Curiosity

Hello.

My name is Stephen Hawking --

physicist, cosmologist,

and something of a dreamer.

Although l cannot move

and l have to speak through a computer,

in my mind...

Narrator: l am free...

...free to explore

the deepest questions of the Universe.

Among them, the deepest of all...

ls there a God who created and controls the Universe --

from the stars and the planets

to you and me?

Finding out takes us on a journey

through the laws of nature,

for there, l think, lies the answer

to the age-old mystery

of how the Universe was made and how it really works.

Check it out.

Hawking : l recently published a book

that asked if God created the Universe.

lt caused something of a stir.

People got upset that a scientist

should have anything to say on matters of religion.

l have no desire to tell anyone what to believe,

but for me, asking if God exists

is a valid question for science.

After all, it is hard to think

of a more important or fundamental mystery

than what or who created and controls the Universe.

Narrator: Long ago, the answer was almost always the same.

Gods made everything.

The world was a scary place.

So even people as tough as the Vikings

believed in supernatural beings

to make sense of natural phenomena,

like lightning or storms.

The Vikings had many different gods.

Thor was the god of lightning.

Another god, Aegir, caused stormy seas.

But the god they feared the most was named Skoll.

He was responsible for the terrifying natural event

that we now call a solar eclipse.

Skoll was a wolf god who lived in the sky.

Sometimes, he would eat the Sun,

causing the dreadful moment when day turned to night.

Without a scientific explanation,

imagine how disturbing it would have been

to see the Sun vanish.

The Vikings responded

in the only way that made sense to them.

They tried to scare away the wolf.

The Vikings believed

that their actions caused the Sun to return.

Of course, we now know they had nothing to do with it.

The Sun would have reappeared anyway.

lt turns out that the Universe

is not as supernatural or mysterious as it seems.

But it takes more courage

than even the Vikings had to discover the truth.

Mere mortals like you and l

can understand how the Universe works.

This was realized long before the Vikings

in ancient Greece.

ln about 300 B.C.,

a philosopher called Aristarchus was fascinated by eclipses, too,

especially eclipses of the Moon.

He was brave enough to question

whether they really were caused by gods.

Aristarchus was a true scientific pioneer.

He studied the heavens carefully and reached a bold conclusion.

He realized the eclipse was actually the shadow of the Earth

passing over the Moon

and not a divine event.

Liberated by this discovery,

he was able to work out

what was really going on above his head

and draw diagrams that showed the true relationship

of the Sun...

The Earth...

And the Moon.

From there, he reached even more remarkable conclusions.

He deduced that the Earth was not the center of the Universe,

as everyone had thought,

but instead orbits the Sun.

ln fact, understanding this arrangement

explains all eclipses.

When the Moon casts its shadow on the Earth,

that's a solar eclipse.

And when the Earth shades the Moon,

that's a lunar eclipse.

But Aristarchus took it even further.

He suggested the stars were not chinks in the floor of heaven,

as his contemporaries believed,

but that stars were other suns like ours,

only a very long way away.

What a stunning realization it must have been.

The Universe is a machine

governed by principles, or laws,

laws that can be understood by the human mind.

Hawking : l believe the discovery of these laws

has been humankind's greatest achievement,

for it's these laws of nature, as we now call them,

that will tell us

whether we need a God to explain the Universe at all.

For centuries, it was believed that disabled people like me

were living under a curse inflicted by God.

While l suppose it's possible

that l've upset someone up there,

l prefer to think

that everything can be explained another way --

by the laws of nature.

So, what exactly is a law of nature,

and why is it so powerful?

l'll show you with a game of tennis.

Narrator: Tennis is governed by two sets of laws.

One set is man-made --

the rules of the game.

They govern things such as the size of the court,

the height of the net,

and what determines if a shot is in...

...or if a shot is out.

These rules could conceivably be changed

if the governing body of tennis so desired.

But the other set of laws that apply to the game

are fixed, immutable.

They govern what happens to the ball...

When it is hit.

The force and angle of the racket strike

determines exactly what happens next.

The laws of nature

are a description of how things actually work

in the past, present, and future.

ln tennis,

the ball always goes exactly where they say it will.

And there are many other laws at work here, too.

They govern everything that is going on --

from how the energy of the shot

is produced in the players' muscles...

...to the speed at which the grass grows

beneath their feet.

But what's really important is that these physical laws,

as well as being unchangeable, are universal.

They apply not just to the flight of a ball

but to the motion of a planet

and everything else in the Universe.

Unlike laws made by humans,

the laws of nature cannot ever be broken.

That's why they are so powerful

and, when seen from a religious standpoint,

controversial, too.

Hawking : lf you accept, as l do,

that the laws of nature are fixed,

then it doesn't take long to ask,

what role is there for God?

This is a big part of the contradiction

between science and religion.

And although my views have recently made headlines,

it is actually an ancient conflict.

Narrator: Back in 1 27 7,

Pope John XXl felt so threatened by the idea of laws of nature

that he decreed them a heresy.

Unfortunately,

that did nothing to change the law governing gravity.

A few months later,

the palace roof collapsed and fell on the Pope's head.

But organized religion soon found a solution.

For the next few hundred years,

it was simply stated

that the laws of nature were the work of God,

and God could break them if he wished to.

This view was reinforced

by the idea that our perfect blue planet

was quite still at the center of it all,

that all the stars and planets rotated around the Earth

like some carefully designed clockwork.

Aristarchus' idea to the contrary

had been long forgotten.

But humans are naturally inquisitive,

and some, such as Galileo Galilei,

couldn't help but look at God's clockwork once more.

lt was 1 609, and this time,

the results would change everything.

Galileo is the founder of modern-day science

and one of my heroes.

He thought, as l do,

that if you looked at the Universe closely enough,

you could discern what was really going on.

He was so determined

that he perfected lenses that, for the first time,

could magnify the night sky by 20 times.

Carefully, he assembled them into a telescope.

From his house in Padua,

he used this telescope

to study Jupiter night after night

and made a wonderful discovery --

three tiny dots very close to the giant planet.

To begin with,

he thought the dots must be very faint stars,