So let's go through the fabric of reality, the four theories.

Feel free to start wherever you'd like, but the four theories that you think comprise the theory of everything.

And maybe especially one of the biggest things that even peers, colleagues, contemporaries don't understand or don't fully appreciate that makes each one of these deeper or perhaps more counterintuitive or more interesting that it might be at first glance.

Well, I don't know, we can start with computers.

As I said, the book is it's hard actually to speak about any one of those things without mentioning the other three.

But if we start with computers, I think there's something really fundamental that Turing discovered or rediscovered,

because I think that Babbage and Lovelace also understood it, more or less,

that's the universality of computation, that computation is physically universal.

So there are several ways of putting this, like a computer can mimic any physical object,

or a computer can perform the computations

that any other computer can perform.

Now, putting it the second way,

it sounds like it's a statement

about all kinds of different computers

and has nothing to do with trees

and garages and windows and so on,

but actually it has to do with everything.

And therefore, people still, even today, are saying things like, how do we know the brain

is a computer?

You're just assuming the brain is a computer.

Like, in the 19th century, people thought the brain was a steam engine.

And I think Searle is one of the

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