Adam Brown

There is, however, one fact about that merger that we are most confident about, about anything about the merger, and that exactly...

returns to this question of how much information can you store in a given region of spacetime.

And in fact, how much region... And the answer to that involves black holes.

So the answer is how much... If you have a region of a certain area...

maybe a sphere of a certain area, and you said how much information can you store in that region?

The amount of information you can store measured in bits, the entropy of that region, is given by the area of that region divided by g, Newton's constant, and h bar, Planck's constant.

So that's how you know that this is something to do with quantum gravity because it involves both g

and h bar.

That is not the only situation, no.

Anytime you have quantum gravity, they'll tend to be in the same place.

And sometimes even when you don't have

quantum gravity, but you have the interplay of gravitational forces and quantum degeneracy pressures.

Those will also... That'll end up in those... But it's in some sense the simplest situation in which it occurs, which is why so much time has been spent thinking about thought experiments to do with black holes.

So the...

There was a physicist called Bekenstein who figured out that that should be the answer at the area divided by g h-bar.

And then Hawking's great contribution to physics was figuring out that it was the area divided by g h-bar, but he also got the pre-factor, and the pre-factor was a quarter.

So this is, you know, Hawking figured out that it's a quarter at the area divided by four g h-bar.

And this is a super interesting answer.

How much information can you store in a given region?

is given by the area.