Stephen Wolfram

Now, the point is, imagine you're an observer in this universe.

And you say, did something get updated?

Well, you don't in any sense know until you yourself have been updated.

So in fact, all that you can be sensitive to is essentially the causal network of how an event over there affects an event that's in you.

Yes, you're part of it, but even to have... So the end result of that is all you're sensitive to is this causal network of what event affects what other event.

I'm not making a big statement about the structure of the observer.

I'm simply making the argument that what happens, the microscopic order of these rewrites, is not something that any conceivable observer in this universe

can be affected by.

Because the only thing the observer can be affected by is this causal network of how the events in the observer are affected by other events that happen in the universe.

So the only thing you have to look at is the causal network.

You don't really have to look at this microscopic rewriting that's happening.

So these rewrites are happening wherever they...

They happen wherever they feel like.

That's what you mean by the causal network.

No, the causal network is given that an update has happened, that's an event.

Then the question is, is that event causally related to?

Does that event, if that event didn't happen,

then some future event couldn't happen yet.

And so you build up this network of what affects what.

And so what that does, so when you build up that network, that's kind of the observable aspect of the universe in some sense.