Adam Elga

Maybe there's a star in the sky.

Maybe it's I remember and not just seem to remember what I had for breakfast this morning.

To the extent that one of those views is true,

Our evidence is stronger.

Whether this is a way out of the Boltzmann brain problem depends on how bad you think it is to be uncertain as to which Boltzmann bubble you are embedded in.

I think it would take a very extreme kind of externalism to think that it's part of my evidence that, um,

Part of my evidence that, for example, I'm part of the first Big Bang as opposed to some other Boltzmann bubbly Big Bang type event.

And someone could have different attitudes to that.

You could think,

that's okay.

I just want to get rid of the scenario of I'm a transient brain formed in space and I'm wrong about everything.

If you get me that I'm right about the observable universe, the history, all the stuff in the history books and so on, and you tell me, oh yeah, but you could be in this bubble or this bubble, maybe that person says, all right, I can live with that.

I'm really not sure.

Really, what makes you think you would be able to tell the difference in those two cases?

I have some sympathy with that.

Myself, I've

always been more, have been somewhat suspicious of externalism, the extreme externalist views.

And so as a result, unfortunately, pinched harder by the Boltzmann brain problem.

Is the data the fancy cosmology data or is the data like I look at my hand or I look out my window and I see that I'm not floating in space?

The latter.