economic times, of course.

And one of the first victims

of difficult economic times,

I think, is public spending of any kind,

but certainly in the firing line at the moment

is public spending for science,

and particularly curiosity-led science

and exploration.

So I want to try and convince you in about 15 minutes

that that's a ridiculous

and ludicrous thing to do.

But I think to set the scene,

I want to show -- the next slide is not my attempt

to show the worst TED slide in the history of TED,

but it is a bit of a mess.

(Laughter)

But actually, it's not my fault; it's from the Guardian newspaper.

And it's actually a beautiful demonstration

of how much science costs.

Because, if I'm going to make the case

for continuing to spend on curiosity-driven science and exploration,

I should tell you how much it costs.

So this is a game called "spot the science budgets."

This is the U.K. government spend.

You see there, it's about 620 billion a year.

The science budget is actually --

if you look to your left, there's a purple set of blobs

and then yellow set of blobs.

And it's one of the yellow set of blobs

around the big yellow blob.

It's about 3.3 billion pounds per year

out of 620 billion.

That funds everything in the U.K.

from medical research, space exploration,

where I work, at CERN in Geneva, particle physics,

engineering, even arts and humanities,

funded from the science budget,

which is that 3.3 billion, that little, tiny yellow blob

around the orange blob at the top left of the screen.

So that's what we're arguing about.

That percentage, by the way, is about the same

in the U.S. and Germany and France.

R&D in total in the economy,

publicly funded, is about

0.6 percent of GDP.

So that's what we're arguing about.

The first thing I want to say,

and this is straight from "Wonders of the Solar System,"

is that our exploration of the solar system and the universe

has shown us that it is indescribably beautiful.

This is a picture that actually was sent back

by the Cassini space probe around Saturn,

after we'd finished filming "Wonders of the Solar System."

So it isn't in the series.

It's of the moon Enceladus.

So that big sweeping, white

sphere in the corner is Saturn,

which is actually in the background of the picture.

And that crescent there is the moon Enceladus,

which is about as big as the British Isles.

It's about 500 kilometers in diameter.

So, tiny moon.

What's fascinating and beautiful ...

this an unprocessed picture, by the way, I should say,

it's black and white, straight from Saturnian orbit.

What's beautiful is, you can probably see on the limb there

some faint, sort of,

wisps of almost smoke

rising up from the limb.

This is how we visualize that in "Wonders of the Solar System."

It's a beautiful graphic.

What we found out were that those faint wisps

are actually fountains of ice

rising up from the surface of this tiny moon.

That's fascinating and beautiful in itself,

but we think that the mechanism

for powering those fountains

requires there to be lakes of liquid water

beneath the surface of this moon.

And what's important about that

is that, on our planet, on Earth,

wherever we find liquid water,

we find life.

So, to find strong evidence

of liquid, pools of liquid, beneath the surface of a moon

750 million miles away from the Earth

is really quite astounding.

So what we're saying, essentially,

is maybe that's a habitat for life in the solar system.

Well, let me just say, that was a graphic. I just want to show this picture.

That's one more picture of Enceladus.

This is when Cassini flew beneath Enceladus.

So it made a very low pass,

just a few hundred kilometers above the surface.

And so this, again, a real picture of the ice fountains rising up into space,

absolutely beautiful.

But that's not the prime candidate for life in the solar system.

That's probably this place,

which is a moon of Jupiter, Europa.

And again, we had to fly to the Jovian system

to get any sense that this moon, as most moons,

was anything other than a dead ball of rock.

It's actually an ice moon.

So what you're looking at is the surface of the moon Europa,

which is a thick sheet of ice, probably a hundred kilometers thick.

But by measuring the way that

Europa interacts

with the magnetic field of Jupiter,

and looking at how those cracks in the ice

that you can see there on that graphic move around,

we've inferred very strongly

that there's an ocean of liquid surrounding

the entire surface of Europa.

So below the ice, there's an ocean of liquid around the whole moon.

It could be hundreds of kilometers deep, we think.

We think it's saltwater, and that would mean that

there's more water on that moon of Jupiter

than there is in all the oceans of the Earth combined.

So that place, a little moon around Jupiter,

is probably the prime candidate

for finding life on a moon

or a body outside the Earth, that we know of.

Tremendous and beautiful discovery.

Our exploration of the solar system

has taught us that the solar system is beautiful.

It may also have pointed the way to answering

one of the most profound questions that you can possibly ask,

which is: "Are we alone in the universe?"

Is there any other use to exploration and science,

other than just a sense of wonder?

Well, there is.

This is a very famous picture

taken, actually, on my first Christmas Eve,

December 24th, 1968,

when I was about eight months old.

It was taken by Apollo 8

as it went around the back of the moon.

Earthrise from Apollo 8.

A famous picture; many people have said that it's the picture

that saved 1968,

which was a turbulent year --

the student riots in Paris,

the height of the Vietnam War.

The reason many people think that about this picture,

and Al Gore has said it many times, actually, on the stage at TED,

is that this picture, arguably, was

the beginning of the environmental movement.

Because, for the first time,

we saw our world,

not as a solid, immovable,

kind of indestructible place,

but as a very small, fragile-looking world

just hanging against the blackness of space.

What's also not often said

about the space exploration, about the Apollo program,

is the economic contribution it made.

I mean while you can make arguments that it was wonderful

and a tremendous achievement

and delivered pictures like this,

it cost a lot, didn't it?

Well, actually, many studies have been done

about the economic effectiveness,

the economic impact of Apollo.

The biggest one was in 1975 by Chase Econometrics.

And it showed that for every $1 spent on Apollo,

14 came back into the U.S. economy.

So the Apollo program paid for itself

in inspiration,

in engineering, achievement

and, I think, in inspiring young scientists and engineers

14 times over.

So exploration can pay for itself.

What about scientific discovery?

What about driving innovation?

Well, this looks like a picture of virtually nothing.

What it is, is a picture of the spectrum

of hydrogen.

See, back in the 1880s, 1890s,

many scientists, many observers,

looked at the light given off from atoms.

And they saw strange pictures like this.

What you're seeing when you put it through a prism

is that you heat hydrogen up and it doesn't just glow

like a white light,

it just emits light at particular colors,

a red one, a light blue one, some dark blue ones.

Now that led to an understanding of atomic structure

because the way that's explained

is atoms are a single nucleus

with electrons going around them.

And the electrons can only be in particular places.

And when they jump up to the next place they can be,

and fall back down again,

they emit light at particular colors.

And so the fact that atoms, when you heat them up,

only emit light at very specific colors,

was one of the key drivers

that led to the development of the quantum theory,

the theory of the structure of atoms.

I just wanted to show this picture because this is remarkable.

This is actually a picture of the spectrum of the Sun.

And now, this is a picture of atoms in the Sun's atmosphere

absorbing light.

And again, they only absorb light at particular colors

when electrons jump up and fall down,

jump up and fall down.

But look at the number of black lines in that spectrum.

And the element helium

was discovered just by staring at the light from the Sun

because some of those black lines were found

that corresponded to no known element.

And that's why helium's called helium.

It's called "helios" -- helios from the Sun.

Now, that sounds esoteric,

and indeed it was an esoteric pursuit,

but the quantum theory quickly led

to an understanding of the behaviors of electrons in materials

like silicon, for example.

The way that silicon behaves,

the fact that you can build transistors,

is a purely quantum phenomenon.

So without that curiosity-driven

understanding of the structure of atoms,

which led to this rather esoteric theory, quantum mechanics,

then we wouldn't have transistors, we wouldn't have silicon chips,

we wouldn't have pretty much the basis

of our modern economy.

There's one more, I think, wonderful twist to that tale.

In "Wonders of the Solar System,"

we kept emphasizing the laws of physics are universal.

It's one of the most incredible things about the physics

and the understanding of nature that you get on Earth,

is you can transport it, not only to the planets,

but to the most distant stars and galaxies.

And one of the astonishing predictions

of quantum mechanics,

just by looking at the structure of atoms --

the same theory that describes transistors --

is that there can be no stars in the universe

that have reached the end of their life

that are bigger than, quite specifically, 1.4 times the mass of the Sun.

That's a limit imposed on the mass of stars.

You can work it out on a piece of paper in a laboratory,

get a telescope, swing it to the sky,

and you find that there are no dead stars

bigger than 1.4 times the mass of the Sun.

That's quite an incredible prediction.

What happens when you have a star that's right on the edge of that mass?

Well, this is a picture of it.

This is the picture of a galaxy, a common "our garden" galaxy

with, what, 100 billion

stars like our Sun in it.

It's just one of billions of galaxies in the universe.

There are a billion stars in the galactic core,

which is why it's shining out so brightly.

This is about 50 million light years away,

so one of our neighboring galaxies.