Robert Krulwich

He was trying to figure out where the planets were and the nature of their orbits and stuff.

Mars, for example, is 141 million miles from the sun.

Jupiter...

483 million.

And when you start comparing the different distances of planets from the Sun, you realize that the fact that the Earth is 93 million miles away, it doesn't seem like a deep law of the universe anymore.

It just feels kind of arbitrary.

And then that forces you to change the question.

Not, why 93 million?

No, why are all these different planets at different distances from the Sun, and yet they all stick around the Sun?

They're all trapped in the neighborhood.

That question puts you on the road to a deeper thought.

The theory of gravity.

The point is, says Brian, if you're focused on one thing, you're going to think that one thing is the key to everything.

When your one turns to many, then you think, ah, well, the one thing really wasn't so special.

But...

The way Brian sees it.

And Brian says you can make the exact same kind of progress if you compare universes.

So instead of asking, why is our one universe the way it is?

Now you can ask, well, what do all of these universes so different one from the other still have in common?

There are an infinite number of them.