basically,

...