Sean Carroll

At any individual moment, the agent only sees a little bit of their immediate environment, but they attribute reality in the casual presentist kind of way of doing it to a whole slice of the universe very far away from what they see. So my worry about saying it's a perfectly good analogy is that there is more extrapolation in the presentism case, right? It's more model dependent.

At any individual moment, the agent only sees a little bit of their immediate environment, but they attribute reality in the casual presentist kind of way of doing it to a whole slice of the universe very far away from what they see. So my worry about saying it's a perfectly good analogy is that there is more extrapolation in the presentism case, right? It's more model dependent.

It is more relying on the fact that I'm not only considering what I see around me right now, but I'm also treating everything at this one moment of time as equally real. And of course, everyone knows that relativity is a huge challenge to presentism because different people moving at different velocities would extend their present moment of time differently.

It is more relying on the fact that I'm not only considering what I see around me right now, but I'm also treating everything at this one moment of time as equally real. And of course, everyone knows that relativity is a huge challenge to presentism because different people moving at different velocities would extend their present moment of time differently.

So how in the world can it be true that only one slice is real? Of course, the sophisticated presentists have answers to that. Since I'm not a presentist, I've never put any work into understanding what those answers are. Joan Beluda says, priority question. If you could get the definitive true answer to any open-ended question, what would that question be?

So how in the world can it be true that only one slice is real? Of course, the sophisticated presentists have answers to that. Since I'm not a presentist, I've never put any work into understanding what those answers are. Joan Beluda says, priority question. If you could get the definitive true answer to any open-ended question, what would that question be?

The answer would be complete and thorough in a scientific paper. Yeah, it's a boring answer, but I guess I would say what is the correct theory of everything? You know, what is the correct theory of gravity and space and time and all the forces and quantum mechanics and all that? Just tell that to me.

The answer would be complete and thorough in a scientific paper. Yeah, it's a boring answer, but I guess I would say what is the correct theory of everything? You know, what is the correct theory of gravity and space and time and all the forces and quantum mechanics and all that? Just tell that to me.

I think that hopefully a scientific paper will be long enough to explain it in language I can understand. I don't know. I'm not expecting anyone to give me that paper anytime soon, but, you know, that would be pretty awesome if it happened.

I think that hopefully a scientific paper will be long enough to explain it in language I can understand. I don't know. I'm not expecting anyone to give me that paper anytime soon, but, you know, that would be pretty awesome if it happened.

Alexander Knirkel says, is there a theoretical mechanism how, when time emerges separately from space, the whole of space-time still ends up exhibiting this high degree of symmetry?

Alexander Knirkel says, is there a theoretical mechanism how, when time emerges separately from space, the whole of space-time still ends up exhibiting this high degree of symmetry?

Lorentz invariance, or diffeomorphism invariance, all these different ways in which relativity convinces us, this is me, Sean, talking now, not Alexander, all the different ways that relativity teaches us that space and time are unified into spacetime. How does that come out of this?

Lorentz invariance, or diffeomorphism invariance, all these different ways in which relativity convinces us, this is me, Sean, talking now, not Alexander, all the different ways that relativity teaches us that space and time are unified into spacetime. How does that come out of this?

And then Alexander continues, naively, I would expect that an emergent time parameter would not magically fall in place to form a nice representation of these exact symmetries. with the rest of space-time, and all the fields being in representation of these as well, but instead stick out like a sore thumb? So I think this is a very good question, a very, very important question.

And then Alexander continues, naively, I would expect that an emergent time parameter would not magically fall in place to form a nice representation of these exact symmetries. with the rest of space-time, and all the fields being in representation of these as well, but instead stick out like a sore thumb? So I think this is a very good question, a very, very important question.

We don't know how this is supposed to work. So I think that there's two kind of competing intuitions going on here. One is... If I started with a theory in which time and space were clearly different, I just told you what was going on in space and separately had an equation telling you how things evolve in time, why in the world would that knit together?

We don't know how this is supposed to work. So I think that there's two kind of competing intuitions going on here. One is... If I started with a theory in which time and space were clearly different, I just told you what was going on in space and separately had an equation telling you how things evolve in time, why in the world would that knit together?

So you build up by evolving in time, here's space, here's space at a moment later, here's space a moment later. And by space I mean not just space itself, but everything in space, the whole configuration of the universe. And I build up a bunch of these, okay? And then I say, okay, I've knitted together a four-dimensional spacetime.

So you build up by evolving in time, here's space, here's space at a moment later, here's space a moment later. And by space I mean not just space itself, but everything in space, the whole configuration of the universe. And I build up a bunch of these, okay? And then I say, okay, I've knitted together a four-dimensional spacetime.