Sean Carroll

I'll give you the science answer because it's quite good.

Our brain does not perceive the present.

Our brain puts together a picture of the world that is on a slight time delay.

Like our brain wants to be able to bleep out things it doesn't like.

If you watch someone dribble a basketball,

and they're right next to you, you will see the basketball hit the ground, and you will hear the thump of the basketball against the ground, and they coincide.

They go along with each other.

If that person walks away, still true.

You see and hear the same thing at the same time, even though the light gets to you much quicker than the sound.

And what happens is if they keep walking away,

suddenly, they will go out of sync.

The vision of the basketball hitting the ground and the sound of it.

Holy shit.

Because your brain corrects for it as long as it's near enough, your brain says, this is all now.

And you can even measure how much it is.

It depends on what sense you're talking about and what perception, but roughly think about

40 or 50 milliseconds of time is a little window in which your brain collects things and says, I'm going to put this together into a picture of the present.

You know, look, as I'm sure you already know, neuroscience, biology, psychology.

That's a whole frontier right there.

I was going to say optical illusions, but sure.