This series of lectures is called "Growing Up In The Universe".
Growing up means three things.
First, it means the growing up of an individual, like you or me, or a redwood tree.
We all grow up from a tiny, single cell,
up to a massive edifice of hundreds of trillions of cells during our own lifetime.
Secondly, growing up means the growing up of an entire life form on a planet,
what we call its evolution.
Evolution is a change that we see only when we go through a lot of generations
and see each generation after the other.
The third sort of growing up is what this lecture is about.
It's growing up in the sense of achieving a grown-up understanding of the universe.
In order for a life form to achieve an understanding of the universe, it has to have the right apparatus,
and on our planet, that means a brain.
When the brain has grown very large indeed,
it becomes capable of comprehending the universe.
And it does this by putting a model of the universe inside itself.
In fact, this lecture might have been called "How to Put the Universe Inside Your Skull".
But long before a brain can do that, it must grow up on its planet through intermediate stages.
It serves an apprenticeship of setting up models of much more ordinary, mundane things.
Brains never evolve for grand purposes like simulating the universe,
brains begin by simulating ordinary things, like food or like the geography around your home.
This is a digger wasp, which is in the act of stinging a grasshopper.
A digger wasp is a solitary wasp, not like the wasps that bother us in the autumn,
and it stings grasshoppers or other prey and takes them back to its burrow.
Now this represents the digger wasp, and this is its burrow,
and every time it goes off and catches a grasshopper it brings it back
and puts it in the burrow to feed to its young.
But in order to do that, it's got to be able to find its way home,
because it's foraging for grasshoppers for quite a long distance.
So what does it do?
It comes out of its burrow and then it flies around its burrow
on a couple of reconnaissance flights, learning the geography of the terrain.
Then, it flies off, quite a long way, catches a grasshopper, and then brings it back
then goes down into the burrow, comes back out, picks up the grasshopper and takes it in.
Then it sets off to catch another one, and so on.
Each one it catches it takes down to feed to its young.
Now, the great ethologist, Niko Tinbergen, did a very ingenious experiment.
He waited until a digger wasp was down in its burrow, so it couldn't see,
then he quickly put four fir cones around the burrow.
And he waited, and out came the digger wasp,
and it flew round and round on its reconnaissance flight,
this time taking notice of the fir cones, flew away and picked up a grasshopper.
While it was doing that, Tinbergen swiftly moved the fir cones,
like that.
The digger wasp came back with its grasshopper,
came back and what did it see?
It saw four fir cones.
That's what it had learned, were the landmarks around its burrow.
So it went straight for the middle of the fir cones, didn't find its corn at all.
The digger wasp had built up a mental model, a mental map of the surroundings of its burrow.
Now, even a digger wasp's brain can do that.
But if you want to simulate the universe, you've got to have a much bigger brain than that.
And digger wasps' brains aren't up to that.
We can easily see that by another experiment that Tinbergen did,
actually it was first done by the great French entomologist, Fabre. What he did was this:
I told you, when the digger wasp comes back with its grasshopper,
it briefly leaves it on the side of the burrow
and then it goes down the burrow,
and what it seems to be doing there is checking that the burrow is clear,
that there's nothing in the way.
And then it comes out again, and picks up the grasshopper and drags it in.
Well that's what normally happens.
But what Tinbergen did was this:
he waited till the digger wasp came back with the grasshopper, planted it there,
digger wasp went down the burrow.
Now while it was down there, Tinbergen picked up the grasshopper
and just moved it, a little bit, like that.
The digger wasp came out, went to where the grasshopper was
and didn't find it.
So it looked around, eventually it found it, and it then said to itself, so to speak,
"Right, I've got a grasshopper, I've now got to go down the burrow again."
Well, he didn't say again,
I've got to go down the burrow and check that there are no obstacles in it,
so it did that.
Then Tinbergen moved the grasshopper a bit more
out it came, back to where it had left it,
wasn't there. Looked for it, found it.
Ah, a grasshopper! Down the burrow again
it went on and on doing this, 40 times, until Tinbergen got bored and just stopped doing it.
So there are limitations to the digger wasp's brain
and in fact, on our planet there's only ever been one brain
that even begins to be capable of simulating the universe,
and that of course is the human brain.
Well here is a human brain, in a rather unfortunate state,
it's in a - it's in pickle.
So let's look at a human brain of a living person.
This very brain that you're looking at on the screen now,
is at this very moment, thinking about a yellow rose.
This very brain is now thinking about thinking about a yellow rose.
It's now thinking about the Royal Institution Lecture Theater,
and it's now thinking about -
oh, what's your name?
Sarah. Sarah.
It's now got a mental picture of Sarah's face inside it.
It gets that mental picture through this thing, which is the eye.
There's the lens of the eye, there's the retina.
There is now a picture of Sarah's face, upside down, there.
And that picture is being transmitted up a great trunk cable of a million wires,
through there to the back, and the picture of Sarah's face
is now projected on the back of the brain, there.
More mysterious still, somewhere in here -
and we don't know where, it could be distributed all over -
there is a conscious feeling, a conscious image.
That brain, is of course, my brain.
It was done by a brilliant new technique called Magnetic Resonance Imaging,
which is a lovely way in which doctors can now get right inside,
look right inside somebody's body without cutting them open,
and without using harmful rays like X-rays.
And I went and had that done earlier this year, for the purpose of this lecture.
The brain could be called the on-board computer of the body.
The body moves around in a big, complicated three-dimensional world.
But the eyes that are feeding the brain with information, are giving it two-dimensional information.
The two retinas of the eyes are each seeing a two-dimensional picture of the world.
What's more, it's upside down.
Somehow, the brain manages to use that information
to see in three dimensions.
Now, would you just do something very easy for me -
and this can be done by people at home as well watching on the television -
just hold up your right hand, please,
just hold up your right hand in front of you,
and look at me. Don't look at your hand, look at me.
And what you'll see is two hands, two of your hands.
And these two hands, of course, are the one that's being seen by your left eye
and the one that's being seen by your right eye. That's why there are two.
But now, just focus your eyes on your hand. Don't look at me any more, look at your hand.
Now you'll see two pictures of me, and only one picture of your hand.
Okay, that's enough.
So what's happening here?
You've still got two images of your hand.
There's still two images: one on the left retina, and one on the right retina.
But somehow the brain has managed to pull those two images together and make them form a single, composite,
three-dimensional image, somewhere in the head.
The brain has built a single model of the hand, or whatever it is, in your head.
Whenever we think we see 'out there', whenever we see what we call reality out there,
what we're actually seeing is a representation in the head,
a model in the head. A simulation in the head.
It's a very useful simulation
because it's constantly being updated by information coming in from the sense organs.
It's not just sitting there.
The sense organs are pouring information in but that information is not being seen raw,
it's being used to update the model that's sitting there in the head.
The reality that we see, in other words,
is constructed, in our skulls, as virtual reality,
to use the computer jargon.
So now let's look at virtual reality in a computer.
Here we have a very powerful, fast computer
and inside that computer, you're going to see in a moment,
is a model of a world. A microcosm. A small world.
It's a house, with a corridor and some rooms leading off it.
And I'm going to ask somebody to come down and experience what it's like to walk through that world.
Karen is going to come down and help us.
Stand there, on that spot there,
and first of all I ought to just explain that the headset here has two little television screens,
and the images of those two screens are cunningly offset in the computer,
so that what she will see is just what she would see if she were seeing in 3-D, in stereo.
Now if you could put that on -
Now we're beginning to see, on the screen, what she can see.
Now, Karen, could you please just turn your head gently from side to side.
Notice that when she does that, the world appears to move.
Now, if you were in this helmet, as she is, this would seem very natural to you,
because as you turn your head, the world appears to move in just the right way.
Move your head up and down as well, and see - let's see what happens.
If she moves her head up, and moves her head down.
Remember that she's seeing it in stereo,
we're only seeing what one of her two eyes is seeing, so we're seeing it in mono.
So you have the idea that Karen, although she's standing in front of you there,
she thinks that she's standing in a corridor with a row of doors on one side,
and she thinks that she's going to be able - indeed she is going to be able - to walk down that corridor.
She's not going to actually move her feet very much,
she's going to press buttons on the little thing you see her holding in her hand.
This is a little controlling box, and if she presses one button she can go forward -
can you go forward a bit?
And if she presses another button she can go backwards.
Right.
Now, have a little walk around, Karen, and see what you find if you go into one of those doors.
Here she is, walking along the corridor
and she's going to turn
I don't know which door she's going into, that's her choice.
She can go into any door she likes, and she'll find something behind the door.
She's going through the door -
now, what's she got here? This looks like fish.
She's - she's swimming around, in a roomful of fish,
but I think I see a butterfly as well.
Remember, this is not a real world, this is a virtual world.
Anything you like can be put into this world.
It's an imaginary world, in the computer.
Those fish are each programmed, individually,
to behave as autonomous entities. As though there were real fish.
Would you like to tell us what you're doing now, Karen?
Well, if I go out here, into space -
Alright, she's backed out through a wall I think! It's a game.
and then turn round 180 degrees, I can look onto it all.
Right,
go back into the room then, into the room -
To get out...
That arrow that you see hanging in front of her, in the virtual space, is her hand.
That represents her hand.
Now if she waves her hand around you can see the arrow moving,
and soon she's going to approach the door and touch it with the hand, with the arrow,
it opens the door.
And through we go into the corridor.
Now where're you going to go Karen?
Turning round, okay, turning right round -
And everywhere she looks she sees something. She can go wherever she likes -
back along the corridor -
Maybe into another room?
Yes. Go and see what's in that door there.
Right, now what have we here? This seems to be a chess set.
Can you walk around among the chess men?
There's a pawn. Can you pick that up?
Mm hmm. Let's try again.
Touch it with the hand.
There it goes, she's lifting up the pawn with her hand.
Do you see her hand moving? And then also the chess man is moving.
She's let go of it.
Yeah...no No she hasn't. If I can let go, there.
It drops. Okay.
Now what's that curious sort of plank there?
Go and see what's over there.
She's - oh, she's going to fall over an edge!
There's another chessboard down there.
She's falling!
Right, she's on the lower chessboard, there's another pawn.
Go wherever you like, Karen - do you want to fly about a bit? Do you want to carry the pawn about?
She's dropped it! Where's it going?
It's disappearing, it's gone, right.
Now where are you?
Help! We're now underneath the chess board! .
We're right underneath the lower - now we're up - we're going up the cliff,
there's a castle - up the - whoops!
Okay, well thank you very much indeed, Karen.
Well, what was really going on there?
Was there really a chess man there? Was there really a chess board?
In a sort of sense there was. There was a mathematical representation
that is read out on the television screens, as though it was
a chess board, as though it was chess men.
And it behaved in a realistic way:
you could pick things up, throw them around, you could go through doors,
you could move around that world, and if you threw chess men down to the lower board,
then they would stay there until you went down and picked them up again.
So there was something that corresponded to reality there,
and what I'm trying to suggest to you
is that just that same something is going on inside your own skulls at this very moment.
There is a virtual reality simulation of the world
going on inside your heads, and that's what you're seeing.
But how do I know that? How do I know that that's what our brain is doing?
Well one way we can get a clue is by looking at illusions.
Now here's a mask of Charlie Chaplin.
It's perfectly ordinary, nothing trickery about it,
it's just an ordinary mask.
And when you look at the front side, it looks solid and normal, as you'd expect.
The odd thing that you'll see is when you start looking at the back side, at the hollow side,
because although it is in fact hollow, if you look at it,
I think you'll agree that it looks solid.
And what's more, it not only looks solid but it seems to be going around in the wrong direction,
so that when the real front side comes round, it seems to sort of eat it up.
There's the real front side - now that really is solid -
and when the other side comes round, that is going to look solid as well. Even though it isn't.
Well what's going on here?
When the brain sees anything that looks like two eyes, a nose and a mouth,
it immediately sets up inside the head a model of a face.
It's desperately eager to see a face.
It will see a face if there's the slightest excuse to do so,
and the back side of this mask is the slightest excuse.
There is two eyes, a nose and a mouth, and that makes the brain
get out, dust off, its model of a three-dimensional face.
Now if you think about what would happen to the images on the two retinas,
if the image really was solid,
if the thing really was solid,
the actual movements on the retinas
is compatible with the idea of a solid face moving in the opposite direction.
And so the brain eagerly seizes upon that, and it makes the solid face rotate in the wrong direction.
Now, for the next demonstration we need a volunteer to be taken off and...
yes...thank you...
Bryson is going to take you off and you'll come back in a moment.
Now here we have an impossible triangle.
We look first at this corner and it's telling us that there is a wooden triangle,
which is facing in that direction.
Now if we go up here we see this corner and we're told by our eyes
that there's a triangle facing in that direction,
and now we're told there's a triangle facing in a third direction.
Those three angles don't match up together.
They can't mix together And yet the brain sees it,
constructs in the brain a model of an impossible figure, an impossible triangle.
And I imagine all of you can see that.
Now we're going to shatter the illusion, rudely.
What's happened?
Out again?
The triangle's reformed.
In again?
Out again -
thank you very much. Would you like to bring in the object now and we can see what it really is?
Thank you, I'm sorry I didn't get your name.
Sarah.
You can stay there for a moment, Sarah.
You see, there's nothing special about it at all.
It's just three bits of wood, glued in opposite directions, like that.
I'm going to move it round and try to recreate the illusion.
I haven't done it terribly well
but there it is, and now I think if I put my face in, you can again see it happening, like that.
Okay, thank you very much, Sarah.
Now here's one of the great classic illusions,
which is the best one I have to make the point I'm trying to make.
This is called the Necker cube. And it's just a picture of a cube, drawn on paper.
If you look at it, I think you'll see it doing a rather strange thing:
it'll be alternating
the side that seems to be nearer to you, will change.
Sometimes it'll be one side, sometimes it'll be another.
What's going on here?
The two-dimensional pattern of ink on the paper
is equally compatible with two alternative three-dimensional cubes.
So the brain doesn't know which of its three-dimensional cubes to use.
It's got two potential models of three-dimensional cubes in there, waiting to be used,
and it doesn't know which one to use because both of them are equally compatible
with the two-dimensional pattern of ink on the paper.
So what does it do?
Well it could plump for one or other of them but it doesn't do that,
what it does is alternate.
And so you sometimes see one, and you sometimes see the other.
Now this is a more elaborate version of the same thing,
because this is a real cube - as you can see, made of metal - and it's rotating.
But once again, if you get the lighting right, it is sufficiently -
perhaps it's best if you look at it on the screen here -
the two-dimensional pattern that's moving round your retina
is equally compatible with two different three-dimensional cubes.
And so, if you look at it and perhaps blink, look away and come back again,
you may see it change direction.
And what's happening is that the brain doesn't know which of two models to use,
and so it chooses them alternately.
But we don't have to go to the lengths of setting up illusions
with apparatus to satisfy ourselves that the brain does set up a virtual reality model.
Here's something we can all do without any apparatus at all, again including people at home.
So this is something to do to yourself, you won't see anything on the television screen
if you're at home, you'll just do it to - to yourself.
Just very gently, with your finger, move your own eyeball.
Just poke it up where I'm doing it - do you see where I'm doing it?
And I think what you'll see is that the world moves as you do it, doesn't it?
It's like a little minor earthquake when you do that.
Well of course, that's exactly what you'd expect, isn't it?
Because the image on your retina is being moved, the eyeball is being moved,
and so the apparent position of the object you're looking at is moving,
so you see it as movement.
What's so strange about that? Nothing's strange about that, that's just what you'd expect.
But now let's think a bit further,
because doesn't something very similar happen whenever you roll your eyes about?
If I roll my eyes like - do it now, just roll your eyes, move your head about, roll your eyes.
The image on your retina is going crazy.
Much worse, in fact, than when you simply poke your eyeball with your finger.
The image on the retina is moving but what are you actually seeing?
You're not seeing the world moving like an earthquake.
When you roll your eyes about, the world appears to be as steady as a rock.
So on the one hand, when you poke your eye, the world appears to move as though there's an earthquake,
on the other hand, when you voluntarily wiggle your eyes about like that,
although the same thing's happening on the retina, what you see is a perfectly steady world.
Why is that? What's the difference between those two cases?
Well, it's this.
There might really be an earthquake going on and it's important for the brain to know
On the other hand, it's also important that the brain should not constantly
think there's an earthquake whenever you move your eyes about.
So what the brain does when it sends an order to the eye muscles
to move the eye, to roll the eye, which it often does,
it sends a copy of that order to the virtual reality software
that's engaged, that's busy setting up the model of the world.
And the virtual reality software is told,
"Okay, the eye's about to move - expect the world to move."
And so, the virtual reality software does not see an earthquake,
because it's been told to expect it.
The model in the head is precisely compensating for the anticipated movement.
But when you poke your eye,
no copy of any order is ever received. And so the world really does appear to move
as if there was an earthquake. And indeed there might be an earthquake and it would be important
for the brain to know that and not just to immediately discount it.
Now a very clever experiment on this was once done by a German scientist,
who put his own eye muscles out of action with an anesthetic.
Now, I was going to call for a volunteer for this experiment
ah, we have a volunteer but I think, unfortunately, there isn't any time,
so I'll just have to tell you what happened.
What this German did was he anesthetized his own eye muscles.
Now think what would happen?
Whenever he told his eyes to move, they didn't. Nothing happened.
They stayed absolutely stock-still. And, the image on the retina stayed absolutely stock-still as well.
But the copy of the order had gone out to the virtual reality software in the brain,
and the virtual reality program was told to expect a movement.
So when no movement came, it interpreted it as if was an earthquake.
So whenever this German told his eyes to move, whenever he
gave out the order for his eye muscles to pull the eyes around,
the eyeballs stayed absolutely still,
the image on the retinas stayed absolutely still,
but the model in the brain moved, and he saw an earthquake.
So that's my evidence that the brain is setting up a model of the world.
We're seeing virtual reality.
I now want to switch temporarily from that topic, and talk about the evolution,
the growing up, of the human brain itself.
By evolutionary standards, the brain seems to have grown up very, very fast indeed.
One authority has said that the evolution of the human brain
over the last million years or so, is perhaps the fastest advance recorded
for any complex organ in the entire history of life.
And compared with the skulls of other apes like chimpanzees,
our brain is indeed - our skull is indeed very big.
It seems to have blown up like a balloon.
And here's an animation of that.
This is the head of Australopithecus, which is one of our ancestors,
and now you can see the evolution gradually happening before your eyes,
it's becoming a Homo erectus, it's an early Homo sapiens,
it's changing now to becoming a modern Homo sapiens like us.
Look how the skull is ballooning out, the head is ballooning out, as evolution goes by.
We've compressed about three million years of evolution into that animation.
Now here's the same thing from the side view of the skulls.
Here's Australopithecus again, look, quite a low head - now it's growing bigger,
the jaw's coming in,
evolution's going by, millions of years going by, and the skull is blowing up like a balloon,
blowing up, blowing up. There it is. There's a modern skull,
there's a modern human skull. Chock-full of brains.
One way of understanding what's happening there,
is to look at computers again
because something similar - very fast evolution - seems to have happened with the computer.
And here's a dramatic quotation to illustrate that, from a psychologist, Christopher Evans.
Here's what he said:
"Today's car differs from those of the immediate postwar years on a number of counts.
It is cheaper, allowing for the ravages of inflation, and it's more economical and efficient.
All this can be put down to advances in automobile engineering,
more efficient methods of production, and a wider market.
But, suppose for a moment that the automobile industry had developed
at the same rate as computers, and over the same period.
How much cheaper and more efficient would the current models be?
If you have not already heard the analogy, the answer is shattering.
Today, you would be able to buy a Rolls Royce for ¡ê1.35,
it would do 3 million miles to the gallon,
and it would deliver enough power to drive the Queen Elizabeth II.
And if you were interested in miniaturization, you could place half a dozen of them on a pinhead."
So if the human brain has blown up like a balloon,
it looks as though the computer has advanced even more spectacularly.
Although of course it's rather unfair to compare the timescales directly,
because the evolutionary timescale is limited by the fact
that in order for evolution to happen, people have got to die.
Generation after generation. And other people have got to reproduce.
It necessarily takes a lot longer than technology,
which happens - which can advance all the time.
Nobody knows for certain what it was that caused the ballooning of the human brain.
There're lots of theories but as I said, perhaps we can get a clue from computers.
If we look at what it is that's made them develop so fast, improve so fast,
it might help us to guess why our brains have, too.
Well there are lots of differences between computers and brains,
lots of things won't help us, it's no good looking at, for example,
the improvement from valves to transistors to integrated circuits,
because brains don't work like that anyway.
But there is one source of computer advancement,
one thing that's been going on in the development of the computer,
which just might give us a clue about what happened with the brain.
I'm going to give it a long name, and you'll see what it means later.
I'm going to call it self-feeding co-evolution.
Co-evolution just means evolving together.
Self-feeding is the name I'm going to give to any process
in which the more you have, the more you get.
Think about the arms race, for instance.
As the missiles on one side in the arms race get bigger and better and faster,
so the interceptor devices on the other side, the radars and counter missiles,
have to get better and faster and more accurate as well.
And when they've got better, then the missiles on the first side have to get better still.
And so the radars and interceptors have to get better still.
And the process escalates, indefinitely, like that.
I call it "self-feeding"
because there is a sense in which improvements in the original radars
directly necessitate later improvements in the same radar,
even though it's going via the loop of making the radars on the other side get better,
so the more you have, the more you need, the more you get.
Arms races happen in evolution, as well.
Here's a peregrine falcon which is flying along, a beautiful piece of flying machinery,
and soon it's going to see some prey which it's going to dive to attack.
Here it is: the wings go in,
it screams down at nearly 100 miles an hour on its prey,
which in this case happens to be a duck, also flying very, very fast.
The duck's flying fast - there it comes.
Both the duck and the hawk are end products
of a long evolutionary arms race.
Both of them are extremely good at flying,
and the reason is that the other one is.
In their ancestry, improvements on one side necessitated improvements on the other.
As hawks got better ducks had to get better,
and as ducks got better hawks had to get better.
So, indirectly, it was the improvements in the hawks
that made their descendants have to get even better later.
And improvements in the ducks made their descendants have to get even better later.
That's why I call it "self-feeding."
Now what this is all leading up to
is that something like that self-feeding co-evolution
may have gone on in the development of computers and, more importantly, brains.
In computers, both hardware and software co-evolve.
"Hardware" means the physical bits, like this. Things you can touch and feel.
"Software" means programs, and improvements in both are important.
Here's a very simple piece of hardware: the mouse.
It's just a ball and socket, a ball there in a socket,
and as you move it around you see a little pointer moving around on the screen,
and this gives you a very, very powerful illusion.
You almost feel as though your hand is in there, moving things around the screen.
It's a natural thing to do.
In the bad old days of computing, if you wanted to do something like throw away a file,
then you had to go to the keyboard and you had to type some ridiculous rigmarole
like: delete mydir: baslib: codsw.tx all sorts of stuff like that
If you made a mistake you had to correct it, and you usually did make a mistake,
you nearly always forgot what the command was anyway.
Nowadays, all you have to do, if you want a throwaway comment,
is just pick it up move it to the wastepaper basket and let go.
Now we have to empty the wastepaper basket, which you see has bulged,
and agree to let it go, and it goes.
That's just a trivial example.
What's much more important
is that the modern computer world is entirely dominated by using a mouse
or using some kind of pointing device to quickly move things around,
do things very, very naturally,
as though you were moving bits of paper around on your desktop.
Pick things up, move them around, make them appear,
make menus appear, and so on, like that.
It's all now very easy,
where once upon a time you'd have had to remember difficult rigmaroles to type.
Now, the reason for bringing this up
is that it was all triggered by an original, very simple, hardware device.
That in itself is trivial, there's nothing much to it, it's very easy,
but what it spawned was a whole new generation of software
and software building upon other software, building upon other software,
and so you build up a complete edifice of mutually working co-evolving software.
Another example of computers getting into a self-feeding spiral
is the way computers themselves are designed.
Modern computers are far too complicated
to be designed in detail by humans.
This chart here is one-eighth of the circuit diagram of this chip here.
So that is one computer chip,
and the circuit diagram for that computer chip is eight times as big as what you see here.
Now let's just walk around this a little bit.
Each of these red marks here is one wire.
Following them up round here, let's follow these main trunks round here.
let your eye roam over this remarkable document, and realize
that no human could really sit down and design that.
A human has the basic ideas, a human programs the computer to do it,
but modern computers are very largely designed
by the previous generation of computers.
Modern computers are piggy-backing on the back of an earlier generation of computers
Once again we have an example of a self-feeding spiral.
Early advances lead into later advances, and they go into a spiral.
Well, we've seen self-feeding co-evolution in the computer and the purpose of that,
of course, was to develop an analogy with the human brain.
Can we see there's something like the same thing going on in the human brain?
Unfortunately, unlike computers we can't look directly at the intermediates.
All that we have by way of evidence is skulls, and to a limited extent, skills.
We have the outer casings, and by way of software, we have the products
which are things like flint arrowheads produced by our ancestors,
and we have pictures like these two bison here, a cave painting.
This is a relic of the product of an early human brain,
and much later, of course, we have writings like this cuneiform tablet or like this book.
But what happened to make the human brain take off?
What was the equivalent of the mouse, the thing that made our species leap forward in the way that it did?
Well, it has to be largely guesswork.
About 3 million years ago, when our ancestor Australopithecus roamed about Africa,
his brain was no bigger than that of a chimpanzee.
This again is Australopithecus.
And if this ancestor of ours had met a chimpanzee,
they would have been on roughly equal terms as far as brains are concerned.
Either of those species, any ape species at that time,
could have been the one that took off.
But the whole point of talking about self-feeding spirals
is that to begin with there won't be anything very dramatic.
One of those species made some kind of minor breakthrough in software,
some software advancement, I'm suggesting.
The result of that wasn't seen till much later. You wouldn't have seen anything for a while,
it would've gone into a spiral, and eventually reached the heights that we have now reached.
But I still haven't said what the software innovation was that sparked it all off.
We don't know and we can only guess.
One possibility is an improvement in our ability to simulate models of the world.
We've seen that our brains make a model of what's actually going on in the real world,
but we also know that they can make models of what might be going on in the world.
Our ancestor Homo erectus lived a million years ago,
and let's imagine that a particular female Homo erectus was trying to solve the problem
how to get her family across a gorge like that.
Nobody had ever built a bridge before.
Bridge technology wasn't around,
but she suddenly saw in her mind's eye a tree fallen across the gorge,
and she realized that it could function as a bridge.
She also thought, "How can I get that to happen?" and she's imagined,
she saw in her imagination, a fire at the base of the tree.
She had the idea of burning the tree down to make it fall and make a bridge.
Now this of course is entirely speculation.
We don't know if that ever happened, we don't even know if it would have worked.
The point I'm making
is that she had a model in her head of a tree fallen across a gorge with fire
and that something hadn't yet happened.
She was anticipating something that might happen in the future,
and if you can do that you've got a trick that's really worth having,
because you can solve problems that other animals can't solve.
So that's one possibility.
Imaginative simulation may have been the software trick
that took our species off.
Another possibility is language. It's often been suggested,
it's an obvious suggestion, because language seems tailor-made to get a piggy-back spiral going.
If you've got language, then each generation can learn from its predecessors,
learn from the previous generation, learn from their mistakes,
build on their experience. So maybe it was language.
Unfortunately, there's a snag.
There's some evidence that language, in the form of speech at least, proper speaking,
didn't arise until after the ballooning of the brain.
But perhaps we can get out of that by suggesting that
language had an early apprenticeship in the form of a kind of sign language,
or drawing in the sand, or perhaps language arose before actual speech arose,
as a sort of way of talking to yourself
to get your thoughts into a logical order,
to plan your actions in a logical order,
and only later perhaps, did it become externalized in the form of speech
using the tongue, lips, and voice so that brains became, as it were, networked together.
We can also think of technology, tools, say, like these tools here,
as external devices used by brains
for extending the power of the hands,
or other devices like telescopes and microscopes as devices for extending the power of the eye.
Maybe it was technology that provided the breakthrough for humans to take off.
So we've identified imagination, language, and technology as three possible candidates
for our trigger innovation,
and perhaps all three played a role.
Perhaps they reinforced each other in a three-way spiraling explosion.
But each of those three mental tools: imagination, language, and technology,
is double edged.
If we use them right, we can perhaps end up making a model of the universe,
but the double edge is always there.
Take imagination and the brilliant simulating software that we saw earlier.
It can be immensely useful but it can also have unfortunate consequences.
A brain that's good at simulating models in imagination, things that aren't there,
is unfortunately also almost inevitably in danger of self-delusion.
How many of us have lain in bed, terrified because we thought we saw a ghost
or a monstrous face staring in the bedroom window,
only to discover eventually that it was just a trick of the light, the moonlight playing on the curtains?
We've seen from Charlie Chaplin how easy it is, how eager the brain is,
to make a face even when there's only a hollow back to a mask.
That same software can do the same trick if it sees some folds in the curtain
that just happen to suggest eyes, a nose and a mouth perhaps, so we see a face when there isn't one there.
Every night of our lives we dream.
That same simulating software sets up worlds that don't exist - people, animals, countries
that never existed, perhaps never could exist.
At the time, we experience those simulations as though they were reality.
And why shouldn't we,
given that we habitually experience reality in just the same way
by looking at simulation models in our heads?
The simulation software can delude us when we're awake, too.
So I think the lesson from this is that if ever we hear a story
that somebody has seen a vision, been visited by an archangel,
heard voices in his head, we should be immediately suspicious.
Secondly, language. What's the downside of that? Why is that a double-edged sword?
Well, good information can spread around the world, round the network of brains, very easily,
but so can everything else. It doesn't have to be good.
Even something as trivial as this:
Ten years ago you never saw anyone going around with a baseball cap on backwards.
In fact, in this country you never saw anyone with a baseball cap on at all.
But now, if you go down a street, either in this country or America
you almost can't help seeing a young man with a baseball cap on backwards.
The reversed baseball cap has spread like chickenpox,
first in America and then here.
It's a mind epidemic, a kind of virus of the mind.
And like a chickenpox epidemic, epidemics of mind viruses also,
I'm glad to say, die out remarkably quickly.
And my guess is that before very long the reversed baseball cap will go the way of this.
Well, baseball caps and turtles are, of course, harmless,
but there are other more powerful idea systems that are more sinister
and that do actively hold back progress towards our understanding of the universe.
In 1633 the Holy Inquisition condemned Galileo Galilei, the great Italian physicist,
to life imprisonment.
His crime was to publish a book arguing, correctly,
that the world moved round the sun.
He was condemned, on vehement suspicion of heresy,
because his science contradicted the beliefs of the dominant culture of his time.
And don't let's be complacent about our time.
It's in our time that an entire religious sect has been actively incited
by its leadersto murder a distinguished novelist
because he wrote a book
that was seen as threatening the verbally handed-down beliefs of that sect.
And it is in our century, too, that perhaps the most pernicious language virus ever known was spread.
There's no need for me to add words there.
Let me return to the general problem of language and its power for ill as well as good.
Human children have an awful lot to learn as they grow up.
Language is a magnificent tool for learning.
It enables us to cram in a few years the best of the wisdom of centuries.
No doubt that's why children are so receptive when they're young.
Children of a certain age believe whatever they're told.
Father Christmas and tooth fairies are harmless enough,
but a mind that's capable of believing in fairies
is also a mind that's vulnerable to all manner of other stuff.
Anybody who heard my first lecture may remember this picture of the distribution of, it's a spoof really,
showing a map of the world in which people believed in different ideas,
like different theories of the dinosaurs in different areas.
And the point was to say how absurd it would be
if science really worked like that, if what you believed about the world or the universe
depended upon where you happened to be brought up.
And I won't repeat the details of that.
But do take the lesson seriously.
Look at your own beliefs about the world, about life, beliefs about the universe.
Do you believe them because you have some reason to believe them,
or do you believe them simply because of where you were born?
Would your beliefs about the universe fit comfortably on a map of the world like that?
If so, be intensely suspicious of them.
If only because the facts about the universe
can hardly be different in different countries of the world.
Now to our third double-edged sword: technology.
Gadgets like these telescopes, microscopes, and so on are immensely powerful.
It's through them that we shall comprehend the universe if we ever do.
So what's their downside? What's wrong with them?
Obviously, the first thing
we think of when we think of bad effects of technology is hydrogen bombs
and all the other ghastly inventions of destruction.
And that goes without saying. That's the most important effect.
But I'm talking about something less obvious:
an effect on the mind, quite an interesting effect,
which I believe has held up our species' mental growing up.
And it's this: we're so used to seeing complicated, elegant
working things that humans have designed
that we naturally tend to think that all complicated, elegant,
working things must have been designed.
In an earlier lecture I made a distinction
between "designed" and "designoid" objects.
And "designed" objects are things like telescopes and microscopes
that really have been designed by somebody.
"Designoid" objects are things like eyes,
which look as though they've been designed,
and work in often very much the same way, but haven't.
They've arisen by an entirely different process,
namely evolution by natural selection,
Darwin's theory of how things came about.
Now, unlike, say, Einstein's General Theory of Relativity,
evolution by natural selection is really a very simple idea. Anybody can grasp it.
But in past centuries, nobody grasped it.
Not the cleverest people in the world. Not Aristotle, not any of the great philosophers,
no great mathematician. Nobody got this simple idea until the middle of the 19th century
when a couple of naturalists, Darwin and Wallace, got it.
Why did it take so long?
There could be a number of reasons,
but the one I'm talking about now is this:
I suspect that it may have been partly the distracting effects of technology.
Precisely because we were so used to seeing things that we had made,
that engineers had made, things like telescopes, microscopes,
ordinary little carpenters' tools and things,
we got the idea, children grew up with the idea, that everything had to have a purpose.
But now we can see human purpose for what it is.
It is a product of brains, and brains are a product of evolution.
Purpose has evolved like anything else.
For millions of years, three thousand million years,
life forms grew up on this planet that were very "designoid,"
that looked designed, but did not have the concept of design themselves.
Finally, one species, ours, grew up that was capable of designing things deliberately,
was capable of having purposes.
Purpose itself has arisen in the universe, has grown up in the universe, recently.
But purpose itself, now that it has arisen in human brains,
has the potential to be yet another of those software innovations
that is capable of taking off into a progressive self-feeding spiral.
Especially when teams of humans share the same purpose.
This is a picture of the lunar lander of NASA, about to land on the moon,
a magnificent example of what groups of human minds can do
when they get together with a common purpose.
Once the team purpose of standing on the moon had been announced by an American president,
it was achieved in less than a decade.
A similar group purpose of completely mapping the human genome
has recently been agreed, and it, too, will be achieved.
Science itself, the understanding of the universe in which we've woken up,
is another group purpose with almost limitless potential.
We can get outside the universe,
I mean in the sense of putting a model of the universe inside our skulls.
We've seen that whenever we perceive anything, we're putting a model of it inside our skulls.
Our model of the universe will be inside our skulls
in a similar way to a virtual-reality model in a computer.
Now, we have a final virtual-reality model,
and I think we have somebody already trained up to do this.
It's Alistair, isn't it?
Come along, Alistair.
To begin with, he can fly us around under his own control,
so we can go wherever he wants to go.
And it's quite a difficult operation.
We're now flying around this virtual model, which is in a computer.
And there's a picture outside a door,
and some of you may recognize what that picture is.
Now we're moving away from it again.
Remember we're in a model, in a computer.
Now we're going to go, I think, through that door.
In we go, burst through the door, where are we?
Lo and behold, we're in the Royal Institution lecture Theater.
That is a model of the Institution lecture Theater in the computer.
There's this lecturer's dais,
there's the exit there, there are the blue seats, there's the bit of wall under the gallery
OK, I think that's enough. We've got the idea. Thanks very much, Alastair. We've got the idea.
But once again we had a model of a world, in this case a little microcosm,
a small world, inside the computer.
But our model of the universe would not be a little, local model like this one.
It will be a far grander undertaking.
Building it is a shared enterprise.
The model is distributed over the network of brains that are participating.
Bits of the model are in books and libraries, pictures, computer databases.
As time goes by, and our civilization grows up more,
the model of the universe that we share with one another will get better.
It will become progressively more refined and more accurate in its mirroring of reality.
And at the same time, as we grow up,
our shared model will become progressively less superstitious,
less small-minded, less parochial.
It will lose its remaining ghosts, hobgoblins, and spirits.
It will be a realistic model correctly regulated and updated
by incoming information from the real world.
A powerful model, with parts that move relative to one another,
a model capable of running on into the future and making accurate predictions
of what's going to happen to us and our world.
We, perhaps alone in the universe,
are capable of finally growing up.
Thank you very much.
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