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This series of lectures is called
"Growing Up In The Universe".

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Growing up means three things.

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First, it means the growing up
of an individual, like you or me,
or a redwood tree.

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We all grow up from a tiny,
single cell,

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up to a massive edifice
of hundreds of trillions of cells
during our own lifetime.

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Secondly, growing up means
the growing up of an entire
life form on a planet,

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what we call its evolution.

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Evolution is a change
that we see only when we go
through a lot of generations

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and see each generation
after the other.

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The third sort of growing up
is what this lecture is about.

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It's growing up in the sense of
achieving a grown-up understanding
of the universe.

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In order for a life form to achieve
an understanding of the universe,
it has to have the right apparatus,

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and on our planet,
that means a brain.

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When the brain has grown
very large indeed,

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it becomes capable of
comprehending the universe.

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And it does this by putting
a model of the universe inside itself.

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In fact, this lecture
might have been called "How to
Put the Universe Inside Your Skull".

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But long before a brain can do that,
it must grow up on its planet
through intermediate stages.

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It serves an apprenticeship
of setting up models of much more
ordinary, mundane things.

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Brains never evolve for grand purposes
like simulating the universe,

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brains begin by simulating
ordinary things, like food or like
the geography around your home.

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This is a digger wasp,
which is in the act
of stinging a grasshopper.

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A digger wasp is a solitary wasp,
not like the wasps that
bother us in the autumn,

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and it stings grasshoppers
or other prey and takes them back
to its burrow.

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Now this represents the digger wasp,
and this is its burrow,

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and every time it goes off and
catches a grasshopper it brings it back

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and puts it in the burrow
to feed to its young.

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But in order to do that, it's got
to be able to find its way home,

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because it's foraging for grasshoppers
for quite a long distance.

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So what does it do?

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It comes out of its burrow and
then it flies around its burrow

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on a couple of reconnaissance flights,
learning the geography of the terrain.

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Then, it flies off, quite a long way,
catches a grasshopper,
and then brings it back

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then goes down into the burrow,
comes back out, picks up
the grasshopper and takes it in.

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Then it sets off to catch
another one, and so on.

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Each one it catches it takes down
to feed to its young.

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Now, the great ethologist,
Niko Tinbergen, did a very
ingenious experiment.

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He waited until a digger wasp
was down in its burrow,
so it couldn't see,

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then he quickly put four fir cones
around the burrow.

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And he waited, and out
came the digger wasp,

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and it flew round and round
on its reconnaissance flight,

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this time taking notice of the fir cones,
flew away and picked up a grasshopper.

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While it was doing that,
Tinbergen swiftly moved the fir cones,

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like that.

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The digger wasp came back
with its grasshopper,

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came back and what did it see?

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It saw four fir cones.

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That's what it had learned,
were the landmarks around its burrow.

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So it went straight
for the middle of the fir cones,
didn't find its corn at all.

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The digger wasp had built up
a mental model, a mental map
of the surroundings of its burrow.

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Now, even a digger wasp's brain
can do that.

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But if you want to simulate
the universe, you've got to have
a much bigger brain than that.

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And digger wasps' brains
aren't up to that.

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We can easily see that by another
experiment that Tinbergen did,

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actually it was first done
by the great French entomologist,
Fabre. What he did was this:

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I told you, when the digger wasp
comes back with its grasshopper,

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it briefly leaves it on the side
of the burrow

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and then it goes down the burrow,

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and what it seems to be doing there
is checking that the burrow is clear,

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that there's nothing in the way.

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And then it comes out again,
and picks up the grasshopper
and drags it in.

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Well that's what normally happens.

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But what Tinbergen did was this:

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he waited till the digger wasp
came back with the grasshopper,
planted it there,

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digger wasp went down the burrow.

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Now while it was down there,
Tinbergen picked up the grasshopper

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and just moved it,
a little bit, like that.

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The digger wasp came out,
went to where the grasshopper was

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and didn't find it.

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So it looked around, eventually
it found it, and it then said
to itself, so to speak,

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"Right, I've got a grasshopper,
I've now got to go down the burrow again."

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Well, he didn't say again,

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I've got to go
down the burrow and check that
there are no obstacles in it,

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so it did that.

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Then Tinbergen moved
the grasshopper a bit more

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out it came, back to where
it had left it,

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wasn't there.
Looked for it, found it.

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Ah, a grasshopper!
Down the burrow again

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it went on and on doing this,
40 times, until Tinbergen got bored
and just stopped doing it.

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So there are limitations
to the digger wasp's brain

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and in fact, on our planet
there's only ever been one brain

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that even begins to be capable
of simulating the universe,

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and that of course
is the human brain.

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Well here is a human brain,
in a rather unfortunate state,

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it's in a - it's in pickle.

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So let's look at a human brain
of a living person.

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This very brain that you're looking
at on the screen now,

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is at this very moment,
thinking about a yellow rose.

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This very brain is now thinking
about thinking about a yellow rose.

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It's now thinking about the Royal
Institution Lecture Theater,

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and it's now thinking about -

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oh, what's your name?

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Sarah. Sarah.

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It's now got a mental picture
of Sarah's face inside it.

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It gets that mental picture through
this thing, which is the eye.

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There's the lens of the eye,
there's the retina.

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There is now a picture of Sarah's face,
upside down, there.

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And that picture is being transmitted
up a great trunk cable of a million wires,

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through there to the back,
and the picture of Sarah's face

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is now projected on the back
of the brain, there.

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More mysterious still,
somewhere in here -

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and we don't know where,
it could be distributed all over -

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there is a conscious feeling,
a conscious image.

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That brain, is of course, my brain.

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It was done by a brilliant new technique
called Magnetic Resonance Imaging,

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which is a lovely way in which doctors
can now get right inside,

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look right inside somebody's body
without cutting them open,

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and without using harmful rays
like X-rays.

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And I went and had that done earlier
this year, for the purpose of this lecture.

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The brain could be called
the on-board computer of the body.

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The body moves around in a big,
complicated three-dimensional world.

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But the eyes that are feeding
the brain with information,
are giving it two-dimensional information.

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The two retinas of the eyes
are each seeing a two-dimensional
picture of the world.

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What's more, it's upside down.

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Somehow, the brain manages
to use that information

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to see in three dimensions.

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Now, would you just do something
very easy for me -

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and this can be done by people at home
as well watching on the television -

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just hold up your right hand, please,

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just hold up your right hand
in front of you,

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and look at me.
Don't look at your hand,
look at me.

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And what you'll see is two hands,
two of your hands.

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And these two hands, of course,
are the one that's being seen
by your left eye

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and the one that's being seen
by your right eye.
That's why there are two.

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But now, just focus your eyes
on your hand. Don't look at me
any more, look at your hand.

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Now you'll see two pictures of me,
and only one picture of your hand.

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Okay, that's enough.

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So what's happening here?

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You've still got two images
of your hand.

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There's still two images:
one on the left retina,
and one on the right retina.

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But somehow the brain has managed
to pull those two images together
and make them form a single, composite,

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three-dimensional image,
somewhere in the head.

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The brain has built
a single model of the hand,
or whatever it is, in your head.

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Whenever we think we see 'out there',
whenever we see what we call
reality out there,

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what we're actually seeing
is a representation in the head,

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a model in the head.
A simulation in the head.

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It's a very useful simulation

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because it's constantly being updated
by information coming in
from the sense organs.

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It's not just sitting there.

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The sense organs are pouring information in
but that information is not being seen raw,

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it's being used to update the model
that's sitting there in the head.

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The reality that we see, in other words,

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is constructed, in our skulls,
as virtual reality,

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to use the computer jargon.

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So now let's look at virtual
reality in a computer.

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Here we have a very powerful,
fast computer

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and inside that computer,
you're going to see in a moment,

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is a model of a world.
A microcosm. A small world.

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It's a house, with a corridor
and some rooms leading off it.

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And I'm going to ask somebody
to come down and experience what
it's like to walk through that world.

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Karen is going to come down
and help us.

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Stand there, on that spot there,

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and first of all I ought to
just explain that the headset here
has two little television screens,

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and the images of those two screens
are cunningly offset in the computer,

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so that what she will see
is just what she would see
if she were seeing in 3-D, in stereo.

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Now if you could put that on -

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Now we're beginning to see,
on the screen, what she can see.

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Now, Karen, could you please just
turn your head gently from side to side.

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Notice that when she does that,
the world appears to move.

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Now, if you were in this helmet,
as she is, this would
seem very natural to you,

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because as you turn your head,
the world appears to move
in just the right way.

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Move your head up and down as well,
and see - let's see what happens.

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If she moves her head up,
and moves her head down.

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Remember that she's seeing it
in stereo,

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we're only seeing
what one of her two eyes is seeing,
so we're seeing it in mono.

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So you have the idea that Karen,
although she's standing
in front of you there,

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she thinks that she's standing
in a corridor with a row of doors
on one side,

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and she thinks that she's going to be able
- indeed she is going to be able
- to walk down that corridor.

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She's not going to actually
move her feet very much,

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she's going to press buttons
on the little thing you see
her holding in her hand.

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This is a little controlling box,
and if she presses one button
she can go forward -

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can you go forward a bit?

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And if she presses another button
she can go backwards.

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Right.

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Now, have a little walk around, Karen,
and see what you find if you
go into one of those doors.

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Here she is,
walking along the corridor

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and she's going to turn

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I don't know which door
she's going into, that's her choice.

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She can go into any door she likes,
and she'll find something behind the door.

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She's going through the door -

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now, what's she got here?
This looks like fish.

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She's - she's swimming around,
in a roomful of fish,

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but I think I see a butterfly as well.

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Remember, this is not a real world,
this is a virtual world.

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Anything you like can be put
into this world.

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It's an imaginary world,
in the computer.

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Those fish are each programmed,
individually,

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to behave as autonomous entities.
As though there were real fish.

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Would you like to tell us
what you're doing now, Karen?

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Well, if I go out here, into space -

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Alright, she's backed out through
a wall I think! It's a game.

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and then turn round 180 degrees,
I can look onto it all.

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Right,

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go back into the room then,
into the room -

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To get out...

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That arrow that you see hanging
in front of her, in the virtual space,
is her hand.

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That represents her hand.

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Now if she waves her hand around
you can see the arrow moving,

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and soon she's going to approach the door
and touch it with the hand, with the arrow,

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it opens the door.

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And through we go into the corridor.

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Now where're you going to go Karen?

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Turning round, okay,
turning right round -

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And everywhere she looks
she sees something.
She can go wherever she likes -

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back along the corridor -

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Maybe into another room?

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Yes. Go and see
what's in that door there.

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Right, now what have we here?
This seems to be a chess set.

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Can you walk around
among the chess men?

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There's a pawn.
Can you pick that up?

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Mm hmm. Let's try again.

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Touch it with the hand.

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There it goes, she's lifting up
the pawn with her hand.

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Do you see her hand moving?
And then also the chess man
is moving.

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She's let go of it.

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Yeah...no No she hasn't.
If I can let go, there.

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It drops. Okay.

218
00:15:36,720 --> 00:15:40,090
Now what's that curious
sort of plank there?

219
00:15:41,020 --> 00:15:42,490
Go and see what's over there.

220
00:15:44,730 --> 00:15:46,400
She's - oh, she's going to
fall over an edge!

221
00:15:46,800 --> 00:15:48,360
There's another chessboard down there.

222
00:15:48,500 --> 00:15:49,260
She's falling!

223
00:15:51,000 --> 00:15:54,000
Right, she's on the lower chessboard,
there's another pawn.

224
00:15:56,610 --> 00:16:00,280
Go wherever you like, Karen -
do you want to fly about a bit?
Do you want to carry the pawn about?

225
00:16:01,510 --> 00:16:03,150
She's dropped it! Where's it going?

226
00:16:05,150 --> 00:16:07,620
It's disappearing, it's gone, right.

227
00:16:07,880 --> 00:16:08,950
Now where are you?

228
00:16:09,250 --> 00:16:12,020
Help! We're now underneath
the chess board! .

229
00:16:13,390 --> 00:16:17,160
We're right underneath the lower -
now we're up - we're going up the cliff,

230
00:16:17,290 --> 00:16:19,030
there's a castle - up the - whoops!

231
00:16:22,800 --> 00:16:24,730
Okay, well thank you
very much indeed, Karen.

232
00:16:39,720 --> 00:16:41,480
Well, what was really going on there?

233
00:16:41,650 --> 00:16:45,020
Was there really a chess man there?
Was there really a chess board?

234
00:16:45,590 --> 00:16:48,960
In a sort of sense there was.
There was a mathematical representation

235
00:16:49,090 --> 00:16:52,960
that is read out on the television
screens, as though it was

236
00:16:53,100 --> 00:16:54,760
a chess board,
as though it was chess men.

237
00:16:54,900 --> 00:16:56,830
And it behaved in a realistic way:

238
00:16:56,970 --> 00:16:59,400
you could pick things up,
throw them around,
you could go through doors,

239
00:16:59,540 --> 00:17:04,710
you could move around that world,
and if you threw chess men
down to the lower board,

240
00:17:04,840 --> 00:17:07,540
then they would stay there
until you went down
and picked them up again.

241
00:17:08,010 --> 00:17:10,610
So there was something that
corresponded to reality there,

242
00:17:10,780 --> 00:17:11,850
and what I'm trying to suggest to you

243
00:17:11,980 --> 00:17:17,520
is that just that same something
is going on inside your own skulls
at this very moment.

244
00:17:17,650 --> 00:17:21,060
There is a virtual reality
simulation of the world

245
00:17:21,220 --> 00:17:24,560
going on inside your heads,
and that's what you're seeing.

246
00:17:26,560 --> 00:17:30,800
But how do I know that?
How do I know that that's
what our brain is doing?

247
00:17:31,400 --> 00:17:35,500
Well one way we can get a clue
is by looking at illusions.

248
00:17:35,940 --> 00:17:38,140
Now here's a mask of Charlie Chaplin.

249
00:17:38,270 --> 00:17:40,110
It's perfectly ordinary,
nothing trickery about it,

250
00:17:40,280 --> 00:17:41,440
it's just an ordinary mask.

251
00:17:41,580 --> 00:17:46,520
And when you look at the front side,
it looks solid and normal,
as you'd expect.

252
00:17:47,280 --> 00:17:51,950
The odd thing that you'll see is
when you start looking at the
back side, at the hollow side,

253
00:17:52,090 --> 00:17:54,560
because although it is in fact hollow,
if you look at it,

254
00:17:54,720 --> 00:17:56,990
I think you'll agree
that it looks solid.

255
00:17:59,160 --> 00:18:03,800
And what's more, it not only looks solid
but it seems to be going around
in the wrong direction,

256
00:18:03,970 --> 00:18:08,670
so that when the real front side
comes round, it seems to sort of eat it up.

257
00:18:09,070 --> 00:18:12,270
There's the real front side -
now that really is solid -

258
00:18:12,570 --> 00:18:17,950
and when the other side comes round,
that is going to look solid as well.
Even though it isn't.

259
00:18:18,480 --> 00:18:19,820
Well what's going on here?

260
00:18:21,920 --> 00:18:27,060
When the brain sees anything
that looks like two eyes,
a nose and a mouth,

261
00:18:27,290 --> 00:18:31,160
it immediately sets up inside
the head a model of a face.

262
00:18:31,290 --> 00:18:33,900
It's desperately eager to see a face.

263
00:18:34,330 --> 00:18:37,270
It will see a face if there's the
slightest excuse to do so,

264
00:18:37,430 --> 00:18:40,900
and the back side of this mask
is the slightest excuse.

265
00:18:41,040 --> 00:18:44,140
There is two eyes, a nose
and a mouth, and that makes the brain

266
00:18:44,270 --> 00:18:48,510
get out, dust off, its model
of a three-dimensional face.

267
00:18:49,810 --> 00:18:53,780
Now if you think about what
would happen to the images
on the two retinas,

268
00:18:54,320 --> 00:18:57,150
if the image really was solid,

269
00:18:57,420 --> 00:18:58,820
if the thing really was solid,

270
00:18:59,220 --> 00:19:02,090
the actual movements on the retinas

271
00:19:02,220 --> 00:19:07,230
is compatible with the idea of a solid face
moving in the opposite direction.

272
00:19:07,830 --> 00:19:14,970
And so the brain eagerly seizes upon that,
and it makes the solid face rotate
in the wrong direction.

273
00:19:15,800 --> 00:19:21,880
Now, for the next demonstration
we need a volunteer to be taken off and...

274
00:19:22,010 --> 00:19:23,280
yes...thank you...

275
00:19:24,780 --> 00:19:27,950
Bryson is going to take you off
and you'll come back in a moment.

276
00:19:30,750 --> 00:19:35,490
Now here we have
an impossible triangle.

277
00:19:37,590 --> 00:19:42,870
We look first at this corner
and it's telling us that there
is a wooden triangle,

278
00:19:43,030 --> 00:19:44,600
which is facing in that direction.

279
00:19:44,730 --> 00:19:46,770
Now if we go up here we see this corner
and we're told by our eyes

280
00:19:47,270 --> 00:19:51,170
that there's a triangle facing
in that direction,

281
00:19:51,310 --> 00:19:53,940
and now we're told there's a triangle
facing in a third direction.

282
00:19:54,210 --> 00:19:56,980
Those three angles
don't match up together.

283
00:19:57,210 --> 00:20:00,250
They can't mix together
And yet the brain sees it,

284
00:20:00,750 --> 00:20:07,160
constructs in the brain a model
of an impossible figure,
an impossible triangle.

285
00:20:08,020 --> 00:20:10,260
And I imagine all of you
can see that.

286
00:20:11,030 --> 00:20:14,960
Now we're going to shatter
the illusion, rudely.

287
00:20:16,730 --> 00:20:17,570
What's happened?

288
00:20:20,240 --> 00:20:21,040
Out again?

289
00:20:23,010 --> 00:20:23,940
The triangle's reformed.

290
00:20:24,070 --> 00:20:24,910
In again?

291
00:20:27,010 --> 00:20:27,940
Out again -

292
00:20:30,950 --> 00:20:36,720
thank you very much. Would you like
to bring in the object now
and we can see what it really is?

293
00:20:41,060 --> 00:20:42,660
Thank you, I'm sorry
I didn't get your name.

294
00:20:42,790 --> 00:20:43,460
Sarah.

295
00:20:44,190 --> 00:20:47,360
You can stay there
for a moment, Sarah.

296
00:20:47,530 --> 00:20:49,630
You see, there's nothing special
about it at all.

297
00:20:49,770 --> 00:20:52,530
It's just three bits of wood,
glued in opposite directions, like that.

298
00:20:52,800 --> 00:20:58,970
I'm going to move it round
and try to recreate the illusion.

299
00:20:59,470 --> 00:21:01,380
I haven't done it terribly well

300
00:21:01,510 --> 00:21:07,380
but there it is, and now I think
if I put my face in, you can
again see it happening, like that.

301
00:21:07,520 --> 00:21:08,680
Okay, thank you very much, Sarah.

302
00:21:16,690 --> 00:21:19,130
Now here's one of the great
classic illusions,

303
00:21:19,260 --> 00:21:21,830
which is the best one I have to
make the point I'm trying to make.

304
00:21:21,960 --> 00:21:26,770
This is called the Necker cube.
And it's just a picture
of a cube, drawn on paper.

305
00:21:27,970 --> 00:21:30,540
If you look at it, I think you'll see it
doing a rather strange thing:

306
00:21:30,710 --> 00:21:32,140
it'll be alternating

307
00:21:32,270 --> 00:21:34,310
the side that seems to be nearer
to you, will change.

308
00:21:34,480 --> 00:21:37,510
Sometimes it'll be one side,
sometimes it'll be another.

309
00:21:39,850 --> 00:21:41,180
What's going on here?

310
00:21:41,550 --> 00:21:45,420
The two-dimensional pattern
of ink on the paper

311
00:21:45,920 --> 00:21:51,530
is equally compatible with two
alternative three-dimensional cubes.

312
00:21:52,030 --> 00:21:55,130
So the brain doesn't know which
of its three-dimensional cubes to use.

313
00:21:55,260 --> 00:22:00,040
It's got two potential models of
three-dimensional cubes in there,
waiting to be used,

314
00:22:00,170 --> 00:22:03,670
and it doesn't know which one
to use because both of them
are equally compatible

315
00:22:03,810 --> 00:22:06,380
with the two-dimensional pattern
of ink on the paper.

316
00:22:06,510 --> 00:22:07,210
So what does it do?

317
00:22:07,340 --> 00:22:09,550
Well it could plump
for one or other of them
but it doesn't do that,

318
00:22:09,680 --> 00:22:10,780
what it does is alternate.

319
00:22:11,150 --> 00:22:13,450
And so you sometimes see one,
and you sometimes see the other.

320
00:22:13,680 --> 00:22:16,120
Now this is a more elaborate
version of the same thing,

321
00:22:16,250 --> 00:22:20,390
because this is a real cube -
as you can see, made of metal -
and it's rotating.

322
00:22:20,660 --> 00:22:24,860
But once again,
if you get the lighting right,
it is sufficiently -

323
00:22:25,030 --> 00:22:27,060
perhaps it's best if you look
at it on the screen here -

324
00:22:28,030 --> 00:22:30,970
the two-dimensional pattern
that's moving round your retina

325
00:22:31,200 --> 00:22:34,300
is equally compatible with two
different three-dimensional cubes.

326
00:22:34,470 --> 00:22:37,040
And so, if you look at it and perhaps
blink, look away and come back again,

327
00:22:37,170 --> 00:22:38,840
you may see it change direction.

328
00:22:39,270 --> 00:22:44,780
And what's happening
is that the brain doesn't know
which of two models to use,

329
00:22:44,950 --> 00:22:46,650
and so it chooses them alternately.

330
00:22:48,650 --> 00:22:52,150
But we don't have to go to the lengths
of setting up illusions

331
00:22:52,290 --> 00:22:57,160
with apparatus to satisfy ourselves
that the brain does set up
a virtual reality model.

332
00:22:57,530 --> 00:23:01,800
Here's something we can all do
without any apparatus at all,
again including people at home.

333
00:23:01,930 --> 00:23:05,000
So this is something to do
to yourself, you won't see anything
on the television screen

334
00:23:05,170 --> 00:23:07,270
if you're at home,
you'll just do it to - to yourself.

335
00:23:07,540 --> 00:23:12,010
Just very gently, with your finger,
move your own eyeball.

336
00:23:13,340 --> 00:23:16,250
Just poke it up where I'm doing it -
do you see where I'm doing it?

337
00:23:16,510 --> 00:23:21,320
And I think what you'll see
is that the world moves
as you do it, doesn't it?

338
00:23:21,550 --> 00:23:23,820
It's like a little minor earthquake
when you do that.

339
00:23:24,590 --> 00:23:27,260
Well of course, that's exactly
what you'd expect, isn't it?

340
00:23:27,490 --> 00:23:31,830
Because the image on your
retina is being moved,
the eyeball is being moved,

341
00:23:32,060 --> 00:23:36,370
and so the apparent position of the
object you're looking at is moving,

342
00:23:36,530 --> 00:23:37,830
so you see it as movement.

343
00:23:38,100 --> 00:23:41,500
What's so strange about that?
Nothing's strange about that,
that's just what you'd expect.

344
00:23:43,040 --> 00:23:44,740
But now let's think a bit further,

345
00:23:45,070 --> 00:23:49,410
because doesn't something
very similar happen whenever
you roll your eyes about?

346
00:23:49,780 --> 00:23:53,750
If I roll my eyes like - do it now,
just roll your eyes,
move your head about, roll your eyes.

347
00:23:54,250 --> 00:23:57,690
The image on your retina
is going crazy.

348
00:23:58,050 --> 00:24:03,190
Much worse, in fact,
than when you simply poke
your eyeball with your finger.

349
00:24:03,760 --> 00:24:07,330
The image on the retina is moving
but what are you actually seeing?

350
00:24:07,830 --> 00:24:10,200
You're not seeing the world
moving like an earthquake.

351
00:24:10,630 --> 00:24:14,670
When you roll your eyes about,
the world appears to be as steady as a rock.

352
00:24:16,240 --> 00:24:20,610
So on the one hand, when you poke
your eye, the world appears to move
as though there's an earthquake,

353
00:24:20,740 --> 00:24:24,780
on the other hand, when you voluntarily
wiggle your eyes about like that,

354
00:24:25,280 --> 00:24:31,750
although the same thing's happening
on the retina, what you see
is a perfectly steady world.

355
00:24:33,220 --> 00:24:36,160
Why is that? What's the difference
between those two cases?

356
00:24:37,390 --> 00:24:39,290
Well, it's this.

357
00:24:39,800 --> 00:24:43,800
There might really be
an earthquake going on and
it's important for the brain to know

358
00:24:44,230 --> 00:24:47,570
On the other hand, it's also important
that the brain should not constantly

359
00:24:47,700 --> 00:24:49,910
think there's an earthquake
whenever you move your eyes about.

360
00:24:50,540 --> 00:24:55,180
So what the brain does when it
sends an order to the eye muscles

361
00:24:55,310 --> 00:24:59,010
to move the eye, to roll the eye,
which it often does,

362
00:24:59,280 --> 00:25:04,520
it sends a copy of that order
to the virtual reality software

363
00:25:04,650 --> 00:25:08,020
that's engaged, that's busy
setting up the model of the world.

364
00:25:08,490 --> 00:25:10,460
And the virtual reality software
is told,

365
00:25:10,590 --> 00:25:13,760
"Okay, the eye's about to move -
expect the world to move."

366
00:25:14,430 --> 00:25:18,500
And so, the virtual reality software
does not see an earthquake,

367
00:25:18,630 --> 00:25:20,300
because it's been told to expect it.

368
00:25:20,470 --> 00:25:27,010
The model in the head
is precisely compensating
for the anticipated movement.

369
00:25:27,710 --> 00:25:29,210
But when you poke your eye,

370
00:25:29,610 --> 00:25:34,120
no copy of any order is ever received.
And so the world really
does appear to move

371
00:25:34,250 --> 00:25:37,620
as if there was an earthquake.
And indeed there might be an earthquake
and it would be important

372
00:25:37,750 --> 00:25:41,960
for the brain to know that and
not just to immediately discount it.

373
00:25:42,690 --> 00:25:46,930
Now a very clever experiment on this
was once done by a German scientist,

374
00:25:47,160 --> 00:25:51,400
who put his own eye muscles out
of action with an anesthetic.

375
00:25:51,800 --> 00:25:56,940
Now, I was going to call for a volunteer
for this experiment

376
00:25:57,070 --> 00:26:00,140
ah, we have a volunteer but I think,
unfortunately, there isn't any time,

377
00:26:00,280 --> 00:26:03,650
so I'll just have to tell you
what happened.

378
00:26:04,410 --> 00:26:08,550
What this German did was
he anesthetized his own eye muscles.

379
00:26:09,920 --> 00:26:11,250
Now think what would happen?

380
00:26:12,090 --> 00:26:16,990
Whenever he told his eyes to move,
they didn't. Nothing happened.

381
00:26:17,230 --> 00:26:23,270
They stayed absolutely stock-still.
And, the image on the retina
stayed absolutely stock-still as well.

382
00:26:24,100 --> 00:26:30,140
But the copy of the order
had gone out to the virtual
reality software in the brain,

383
00:26:30,470 --> 00:26:34,280
and the virtual reality program
was told to expect a movement.

384
00:26:35,210 --> 00:26:40,050
So when no movement came,
it interpreted it
as if was an earthquake.

385
00:26:41,020 --> 00:26:44,690
So whenever this German told
his eyes to move, whenever he

386
00:26:44,920 --> 00:26:47,990
gave out the order for his eye
muscles to pull the eyes around,

387
00:26:48,260 --> 00:26:50,230
the eyeballs stayed absolutely still,

388
00:26:50,530 --> 00:26:52,790
the image on the retinas
stayed absolutely still,

389
00:26:53,060 --> 00:26:56,900
but the model in the brain moved,
and he saw an earthquake.

390
00:27:01,200 --> 00:27:07,410
So that's my evidence that the brain
is setting up a model of the world.

391
00:27:07,980 --> 00:27:09,680
We're seeing virtual reality.

392
00:27:10,710 --> 00:27:15,880
I now want to switch temporarily
from that topic,
and talk about the evolution,

393
00:27:16,020 --> 00:27:18,390
the growing up,
of the human brain itself.

394
00:27:20,020 --> 00:27:24,530
By evolutionary standards,
the brain seems to have grown up
very, very fast indeed.

395
00:27:24,860 --> 00:27:28,830
One authority has said that
the evolution of the human brain

396
00:27:29,030 --> 00:27:33,570
over the last million years or so,
is perhaps the fastest advance recorded

397
00:27:33,740 --> 00:27:36,770
for any complex organ
in the entire history of life.

398
00:27:37,840 --> 00:27:40,780
And compared with the skulls
of other apes like chimpanzees,

399
00:27:40,910 --> 00:27:43,750
our brain is indeed -
our skull is indeed very big.

400
00:27:43,880 --> 00:27:46,580
It seems to have blown up
like a balloon.

401
00:27:46,950 --> 00:27:49,890
And here's an animation of that.

402
00:27:50,020 --> 00:27:54,890
This is the head of Australopithecus,
which is one of our ancestors,

403
00:27:55,020 --> 00:27:58,360
and now you can see the evolution
gradually happening before your eyes,

404
00:27:58,530 --> 00:28:03,300
it's becoming a Homo erectus,
it's an early Homo sapiens,

405
00:28:03,470 --> 00:28:06,700
it's changing now to becoming
a modern Homo sapiens like us.

406
00:28:06,840 --> 00:28:11,840
Look how the skull is ballooning out,
the head is ballooning out,
as evolution goes by.

407
00:28:11,970 --> 00:28:15,510
We've compressed about three million
years of evolution into that animation.

408
00:28:15,780 --> 00:28:19,010
Now here's the same thing
from the side view of the skulls.

409
00:28:19,250 --> 00:28:23,090
Here's Australopithecus again,
look, quite a low head -
now it's growing bigger,

410
00:28:23,220 --> 00:28:24,320
the jaw's coming in,

411
00:28:24,590 --> 00:28:29,630
evolution's going by, millions
of years going by, and the skull
is blowing up like a balloon,

412
00:28:29,760 --> 00:28:32,160
blowing up, blowing up.
There it is.
There's a modern skull,

413
00:28:32,290 --> 00:28:35,230
there's a modern human skull.
Chock-full of brains.

414
00:28:38,970 --> 00:28:42,440
One way of understanding
what's happening there,

415
00:28:42,570 --> 00:28:44,310
is to look at computers again

416
00:28:44,440 --> 00:28:49,780
because something similar -
very fast evolution - seems
to have happened with the computer.

417
00:28:50,080 --> 00:28:56,250
And here's a dramatic quotation
to illustrate that,
from a psychologist, Christopher Evans.

418
00:28:57,420 --> 00:28:58,890
Here's what he said:

419
00:28:59,020 --> 00:29:03,890
"Today's car differs from those
of the immediate postwar years
on a number of counts.

420
00:29:04,160 --> 00:29:09,500
It is cheaper, allowing
for the ravages of inflation,
and it's more economical and efficient.

421
00:29:10,000 --> 00:29:13,270
All this can be put down to advances
in automobile engineering,

422
00:29:13,400 --> 00:29:16,210
more efficient methods of production,
and a wider market.

423
00:29:17,010 --> 00:29:21,110
But, suppose for a moment that
the automobile industry had developed

424
00:29:21,240 --> 00:29:24,750
at the same rate as computers,
and over the same period.

425
00:29:24,980 --> 00:29:28,550
How much cheaper and more efficient
would the current models be?

426
00:29:29,250 --> 00:29:32,720
If you have not already heard
the analogy, the answer is shattering.

427
00:29:33,460 --> 00:29:37,960
Today, you would be able to
buy a Rolls Royce for ¡ê1.35,

428
00:29:38,560 --> 00:29:40,660
it would do 3 million miles
to the gallon,

429
00:29:41,460 --> 00:29:44,900
and it would deliver enough power
to drive the Queen Elizabeth II.

430
00:29:45,670 --> 00:29:51,240
And if you were interested
in miniaturization, you could place
half a dozen of them on a pinhead."

431
00:29:52,770 --> 00:29:56,010
So if the human brain has blown up
like a balloon,

432
00:29:56,150 --> 00:29:58,980
it looks as though the computer
has advanced even more spectacularly.

433
00:29:59,520 --> 00:30:02,850
Although of course it's rather unfair
to compare the timescales directly,

434
00:30:03,150 --> 00:30:06,020
because the evolutionary timescale
is limited by the fact

435
00:30:06,160 --> 00:30:09,530
that in order for evolution
to happen, people have got to die.

436
00:30:09,890 --> 00:30:12,760
Generation after generation.
And other people have got to reproduce.

437
00:30:12,900 --> 00:30:16,400
It necessarily takes a lot longer
than technology,

438
00:30:16,530 --> 00:30:18,530
which happens -
which can advance all the time.

439
00:30:21,270 --> 00:30:25,740
Nobody knows for certain what it was that
caused the ballooning of the human brain.

440
00:30:25,910 --> 00:30:29,950
There're lots of theories
but as I said, perhaps we can
get a clue from computers.

441
00:30:30,080 --> 00:30:34,450
If we look at what it is
that's made them develop so fast,
improve so fast,

442
00:30:34,580 --> 00:30:37,450
it might help us to guess
why our brains have, too.

443
00:30:38,020 --> 00:30:40,460
Well there are lots of differences
between computers and brains,

444
00:30:40,590 --> 00:30:43,190
lots of things won't help us,
it's no good looking at, for example,

445
00:30:43,330 --> 00:30:46,400
the improvement from valves
to transistors to integrated circuits,

446
00:30:46,530 --> 00:30:48,760
because brains don't work
like that anyway.

447
00:30:49,530 --> 00:30:51,970
But there is one source
of computer advancement,

448
00:30:52,400 --> 00:30:54,870
one thing that's been going on
in the development of the computer,

449
00:30:55,000 --> 00:30:59,510
which just might give us a clue
about what happened with the brain.

450
00:31:00,010 --> 00:31:02,540
I'm going to give it a long name,
and you'll see what it means later.

451
00:31:02,710 --> 00:31:06,480
I'm going to call it
self-feeding co-evolution.

452
00:31:07,750 --> 00:31:10,990
Co-evolution just means
evolving together.

453
00:31:12,090 --> 00:31:16,330
Self-feeding is the name
I'm going to give to any process

454
00:31:16,490 --> 00:31:19,600
in which the more you have,
the more you get.

455
00:31:20,760 --> 00:31:22,730
Think about the arms race,
for instance.

456
00:31:24,000 --> 00:31:28,040
As the missiles on one side
in the arms race get bigger
and better and faster,

457
00:31:28,540 --> 00:31:33,380
so the interceptor devices
on the other side, the radars
and counter missiles,

458
00:31:33,510 --> 00:31:36,280
have to get better and faster
and more accurate as well.

459
00:31:36,410 --> 00:31:40,480
And when they've got better,
then the missiles on the first side
have to get better still.

460
00:31:40,750 --> 00:31:43,520
And so the radars and interceptors
have to get better still.

461
00:31:43,820 --> 00:31:47,020
And the process escalates,
indefinitely, like that.

462
00:31:47,920 --> 00:31:49,420
I call it "self-feeding"

463
00:31:49,830 --> 00:31:53,300
because there is a sense in which
improvements in the original radars

464
00:31:53,530 --> 00:31:57,300
directly necessitate later improvements
in the same radar,

465
00:31:57,530 --> 00:32:04,140
even though it's going
via the loop of making the radars
on the other side get better,

466
00:32:04,270 --> 00:32:07,240
so the more you have,
the more you need, the more you get.

467
00:32:07,780 --> 00:32:10,010
Arms races happen in evolution,
as well.

468
00:32:10,380 --> 00:32:16,450
Here's a peregrine falcon
which is flying along, a beautiful
piece of flying machinery,

469
00:32:16,850 --> 00:32:22,660
and soon it's going to see some prey
which it's going to dive to attack.

470
00:32:22,790 --> 00:32:24,390
Here it is: the wings go in,

471
00:32:24,790 --> 00:32:29,570
it screams down at nearly
100 miles an hour on its prey,

472
00:32:30,300 --> 00:32:34,770
which in this case happens to be
a duck, also flying very, very fast.

473
00:32:35,270 --> 00:32:37,140
The duck's flying fast -
there it comes.

474
00:32:42,140 --> 00:32:45,310
Both the duck and the hawk
are end products

475
00:32:45,480 --> 00:32:48,320
of a long evolutionary arms race.

476
00:32:49,350 --> 00:32:51,320
Both of them are extremely
good at flying,

477
00:32:52,220 --> 00:32:54,420
and the reason is
that the other one is.

478
00:32:55,720 --> 00:33:01,130
In their ancestry, improvements
on one side necessitated
improvements on the other.

479
00:33:01,260 --> 00:33:04,070
As hawks got better ducks
had to get better,

480
00:33:04,400 --> 00:33:07,000
and as ducks got better
hawks had to get better.

481
00:33:07,300 --> 00:33:10,270
So, indirectly, it was
the improvements in the hawks

482
00:33:10,410 --> 00:33:13,510
that made their descendants
have to get even better later.

483
00:33:13,780 --> 00:33:17,850
And improvements in the ducks
made their descendants
have to get even better later.

484
00:33:18,010 --> 00:33:20,020
That's why I call it "self-feeding."

485
00:33:21,450 --> 00:33:22,620
Now what this is all leading up to

486
00:33:22,750 --> 00:33:26,020
is that something like that
self-feeding co-evolution

487
00:33:26,190 --> 00:33:31,090
may have gone on
in the development of computers
and, more importantly, brains.

488
00:33:33,030 --> 00:33:37,670
In computers, both hardware
and software co-evolve.

489
00:33:37,800 --> 00:33:42,170
"Hardware" means the physical bits,
like this. Things you can touch and feel.

490
00:33:42,300 --> 00:33:46,410
"Software" means programs, and
improvements in both are important.

491
00:33:47,310 --> 00:33:51,480
Here's a very simple piece
of hardware: the mouse.

492
00:33:51,850 --> 00:33:55,820
It's just a ball and socket,
a ball there in a socket,

493
00:33:56,190 --> 00:34:03,730
and as you move it around
you see a little pointer
moving around on the screen,

494
00:34:04,530 --> 00:34:06,830
and this gives you a very,
very powerful illusion.

495
00:34:06,960 --> 00:34:11,930
You almost feel as though
your hand is in there,
moving things around the screen.

496
00:34:12,070 --> 00:34:13,800
It's a natural thing to do.

497
00:34:14,900 --> 00:34:20,940
In the bad old days of computing,
if you wanted to do something
like throw away a file,

498
00:34:21,240 --> 00:34:24,950
then you had to go to the keyboard
and you had to type
some ridiculous rigmarole

499
00:34:25,180 --> 00:34:29,150
like: delete mydir: baslib: codsw.tx
all sorts of stuff like that

500
00:34:29,280 --> 00:34:31,990
If you made a mistake
you had to correct it,
and you usually did make a mistake,

501
00:34:32,220 --> 00:34:34,760
you nearly always forgot
what the command was anyway.

502
00:34:35,360 --> 00:34:40,630
Nowadays, all you have to do,
if you want a throwaway comment,

503
00:34:41,060 --> 00:34:46,170
is just pick it up move it
to the wastepaper basket
and let go.

504
00:34:47,040 --> 00:34:51,110
Now we have to empty
the wastepaper basket,
which you see has bulged,

505
00:34:53,480 --> 00:34:57,710
and agree to let it go,
and it goes.

506
00:34:59,850 --> 00:35:01,820
That's just a trivial example.

507
00:35:01,950 --> 00:35:02,950
What's much more important

508
00:35:03,120 --> 00:35:07,790
is that the modern computer world
is entirely dominated by using a mouse

509
00:35:07,920 --> 00:35:11,560
or using some kind of pointing device
to quickly move things around,

510
00:35:11,690 --> 00:35:13,160
do things very, very naturally,

511
00:35:13,330 --> 00:35:19,000
as though you were moving bits
of paper around on your desktop.

512
00:35:19,640 --> 00:35:23,080
Pick things up, move them around,
make them appear,

513
00:35:23,440 --> 00:35:28,380
make menus appear,
and so on, like that.

514
00:35:29,410 --> 00:35:30,850
It's all now very easy,

515
00:35:30,980 --> 00:35:36,120
where once upon a time
you'd have had to remember
difficult rigmaroles to type.

516
00:35:36,850 --> 00:35:38,990
Now, the reason for bringing this up

517
00:35:39,490 --> 00:35:44,430
is that it was all triggered
by an original, very simple,
hardware device.

518
00:35:44,860 --> 00:35:47,630
That in itself is trivial,
there's nothing much to it,
it's very easy,

519
00:35:47,860 --> 00:35:51,930
but what it spawned was a whole
new generation of software

520
00:35:52,070 --> 00:35:55,540
and software building upon other software,
building upon other software,

521
00:35:55,670 --> 00:36:01,440
and so you build up a complete edifice
of mutually working co-evolving software.

522
00:36:03,580 --> 00:36:08,780
Another example of computers
getting into a self-feeding spiral

523
00:36:09,380 --> 00:36:14,190
is the way computers themselves
are designed.

524
00:36:15,320 --> 00:36:17,760
Modern computers are far too complicated

525
00:36:17,930 --> 00:36:21,100
to be designed in detail by humans.

526
00:36:21,730 --> 00:36:29,970
This chart here is one-eighth of
the circuit diagram of this chip here.

527
00:36:31,910 --> 00:36:33,780
So that is one computer chip,

528
00:36:35,080 --> 00:36:41,120
and the circuit diagram for
that computer chip is eight times
as big as what you see here.

529
00:36:41,380 --> 00:36:44,190
Now let's just walk around
this a little bit.

530
00:36:44,320 --> 00:36:48,290
Each of these red marks here
is one wire.

531
00:36:49,220 --> 00:36:52,790
Following them up round here,
let's follow these main trunks round here.

532
00:36:56,170 --> 00:37:01,940
let your eye roam over this
remarkable document, and realize

533
00:37:02,070 --> 00:37:06,040
that no human could really
sit down and design that.

534
00:37:06,410 --> 00:37:10,850
A human has the basic ideas,
a human programs the computer to do it,

535
00:37:11,180 --> 00:37:14,280
but modern computers
are very largely designed

536
00:37:14,420 --> 00:37:17,320
by the previous generation
of computers.

537
00:37:18,050 --> 00:37:24,260
Modern computers are piggy-backing
on the back of an earlier
generation of computers

538
00:37:24,390 --> 00:37:28,300
Once again we have an example
of a self-feeding spiral.

539
00:37:28,530 --> 00:37:33,670
Early advances lead into later
advances, and they go into a spiral.

540
00:37:35,040 --> 00:37:39,210
Well, we've seen self-feeding
co-evolution in the computer
and the purpose of that,

541
00:37:39,340 --> 00:37:42,410
of course, was to develop
an analogy with the human brain.

542
00:37:44,150 --> 00:37:47,820
Can we see there's something
like the same thing going on
in the human brain?

543
00:37:48,250 --> 00:37:52,890
Unfortunately, unlike computers
we can't look directly at the intermediates.

544
00:37:53,190 --> 00:37:59,090
All that we have by way of evidence
is skulls, and to a limited extent, skills.

545
00:37:59,430 --> 00:38:06,440
We have the outer casings,
and by way of software,
we have the products

546
00:38:06,570 --> 00:38:12,710
which are things like flint
arrowheads produced by our ancestors,

547
00:38:12,840 --> 00:38:18,380
and we have pictures like these
two bison here, a cave painting.

548
00:38:18,710 --> 00:38:21,450
This is a relic of the product
of an early human brain,

549
00:38:21,620 --> 00:38:31,460
and much later, of course,
we have writings like this cuneiform
tablet or like this book.

550
00:38:36,200 --> 00:38:39,670
But what happened to make
the human brain take off?

551
00:38:41,900 --> 00:38:47,240
What was the equivalent of the mouse,
the thing that made our species leap
forward in the way that it did?

552
00:38:48,010 --> 00:38:50,580
Well, it has to be largely guesswork.

553
00:38:51,780 --> 00:38:58,150
About 3 million years ago,
when our ancestor Australopithecus
roamed about Africa,

554
00:38:58,890 --> 00:39:02,090
his brain was no bigger
than that of a chimpanzee.

555
00:39:02,220 --> 00:39:04,760
This again is Australopithecus.

556
00:39:05,360 --> 00:39:09,000
And if this ancestor of ours
had met a chimpanzee,

557
00:39:09,100 --> 00:39:13,000
they would have been
on roughly equal terms
as far as brains are concerned.

558
00:39:14,870 --> 00:39:18,070
Either of those species,
any ape species at that time,

559
00:39:18,240 --> 00:39:20,580
could have been the one
that took off.

560
00:39:21,210 --> 00:39:24,010
But the whole point of talking
about self-feeding spirals

561
00:39:24,150 --> 00:39:27,020
is that to begin with there won't
be anything very dramatic.

562
00:39:27,150 --> 00:39:31,690
One of those species made some kind
of minor breakthrough in software,

563
00:39:32,020 --> 00:39:34,320
some software advancement,
I'm suggesting.

564
00:39:35,520 --> 00:39:39,390
The result of that wasn't seen
till much later. You wouldn't
have seen anything for a while,

565
00:39:39,560 --> 00:39:45,430
it would've gone into a spiral,
and eventually reached the heights
that we have now reached.

566
00:39:47,770 --> 00:39:52,540
But I still haven't said
what the software innovation
was that sparked it all off.

567
00:39:52,670 --> 00:39:55,210
We don't know
and we can only guess.

568
00:39:55,810 --> 00:40:00,280
One possibility is an improvement
in our ability to simulate
models of the world.

569
00:40:00,420 --> 00:40:05,650
We've seen that our brains
make a model of what's actually
going on in the real world,

570
00:40:06,120 --> 00:40:11,660
but we also know that
they can make models of what
might be going on in the world.

571
00:40:12,730 --> 00:40:21,340
Our ancestor Homo erectus
lived a million years ago,

572
00:40:21,470 --> 00:40:27,210
and let's imagine that
a particular female Homo erectus
was trying to solve the problem

573
00:40:27,340 --> 00:40:31,350
how to get her family
across a gorge like that.

574
00:40:31,480 --> 00:40:33,020
Nobody had ever built a bridge before.

575
00:40:33,180 --> 00:40:34,780
Bridge technology wasn't around,

576
00:40:34,950 --> 00:40:40,290
but she suddenly saw in her mind's eye
a tree fallen across the gorge,

577
00:40:40,760 --> 00:40:43,930
and she realized that
it could function as a bridge.

578
00:40:44,460 --> 00:40:47,430
She also thought,
"How can I get that to happen?"
and she's imagined,

579
00:40:47,600 --> 00:40:51,230
she saw in her imagination,
a fire at the base of the tree.

580
00:40:51,370 --> 00:40:56,100
She had the idea of burning the tree down
to make it fall and make a bridge.

581
00:40:56,240 --> 00:40:58,140
Now this of course
is entirely speculation.

582
00:40:58,270 --> 00:41:00,980
We don't know if that ever happened,
we don't even know if it would have worked.

583
00:41:01,110 --> 00:41:02,480
The point I'm making

584
00:41:02,610 --> 00:41:07,520
is that she had a model
in her head of a tree
fallen across a gorge with fire

585
00:41:07,650 --> 00:41:09,590
and that something
hadn't yet happened.

586
00:41:09,750 --> 00:41:13,590
She was anticipating something
that might happen in the future,

587
00:41:13,760 --> 00:41:17,330
and if you can do that you've got
a trick that's really worth having,

588
00:41:17,460 --> 00:41:21,260
because you can solve problems
that other animals can't solve.

589
00:41:23,270 --> 00:41:24,270
So that's one possibility.

590
00:41:24,400 --> 00:41:27,670
Imaginative simulation may
have been the software trick

591
00:41:27,800 --> 00:41:29,440
that took our species off.

592
00:41:30,640 --> 00:41:33,210
Another possibility is language.
It's often been suggested,

593
00:41:33,340 --> 00:41:38,250
it's an obvious suggestion,
because language seems tailor-made
to get a piggy-back spiral going.

594
00:41:38,380 --> 00:41:42,050
If you've got language,
then each generation can
learn from its predecessors,

595
00:41:42,380 --> 00:41:45,050
learn from the previous generation,
learn from their mistakes,

596
00:41:45,220 --> 00:41:48,660
build on their experience.
So maybe it was language.

597
00:41:49,120 --> 00:41:50,330
Unfortunately, there's a snag.

598
00:41:50,460 --> 00:41:55,530
There's some evidence
that language, in the form of speech
at least, proper speaking,

599
00:41:55,700 --> 00:42:00,970
didn't arise until after
the ballooning of the brain.

600
00:42:01,400 --> 00:42:03,540
But perhaps we can get out of that
by suggesting that

601
00:42:03,670 --> 00:42:07,810
language had an early apprenticeship
in the form of a kind of sign language,

602
00:42:08,040 --> 00:42:14,920
or drawing in the sand,
or perhaps language arose
before actual speech arose,

603
00:42:15,050 --> 00:42:16,790
as a sort of way of
talking to yourself

604
00:42:16,920 --> 00:42:18,590
to get your thoughts
into a logical order,

605
00:42:18,720 --> 00:42:20,890
to plan your actions
in a logical order,

606
00:42:21,060 --> 00:42:25,160
and only later perhaps, did it become
externalized in the form of speech

607
00:42:25,290 --> 00:42:31,630
using the tongue, lips,
and voice so that brains became,
as it were, networked together.

608
00:42:33,800 --> 00:42:38,140
We can also think of technology,
tools, say, like these tools here,

609
00:42:38,270 --> 00:42:40,840
as external devices used by brains

610
00:42:40,980 --> 00:42:43,580
for extending the power
of the hands,

611
00:42:43,710 --> 00:42:51,820
or other devices like telescopes
and microscopes as devices
for extending the power of the eye.

612
00:42:52,820 --> 00:42:58,590
Maybe it was technology
that provided the breakthrough
for humans to take off.

613
00:43:00,200 --> 00:43:06,640
So we've identified imagination,
language, and technology
as three possible candidates

614
00:43:06,770 --> 00:43:08,370
for our trigger innovation,

615
00:43:08,500 --> 00:43:10,170
and perhaps all three played a role.

616
00:43:10,310 --> 00:43:14,810
Perhaps they reinforced each other
in a three-way spiraling explosion.

617
00:43:16,040 --> 00:43:21,150
But each of those three mental tools:
imagination, language, and technology,

618
00:43:21,280 --> 00:43:22,580
is double edged.

619
00:43:23,250 --> 00:43:27,220
If we use them right,
we can perhaps end up
making a model of the universe,

620
00:43:27,590 --> 00:43:29,960
but the double edge
is always there.

621
00:43:30,860 --> 00:43:35,630
Take imagination and the brilliant
simulating software that we saw earlier.

622
00:43:36,370 --> 00:43:41,440
It can be immensely useful
but it can also have
unfortunate consequences.

623
00:43:41,570 --> 00:43:46,180
A brain that's good at
simulating models in imagination,
things that aren't there,

624
00:43:46,840 --> 00:43:52,380
is unfortunately also almost inevitably
in danger of self-delusion.

625
00:43:53,180 --> 00:43:57,190
How many of us have lain in bed, terrified
because we thought we saw a ghost

626
00:43:57,320 --> 00:44:00,660
or a monstrous face
staring in the bedroom window,

627
00:44:00,790 --> 00:44:05,260
only to discover eventually that
it was just a trick of the light,
the moonlight playing on the curtains?

628
00:44:05,390 --> 00:44:09,830
We've seen from Charlie Chaplin
how easy it is, how eager the brain is,

629
00:44:09,970 --> 00:44:14,640
to make a face even when there's
only a hollow back to a mask.

630
00:44:15,240 --> 00:44:19,980
That same software can do the same trick
if it sees some folds in the curtain

631
00:44:20,110 --> 00:44:25,650
that just happen to suggest eyes,
a nose and a mouth perhaps,
so we see a face when there isn't one there.

632
00:44:26,220 --> 00:44:28,150
Every night of our lives we dream.

633
00:44:28,550 --> 00:44:34,960
That same simulating software
sets up worlds that don't exist -
people, animals, countries

634
00:44:35,090 --> 00:44:37,460
that never existed,
perhaps never could exist.

635
00:44:38,490 --> 00:44:43,030
At the time,
we experience those simulations
as though they were reality.

636
00:44:43,870 --> 00:44:45,870
And why shouldn't we,

637
00:44:46,000 --> 00:44:50,310
given that we habitually experience
reality in just the same way

638
00:44:50,440 --> 00:44:52,840
by looking at
simulation models in our heads?

639
00:44:54,580 --> 00:44:58,450
The simulation software
can delude us when we're awake, too.

640
00:44:59,550 --> 00:45:03,720
So I think the lesson from this
is that if ever we hear a story

641
00:45:03,850 --> 00:45:07,360
that somebody has seen a vision,
been visited by an archangel,

642
00:45:07,490 --> 00:45:11,960
heard voices in his head,
we should be immediately suspicious.

643
00:45:12,090 --> 00:45:18,230
Secondly, language.
What's the downside of that?
Why is that a double-edged sword?

644
00:45:19,670 --> 00:45:27,310
Well, good information
can spread around the world,
round the network of brains, very easily,

645
00:45:27,440 --> 00:45:29,580
but so can everything else.
It doesn't have to be good.

646
00:45:29,710 --> 00:45:35,280
Even something as trivial as this:

647
00:45:37,450 --> 00:45:42,490
Ten years ago you never saw
anyone going around with
a baseball cap on backwards.

648
00:45:42,660 --> 00:45:46,930
In fact, in this country
you never saw anyone with
a baseball cap on at all.

649
00:45:47,060 --> 00:45:50,970
But now, if you go down a street,
either in this country or America

650
00:45:51,100 --> 00:45:54,970
you almost can't help
seeing a young man with a
baseball cap on backwards.

651
00:45:55,470 --> 00:45:59,310
The reversed baseball cap
has spread like chickenpox,

652
00:45:59,440 --> 00:46:01,580
first in America and then here.

653
00:46:01,710 --> 00:46:05,310
It's a mind epidemic,
a kind of virus of the mind.

654
00:46:07,050 --> 00:46:12,860
And like a chickenpox epidemic,
epidemics of mind viruses also,

655
00:46:12,990 --> 00:46:16,130
I'm glad to say,
die out remarkably quickly.

656
00:46:16,290 --> 00:46:22,970
And my guess is that
before very long the reversed
baseball cap will go the way of this.

657
00:46:33,610 --> 00:46:37,950
Well, baseball caps and turtles are,
of course, harmless,

658
00:46:38,380 --> 00:46:42,450
but there are other more powerful
idea systems that are more sinister

659
00:46:42,620 --> 00:46:47,920
and that do actively
hold back progress towards
our understanding of the universe.

660
00:46:48,420 --> 00:46:55,830
In 1633 the Holy Inquisition
condemned Galileo Galilei,
the great Italian physicist,

661
00:46:55,960 --> 00:46:57,600
to life imprisonment.

662
00:46:58,200 --> 00:47:02,300
His crime was to publish
a book arguing, correctly,

663
00:47:02,440 --> 00:47:04,440
that the world moved
round the sun.

664
00:47:04,570 --> 00:47:07,680
He was condemned,
on vehement suspicion of heresy,

665
00:47:08,210 --> 00:47:12,550
because his science
contradicted the beliefs of
the dominant culture of his time.

666
00:47:13,950 --> 00:47:16,420
And don't let's be complacent
about our time.

667
00:47:16,550 --> 00:47:20,820
It's in our time that an entire religious
sect has been actively incited

668
00:47:20,990 --> 00:47:24,060
by its leadersto murder
a distinguished novelist

669
00:47:24,430 --> 00:47:25,690
because he wrote a book

670
00:47:25,830 --> 00:47:30,100
that was seen as threatening
the verbally handed-down
beliefs of that sect.

671
00:47:31,800 --> 00:47:37,700
And it is in our century, too,
that perhaps the most pernicious
language virus ever known was spread.

672
00:47:47,980 --> 00:47:50,850
There's no need for me
to add words there.

673
00:47:52,750 --> 00:47:56,790
Let me return to the general problem
of language and its power
for ill as well as good.

674
00:47:57,560 --> 00:48:01,330
Human children have an awful lot
to learn as they grow up.

675
00:48:01,460 --> 00:48:03,370
Language is a magnificent tool
for learning.

676
00:48:03,500 --> 00:48:08,370
It enables us to cram in a few years
the best of the wisdom of centuries.

677
00:48:09,240 --> 00:48:15,410
No doubt that's why children
are so receptive when they're young.

678
00:48:16,040 --> 00:48:18,850
Children of a certain age
believe whatever they're told.

679
00:48:19,980 --> 00:48:22,990
Father Christmas and tooth
fairies are harmless enough,

680
00:48:23,890 --> 00:48:26,290
but a mind that's capable
of believing in fairies

681
00:48:26,420 --> 00:48:30,630
is also a mind that's vulnerable
to all manner of other stuff.

682
00:48:32,690 --> 00:48:41,140
Anybody who heard my first lecture
may remember this picture of the
distribution of, it's a spoof really,

683
00:48:41,270 --> 00:48:44,740
showing a map of the world in which
people believed in different ideas,

684
00:48:44,870 --> 00:48:49,140
like different theories
of the dinosaurs in different areas.

685
00:48:49,310 --> 00:48:51,650
And the point was to say
how absurd it would be

686
00:48:51,780 --> 00:48:56,290
if science really worked
like that, if what you believed
about the world or the universe

687
00:48:56,420 --> 00:49:00,560
depended upon where you happened
to be brought up.

688
00:49:00,690 --> 00:49:03,130
And I won't repeat the details of that.

689
00:49:03,590 --> 00:49:05,490
But do take the lesson seriously.

690
00:49:05,630 --> 00:49:10,900
Look at your own beliefs
about the world, about life,
beliefs about the universe.

691
00:49:11,400 --> 00:49:14,870
Do you believe them because you
have some reason to believe them,

692
00:49:15,500 --> 00:49:19,070
or do you believe them simply
because of where you were born?

693
00:49:19,810 --> 00:49:25,450
Would your beliefs about
the universe fit comfortably
on a map of the world like that?

694
00:49:26,080 --> 00:49:29,220
If so, be intensely suspicious of them.

695
00:49:29,990 --> 00:49:32,690
If only because the facts
about the universe

696
00:49:32,820 --> 00:49:36,020
can hardly be different
in different countries of the world.

697
00:49:37,760 --> 00:49:40,330
Now to our third double-edged
sword: technology.

698
00:49:41,230 --> 00:49:45,930
Gadgets like these telescopes,
microscopes, and so on
are immensely powerful.

699
00:49:46,070 --> 00:49:49,640
It's through them that
we shall comprehend the universe
if we ever do.

700
00:49:49,770 --> 00:49:52,710
So what's their downside?
What's wrong with them?

701
00:49:53,780 --> 00:49:54,980
Obviously, the first thing

702
00:49:55,110 --> 00:49:59,280
we think of when we think of bad effects
of technology is hydrogen bombs

703
00:49:59,450 --> 00:50:02,320
and all the other ghastly
inventions of destruction.

704
00:50:02,790 --> 00:50:05,250
And that goes without saying.
That's the most important effect.

705
00:50:05,390 --> 00:50:07,960
But I'm talking about something
less obvious:

706
00:50:08,090 --> 00:50:10,230
an effect on the mind,
quite an interesting effect,

707
00:50:10,360 --> 00:50:14,030
which I believe has held up
our species' mental growing up.

708
00:50:14,460 --> 00:50:19,970
And it's this: we're so used to
seeing complicated, elegant

709
00:50:20,100 --> 00:50:22,600
working things that
humans have designed

710
00:50:22,740 --> 00:50:26,340
that we naturally tend to think
that all complicated, elegant,

711
00:50:26,510 --> 00:50:29,010
working things
must have been designed.

712
00:50:29,680 --> 00:50:32,210
In an earlier lecture
I made a distinction

713
00:50:32,350 --> 00:50:34,780
between "designed"
and "designoid" objects.

714
00:50:34,920 --> 00:50:37,920
And "designed" objects are things
like telescopes and microscopes

715
00:50:38,050 --> 00:50:40,090
that really have been designed
by somebody.

716
00:50:40,420 --> 00:50:43,060
"Designoid" objects
are things like eyes,

717
00:50:43,190 --> 00:50:45,060
which look as though
they've been designed,

718
00:50:45,130 --> 00:50:48,500
and work in often very much
the same way, but haven't.

719
00:50:48,730 --> 00:50:50,900
They've arisen by an entirely
different process,

720
00:50:51,030 --> 00:50:54,300
namely evolution by natural selection,

721
00:50:54,970 --> 00:50:58,440
Darwin's theory of how things
came about.

722
00:50:59,340 --> 00:51:02,140
Now, unlike, say, Einstein's
General Theory of Relativity,

723
00:51:02,280 --> 00:51:07,480
evolution by natural selection
is really a very simple idea.
Anybody can grasp it.

724
00:51:08,380 --> 00:51:11,050
But in past centuries,
nobody grasped it.

725
00:51:11,220 --> 00:51:15,060
Not the cleverest people
in the world. Not Aristotle,
not any of the great philosophers,

726
00:51:15,190 --> 00:51:21,060
no great mathematician.
Nobody got this simple idea
until the middle of the 19th century

727
00:51:21,200 --> 00:51:24,430
when a couple of naturalists,
Darwin and Wallace, got it.

728
00:51:24,570 --> 00:51:26,540
Why did it take so long?

729
00:51:27,800 --> 00:51:28,940
There could be a number of reasons,

730
00:51:29,070 --> 00:51:31,510
but the one I'm talking about
now is this:

731
00:51:31,640 --> 00:51:35,810
I suspect that it may have been partly
the distracting effects of technology.

732
00:51:36,310 --> 00:51:39,880
Precisely because we were so used
to seeing things that we had made,

733
00:51:40,020 --> 00:51:44,020
that engineers had made,
things like telescopes, microscopes,

734
00:51:44,150 --> 00:51:47,260
ordinary little carpenters'
tools and things,

735
00:51:47,950 --> 00:51:53,760
we got the idea,
children grew up with the idea,
that everything had to have a purpose.

736
00:51:54,330 --> 00:51:57,230
But now we can see human purpose
for what it is.

737
00:51:57,370 --> 00:52:01,670
It is a product of brains, and
brains are a product of evolution.

738
00:52:02,300 --> 00:52:04,670
Purpose has evolved
like anything else.

739
00:52:04,810 --> 00:52:08,780
For millions of years,
three thousand million years,

740
00:52:08,810 --> 00:52:12,780
life forms grew up on this planet
that were very "designoid,"

741
00:52:12,920 --> 00:52:16,520
that looked designed, but did not
have the concept of design themselves.

742
00:52:16,650 --> 00:52:21,590
Finally, one species, ours,
grew up that was capable of
designing things deliberately,

743
00:52:21,720 --> 00:52:24,290
was capable of having purposes.

744
00:52:24,930 --> 00:52:31,730
Purpose itself has arisen in the universe,
has grown up in the universe, recently.

745
00:52:34,370 --> 00:52:38,010
But purpose itself,
now that it has arisen
in human brains,

746
00:52:38,140 --> 00:52:42,810
has the potential to be yet another
of those software innovations

747
00:52:42,950 --> 00:52:48,850
that is capable of taking off
into a progressive self-feeding spiral.

748
00:52:48,980 --> 00:52:54,390
Especially when teams of humans
share the same purpose.

749
00:52:55,290 --> 00:53:00,330
This is a picture of the lunar lander
of NASA, about to land on the moon,

750
00:53:00,800 --> 00:53:04,400
a magnificent example of
what groups of human minds can do

751
00:53:04,530 --> 00:53:07,470
when they get together
with a common purpose.

752
00:53:07,970 --> 00:53:12,770
Once the team purpose of standing
on the moon had been announced
by an American president,

753
00:53:12,910 --> 00:53:15,310
it was achieved in less than a decade.

754
00:53:15,510 --> 00:53:20,080
A similar group purpose of completely
mapping the human genome

755
00:53:20,120 --> 00:53:22,720
has recently been agreed,
and it, too, will be achieved.

756
00:53:23,020 --> 00:53:27,190
Science itself, the understanding
of the universe in which we've woken up,

757
00:53:27,320 --> 00:53:30,430
is another group purpose
with almost limitless potential.

758
00:53:31,260 --> 00:53:33,500
We can get outside the universe,

759
00:53:33,630 --> 00:53:38,770
I mean in the sense of putting
a model of the universe inside our skulls.

760
00:53:39,800 --> 00:53:44,340
We've seen that whenever we perceive
anything, we're putting a model
of it inside our skulls.

761
00:53:45,110 --> 00:53:48,340
Our model of the universe
will be inside our skulls

762
00:53:48,840 --> 00:53:54,120
in a similar way to a virtual-reality
model in a computer.

763
00:53:54,250 --> 00:53:57,420
Now, we have a final
virtual-reality model,

764
00:53:57,550 --> 00:54:00,360
and I think we have somebody
already trained up to do this.

765
00:54:00,490 --> 00:54:01,560
It's Alistair, isn't it?

766
00:54:01,690 --> 00:54:03,090
Come along, Alistair.

767
00:54:03,590 --> 00:54:08,300
To begin with, he can fly us
around under his own control,

768
00:54:08,430 --> 00:54:10,900
so we can go
wherever he wants to go.

769
00:54:11,030 --> 00:54:12,700
And it's quite a difficult operation.

770
00:54:12,870 --> 00:54:17,040
We're now flying around this virtual
model, which is in a computer.

771
00:54:18,110 --> 00:54:21,740
And there's a picture outside a door,

772
00:54:21,880 --> 00:54:24,480
and some of you may recognize
what that picture is.

773
00:54:25,150 --> 00:54:26,280
Now we're moving away from it again.

774
00:54:26,420 --> 00:54:29,450
Remember we're in a model,
in a computer.

775
00:54:30,250 --> 00:54:33,590
Now we're going to go,
I think, through that door.

776
00:54:36,790 --> 00:54:39,330
In we go, burst through the door,
where are we?

777
00:54:39,460 --> 00:54:43,100
Lo and behold, we're in the Royal
Institution lecture Theater.

778
00:54:43,600 --> 00:54:47,200
That is a model of the Institution
lecture Theater in the computer.

779
00:54:47,340 --> 00:54:50,010
There's this lecturer's dais,

780
00:54:51,070 --> 00:54:56,780
there's the exit there,
there are the blue seats,
there's the bit of wall under the gallery

781
00:54:57,680 --> 00:55:02,280
OK, I think that's enough.
We've got the idea.
Thanks very much, Alastair.
We've got the idea.

782
00:55:09,090 --> 00:55:12,290
But once again
we had a model of a world,
in this case a little microcosm,

783
00:55:12,430 --> 00:55:16,330
a small world, inside the computer.

784
00:55:16,470 --> 00:55:21,140
But our model of the universe
would not be a little,
local model like this one.

785
00:55:21,270 --> 00:55:23,770
It will be a far grander undertaking.

786
00:55:24,340 --> 00:55:27,480
Building it is a shared enterprise.

787
00:55:28,080 --> 00:55:34,220
The model is distributed
over the network of brains
that are participating.

788
00:55:34,350 --> 00:55:40,660
Bits of the model
are in books and libraries,
pictures, computer databases.

789
00:55:41,090 --> 00:55:45,230
As time goes by, and
our civilization grows up more,

790
00:55:45,360 --> 00:55:49,360
the model of the universe
that we share with one another
will get better.

791
00:55:49,500 --> 00:55:55,070
It will become progressively
more refined and more accurate
in its mirroring of reality.

792
00:55:55,540 --> 00:55:57,970
And at the same time, as we grow up,

793
00:55:58,110 --> 00:56:02,010
our shared model
will become progressively
less superstitious,

794
00:56:02,150 --> 00:56:04,410
less small-minded, less parochial.

795
00:56:04,550 --> 00:56:09,020
It will lose its remaining ghosts,
hobgoblins, and spirits.

796
00:56:09,150 --> 00:56:13,520
It will be a realistic model
correctly regulated and updated

797
00:56:13,650 --> 00:56:16,390
by incoming information
from the real world.

798
00:56:16,530 --> 00:56:20,430
A powerful model,
with parts that move relative
to one another,

799
00:56:20,600 --> 00:56:25,470
a model capable of running on into
the future and making accurate predictions

800
00:56:25,600 --> 00:56:28,540
of what's going to happen to us
and our world.

801
00:56:29,000 --> 00:56:32,240
We, perhaps alone in the universe,

802
00:56:32,380 --> 00:56:35,380
are capable of finally growing up.

803
00:56:35,510 --> 00:56:37,110
Thank you very much.

804
00:56:38,010 --> 00:56:41,520
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