Human Universe (2014–…): Season 1, Episode 2 - Why Are We Here? - full transcript
Human Universe
Each one of us is made
from mere matter...
..yet we are matter
with curiosity,
we ask questions.
And, in the private world
of our minds,
one particular question burns...
Why are we here?
There is air and water here on Earth
So life come into existence here
God created us so we can help others
We have come here
to suffer our sins
I feel we all exist
for a reason
for ourselves or someone else
A scientific answer to this question
may not be far away.
HUMAN UNIVERSE
Part Two
Why are we here?
Edited Version
If the existence of any one of us
is singled out
the answer to the question
"Why are we here?"
looks like pure chance.
Like any particular individual,
baby Shurik was born into this world as the
culmination of a chain of apparent coincidences.
A chain so long that,
at first sight,
it looks highly improbable.
The chance that a particular sperm
reached a particular egg...
The chance that baby Shurik's
parents happened to meet...
and their parents too...
and generations of ancestors
before that.
But don't stop there.
The apparent coincidences go back
much further than that...
..to our planet
and its position in space.
We appear to live on a perfect
planet in a perfect universe.
It feels as if it's been made
for us.
The Earth orbits at just the right
distance around just the right star
for the temperatures on its surface
to be just right
to permit liquid water to exist.
And those temperatures have remained
just right for four billion years,
which is just the right amount
of time for us to have evolved.
And this seeming luck
continues beyond our solar system.
We live in a universe that's
expanding at just the right rate
for stars and galaxies to form.
And within those stars, the forces
of nature are just
the right strength to allow them to
assemble the elements of life,
carbon, oxygen and iron,
in their cores.
If you trace it right back,
the odds of YOU existing in this
universe don't just look small,
they seem almost
infinitesimally small.
Why are we here?
Is our existence merely accidental?
And if we are just happy accidents,
then what about the universe?
Is its form, its nature,
its very existence
also accidental?
And if that's the case,
what does it mean to you?
Well, I think modern science is very
close to answering these questions
and, in this film,
I want to tell you why I think that.
Brahmaswam Madham School
Kerala
Shankar is 12 years old
and has lived at this school
since he was eight.
He sees his parents only every
three months...
But, to him, it's worth it
because he has a singular life ahead
of him as a Hindu priest, or Brahman.
I need to be a Priest
I am intersted in that
I'm intersted in other things also
What I like most is cricket
Shankar is one of 40 students here,
all of them
training for the Hindu priesthood.
Their day follows a strict routine
starting at 5am.
Almost every day the students chant
between seven in the morning
and seven at night.
They're chanting Vedas,
ancient verses which date back
4,000 years, containing
the poetry and myths
on which Hinduism is based.
These religious verses hold
some unexpected thoughts.
They contain the concept of zero
and they touch on the notion
of infinity.
And they use mathematical
concepts such as Pi, square roots
and Pythagoras' theorem.
And, in one part of the Rig Veda
learned by the older boys,
you can find a very
interesting thought.
It addresses a crucial question
about the formation of the universe.
The gods themselves
are later than creation
So who knows truly
whence it has arisen?
"The gods are later than creation."
I think that's
a remarkable sentence.
It displays real intellectual
rigour and honesty.
The gods are later than creation
So who knows truly
whence it has arisen?
It's obviously not a sufficiently
good answer to say,
"Well, all this exists because it was willed
into existence "merely by some kind of deity."
It's reasonable to then ask
the question,
"Well, what's the origin of
the deity?
"Has the deity existed forever,
has the universe existed forever?"
So, I think, just seeing
signs of that...
that kind of thinking which is
really what you might say
the prerequisite or the first signs
of a scientific way of thinking.
The scientific approach acknowledges
that if we're ever going to ask
grand questions like
"Why are we here?"
we have to begin with "how".
In my view science
is a...a humble pursuit.
It starts by asking very simple
questions, asks questions like,
"Why is it that when you let
something go
"it falls to the ground?"
You let it go, it falls to
the ground again,
falls to the ground again,
you observe regularities in nature,
tiny, small regularities,
and try and explain them
and model them, understand them.
Through that process
we've been led to
an intellectual framework
that maybe allows us
to answer questions about the
very origin of reality itself.
From the marketplace
to outer space,
those regularities in nature can be
found almost everywhere you look.
Galileo said nature is a book
written in the language
of mathematics.
And, the more you start
to look for that language,
the more you see it...
..everywhere.
Chambal River
Rivers meander through the landscape
in a seemingly random way
and if you just look at a few turns
then they will be random.
The river might change its course
because of some geology,
a big rock formation.
But if you look at a river
over a large length,
say tens or hundreds of kilometres,
then you see that the meanders
aren't quite random,
a pattern emerges,
there's order there.
This is the satellite picture
of the bend in the river,
the meander you can see here,
and the mathematical relationship,
the pattern that we're
looking for, is this.
If I measure the wavelength
of the meander,
which is just the length
between the point
where the river starts to turn
and meanders up and then
meanders down and comes back again,
you see it's around
11 centimetres on this map.
And then if I measure the width
of the river at this point
then it's something
like one centimetre,
so the ratio of the wave length
of the meander to the width of the
river, in this case, is about 11.
Now, the interesting thing is that
if you take this whole river,
so not just one bend
but hundreds of bends,
you'll find that that ratio
is always somewhere
between about 10 and 14.
What's very interesting is
it's not just this river,
this isn't a special river.
If you look at any river
on the planet,
no matter how small or wide,
you'll find that it's always
somewhere between 10 and 14.
There's obviously some
pattern there,
it reflects something fundamental
about the way that fluids
flow across the surface
of Planet Earth.
And this rule can even be
seen on other planets.
On Mars, the rivers have long
since dried up,
but the arid river beds show
the same meandering pattern.
And on Titan, the largest moon
of the planet Saturn,
the rivers are made of methane
cutting through a bedrock of ice.
But even here the same ratio
appears to exist.
This rule seems to hold true
for every river
found across the solar system.
Bera
Rajasthan
Order is hidden in everything,
from rivers, rocks and landscapes
to living things,
even the most exotic
and elusive of creatures.
"In the days when everybody started
fair, Best Beloved,
"the Leopard lived in a place
called the High Veldt.
"The Giraffe and the Zebra
and the Eland and the Koodoo
"and the Hartebeest lived there,
"but the Leopard,
he was the 'sclusivest
"sandiest-yellowish-brownest
of them all."
Rudyard Kipling's Just So story,
How The Leopard Got Its Spots,
tells the story of an Ethiopian man
who was the Leopard's friend,
he used to go hunting
with the Leopard.
And one day he noticed that
the Leopard wasn't being
very successful, it had a plain,
sandy coat,
whereas all the other animals
had camouflage.
He said, "That's a trick worth
learning, Leopard."
So he took his fingers and his thumb
and he pressed
into the Leopard's coat to give it
that distinctive
five-pointed camouflage pattern.
So, in the absence of an Ethiopian
hunter present at the birth
of every leopard, how did
the leopard get its spots?
No-one disputes the reason
why leopards have spots,
they evolved as camouflage.
What's less obvious is how
the pattern appears on their coats.
Let's have a look.
Fantastic.
He's ducked down into a little...
little valley.
It's really interesting, the moment
you lose sight of the leopard
then you turn round to see it again,
it's very, very difficult
to find it.
You've essentially got to wait
till it moves.
It just shows you
the effectiveness of camouflage.
How does that complex camouflage
emerge from the millions
of separate cells
across the leopard's skin?
Measure out...
..a precise amount of indicator.
Then I'm just going to add it in.
It turns out that complex patterns
can emerge from simple ingredients.
And, mix them up.
Now, if I pour this
into this Petri dish...
There, you see?
And now can you see the colour
coming back,
fading back in?
It's not the usual chemical
reaction,
you mix two things together, you get
a big bang or a cloud of blue smoke,
which is what all chemists love.
This reaction is continually
oscillating
backwards and forwards.
So we started with the simplest
of ingredients,
mixed them together
and they reacted in such a way
that complexity,
that pattern, emerged
from the underlying simplicity.
A similar process
happens in living things.
When the leopard
was still an embryo,
it's thought that two competing
chemicals, washing over the skin,
created the distinctive spots.
So if you have a sandy background,
then you can imagine
one of these chemicals
that causes or stimulates
pigment to appear,
so as it grows you get a dark spot.
Where it's inhibited and drops
you return to the sandy background.
It grows again, you get a dark spot
and returns to the sandy background.
The same principle is believed to
create the stripes of the tiger,
the zebra and the sea snail,
to name just a few.
Scientists get very excited
when they discover
an explanation like this
because it means we've understood
something much deeper about nature
and that's that complexity masks
an underlying simplicity.
All the intricacy that we
see across the natural world
emerges from a few simple laws.
The meander of a river
and a leopard's spots
are just two examples
of patterns in nature,
but there are countless more.
By looking carefully
at the patterns in nature
and trying to understand
their origin,
that's what Copernicus and Kepler
and Newton and Einstein and Galileo
and Curie and Dirac and Feynman and
a thousand others have discovered.
There are regularities in nature,
there are patterns as far
as the eye can see,
on every scale from atoms
to galaxies
and those patterns are a reflection of the simplicity
and beauty of the underlying laws of nature.
A blueprint for creation does exist,
a scientific one.
But how do the laws of physics
explain the existence of human beings?
How, or why, did atoms come together
to form us in particular?
The game of cricket is
unfathomable to some
but to those who understand it
it's bewitching.
I really love it,
I just can't express it...
I...I don't express it in words.
My dream is to play for India.
This is what I've been aiming for
since my childhood.
Today Subitu Bose and his team-mates
are playing against rivals
Neerja Modi School.
Cricket is based on a set of rules
and they haven't altered
significantly since the 1800s.
But, despite the existence of these
rules, no match is ever predictable.
Take, for instance, the ball.
Climate makes a big difference
to its swing,
dew picked up from wet grass
or scuffing from dry ground...
..not to mention how it's bowled.
And then there's the bat.
Each batsman has a preference
for a bat of a particular weight
and that will affect his stroke.
Not forgetting the temperament
of each player,
the mood of the umpire
and the mood of the crowd.
When you get so many variables,
the number of possibilities
becomes enormous
and yet all this complexity
emerged from a set of fixed rules.
A game of cricket is played out
according to a set of simple laws
and so it is for the universe,
and here are the laws
of the universe.
This is the standard model of
particle physics
and this is Einstein's General
Theory of Relativity
and you can fit them
easily on a scorecard.
And here are the laws of cricket
and it has to be said,
at least in this notation,
that cricket is more complicated
than the universe.
But even given these simple laws,
the number of ways that both games
can play out
is effectively infinite.
So the laws do not make
the outcome predictable.
But all we really
care about is the outcome.
In the case of the game
of cricket - who won?
In the case of the game
of the universe - we exist.
And for the cricket match,
the result could have turned on the
tiniest, most insignificant little event,
the way the ball gripped the pitch
and deflected off
a couple of blades of grass,
clipped the edge of the bat
and was caught
by the wicketkeeper.
And it's the same for the universe.
Some collision of two dust particles
ten billion years ago
could have led to a chain of
seemingly insignificant,
infinitesimally unlikely
little events
that led to something that we care
deeply about.
Our existence.
Today the way the game of cricket
played out
had an undesired outcome for Bose.
The fielder caught my, er...
caught the ball here.
Had I have hit the ball
a little to the...
to his left or right, it would
have gone to the boundary.
But, sadly, it went straight
to the fielder.
I was like, "Ahh...
"What have I done?"
Just like a game of cricket,
the way the universe played out
to create us humans
was not determined
by the rules alone.
Chance played a part, too.
Bhand Devra Temple
Baran
This temple's over
a thousand years old,
it's dedicated to
Lord Shiva the Destroyer
and it's built
in the Tantric tradition,
which is at least in part
a celebration of pleasure.
But whilst I find some of these
suggestions instructive,
that's not why we're here.
We're here because of the location
of this temple.
Because this temple is in the centre
of a crater, three kilometres wide.
Geologists are still debating
what made it
but it could well be the scar left by
a meteorite smashing into the Earth.
Throughout its lifetime the Earth has been
constantly bombarded by objects from space.
Think about one particular
collision,
the impact that probably wiped out
the dinosaurs 66 million years ago,
and think about the history,
the lifetime of that rock
that smashed into the Earth.
Imagine one particular day
in the lifetime of that rock,
on one orbit, perhaps billions
of years ago,
when another rock,
no bigger than that,
instead of missing it, hit it,
smashed into it and changed
its orbit very, very slightly.
And, over millions and millions of orbits, that change
would have got amplified, until, perhaps, that day,
66 million years ago, instead
of smashing into the Earth,
the dinosaurs were looking up
at the sky
and they saw a fireball
blaze across the sky
and miss rather than hit.
That would have changed history.
In all probability the dinosaurs
would still be roaming
the surface of the Earth today
and we probably wouldn't exist.
But the rock DID strike,
the dinosaurs WERE wiped out,
and purely by chance our human
existence became possible.
And fateful accidents of equal
importance for our existence
have also happened on a much
smaller scale.
Pushkar
Rajasthan
In Pushkar they have quite
a tradition of camel racing.
There's a saying, apparently,
which is the camel
and its driver go their own way...
..and there's the proof.
Despite that, there's a surprising
similarity between camels and us.
Now what I'm going to do is I'm going to take a
sample of my cells and a sample of the camel's cells.
What's his name? Rapi. Rapi.
Rapi? Yeah. Right.
So to take my cell sample
is quite easy.
I just have to...
..rub that on the corner
of my cheek
so there are my cheek cells
on there.
I'm going to do the same now
to Rapi, but could you hold him,
hold his mouth open?
Actually, you know what,
can I ask you to come?
There's no way I'm going in there!
Can you just rub that on his cheek?
That...that's going to be
enough, that's plenty.
That's plenty, yeah, and then
hand it over there.
There we go!
Right, thank you, thank you.
I apologise.
So now we've got a...
a sample of Rapi's cells
and a sample of my cells
and we'll make a comparison.
I apologise again.
So this is the slide
of my cheek cell.
You see there it's stained blue.
Quite small, but I can see
detail inside it.
And this is a slide
of the camel's cheek cells.
And the most obvious thing to say
is they look identical,
impossible to tell them apart,
and that's because for all intents
and purposes they are identical
and that's because myself and
the camels over there are mammals.
But...
if you look more closely,
then you see that the cells have
many structures inside them.
The most obvious feature
is the nucleus,
where most of our DNA is stored.
But you can also see
hundreds of little dots.
Many of these structures
are called mitochondria.
These are the power stations
found in the cells
of every complex living thing.
And, yet, once upon a time these
essential structures
were separate,
free-living creatures.
A long time ago,
two or three billion years ago,
the Earth was populated
only by single-celled organisms,
two great kingdoms of life,
the bacteria and the archaea,
and, it has to be said,
things were pretty dull,
there was nothing that we might call
complex and, in fact,
very little happened.
Those two single-celled things just
stayed the same for billions of years.
But then one day, quite by accident,
everything changed.
What many biologists believe to have
happened is that a bacterium
got inside an archaean
and for some reason wasn't digested.
Instead, a symbiotic
relationship began.
The bacterium may have been
protected by the archaean
while the archaean got access to the
energy generated by the bacterium.
Once that cell had access to
the vast amounts of energy,
the potential that the
internal bacterium gave it,
then basically all hell broke loose.
And that energy allowed the cell to
begin to work in larger colonies,
to begin to build complex
living things.
So the mitochondria in your cells
today are the descendants
of that chance collision
billions of years ago.
That singular event,
that fateful encounter,
was purely accidental, but the cells
that it produced had such
a survival advantage,
the energy made available to them
by the mitochondria, that its effect
was amplified beyond imagination
by natural selection, which is not
accidental and it is non-random.
So it's the interaction
between accident and rules,
chance heavily constrained
in the framework of natural laws,
that led to the evolution
of humans here on the Earth.
In our universe there was
no particular aim,
no intention for us humans to exist.
Instead the life of the universe
is just like a game of cricket...
..where rules
and chance play out together...
..and quite by accident happen to
produce a human universe.
Over the course of centuries
we've worked to find
the combination of rules and
accidents that made today's world.
We now understand the laws of nature
so well
that we have at least a reasonable
scientific understanding
of every step in that chain, from the present day to the first few
moments after the Big Bang, and that is a tremendous achievement,
it's the great achievement
of modern science.
But just as the origin of the
gods themselves is
questioned in the ancient
Hindu hymns and the Rigveda then
so we are faced with a question,
a very profound question -
who wrote the rules of the game,
what is the origin of
the laws of nature?
What is the origin
of the universe itself?
What went before the Big Bang?
It's a question that takes us
to another world entirely.
Kyoto
Japan
A samurai sword is both sharp
and strong.
Able to cut a body in half...
..but precise enough to slice
through a single hair.
Gassan Sadatoshi is
a master sword maker.
His family have been making swords
for over 800 years.
The Japanese sword is totally unique
it's often said to be the symbol of
Japanese mentality
The first stage is to reduce the
carbon content of the raw material.
If there's too little carbon
it'll be soft,
but too much and it'll be brittle.
This is all a remarkably
high-precision process,
everything that they're doing
matters to make the perfect sword.
And even the force
with which they hammer down matters,
that helps set the precise
mixture of ingredients,
and they're aiming for precisely
0.7% carbon in that steel.
Repeated heating and layering mixes
the iron and carbon
so the block is uniform.
This process can take weeks.
The final stage is to harden
the cutting edge of the sword,
a process called quenching.
Quenching is the most
nerve wracking (part) for a swordsmith
as he has to put his soul into the metal
In the case of a Japanese sword, if
you get all the ingredients right,
the precise mixture
of iron and carbon,
if you get the temperature right,
you get the hammering right,
everything right, over a year,
then you get the perfect sword.
Now, in the case of the universe the ingredients aren't things like
iron and carbon, of course, the ingredients are a set of numbers,
they're called constants of nature, they're things like the strength
of gravity, the speed of light and the masses of the particles.
And they also require precision.
They have to be set in just
the right way
if you want a universe
that supports life.
In the same way that
a samurai sword would be weakened
if the ingredients were different,
the universe might be unable
to support life if the constants
of nature were somehow altered.
Now, if I was some all-powerful
deity, which arguably I'm not,
then I could imagine varying
all those constants of nature
to see what happened.
I could imagine some great big control
board with little knobs on it.
One of them changes the strength
of gravity, the next one changes
the mass of the electron, the next
one changes the speed of light.
And the question is how much freedom do
I have if I want living things to exist?
The answer is, not very much
freedom at all.
If at the Big Bang the strength
of gravity were increased
then the universe would have
collapsed in on itself
before life had time to evolve.
But if the strength of gravity were
decreased then galaxies
wouldn't form, so there'd be
no planets, no stars and no life.
If you decrease the speed of light
by just a few percent
our universe would have
no carbon in it.
Increase it by about the same amount
and our universe would have
no oxygen.
Because we have no idea why the
constants are the values that they are
then we're presented with something of a
mystery, because you can ask the question,
well, if it's just random, if indeed
the universe began and somehow
these random numbers got chosen,
then how lucky are we that we exist?
How lucky are we that we live in a
universe where those constants
are just right to allow
galaxies to from and stars to shine
and elements like carbon to form
in the hearts of stars?
So what could account for the uncanny
precision of this set of numbers?
Hello, can I have just one? Yeah.
Thank you.
You know, our universe, with
all its beautiful laws of nature
and its finely tuned constants,
feels incredibly lucky.
I mean, it's like buying a lottery
ticket and winning the lottery,
but it's stranger than that,
because it's like winning
the lottery in which only one ticket
was ever printed.
But that's of course not how
a lottery works.
Yes, it is extremely unlikely that
I'll win the lottery
with this ticket, but there
are millions of tickets printed
so it's not surprising at all
that someone wins it.
So could we think of our universe
in the same way as the lottery?
The reason that we appear to
live in a perfect universe with
the perfect numbers,
the perfect constants of nature,
the perfect laws, is because there
are in fact countless millions,
perhaps an infinite number
of universes, each with different
physical laws, different numbers,
different constants of nature.
Then we shouldn't be so surprised to
live in the perfect universe.
It's like the lottery - somebody's
got to get the right ticket,
somebody's got to win it.
Just as the lottery has many
tickets,
each bearing different numbers...
..so there may be many universes,
each with different values for
the constants of nature.
Universes with stronger or weaker
gravity,
slower light or faster light.
Now, that might make sense
mathematically
but is it really
a sensible suggestion,
an infinite number of universes?
What does that mean for reality?
Miyake Jima island.
North Pacific
3,000 people live here,
making a living from the sea.
But it's a precarious
place to call home.
Because this entire island is
an active volcano.
Occasionally it belches forth
scorching lava that
incinerates anything that
stands in its way.
Until an eruption in 1983,
this was the island's school.
But volcanism doesn't just destroy,
it also creates.
Around 30,000 years ago this
whole island emerged
from the vast emptiness of
the North Pacific Ocean.
And it's not just this island, it's
the whole of the Izu Archipelago
and much of Japan.
All of these islands have risen up
out of the ocean,
seemingly from nothing.
And it's even happening right now.
This island, called Nishinoshima,
has been growing steadily
since it suddenly
appeared in November 2013.
If we didn't know better, we might
ascribe that creation
to the act of the gods,
but we do know better
because we know about geology,
we've done some science,
so we know that the origin of
this island is volcanism.
It comes from the inner heat of the
Earth, which is itself a leftover
from the history of its formation
4½ billion years ago.
So we have a mechanism
for the creation of new land.
Contrast that with the scientific
explanation for the origin
of the most important thing of all,
the origin of the universe itself,
and for decades
we've been happy to say
the universe began at the Big Bang
and it's almost as if we're
not to ask what happened before.
There was nothing before,
there's no scientific mechanism to
explain how the Big Bang occurred.
But there are now plausible
theories that provide
a mechanism for how universes might
be made from apparently nothing.
So what is this magical
theory that explains
the origin of the universe,
and how did we find it?
Well, the answer is it's a theory
called inflation,
and really the clues
to the theory were there all along,
we just had to look for it.
They lie in the rules of the game.
If there's one basic rule
it's this - things have to happen.
Nothing, emptiness,
is about the only thing that's
forbidden by the rules of
quantum mechanics.
Before our universe
became filled with
particles of matter, it wasn't
empty, it was filled with energy,
and like the surface of the sea it
was constantly fluctuating, rippling
with a form of energy that causes
space to expand exponentially fast.
At the trough of one of the waves,
the energy driving
the expansion
fell below a certain level.
So that region stopped inflating and
the energy was transformed
into the recognisable particles
of today's universe.
And that transformation is what we
see as the Big Bang,
the birth of
our observable universe.
The theory of inflation
is extraordinary
and extraordinary claims
require extraordinary evidence.
Well, here is
the extraordinary evidence.
This is a photograph of
the oldest light in the universe
and it's got many intricate
and detailed properties.
The most obvious one is that
it's an extremely uniform glow,
it's almost all at the same
temperature.
This and all the other properties
of this ancient light are best
explained by an inflationary
expansion of the early universe.
No-one has thought of any theory that
can reproduce this other than inflation,
and that is why I love physics.
Isn't that remarkable?
But, just like the formation
of islands or any other
mechanism in nature, inflation
needn't stop at one universe.
Why should it?
The process of inflation could be
going on eternally,
always making universes, even now.
And each one of these universes
could be like a ticket
in a lottery...
..bearing different numbers for
constants of nature...
..such as the strength of gravity
or the speed of light.
So amongst them all...
there has to be a winning ticket.
A human universe.
It's absolutely inevitable.
If the theory of inflation is
correct, it explains
how our universe appeared
apparently from nothing.
And it also strongly suggests that
there's not just our universe
but a vast number,
perhaps even an infinity of them.
Now we've known for a long time
that we're infinitesimal specks
in a vast universe,
but now the suggestion is that
we're infinitesimal specks
in a vast infinity of universes.
Our current best theory for
the origin of the universe,
backed up by experimental evidence,
suggests that there are an infinite
number of universes, an infinite
number of copies of you and me,
and that the existence of the
whole thing is inevitable.
No purpose, nothing special,
you are because you have to be.
How does that make you feel?
Well, the wonderful
thing is nobody knows,
nobody's worked it out yet,
so the answer is up to you.
What do you think?
For small creatures such as we,
For small creatures such as we,
the vastness is bearable only through love
For small creatures such as we, the vastness
is bearable only through love Carl Sagan
End
Each one of us is made
from mere matter...
..yet we are matter
with curiosity,
we ask questions.
And, in the private world
of our minds,
one particular question burns...
Why are we here?
There is air and water here on Earth
So life come into existence here
God created us so we can help others
We have come here
to suffer our sins
I feel we all exist
for a reason
for ourselves or someone else
A scientific answer to this question
may not be far away.
HUMAN UNIVERSE
Part Two
Why are we here?
Edited Version
If the existence of any one of us
is singled out
the answer to the question
"Why are we here?"
looks like pure chance.
Like any particular individual,
baby Shurik was born into this world as the
culmination of a chain of apparent coincidences.
A chain so long that,
at first sight,
it looks highly improbable.
The chance that a particular sperm
reached a particular egg...
The chance that baby Shurik's
parents happened to meet...
and their parents too...
and generations of ancestors
before that.
But don't stop there.
The apparent coincidences go back
much further than that...
..to our planet
and its position in space.
We appear to live on a perfect
planet in a perfect universe.
It feels as if it's been made
for us.
The Earth orbits at just the right
distance around just the right star
for the temperatures on its surface
to be just right
to permit liquid water to exist.
And those temperatures have remained
just right for four billion years,
which is just the right amount
of time for us to have evolved.
And this seeming luck
continues beyond our solar system.
We live in a universe that's
expanding at just the right rate
for stars and galaxies to form.
And within those stars, the forces
of nature are just
the right strength to allow them to
assemble the elements of life,
carbon, oxygen and iron,
in their cores.
If you trace it right back,
the odds of YOU existing in this
universe don't just look small,
they seem almost
infinitesimally small.
Why are we here?
Is our existence merely accidental?
And if we are just happy accidents,
then what about the universe?
Is its form, its nature,
its very existence
also accidental?
And if that's the case,
what does it mean to you?
Well, I think modern science is very
close to answering these questions
and, in this film,
I want to tell you why I think that.
Brahmaswam Madham School
Kerala
Shankar is 12 years old
and has lived at this school
since he was eight.
He sees his parents only every
three months...
But, to him, it's worth it
because he has a singular life ahead
of him as a Hindu priest, or Brahman.
I need to be a Priest
I am intersted in that
I'm intersted in other things also
What I like most is cricket
Shankar is one of 40 students here,
all of them
training for the Hindu priesthood.
Their day follows a strict routine
starting at 5am.
Almost every day the students chant
between seven in the morning
and seven at night.
They're chanting Vedas,
ancient verses which date back
4,000 years, containing
the poetry and myths
on which Hinduism is based.
These religious verses hold
some unexpected thoughts.
They contain the concept of zero
and they touch on the notion
of infinity.
And they use mathematical
concepts such as Pi, square roots
and Pythagoras' theorem.
And, in one part of the Rig Veda
learned by the older boys,
you can find a very
interesting thought.
It addresses a crucial question
about the formation of the universe.
The gods themselves
are later than creation
So who knows truly
whence it has arisen?
"The gods are later than creation."
I think that's
a remarkable sentence.
It displays real intellectual
rigour and honesty.
The gods are later than creation
So who knows truly
whence it has arisen?
It's obviously not a sufficiently
good answer to say,
"Well, all this exists because it was willed
into existence "merely by some kind of deity."
It's reasonable to then ask
the question,
"Well, what's the origin of
the deity?
"Has the deity existed forever,
has the universe existed forever?"
So, I think, just seeing
signs of that...
that kind of thinking which is
really what you might say
the prerequisite or the first signs
of a scientific way of thinking.
The scientific approach acknowledges
that if we're ever going to ask
grand questions like
"Why are we here?"
we have to begin with "how".
In my view science
is a...a humble pursuit.
It starts by asking very simple
questions, asks questions like,
"Why is it that when you let
something go
"it falls to the ground?"
You let it go, it falls to
the ground again,
falls to the ground again,
you observe regularities in nature,
tiny, small regularities,
and try and explain them
and model them, understand them.
Through that process
we've been led to
an intellectual framework
that maybe allows us
to answer questions about the
very origin of reality itself.
From the marketplace
to outer space,
those regularities in nature can be
found almost everywhere you look.
Galileo said nature is a book
written in the language
of mathematics.
And, the more you start
to look for that language,
the more you see it...
..everywhere.
Chambal River
Rivers meander through the landscape
in a seemingly random way
and if you just look at a few turns
then they will be random.
The river might change its course
because of some geology,
a big rock formation.
But if you look at a river
over a large length,
say tens or hundreds of kilometres,
then you see that the meanders
aren't quite random,
a pattern emerges,
there's order there.
This is the satellite picture
of the bend in the river,
the meander you can see here,
and the mathematical relationship,
the pattern that we're
looking for, is this.
If I measure the wavelength
of the meander,
which is just the length
between the point
where the river starts to turn
and meanders up and then
meanders down and comes back again,
you see it's around
11 centimetres on this map.
And then if I measure the width
of the river at this point
then it's something
like one centimetre,
so the ratio of the wave length
of the meander to the width of the
river, in this case, is about 11.
Now, the interesting thing is that
if you take this whole river,
so not just one bend
but hundreds of bends,
you'll find that that ratio
is always somewhere
between about 10 and 14.
What's very interesting is
it's not just this river,
this isn't a special river.
If you look at any river
on the planet,
no matter how small or wide,
you'll find that it's always
somewhere between 10 and 14.
There's obviously some
pattern there,
it reflects something fundamental
about the way that fluids
flow across the surface
of Planet Earth.
And this rule can even be
seen on other planets.
On Mars, the rivers have long
since dried up,
but the arid river beds show
the same meandering pattern.
And on Titan, the largest moon
of the planet Saturn,
the rivers are made of methane
cutting through a bedrock of ice.
But even here the same ratio
appears to exist.
This rule seems to hold true
for every river
found across the solar system.
Bera
Rajasthan
Order is hidden in everything,
from rivers, rocks and landscapes
to living things,
even the most exotic
and elusive of creatures.
"In the days when everybody started
fair, Best Beloved,
"the Leopard lived in a place
called the High Veldt.
"The Giraffe and the Zebra
and the Eland and the Koodoo
"and the Hartebeest lived there,
"but the Leopard,
he was the 'sclusivest
"sandiest-yellowish-brownest
of them all."
Rudyard Kipling's Just So story,
How The Leopard Got Its Spots,
tells the story of an Ethiopian man
who was the Leopard's friend,
he used to go hunting
with the Leopard.
And one day he noticed that
the Leopard wasn't being
very successful, it had a plain,
sandy coat,
whereas all the other animals
had camouflage.
He said, "That's a trick worth
learning, Leopard."
So he took his fingers and his thumb
and he pressed
into the Leopard's coat to give it
that distinctive
five-pointed camouflage pattern.
So, in the absence of an Ethiopian
hunter present at the birth
of every leopard, how did
the leopard get its spots?
No-one disputes the reason
why leopards have spots,
they evolved as camouflage.
What's less obvious is how
the pattern appears on their coats.
Let's have a look.
Fantastic.
He's ducked down into a little...
little valley.
It's really interesting, the moment
you lose sight of the leopard
then you turn round to see it again,
it's very, very difficult
to find it.
You've essentially got to wait
till it moves.
It just shows you
the effectiveness of camouflage.
How does that complex camouflage
emerge from the millions
of separate cells
across the leopard's skin?
Measure out...
..a precise amount of indicator.
Then I'm just going to add it in.
It turns out that complex patterns
can emerge from simple ingredients.
And, mix them up.
Now, if I pour this
into this Petri dish...
There, you see?
And now can you see the colour
coming back,
fading back in?
It's not the usual chemical
reaction,
you mix two things together, you get
a big bang or a cloud of blue smoke,
which is what all chemists love.
This reaction is continually
oscillating
backwards and forwards.
So we started with the simplest
of ingredients,
mixed them together
and they reacted in such a way
that complexity,
that pattern, emerged
from the underlying simplicity.
A similar process
happens in living things.
When the leopard
was still an embryo,
it's thought that two competing
chemicals, washing over the skin,
created the distinctive spots.
So if you have a sandy background,
then you can imagine
one of these chemicals
that causes or stimulates
pigment to appear,
so as it grows you get a dark spot.
Where it's inhibited and drops
you return to the sandy background.
It grows again, you get a dark spot
and returns to the sandy background.
The same principle is believed to
create the stripes of the tiger,
the zebra and the sea snail,
to name just a few.
Scientists get very excited
when they discover
an explanation like this
because it means we've understood
something much deeper about nature
and that's that complexity masks
an underlying simplicity.
All the intricacy that we
see across the natural world
emerges from a few simple laws.
The meander of a river
and a leopard's spots
are just two examples
of patterns in nature,
but there are countless more.
By looking carefully
at the patterns in nature
and trying to understand
their origin,
that's what Copernicus and Kepler
and Newton and Einstein and Galileo
and Curie and Dirac and Feynman and
a thousand others have discovered.
There are regularities in nature,
there are patterns as far
as the eye can see,
on every scale from atoms
to galaxies
and those patterns are a reflection of the simplicity
and beauty of the underlying laws of nature.
A blueprint for creation does exist,
a scientific one.
But how do the laws of physics
explain the existence of human beings?
How, or why, did atoms come together
to form us in particular?
The game of cricket is
unfathomable to some
but to those who understand it
it's bewitching.
I really love it,
I just can't express it...
I...I don't express it in words.
My dream is to play for India.
This is what I've been aiming for
since my childhood.
Today Subitu Bose and his team-mates
are playing against rivals
Neerja Modi School.
Cricket is based on a set of rules
and they haven't altered
significantly since the 1800s.
But, despite the existence of these
rules, no match is ever predictable.
Take, for instance, the ball.
Climate makes a big difference
to its swing,
dew picked up from wet grass
or scuffing from dry ground...
..not to mention how it's bowled.
And then there's the bat.
Each batsman has a preference
for a bat of a particular weight
and that will affect his stroke.
Not forgetting the temperament
of each player,
the mood of the umpire
and the mood of the crowd.
When you get so many variables,
the number of possibilities
becomes enormous
and yet all this complexity
emerged from a set of fixed rules.
A game of cricket is played out
according to a set of simple laws
and so it is for the universe,
and here are the laws
of the universe.
This is the standard model of
particle physics
and this is Einstein's General
Theory of Relativity
and you can fit them
easily on a scorecard.
And here are the laws of cricket
and it has to be said,
at least in this notation,
that cricket is more complicated
than the universe.
But even given these simple laws,
the number of ways that both games
can play out
is effectively infinite.
So the laws do not make
the outcome predictable.
But all we really
care about is the outcome.
In the case of the game
of cricket - who won?
In the case of the game
of the universe - we exist.
And for the cricket match,
the result could have turned on the
tiniest, most insignificant little event,
the way the ball gripped the pitch
and deflected off
a couple of blades of grass,
clipped the edge of the bat
and was caught
by the wicketkeeper.
And it's the same for the universe.
Some collision of two dust particles
ten billion years ago
could have led to a chain of
seemingly insignificant,
infinitesimally unlikely
little events
that led to something that we care
deeply about.
Our existence.
Today the way the game of cricket
played out
had an undesired outcome for Bose.
The fielder caught my, er...
caught the ball here.
Had I have hit the ball
a little to the...
to his left or right, it would
have gone to the boundary.
But, sadly, it went straight
to the fielder.
I was like, "Ahh...
"What have I done?"
Just like a game of cricket,
the way the universe played out
to create us humans
was not determined
by the rules alone.
Chance played a part, too.
Bhand Devra Temple
Baran
This temple's over
a thousand years old,
it's dedicated to
Lord Shiva the Destroyer
and it's built
in the Tantric tradition,
which is at least in part
a celebration of pleasure.
But whilst I find some of these
suggestions instructive,
that's not why we're here.
We're here because of the location
of this temple.
Because this temple is in the centre
of a crater, three kilometres wide.
Geologists are still debating
what made it
but it could well be the scar left by
a meteorite smashing into the Earth.
Throughout its lifetime the Earth has been
constantly bombarded by objects from space.
Think about one particular
collision,
the impact that probably wiped out
the dinosaurs 66 million years ago,
and think about the history,
the lifetime of that rock
that smashed into the Earth.
Imagine one particular day
in the lifetime of that rock,
on one orbit, perhaps billions
of years ago,
when another rock,
no bigger than that,
instead of missing it, hit it,
smashed into it and changed
its orbit very, very slightly.
And, over millions and millions of orbits, that change
would have got amplified, until, perhaps, that day,
66 million years ago, instead
of smashing into the Earth,
the dinosaurs were looking up
at the sky
and they saw a fireball
blaze across the sky
and miss rather than hit.
That would have changed history.
In all probability the dinosaurs
would still be roaming
the surface of the Earth today
and we probably wouldn't exist.
But the rock DID strike,
the dinosaurs WERE wiped out,
and purely by chance our human
existence became possible.
And fateful accidents of equal
importance for our existence
have also happened on a much
smaller scale.
Pushkar
Rajasthan
In Pushkar they have quite
a tradition of camel racing.
There's a saying, apparently,
which is the camel
and its driver go their own way...
..and there's the proof.
Despite that, there's a surprising
similarity between camels and us.
Now what I'm going to do is I'm going to take a
sample of my cells and a sample of the camel's cells.
What's his name? Rapi. Rapi.
Rapi? Yeah. Right.
So to take my cell sample
is quite easy.
I just have to...
..rub that on the corner
of my cheek
so there are my cheek cells
on there.
I'm going to do the same now
to Rapi, but could you hold him,
hold his mouth open?
Actually, you know what,
can I ask you to come?
There's no way I'm going in there!
Can you just rub that on his cheek?
That...that's going to be
enough, that's plenty.
That's plenty, yeah, and then
hand it over there.
There we go!
Right, thank you, thank you.
I apologise.
So now we've got a...
a sample of Rapi's cells
and a sample of my cells
and we'll make a comparison.
I apologise again.
So this is the slide
of my cheek cell.
You see there it's stained blue.
Quite small, but I can see
detail inside it.
And this is a slide
of the camel's cheek cells.
And the most obvious thing to say
is they look identical,
impossible to tell them apart,
and that's because for all intents
and purposes they are identical
and that's because myself and
the camels over there are mammals.
But...
if you look more closely,
then you see that the cells have
many structures inside them.
The most obvious feature
is the nucleus,
where most of our DNA is stored.
But you can also see
hundreds of little dots.
Many of these structures
are called mitochondria.
These are the power stations
found in the cells
of every complex living thing.
And, yet, once upon a time these
essential structures
were separate,
free-living creatures.
A long time ago,
two or three billion years ago,
the Earth was populated
only by single-celled organisms,
two great kingdoms of life,
the bacteria and the archaea,
and, it has to be said,
things were pretty dull,
there was nothing that we might call
complex and, in fact,
very little happened.
Those two single-celled things just
stayed the same for billions of years.
But then one day, quite by accident,
everything changed.
What many biologists believe to have
happened is that a bacterium
got inside an archaean
and for some reason wasn't digested.
Instead, a symbiotic
relationship began.
The bacterium may have been
protected by the archaean
while the archaean got access to the
energy generated by the bacterium.
Once that cell had access to
the vast amounts of energy,
the potential that the
internal bacterium gave it,
then basically all hell broke loose.
And that energy allowed the cell to
begin to work in larger colonies,
to begin to build complex
living things.
So the mitochondria in your cells
today are the descendants
of that chance collision
billions of years ago.
That singular event,
that fateful encounter,
was purely accidental, but the cells
that it produced had such
a survival advantage,
the energy made available to them
by the mitochondria, that its effect
was amplified beyond imagination
by natural selection, which is not
accidental and it is non-random.
So it's the interaction
between accident and rules,
chance heavily constrained
in the framework of natural laws,
that led to the evolution
of humans here on the Earth.
In our universe there was
no particular aim,
no intention for us humans to exist.
Instead the life of the universe
is just like a game of cricket...
..where rules
and chance play out together...
..and quite by accident happen to
produce a human universe.
Over the course of centuries
we've worked to find
the combination of rules and
accidents that made today's world.
We now understand the laws of nature
so well
that we have at least a reasonable
scientific understanding
of every step in that chain, from the present day to the first few
moments after the Big Bang, and that is a tremendous achievement,
it's the great achievement
of modern science.
But just as the origin of the
gods themselves is
questioned in the ancient
Hindu hymns and the Rigveda then
so we are faced with a question,
a very profound question -
who wrote the rules of the game,
what is the origin of
the laws of nature?
What is the origin
of the universe itself?
What went before the Big Bang?
It's a question that takes us
to another world entirely.
Kyoto
Japan
A samurai sword is both sharp
and strong.
Able to cut a body in half...
..but precise enough to slice
through a single hair.
Gassan Sadatoshi is
a master sword maker.
His family have been making swords
for over 800 years.
The Japanese sword is totally unique
it's often said to be the symbol of
Japanese mentality
The first stage is to reduce the
carbon content of the raw material.
If there's too little carbon
it'll be soft,
but too much and it'll be brittle.
This is all a remarkably
high-precision process,
everything that they're doing
matters to make the perfect sword.
And even the force
with which they hammer down matters,
that helps set the precise
mixture of ingredients,
and they're aiming for precisely
0.7% carbon in that steel.
Repeated heating and layering mixes
the iron and carbon
so the block is uniform.
This process can take weeks.
The final stage is to harden
the cutting edge of the sword,
a process called quenching.
Quenching is the most
nerve wracking (part) for a swordsmith
as he has to put his soul into the metal
In the case of a Japanese sword, if
you get all the ingredients right,
the precise mixture
of iron and carbon,
if you get the temperature right,
you get the hammering right,
everything right, over a year,
then you get the perfect sword.
Now, in the case of the universe the ingredients aren't things like
iron and carbon, of course, the ingredients are a set of numbers,
they're called constants of nature, they're things like the strength
of gravity, the speed of light and the masses of the particles.
And they also require precision.
They have to be set in just
the right way
if you want a universe
that supports life.
In the same way that
a samurai sword would be weakened
if the ingredients were different,
the universe might be unable
to support life if the constants
of nature were somehow altered.
Now, if I was some all-powerful
deity, which arguably I'm not,
then I could imagine varying
all those constants of nature
to see what happened.
I could imagine some great big control
board with little knobs on it.
One of them changes the strength
of gravity, the next one changes
the mass of the electron, the next
one changes the speed of light.
And the question is how much freedom do
I have if I want living things to exist?
The answer is, not very much
freedom at all.
If at the Big Bang the strength
of gravity were increased
then the universe would have
collapsed in on itself
before life had time to evolve.
But if the strength of gravity were
decreased then galaxies
wouldn't form, so there'd be
no planets, no stars and no life.
If you decrease the speed of light
by just a few percent
our universe would have
no carbon in it.
Increase it by about the same amount
and our universe would have
no oxygen.
Because we have no idea why the
constants are the values that they are
then we're presented with something of a
mystery, because you can ask the question,
well, if it's just random, if indeed
the universe began and somehow
these random numbers got chosen,
then how lucky are we that we exist?
How lucky are we that we live in a
universe where those constants
are just right to allow
galaxies to from and stars to shine
and elements like carbon to form
in the hearts of stars?
So what could account for the uncanny
precision of this set of numbers?
Hello, can I have just one? Yeah.
Thank you.
You know, our universe, with
all its beautiful laws of nature
and its finely tuned constants,
feels incredibly lucky.
I mean, it's like buying a lottery
ticket and winning the lottery,
but it's stranger than that,
because it's like winning
the lottery in which only one ticket
was ever printed.
But that's of course not how
a lottery works.
Yes, it is extremely unlikely that
I'll win the lottery
with this ticket, but there
are millions of tickets printed
so it's not surprising at all
that someone wins it.
So could we think of our universe
in the same way as the lottery?
The reason that we appear to
live in a perfect universe with
the perfect numbers,
the perfect constants of nature,
the perfect laws, is because there
are in fact countless millions,
perhaps an infinite number
of universes, each with different
physical laws, different numbers,
different constants of nature.
Then we shouldn't be so surprised to
live in the perfect universe.
It's like the lottery - somebody's
got to get the right ticket,
somebody's got to win it.
Just as the lottery has many
tickets,
each bearing different numbers...
..so there may be many universes,
each with different values for
the constants of nature.
Universes with stronger or weaker
gravity,
slower light or faster light.
Now, that might make sense
mathematically
but is it really
a sensible suggestion,
an infinite number of universes?
What does that mean for reality?
Miyake Jima island.
North Pacific
3,000 people live here,
making a living from the sea.
But it's a precarious
place to call home.
Because this entire island is
an active volcano.
Occasionally it belches forth
scorching lava that
incinerates anything that
stands in its way.
Until an eruption in 1983,
this was the island's school.
But volcanism doesn't just destroy,
it also creates.
Around 30,000 years ago this
whole island emerged
from the vast emptiness of
the North Pacific Ocean.
And it's not just this island, it's
the whole of the Izu Archipelago
and much of Japan.
All of these islands have risen up
out of the ocean,
seemingly from nothing.
And it's even happening right now.
This island, called Nishinoshima,
has been growing steadily
since it suddenly
appeared in November 2013.
If we didn't know better, we might
ascribe that creation
to the act of the gods,
but we do know better
because we know about geology,
we've done some science,
so we know that the origin of
this island is volcanism.
It comes from the inner heat of the
Earth, which is itself a leftover
from the history of its formation
4½ billion years ago.
So we have a mechanism
for the creation of new land.
Contrast that with the scientific
explanation for the origin
of the most important thing of all,
the origin of the universe itself,
and for decades
we've been happy to say
the universe began at the Big Bang
and it's almost as if we're
not to ask what happened before.
There was nothing before,
there's no scientific mechanism to
explain how the Big Bang occurred.
But there are now plausible
theories that provide
a mechanism for how universes might
be made from apparently nothing.
So what is this magical
theory that explains
the origin of the universe,
and how did we find it?
Well, the answer is it's a theory
called inflation,
and really the clues
to the theory were there all along,
we just had to look for it.
They lie in the rules of the game.
If there's one basic rule
it's this - things have to happen.
Nothing, emptiness,
is about the only thing that's
forbidden by the rules of
quantum mechanics.
Before our universe
became filled with
particles of matter, it wasn't
empty, it was filled with energy,
and like the surface of the sea it
was constantly fluctuating, rippling
with a form of energy that causes
space to expand exponentially fast.
At the trough of one of the waves,
the energy driving
the expansion
fell below a certain level.
So that region stopped inflating and
the energy was transformed
into the recognisable particles
of today's universe.
And that transformation is what we
see as the Big Bang,
the birth of
our observable universe.
The theory of inflation
is extraordinary
and extraordinary claims
require extraordinary evidence.
Well, here is
the extraordinary evidence.
This is a photograph of
the oldest light in the universe
and it's got many intricate
and detailed properties.
The most obvious one is that
it's an extremely uniform glow,
it's almost all at the same
temperature.
This and all the other properties
of this ancient light are best
explained by an inflationary
expansion of the early universe.
No-one has thought of any theory that
can reproduce this other than inflation,
and that is why I love physics.
Isn't that remarkable?
But, just like the formation
of islands or any other
mechanism in nature, inflation
needn't stop at one universe.
Why should it?
The process of inflation could be
going on eternally,
always making universes, even now.
And each one of these universes
could be like a ticket
in a lottery...
..bearing different numbers for
constants of nature...
..such as the strength of gravity
or the speed of light.
So amongst them all...
there has to be a winning ticket.
A human universe.
It's absolutely inevitable.
If the theory of inflation is
correct, it explains
how our universe appeared
apparently from nothing.
And it also strongly suggests that
there's not just our universe
but a vast number,
perhaps even an infinity of them.
Now we've known for a long time
that we're infinitesimal specks
in a vast universe,
but now the suggestion is that
we're infinitesimal specks
in a vast infinity of universes.
Our current best theory for
the origin of the universe,
backed up by experimental evidence,
suggests that there are an infinite
number of universes, an infinite
number of copies of you and me,
and that the existence of the
whole thing is inevitable.
No purpose, nothing special,
you are because you have to be.
How does that make you feel?
Well, the wonderful
thing is nobody knows,
nobody's worked it out yet,
so the answer is up to you.
What do you think?
For small creatures such as we,
For small creatures such as we,
the vastness is bearable only through love
For small creatures such as we, the vastness
is bearable only through love Carl Sagan
End