Adam Brown

Like how we calculate those, do we just add together the utility in both or is there some non-linearity to do with it?

Basically, for the cosmological multiverse, there isn't a particularly good way to decide what the weighting factor should be.

We don't have the same equivalent of Born's rule in quantum mechanics.

And I think it's at least open for opinions like yours to be, you know, to be in fact, there should be some better way in which we calculate it that's not just a linear function.

You're talking about the two kinds of multiverse, the sort of cosmological multiverse and the quantum mechanical multiverse.

Yeah, they get very bound up if you try and write down a theory that has both of them.

Because whether there's a bubble there, you're trying to make bubble universes.

But what gives rise to bubble universes is often quantum processes.

So often you end up in superpositions over there being a bubble universe and there not being a bubble universe.

And that means that these two kinds of multiverse, the sort of quantum mechanical multiverse and the cosmological multiverse, end up getting totally intermeshed with each other.

Yeah, so again, we only really properly know how to do quantum gravity and do the counting in...

when there's a negative cosmological constant, as we discussed with ADS-CFT.

In these bubble universes where there's a positive cosmological constant, it's still somewhat an open question how to do the accounting of what happens and where and how much it should count.

Which is to say we don't know the answer to that question and your opinion is not ruled out.

Yeah, I think that's a good question.

Certainly some of the possibilities we've discussed so far have different epistemic statuses about how confident we are or not confident.

And as we also discussed, some of these bounds are somewhat fragile.

Can you communicate faster than the speed of light, for example?

Let's just take that as an example bound.

We think you can't, according to the laws of science as we understand it.