Andrew Strominger

It wasn't fully coordinate invariant.

It was only partially coordinate invariant.

It was wrong.

It gave the wrong answer for bending light to the sun by a factor of two.

There was an expedition sent out to measure it during World War I. They were captured.

before they could measure it.

And that gave Einstein four more years to clean his act up, by which time he'd gotten it right.

So it's a very tricky business, but once it's all laid out, it's clear.

Well, something very interesting happens in Schwarzschild's solution of the Einstein equation.

I think his reasoning was ultimately wrong, but let me...

explain to you what it was.

At the center of the black hole, behind the horizon, in a region that nobody can see and live to tell about it, at the center of the black hole, there's a singularity, and if you pass the horizon, you go into the singularity, you get crushed, and that's the end of everything.

Now, the word singularity means that it just means that Einstein's equations break down.

They become infinite.

You write them down.

You put them on the computer.

When the computer hits that singularity, it crashes.

Everything becomes infinite.

There's two.

So the equations are just no good there.