Brian Cox

So he discovers these things glow, and he calculates how they glow. They're very low temperature, but they emit things, which means that they shrink because they're emitting stuff, and so they're shrinking. So that means they have a lifetime. So first of all, one day they'll be gone. So that means that you have to address this question of what happened to all the stuff that fell in.

So he discovers these things glow, and he calculates how they glow. They're very low temperature, but they emit things, which means that they shrink because they're emitting stuff, and so they're shrinking. So that means they have a lifetime. So first of all, one day they'll be gone. So that means that you have to address this question of what happened to all the stuff that fell in.

So he discovers these things glow, and he calculates how they glow. They're very low temperature, but they emit things, which means that they shrink because they're emitting stuff, and so they're shrinking. So that means they have a lifetime. So first of all, one day they'll be gone. So that means that you have to address this question of what happened to all the stuff that fell in.

And his calculation said that there's no record at all of anything that fell in, in all this radiation that's come off the black hole. So it's purely information-less radiation. So what that means is that black holes destroy information, according to that calculation. And that's a big deal because nowhere else in all of physics does anything erase information from the universe.

And his calculation said that there's no record at all of anything that fell in, in all this radiation that's come off the black hole. So it's purely information-less radiation. So what that means is that black holes destroy information, according to that calculation. And that's a big deal because nowhere else in all of physics does anything erase information from the universe.

And his calculation said that there's no record at all of anything that fell in, in all this radiation that's come off the black hole. So it's purely information-less radiation. So what that means is that black holes destroy information, according to that calculation. And that's a big deal because nowhere else in all of physics does anything erase information from the universe.

So it's really true that if I got this notepad and pen, right, and I wrote some things on it, and then I set fire to this, even just incinerated it, put it in a nuclear explosion, whatever. In principle, according to all the laws of nature that we know, if you collected everything that came off, all the radiation, all the bits of ashes and things,

So it's really true that if I got this notepad and pen, right, and I wrote some things on it, and then I set fire to this, even just incinerated it, put it in a nuclear explosion, whatever. In principle, according to all the laws of nature that we know, if you collected everything that came off, all the radiation, all the bits of ashes and things,

So it's really true that if I got this notepad and pen, right, and I wrote some things on it, and then I set fire to this, even just incinerated it, put it in a nuclear explosion, whatever. In principle, according to all the laws of nature that we know, if you collected everything that came off, all the radiation, all the bits of ashes and things,

and you could just measure it all, then just in principle, the idea is you could reconstruct the information. So it all gets scrambled up and thrown out. And so in practice, you can't do it. But just in principle, the laws of nature say that information is not destroyed. It's just scrambled up in a way that you can't reconstruct.

and you could just measure it all, then just in principle, the idea is you could reconstruct the information. So it all gets scrambled up and thrown out. And so in practice, you can't do it. But just in principle, the laws of nature say that information is not destroyed. It's just scrambled up in a way that you can't reconstruct.

and you could just measure it all, then just in principle, the idea is you could reconstruct the information. So it all gets scrambled up and thrown out. And so in practice, you can't do it. But just in principle, the laws of nature say that information is not destroyed. It's just scrambled up in a way that you can't reconstruct.

But this calculation that Stephen did said there is no information in that radiation at all. Zero, just nothing. So it seemed that uniquely in the universe, black holes erase information.

But this calculation that Stephen did said there is no information in that radiation at all. Zero, just nothing. So it seemed that uniquely in the universe, black holes erase information.

But this calculation that Stephen did said there is no information in that radiation at all. Zero, just nothing. So it seemed that uniquely in the universe, black holes erase information.

So really in bits, I mean, the idea is, and I should say it's very much in principle this, so no one thinks in practice you could reconstruct what I wrote down on this if you set fire to it. But in principle... Well, maybe sometime in the future. Yeah, in principle, you could just collect everything.

So really in bits, I mean, the idea is, and I should say it's very much in principle this, so no one thinks in practice you could reconstruct what I wrote down on this if you set fire to it. But in principle... Well, maybe sometime in the future. Yeah, in principle, you could just collect everything.

So really in bits, I mean, the idea is, and I should say it's very much in principle this, so no one thinks in practice you could reconstruct what I wrote down on this if you set fire to it. But in principle... Well, maybe sometime in the future. Yeah, in principle, you could just collect everything.

Then somewhere in all that radiation and ashes and light that's come off the thing is the information. It's there. So you could reconstruct the book or what I wrote on this page in principle. But the thing about Stephen's calculation was that even in principle, it said there is no information.

Then somewhere in all that radiation and ashes and light that's come off the thing is the information. It's there. So you could reconstruct the book or what I wrote on this page in principle. But the thing about Stephen's calculation was that even in principle, it said there is no information.