Sean Carroll

Well, it's once again a reflection of the fact that the early universe had low entropy because gravity was so strong in the early universe.

A more common generic random configuration would have been wild fluctuations like black holes here and empty space there.

And so the fact that it was so smooth does kind of demand an explanation.

And we're not sure what the explanation is.

Okay.

I think our questioner missed the point of the title of my paper, which is that there is something like, you know, we can contemplate that there wouldn't have been anything and there's just nothing.

But what I say in the paper is, can we really contemplate that?

I mean, I think that we have this informal training from our everyday lives, right?

Where we have boxes with things in them and boxes with nothing in them.

And so we think that there's an option.

There can be things or there could be nothings.

But when it comes to the universe,

it is not at all obvious that there is an alternative to the universe existing.

What does it even mean for nothing to exist?

How does nothingness even exist?

That's kind of what I'm getting at in the paper, which is that it's not at all clear that

the reason why the universe exists is the kind of thing that has an answer to a why question.

Maybe we just have to accept it as a brute fact and be lucky about it.

So I do think this stuff is fun to talk about, but I don't think that it is nearly as down-to-earth and simple and physical as certain physicists who like to talk about this make it out to be.

It's fundamentally a philosophy question.