Roger Penrose is physicist, mathematician, and philosopher at University of Oxford. He has made fundamental contributions in many disciplines from the mathematical physics of general relativity and cosmology to the limitations of a computational view of consciousness.

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OUTLINE:
0:00 - Introduction
3:51 - 2001: A Space Odyssey
9:43 - Consciousness and computation
23:45 - What does it mean to "understand"
31:37 - What's missing in quantum mechanics?
40:09 - Whatever consciousness is, it's not a computation
44:13 - Source of consciousness in the human brain
1:02:57 - Infinite cycles of big bangs
1:22:05 - Most beautiful idea in mathematics

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But the Orc part, that's the the OR part at least 1 can see where we're driving as a theory.

You can say it's the quantum choice of going this way or that way.

But The orc part, which is the orchestration of this, is much more mysterious.

And how does the brain somehow orchestrate all these individual OR processes into a genuine conscious experience?

And it might be something that's beautifully simple, but we're completely in the dark about.

Yeah, I think at the moment that's the thing, you know, we happily put the word orc down there to say orchestrated, but that's even more unclear what that really means.

Just like the word material, orchestrated, who knows?

And we've been dancing a little bit between the word intelligence or understanding and consciousness.

Do you kind of see those as sitting in the same space of mystery as we discussed?

Yes, you see, I tend to say you have understanding and intelligence and awareness.

And somehow, understanding is in the middle of it, you see.

I like to say, could you say of an entity that is actually intelligent if it doesn't have the quality of understanding?

Maybe I'm using terms I don't even know how to define, but who cares,

They're somewhat poetic, so if I somehow understand them.

Yes, you see, as a mathematician, I don't know how to define any of them, but at least I can point to the connections.

So the idea is intelligence is something which I believe needs understanding, otherwise you wouldn't say it's really intelligence.

And understanding needs awareness, otherwise you wouldn't really say it's understanding.

Do you say of an entity that it understands something?

Unless it's really aware of it, you know, normal usage.

So there's a 3 sort of awareness, understanding, and intelligence.

And I just tend to concentrate on understanding because that's where I can say something.

And that's the Godel theorem and things like that.

But what does it mean to perceive the color blue or something, I mean, I'm foggiest.

I mean, is it the same if I see a color blue and you see it?

If you're assembling with what is this condition, what's it called?

Yeah, that's right, you get colors and sounds mixed up.

But from the physics perspective, from the fundamentals perspective, we don't.

I think we're way off having much understanding what's going on there.

In your 2010 book, Cycles of Time, you suggest that another universe may have existed before the Big Bang.

Yes, just as a matter of terminology, I don't like to call it another universe, because when you have another universe, you think of it kind of quite separate from us.

Now the Big Bang conventional theory, You see, I was actually brought up in the sense of when I started getting interested in cosmology, there was a thing called the steady-state model, which was sort of philosophically very interesting.

And there wasn't a Big Bang in that theory, that somehow new material was created all the time in the form of hydrogen and the universe kept on expanding, expanding, expanding and there was room for more hydrogen.

It was a rather philosophically nice picture.

It was disproved when the Big Bang, well when I say the Big Bang, this was theoretically discovered by people trying to solve Einstein's equations and apply it to cosmology.

He liked a universe which was there all the time.

And he had a model which was there all the time.

But then there was this discovery, accidental discovery, very important discovery, of this microwave background.

And if you, you know, there's the crackle on your television screen which is already sensing this microwave background, which is coming at us from all directions.

And you can trace it back and back and back and back.

And it came from a very early stage of the universe.

The Big Bang theory was when people tried to solve Einstein's equations, they really found you had to have this initial state near the universe.

It used to be called the primordial atom and things like this.

Friedman was a Russian, Lemaitre was a Belgian.

And they independently, well, basically Friedman first, and Le Maître talked about the initial state, which is a very, very concentrated initial state, which seemed to be the origin of the universe.

And then it became, well Fred Hoyle used the term big bang in a kind of derogatory sense.

Just like with the Schrodinger and the cats, right?

Yes, it's like sort of, it got picked up on, whereas it wasn't his intention originally.

But then the evidence piled up and piled up.

1 of my friends I learned a lot from when I was in Cambridge was Dennis Sharma.

He was a great proponent of steady state.

He went around lecturing and said, I was wrong.

And this microwave background that you see, okay, it's not actually quite the big bang when I said not quite, it's about 380,000 years after the big bang, but that's what you see.

But then you have to have had this big bang before it in order to make the equations work.

Except for 1 little thing, which is this thing called inflation, which people had to put into it to make it work.

When I first heard of it I didn't like it at all.

Inflation is it in the first, I'm gonna give you a very tiny number.

Now I'm gonna give you a fraction of a second, 1 over a number.

Between, well let's say between 36 and 32 digits, tiny, tiny time between those 2 tiny, ridiculous seconds, fraction of a second, the universe was supposed to have expanded in this exponential way, an enormous way, for no apparent reason, you had to invent a particular thing called the inflaton field to make it do it.

There are reasons why people stuck with this idea.

You see, the thing is that I've formed my model for reasons which are very fundamental, if you like.

It has to do with this very fundamental principle, which is known as the second law of thermodynamics.

The second law of thermodynamics says, more or less, things get more and more random as time goes on.

Now, another way of saying exactly the same thing is things get less and less random as things go back.

As you go back in time, they get less and less random.

So you go back and back and back and back.

And the earliest thing you can directly see is this microwave background.

What's 1 of the most striking features of it is that it's random.

It has this, what you call this spectrum of, which is what's called the Planck spectrum, of frequencies, different intensities for different frequencies.

And it's this wonderful curve due to Max Planck.

It's telling you that the entropy is at a maximum.

Started off at a maximum and It's going up ever since.

And so people, why don't cosmologists worry about this?

And then I thought, well, it's not really a paradox because you're looking at matter and radiation at a maximum entropy state.

What you're not seeing directly in that is the gravitation.

It's gravitation which is not thermalized.

The gravitation was very, very low entropy.

And it's low entropy by the uniformity, and you see that in the microwave too, it's very uniform over the whole sky.

I'm compressing a long story into a very short few sentences.

So what I'm saying is that there's a huge puzzle.

Why was gravity in this very low entropy state, very highly organized state, everything else was all random?

And that to me was the biggest problem in cosmology.

The biggest problem, Nobody seems to even worry about it.

People say they've solved all the problems and they don't even worry about it.

Just to clarify, that was your problem with the inflation describing some aspect of the moments right after the big bang.

Inflation is supposed to stretch it out and make it all uniform, you see.

It doesn't do it because it can only do it if it's uniform already at the beginning.

I can't go into the details, but it doesn't solve it.

And it was completely clear to me it doesn't solve it.

But where does the conformal cyclic cosmology of starting to talk about something before that singularity begin?

I was just thinking to myself, how boring this universe is going to be.

This was discovered early in the, in this century, 21st century.

People discovered that these supernova exploding stars showed that the universe is actually undergoing this exponential expansion.

And it seems to be a feature of this term that Einstein introduced into his cosmology for the wrong reason.

He put this new term into his cosmology to make it make sense.

And then when he got convinced that the universe had a big bang, he retracted it, complaining that this was his greatest blunder.

The trouble is it wasn't a blunder, it was actually right.

And so the universe seems to be behaving with this cosmological constant.

Okay, so this universe is expanding and expanding.

Well, it gets more and more boring for a while.

What's the most interesting thing in the universe?

The black holes more or less gulp down entire clusters of galaxies.

The cluster, it'll swallow up most of our galaxy.

We will run into our Andromeda galaxies, black hole, that black hole will swallow our 1, they'll get bigger and bigger, and they'll basically swallow up the whole cluster of galaxies, gulp it all down, pretty well all, most of it, maybe not all, most of it.

Okay, and then that'll happen to, there'll be just these black holes around, pretty boring, but still not as boring as it's going to get.

It's going to get more boring because these black holes, you wait and you wait and you wait and you wait an unbelievable length of time, and Hawking's black hole evaporation starts to come in.

And the black holes, it's incredibly tedious.

Finally evaporate away, each 1 goes away, disappears with a pop at the end.

It was boring then, now this is really boring.

Universe gets colder and colder and colder and colder.

And I thought, this is very, very boring.

So I thought, who's going to be bored by this universe?

And what the photons do, they don't get bored because it's part of relativity, you see.

It's not really that they don't experience anything, that's not the point.

The photons get right out to infinity without experience any time.

And this was part of what I used to do in my old days when I was looking at gravitational radiation and how things behaved in infinity.

As long as you don't have any mass in the world, infinity is just another place.

There's something on the other side, is there?

The usual view is just a mathematical notion.

A nice example is this beautiful series of pictures by the Dutch artist M.C.

They're a very famous 1 with the angels and the devils, and you can see them crowding and crowding and crowding up to the edge.

Now the kind of geometry that these angels and devils inhabit, that's their infinity.

But from our perspective, infinity is just a place.

In just the words you're saying, infinity is just a place.

So for the most part, infinity, sort of even just going back, infinity is a mathematical concept.

You think there's an actual physical manifest, in which way does infinity ever manifest itself in our physical universe?

You see, it's a thing that if you're not a mathematician, you think oh infinity, I can't think about that.

Mathematicians think about infinity all the time.

They get used to the idea and they just play around with different kinds of infinities and it becomes no problem.

But you just have to take my word for it.

1 of the things is you see you take a Euclidean geometry.

Well, it just keeps on going and it goes out to infinity.

Now there's other kinds of geometry and this is what's called hyperbolic geometry.

It's a bit like Euclidean geometry, it's a little bit different.

It's like what Escher was trying to describe in his angels and devils.

And he learned about this from Coxeter and he thinks that's a very nice thing, I shall represent this infinity to this kind of geometry.

So it's not quite Euclidean geometry, it's a bit like it, that the angels and the devils inhabit.

And their infinity, by this nice transformation, you squash their infinity down so you can draw it as this nice circle boundary to their universe.

Now from our outside perspective, we can see their infinity as this boundary.

Now what I'm saying is that it's very like that.

The infinity that we might experience like those angels and devils in their world can be thought of as a boundary.

Now I found this a very useful way of talking about radiation, gravitational radiation, and things like that.

So now what I'm saying is that that mathematical trick becomes real.

That somehow the photons, they need to go somewhere because from their perspective, infinity is just another place.

Now this is a difficult idea to get your mind around.

So that's 1 of the reasons cosmologists are finding a lot of trouble taking me seriously.

But to me, it's not been such a wild idea.

What's on the other side of that infinity?

You have to think, why am I allowed to think of this?

And we in physics have beautiful ways of measuring time.

There are incredibly precise clocks, atomic and nuclear clocks, unbelievably precise.

Because of the 2 most famous equations of 20th century physics.

1 of them is Einstein's E equals mc squared.

The other 1 is even older than that, still 20th century, only just, max Planck E equals h nu.

Nu is a frequency, h is a constant again like C, E is energy.

Put the 2 together, energy and mass are equivalent, Einstein.

Energy and frequency are equivalent, blanks blank.

Put the 2 together, mass and frequency are equivalent.

If you have a massive entity, a massive particle, it is a clock with a very, very precise frequency.

It's not, you can't directly use it, you have to scale it down.

So your atomic and nuclear clocks, but that's the basic principle.

You scale it down to something you can actually perceive.

If you have mass, you have beautiful clocks.

But the other side of that coin is, if you don't have mass, you don't have clocks.

If You don't have clocks, you don't have rulers, you don't have scale.

You don't have a measure of the scale of space

You do have the structure, what's called the conformal structure.

You see, it's what the angels and devils have.

If you look at the eye of the devil, no matter how close to the boundary it is, it has the same shape, but it has a different size.

So you can scale up and you can scale down, but you mustn't change the shape.

So it's basically the same idea, but applied to space-time now.

In the very remote future, you have things which don't measure the scale, but the shape, if you like, is still there.

Now I'm going to go way back into the Big Bang.

Now as you get there, things get hotter and hotter, denser and denser.

Particles moving around almost with the speed of light.

When they get almost to the speed of light, okay, they begin to lose the mass too.

So for a completely opposite reason, they lose the sense of scale as well.

So my crazy idea is the Big Bang and a remote future, they seem completely different.

The other is very, very rarefied and very, very cold.

But if you squash 1 down by this conformal scaling, you get the other.

So although they look and feel very different, They're really almost the same.

The remote future on the other side, I'm claiming, is that where do the photons go?

You've got to get your mind around that Crazy idea.

Taking a step on the other side of the place that is infinity.

I'm saying the other side of our Big Bang, now I'm going back into the Big Bang.

There was the remote future of a previous eon.

And what I'm saying is that previously on, there are signals coming through to us, which we can see and which we do see.

And these are both signals, the 2 main signals are to do with black holes.

1 of them is the collisions between black holes.

And as they spiral into each other, they release a lot of energy in the form of gravitational waves.

Those gravitational waves get through in a certain form into the next eon.

That's fascinating that there's some, I mean, maybe you can correct me if I'm wrong, but that means that some information can travel from another eon.

I mean, I've seen somewhere described sort of the discussion of the Fermi paradox, you know, that if there's intelligent life, communication immediately takes you there.

a paper, my colleague Vaheguru, who I worked with on these ideas for a while, we have a crazy paper on that.

Right, so if the universe is just cycling over and over and over, punctuated by the, punctuated the singularity of the Big Bang, and then intelligent, or any kind of intelligent systems can communicate through from eon to eon, why haven't we heard anything from our alien friends?

I mean, the SETI program is a reasonable thing to do, but still speculation.

It's trying to say, okay, maybe not too far away was a civilization which got there first, before us, early enough that they could send us signals, but how far away would you need to go before, I mean, I don't know.

We haven't seen any signals yet, but it's worth looking.

What I'm trying to say, here's another possible place where you might look.

Now you're not looking at civilizations which got there first.

You're looking at those civilizations which were so successful, probably a lot more successful than they were likely to be by the looks of things, which knew how to handle their own global warming or whatever it is, and to get through it all and to live to a ripe old age in the sense of a civilization to the extent that they could harness signals, that they could propagate through, for some reason of their own desires, whatever we wouldn't know, to other civilizations which might be able to pick up the signals.

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Roger Penrose: Physics of Consciousness and the Infinite Universe | Lex Fridman Podcast #85