Sean Carroll

But that's different than impossible, right?

Like, you know, you might, I don't think there's a theorem that says that something like cold fusion cannot possibly work.

I think what there is is the real world scientific progress that says, you know, we've done the experiments.

We've seen experimentally that a lot of these claims are not true.

We've done the theory.

We see that the particular setup that people have been looking at can't really work this way according to the laws of physics as we understand them.

And we move on.

But we don't claim that things are impossible in science.

Things are just not as clear-cut as that.

We learn by going back and forth between theory and experiment and so forth.

Ed Sedstuff says, if there were practically infinite universes, would math necessarily be useful in all of them?

Well, it depends on what you mean by useful.

I'm tempted to just say yes, that the math would be useful in all of them.

But of course, many of them, well, sorry, I need to back up because you didn't say all conceivable universes.

You just said a practically infinite number of universes.

So you could absolutely imagine a practically infinite number of universes and still nowhere near all conceivable universes, right?

But if you were thinking about all conceivable universes, many of them would be anthropically disallowed.

That is to say, there's no way for intelligent conscious creatures to exist in these universes.

And if you're skeptical about that, if you think, well, maybe life is really much more robust than you think it is, most possible universes don't have laws of physics.

Or at least they don't have predictability and reliability in any way that we can imagine.