Andrew Strominger

It's actually a puzzle why they're so small.

So if you watch the precession of Mercury's perihelion, this was the first indication of something going wrong.

According to Newton's theory, Mercury has an elliptical orbit.

The long part of it moves around.

as other planets come by and perturb it and so on.

And so this was measured by Le Verrier in 1859, and he compared theory and experiment, and he found out that the perihelion process moves around the sun once every 233 centuries instead of every 231 centuries.

Now, this is the wonderful thing about science.

So that's how small, that was the first sign that there was something wrong with Newton.

Now, so the corrections to Newton's law are very, very small, but they're definitely there.

The corrections to electromagnetism, the ones that we see are mostly coming from quantum effects.

That's true, but I would phrase it as saying when it's super accurate.

You know, if you look at the Bohr atom...

Maxwell electromagnetism is not a very good approximation to the force between the proton and the electron.

The quantum mechanics, if you didn't have quantum mechanics, the electron would spiral into the proton and the atom would collapse.

So that's a huge correction there.

So every theory gets corrected as we learn more.

There'd just be no reason to suppose that it should be otherwise.

So when you hit the singularity, you know that you need some improvement to Einstein's theory of gravity.

And that improvement, we understand what kind of things that improvement should involve.

It should involve quantum mechanics.