Adam Brown

We have big plans to go and grab them and turn them into...

vacation destinations or computronium, or in any other ways, extract utility from them.

And we can't, if the cosmological constant is really constant, if this picture is correct, because anything close enough, we can go out and grab it, obviously.

But if it's further away than about a dozen billion light years, the expansion of the universe is dragging it away sufficiently rapidly that even if we send probes out at almost the speed of light, they will never make it.

They will never make it there and make it back.

They'll never even make it there if it's sufficiently far away.

And that means that there's a finite amount of free energy in our future.

And that's bad.

I mean, that means we're doomed to a heat death, if that's true.

But is it true?

I mean, that was the second half of your question.

And...

First of all, we keep changing our minds about these things over the last century or so.

So on first principles grounds, you may be somewhat suspicious that we'll change our minds again.

And none of this is settled physics.

And indeed, it may be that the cosmological constant is not constant.

And you should hope with all your heart that it's not.

It may be that it naturally bleeds away.

It may be, in fact, that our fate is in our hands and that our distant descendants will go and

bleed the cosmological constant away, will force it to go to zero.