Hello, everyone. Welcome to the Mindscape podcast. I'm your host, Sean Carroll. Welcome to a new year by the

conventional calendar, of course, 2025, but also this first podcast episode of 2025 is episode 300.

And looking back on previous episodes that ended with zero, that is to say to say 100 and 200. I did some solo episode

of some sort to celebrate the little milestone. I mean, it's a pretty big milestone. We have

a lot more than 300 episodes because many episodes don't get numbers. The AMAs don't get numbers,

holiday messages don't get numbers, special episodes, etc. But still, having 300 even numbered episodes is pretty darn good. We've been doing it for a while, longer than I might have guessed at the very beginning. So what to do for a solo episode to start things out? I mean, in some sense, I've already been talking too much. I did the hits and misses holiday message, which

went on for a long while. I did a previous solo episode about emergence not too long ago.

But okay, there's a tradition. And when there's a tradition, we might as well stick to it.

But I do worry about doing too many solo episodes because I'm not an expert in that many things.

I don't want to do a solo episode just on me ranting about things. I think it's

okay to admit that one is not an expert on everything or even one doesn't have interesting

things to say about every issue out there. Sometimes it's better just to listen to other people,

which is why we have the format of Mindscape as we have it. But I do have some things that I

know something about. So I couldn't decide. So what I did is I went on to Patreon, where we have our wonderful Patreon supporters for Mindscape. You yourself could be a Patreon supporter if you just go to Patreon.com slash Sean M. Carroll. And of course, Patreon supporters get ad-free versions of the podcast. They get to ask questions for the AMAs and occasional other benefits like I ask them what solo episode should I do.

And I did have some ideas.

And I took suggestions also.

And the idea that I had that eventually won out by the vote, and I think it's a perfectly good one, is, is time real?

Now, just to not keep you in suspense, yes. The answer is yes, time is real. But there are people

in modern physics and philosophy who question whether time is real. In fact, I once wrote a paper

almost as a joke, but I mean the title was a joke. The paper was not a joke, I don't like

to think, but the title was, what if time really exists? Because it has become so common

in physics to not only say, well, maybe time is not fundamental. Maybe time isn't even real.

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