Welcome to UCL lunch hour lectures.
I know this is a long tradition,
but I've just been told it started in
the 1940s,
which is quite
an impressive tradition.
It is my pleasure and honour to
introduce Dr Francisco Diego today.
I'm Nick Lane. I'm a Biochemist
in the Department of Genetics, Evolution
and Environment.
You might wonder why is a biochemist
introducing an astronomer?
Well, the answer is that Francisco
is one of these inspiring figures,
there's something about UCL
that attracts people like Francisco,
and there's a handful of people here
who really rise above
and directly interact with people
outside UCL,
who are really inspiring figures
within UCL.
That's how I got to know Francisco
some years ago now.
Francisco is an astronomer,
he did his first degree actually in
mechanical engineering in Mexico City,
then went to the Society for Astronomy
of Mexico,
which was where he became acquainted
with astronomy
and then to the planetarium,
Luis Erro, again in Mexico City,
then came to UCL to do his PhD here
and he's been at UCL ever since,
to my knowledge.
He's a very prominent broadcaster.
He's done films with people like
Brian Cox and Stephen Hawking.
He's really an excellent communicator,
as you'll find out yourselves
if you don't know him already,
in a few minutes.
He's been running at UCL
for the last few years now
the Your Universe Festival
which I've occasionally taken part in
and it's a really wonderful festival
and again, directly fronting with
wider audiences across London
and further afield,
rather than just inside UCL.
He's a Fellow of the Royal Astronomical
Society
and Vice President of the UK Association
for Astronomical Education.
The real reason I'm introducing him
though,
relates to I think, what he'll be
talking about in part today,
which is that he transcends disciplines.
I think this is really important.
He's an astronomer, but he doesn't
see the boundaries between disciplines.
I think we're now at a stage in science
where there are no boundaries in nature.
There is no distinction between
chemistry, physics, biology and so on.
And to be a scientist is to be
all of these things.
Francisco embodies that perhaps
more than anybody else I know.
So without more ado,
Dr Francisco Diego, thank you.
Thank you very much.
Remember that title.
Every single word
is very carefully chosen there.
We're going to deal with the major
questions about origins,
about where things come from.
We're going to explore
the history of the universe.
We're going to conclude
with our local history here.
What we have here,
where do we come from?
Where does our environment come from?
How important are these things
in the context of the cosmos,
in the cosmological context?
If we all go along history,
we find the myths of creation
this comes from China.
The Universe was a big black egg.
This one with Ra and Tefnut
and Geb,
and the goddess Nut with her
body covered with stars.
These one more familiar to us,
a bit more boring about the creation
of the world.
"Let there be light," he said.
This is more interesting
comes from North America.
Tawa, the Sun God,
and the Spider Woman, their goddess.
This one from Australia with
a rainbow serpent,
the creator of the world,
the creator of planets,
the creator of nature,
the creator of humans.
This one from India,
very symbolic with the strength
of the elephant,
the longevity of the turtle
and the eternity of the sulphur
consuming the snake.
Today we have
other explanations
based on fact
about the origin of everything.
As beautiful as these myths are,
they are not true.
They are beautiful and they are part
of cultural heritage,
the mind of a little child,
leaving behind every preconceived notion
and then show humility.
Humility before nature,
nature leads the way.
We are not going to tell nature
how nature should be.
Nature is telling us the way she is
and we have to find out,
that's our duty here,
to find out how nature works.
Beginning with the fundamental
concept that we have here,
a complexity is a diverse set
of structures.
Very complex, apparently, but we go
closer, we have a pattern emerging.
The pattern may be the same in all these
complicated structures we saw before.
All these bricks are virtually
identical,
and they can assemble themselves
to produce these complex environments
like we have like cities.
Even smaller,
we go to grains of sand or clay.
We realise that the whole thing
comes to grains of sand.
This is the analogy of the universe,
the universe comes from
complex structures, diverse structures,
and it reduces to very simple
structures.
There is a sequence here obviously,
we have to have the sand first
in order to have the bricks,
we have to have bricks to have walls,
to have houses, to have cities,
there is a sequence.
We cannot say, "Let there be a city."
it doesn't work like that.
It has to be assembled.
Not created, but assembled.
That's very important.
Another analogy.
How small can water be?
How small?
What is the minimum amount of water
in each of these little droplets?
I don't know like this one here.
That
will be trillions of water molecules.
What is a water molecule?
An atom of oxygen,
two atoms of hydrogen.
H2O.
How small is that molecule?
I will show you this analogy. I've seen
presenters use it all the time.
It is very powerful because it tells us
how science has made this progress,
finding out about the magic
of the smallest things
and the largest things in the universe.
A glass of water.
How many molecules
are in that glass of water?
Well, at least in the primary school,
the kids say trillions.
I hear dead silence.
Remember this analogy.
There are more molecules of water
in that glass,
than glasses of water
in all the oceans.
Imagine that number.
How many glasses of water
in all the oceans?
All of them.
There are more molecules there.
To give an idea how small things can be
and we know that.
It's made out of oxygen, the red one,
and the white, the hydrogen,
where do we get them from?
Where do we get these atoms from?
Where do they come from?
How do they get together?
The molecule is not made,
it is assembled.
Remember that.
Assemble.
You have to put the atoms together.
Where does that happen?
I want you to get the atoms
in the first place.
These are the fundamental questions
that we are going to deal with
before we go into the development
of the universe,
until we get to today.
Okay, let's start,
remember what Huxley said,
about...
getting rid of preconceived notions
and show humility before nature.
This is what we have found.
We go to origins
and the origins of origins,
we have done a lot of work
in this few decades.
We know that the universe,
this picture of the universe
will look something like this.
That was the only act of creation ever.
This is the Big Bang,
so called the Big Bang.
I don't have time
to go into these details here.
I have a timeline here in front of you.
In the normal scale, this should be
a millimetre for every million years.
Okay, that's a million years there.
So that is 1000 million years,
2000 million years.
Okay, until we get to more or less
14,000 millimetres
or 14,000 million years.
Just to give an idea
because I asked you,
can you imagine 14,000 million years,
I cannot you have to see them.
So how? In a timeline.
Still, it's a big struggle.
The Big Bang is primordial energy.
It comes out of nothing, violating all
the laws of physics as we know today,
the laws of physics are not violated,
obviously, by this event, Big Bang.
The expansion of universes starts
at that point 14,000 million years ago.
Then it's pure energy.
There is no stars,
nothing, it's just energy.
No particles, no atoms, nothing,
just energy
for a small fraction of a second,
trillions, trillions, trillions,
billions of a second,
then the energy is transforming
two fundamental particles,
many more,
but these are the ones that are
interesting for the universe we can see.
We call them quarks and electrons.
They're fundamental you cannot break
them and get something inside them.
You get energy.
So these are the grains
of sand of the universe.
This is the fundamental building blocks,
whatever there is in the universe,
that you can see,
is made out of this.
Absolutely everything that you can see.
There is a universe we cannot see
that's a different story.
So, quantum electrons appear
in our development of complexity here,
the complexity grows
as this inverted pyramid grows.
Then I put this in orange because these
are the fundamental particles
like Lego bricks,
that need to be assembled together.
In order to do that, we need different
kinds of glue.
We have the super glue, which is
the strong force,
we have the weak law,
weak force
and then the electromagnetic law,
gravity,
these four forces  we know in nature are
going to interact with these particles
and put them together.
The process of assembly
goes very quickly.
In a billionth of a second.
The super glue is able
to confine quarks in threes.
You get combined charges here,
you get protons, neutrons and electrons.
So in a billionth of a second,
the universe after the Big Bang.
A billionth of a second, okay,
the universe has put together all
the protons, neutrons, electrons
of all the atoms of the entire universe.
You got that?
I don't!
Okay.
Then the process of assembly takes
another step,
that superglue is going to bring
together protons and neutrons
to have the primordial nuclear fusion
of protons and neutrons,
it's called fusion
because they get together.
And it's nuclear because these particles
that are the result of that fusion
are going to appear in the nuclei
of atoms that are still to be formed.
So we're still in the very first
millimetre of our timeline.
In about 400,000 years,
which is half a millimetre,
the electromagnetic glue brings together
the electrons to be nuclei.
The number of protons defines
the type of chemical element,
one for hydrogen, two for helium,
three for lithium,
and they will have some neutrons,
they're just helping the whole thing
to stay stable.
As many protons are selected
as we have here.
These are the very first atoms that will
appear and emerge out of the Big Bang.
Very simple chemistry.
I emphasise the structure
of the atom,
we're going to do that in a minute
in a more specific way.
So this is the first millimetre
of our timeline.
And that's all there is in the universe.
No look of planets or galaxies
or anything,
that's it in the first millimetre.
Then we have the Dark Ages,
the universe keeps expanding
and cooling down,
and the dark ages are a kind of mystery.
Nothing happens apart from the
universe expanding and cooling down,
it's just a black universe,
which is getting colder and colder
and expanding.
It's just a dark cloud of hydrogen
and helium mainly.
After that, from that dark cloud,
we have gravity now,
the gravity force is going to bring that
cloud together
in millions and millions of places to
form the very first generation of stars.
This is what happens when the universe
is about 4-6 hundred million years.
So we are talking now about
this long in our timeline.
So this is proper, proper sky,
the first stars.
Carl Sagan very famously said,
if you want a chocolate cake,
you got to make the universe first.
So, that is what is happening here.
Now we have the stars.
What are the stars doing?
The stars are very hot in the centre,
those temperatures of millions
of degrees here,
that process of nuclear fusion continues
in a more stable way.
Then we have the possibility of bringing
these particles,
protons and neutrons together,
by large numbers.
You have four, you have beryllium,
you have six, you have carbon,
eight, oxygen etc.
This is what stars do.
They have very high pressure,
very high temperature in the centre,
millions of degrees.
So the atom of carbon six, six and six,
six protons, six neutrons,
six electrons.
Remember that picture.
Those stars don't live a very long time.
They live a few million years and they
explode in supernova explosions.
Those explosions are the environment
at thousands of millions of degrees,
where the nuclear fusion continues
for a very short period of time.
So this is where the super glue
is going to...
Let's give them I don't know
300-400 million years.
That's plenty for the stars.
The stars are very,
they live very short lives.
Now the number of protons and neutrons
increases
because of these high temperatures
allow that to happen.
The protons and neutrons
getting together.
Process of assembly, remember that.
That's where we get the heavy
chemical elements.
Here we have the lighter ones,
we have carbon and oxygen.
Here we have gold, silicon, uranium.
79 for gold, protons,
uranium 92 protons.
So heavy atoms,
we are building
the periodic table.
The stars during their lives, and
especially at the end of their lives
are developing the chemistry.
The stars.
Those of you, I hope not, those of you
that believe in astrology.
This is the real astrology.
This is what the stars do for us
all the time,
produce chemical elements,
because without chemical elements,
there is no life,
there is no planet,
there is nothing.
So this is where the chemical elements,
even as small amounts,
because the universe is still
dominated by halogen and helium,
all these chemical elements are traces
but enough to make
the universe interesting.
Imagine a universe made out
of hydrogen and helium,
come on how boring is that?
This is a chemistry that comes from
the Big Bang,
this is a chemistry more or less
give or take a few elements,
that comes when the stars are alive,
all the way down to 26 iron,
and all these are the chemical elements
produced during or after
the deaths of the stars.
We have them available here,
perhaps two or three billion years
after the Big Bang
They are available.
Well in the universe, gravity takes over
and starts collapsing
and producing new generation of stars,
which now will contain part
of these materials, so molecules,
appear in these clouds,
which are the remains of stars.
Here we have the famous water,
that's where water is put together.
We have other things here like
ammonia, methane, carbon monoxide,
carbon dioxide, etc.
Gravity brings together these clouds
and then produces new generations
of stars and planets.
Now we have metals,
now we have silicas,
now we have carbides,
we have solid material out of which
we can't produce rocks.
One of them we call them meteorites.
This one is made out of hydrogen
and nickel,
one of those chemical elements there.
So, this is what makes planets,
make proper planets,
I mean solid planets.
Our complexity and diversity
keeps expanding.
We are now in this process.
Let me just put this here.
This is the building site
of our solar system,
a star with planets around it,
not ours.
But the possibility of solar systems
was already there
when the universe was a portable affair
of present age.
There will be planets there.
Let me see what is there.
There should be aliens in those planets,
gave them 1000 million years
to develop and do something.
That process of planet formation
is very common in the universe.
There will be millions and trillions
of events like this one
happening almost simultaneously
along this timeline.
There will be trillions and trillions
of possibilities of aliens to be there,
already there when
the universe was there.
The chemistry was there,
conditions were there.
They have no excuse not to be there.
Many of them actually.
Another one here just to make the point.
How does he go?
How do you put an alien
on a timeline?
With no props, okay.
However, these aliens have to
do something
because as we know,
that star is not forever,
that star is going to explode
in a supernova explosions,
it's going to end its life
in a kind of tragic way.
So, they have to avoid the destruction
of their own solar system,
otherwise,
they will be part of that cloud.
It will be our case,
if we keep on this planet long enough,
that will come,
that point will come,
when the sun dies and with the death
of the sun is the death of the planet,
and if we're still here,
we will be part of the cloud,
that was the sun one day.
But in this case,
these clouds keep recycling.
Gravity keeps putting them together.
And now we have the formation
of our own solar system.
I'm in a meteorite here now.
Our solar system was formed...
These are short metres,
because the timeline is a bit...
one, two, three, four thousand...
five hundred and sixty six...
million years old.
We know that because we did
chemical analysis isotopic ratios
in meteorites like this one,
we can tell this meteorite was gas,
it solidified about that time,
4566 million years ago.
Give or take,
most meteorites give you that number.
The age of the solar system, the age
of the sun, the age of the Earth.
Now we are coming
to the interesting part, the Earth.
A very violent place.
That solar system
was full of collisions,
destructive collisions
but also constructive mergers
of bodies, of meteorites, of asteroids,
of planets that get together.
In this case, the Earth's suffered
a collision with another planet
almost the same size.
From that collision, we know now,
comes the moon
and the moon is extremely important,
the result of that collision
is that the axis of the Earth is tilted.
The gyroscopic effect of the moon
going around the Earth
keeps that axis tilted
with the same angle,
which is very important to keep
weather stability for millions of years,
which is what we need
in order to go further
and use the atom of carbon now to
complicate the situation.
By complicate, I mean make it
more interesting, more challenging.
Our planet was a greenhouse planet
with simultaneous volcanic eruptions
with electric storms,
all kinds of nasty things, it was Hell.
So if you want to rewrite the Bible,
you have to say in the beginning,
the earth was Hell.
Any edition of Hell
that we can imagine,
is short of what it really was.
From that Hell,
from that enormous violence that we have
with these greenhouse gases
making the Earth extremely hot,
and also with volcanic eruptions
that were happening in the oceans
in the bottom of the oceans.
We have the chemistry.
Electromagnetic force is going
to bring molecules together
by the millions,
by the trillions,
and eventually we get one of the most,
I don't know if this is
the most complex,
it is the most beautiful, I would say,
and it is the common denominator of life
which is DNA,
deoxyribonucleic acid.
It's made of six molecules,
small molecules.
This is the full basis and the sugars
and the phosphates which are outside.
This is what DNA is,
this is the colour code for the atoms,
this is phosphorus that you can find
outside here in the helicoidal part
and the other ones are carbon, hydrogen,
oxygen and nitrogen,
which are part of the basis
which are in the in the middle here.
I want to say something that perhaps,
I hope,
every single living thing on this planet
is based on DNA
from the very beginning.
That DNA...
is the common denominator,
it is what makes us the same.
Maybe put the Earth here
as we think it was.
Then we have the DNA,
which is a molecule,
it's very simple; it's only five atoms.
Only six molecules,
but it goes on and on and on.
If DNA was at that scale, it would be
the size of the solar system,
because the bases don't repeat
themselves in the same place,
they change the order.
That is what makes the biology
so interesting
and by far the most challenging
part of science,
biology and what is going on
in little cells is fascinating.
It's a replicator.
It can reproduce itself.
It's one of the characteristics
for life.
At that time, it was encapsulated
in membranes
to produce the very first cells,
proper cells,
the archaea and prokaryotic cells
that appear, as you can see
very quickly,
in a few hundred million years
from the formation of the solar system,
we already have life.
That could have been the case here.
We don't know, it's very difficult
to get evidence for that.
But we know the conditions were there
and life at this level of cells
that cannot do anything else apart from
being individuals
is probably very common in the universe.
Primitive life.
What do these cells do?
Some of them that live in the oceans
have the ability to photosynthesize.
They had the ability to wipe out
the carbon dioxide
that was very abundant in the atmosphere
of the Earth at that time
and free oxygen in the atmosphere.
It changed what was Hell as I told you
and that Hell becomes paradise.
Another thing to write in your Bible
is that we owe paradise
to cyanobacteria,
to blue green algae that
are still doing that as we speak.
Now how cool is that?
Should we build a church to
cyanobacteria and worship them?
This is easy, this was fast.
The next step...
is very difficult.
I'll put paradise here.
By the way, this paradise
didn't come that quick.
Those cyanobacteria had to work
for about 1000 - 2000 million years.
In order to produce paradise,
a paradise is not that easy to make.
This is where these kind of processes to
be replicated here
are going to be very difficult.
So we have now the eukaryotic cell.
The eukaryotic cell is a kind of colony
of bacteria inside each other.
This is a cell that is a eukaryotic cell
because it has a nucleus,
it has organelles, it has internal
membranes,
it has chloroplasts and mitochondrion,
all the things that make the cell
extremely important
to assemble themselves into organisms
like plants and animals,
what we will call complex life,
that was so well studied by Darwin.
Darwin started writing in his book.
Remember this, I think this is
the most important thing,
especially the young members
of the audience.
This is the most important thing in life
is to think,
to put things together.
Even if society doesn't want you
to think,
you have to overcome the power.
You have to think, because that's how
we come to these amazing beautiful,
beautiful things.
So the eukaryotic cell
doesn't come that quick either.
It will take another
1000 -1500 million years.
This is today by the way.
Look where we are.
There are no animals yet.
Until we get ammonites
a few million years ago.
Ammonites...
were dominating with many other species
here in the oceans,
until...
That's a fact for biology,
natural selection, evolution.
But we have this tree of life,
that was developing each of these
branches is suspicious.
That tree of life was chopped down
260 million years ago.
95% extinction.
95% of species were made extinct,
almost like this,
by chance,
and this is important,
luckily, the survivors were able
to produce another tree.
The tree is different.
It's a tree. It has branches,
but the branches are different.
They survived this one
but trilobites didn't.
Ammonites will survive
and then roam the earth.
This is where the dinosaurs come from.
Dinosaurs.
I'm trying to find room
in the timeline.
We're talking 200 million years ago.
Very famously now we have more evidence
for this event 64 million years ago,
an asteroid the size of 10 kilometres
more or less
impacts what is today in
the Gulf of Mexico,
and wipes out 75% of the species
in that cataclysmic collision,
including the dinosaurs and some sharks
and some other species survive,
especially species in the oceans
managed to survive.
So our new tree develops again,
by chance,
all these are chance events.
If you remove any of these events
from history,
nothing of this will be happening.
Something else will happen of course,
also by chance,
and this is where we come from.
This is where the mammals have
a chance to flourish,
to really after being repressed
by the dinosaurs,
they finally have a chance to flourish.
And this is where we come from,
the present tree of life.
One of them, there is many versions
you can find in the Internet.
But it is amazing the amount of species
that we have here,
all the ones that we have in this part
here are microscopic.
Here is where we have the plants
and animals there.
These, if you find,
where are we,
it's somewhere in the cordate, these are
the ones that have a spinal cord,
vertebrates.
That's what we are.
Remember [INAUDIBLE} with humility,
this is a big lesson for humility.
That's what we are,
a little twig there.
So we come...
In the last few million years,
humans have evolved.
There are many species
that became extinct in that process.
This is what we are today, homosapiens.
The distance between the beginning
of homosapiens and today,
in time, is the thickness of this piece
of paper.
There in our timeline.
That's another lesson of humility.
So the complexity of the universe
comes now
to culminating with brains,
which is all made out of quarks
and electrons, remember that,
it's just a process of assembly
along this timeline.
I want to finish now by talking
a little bit about ourselves,
a little bit of our environment,
our five races.
Different on the surface,
but identical if we remember
what we come from.
There is still evidence that all humans
come from central parts of Africa.
I have my globe here
to show you that.
We come from a place
between Tanzania and Kenya,
that sort of area there.
By migration, in capital letters,
by migration, we populate Asia
and Europe
and eventually, by migration we populate
America.
It's a continent America, okay?
The continent of America.
United States is only one country
out of 36 I think countries, okay.
And what happened?
This came from the Strait of Baring
20,000 - 30,000 years ago,
populated America.
And the Europeans took the ships
and crossed the Atlantic
and found them in a way
they failed to recognise each other,
they were the same,
they came from the same place
in different routes.
And look what happens today,
we still fail to recognise each other.
big tragedy.
Chemical composition.
That's the DNA with calcium
for the bones.
Not very different from the dinosaur.
DNA.
Our DNA is the same
of all living species, about 50%,
with the apes,
we are 98.6% similar to the chimpanzee.
We are apes as well as a gibbon,
orangutan, chimpanzee,
this one is gorilla and man,
So similarities are astonishing.
This is what science is telling us.
If we look at our environment,
beautiful environment.
What are we doing with it?
I'll keep quiet now.
Why is that?
It is the greed of a few
and ignorance and apathy of many.
Nothing else.
We have to invoke the wisdom
of our ancient cultures,
of those myths,
they didn't know
about quarks and electrons,
they had a lot of wisdom.
We better use that wisdom
that lives in harmony with each other,
in harmony with nature.
And they say, we have a state of life
that calls for another way of living.
If we dig precious things from the land,
we will invite disaster.
This is the wisdom of ancient cultures
that didn't know about galaxies
or anything.
A state of life that calls
for another way of living.
So, what we have now,
more and more unfortunately, is this.
The economy is the top of importance
in human activities.
It is feeding from humanity
and from the natural environment.
So very simple,
is put it the other way around.
So the economy is going to feed humanity
and it's going to feed
the natural environment.
Very simple.
How you do that?
That is the problem.
We have education,
as Nick said just now,
we have projects that are educating kids
about all we have been talking about,
with molecules, with the structure
of atoms,
periodic tables made out of biscuits,
and all this kind of thing.
We need to really have a very strong
movement in education to do that.
Thank you very much.
Well, thank you, Francisco
for a masterpiece.
We have a few minutes
for some questions.
There are microphones.
So please wait for a moment until
the microphone arrives.
First question here, please.
If we go back to the quarks
and electrons as we are capable of,
is it possible for us to use some form
of fission
to create briefly the primordial energy?
Because that is the thing
we don't know, isn't it?
To break the quarks,
I was told once
that you need a particle accelerator,
the size of the galaxy.
That sort of energy.
I think it was the idea.
So the answer is no, essentially.
We have to accept that we don't know
what primordial energy is
or where it came from.
Well,
the Planck Era is one of the regions,
the epochs of the universe,
that we know very little.
It violates the laws of physics
and all these little space,
so we need to find out a lot more.
Just thinking about the probability
of life elsewhere,
so that if life happened
once in 4 billion years
with the chance occurrence of a self
replicating molecule on this planet,
can you work out a probability that it
might have happened again,
in terms of what we estimate as other
liveable planets in the universe?
Yes.
It didn't take that long.
I mean, primitive life only took
a few hundred million years here, okay?
To have bacteria.
Then what follows is a long chain
of cataclysmic events,
accidental things,
and events that happen for example,
in the case of the transformation
or the assembly of bacteria
into eukaryotic cells,
is something that happened only once
in one place.
It is a miracle essentially.
So to have these events replicated
elsewhere in the universe
is going to be extremely difficult,
despite that we have trillions
and trillions of planets.
Thank you very much for the lecture,
it was very enjoyable.
I am wondering, you hinted earlier on
about the things we do know
the parts of the universe we do know,
and obviously, there's a lot of research
into what we don't know currently that's
out there.
Do you have an instinct,
a gut feeling at all?
No, I'd better not go into that.
I have to say what we have seen here
is 4% of the universe, okay.
There is 96%
that we don't know what it is.
Most of it is dark energy.
A lot of that is six times more matter
that we can see here.
Which is called Dark Matter,
it should be called transparent matter,
which is what it is.
We still don't know.
So let alone the Big Bang
and let alone many other things,
but what we know is not bad, really,
I mean, in this amount of time,
we have achieved so much.
I mean, it's a sense of pride,
of course, it's humility,
but still, look what we have done.
We should keep going.
There's plenty of timeline there
to continue in the future.
So future generations can take over
and then find out more things.
But certainly,
lots of things we don't know.
Stephen Hawking very famously said
in one interview,
he had an event
in the Royal Albert Hall,
[UNCLEAR] was chairing that meeting
and he said,
well, there were pre-recorded questions
at the end from the audience,
and he pre-recorded,
he was in his wheelchair then.
The last question, Dr Hawking,
do you think that one day we will know
everything about everything.
What was his answer?
I hope not.
Hi, thank you.
My question is about other universes.
I have heard from quantum physics
that if you have quarks,
they seem to be in multiple places
at the same time.
It's like one of these arguments
to expand that [UNCLEAR] exists.
So I just want to know,
what is your take on that?
Parallel universes?
You cannot say no,
it is a possibility.
A lot of astronomers and cosmologists
are advocating a possibility
of several universes existing
in their own timelines
with their own things independently
and simultaneously.
But if we're thinking about ways of...
trying to learn more about the universe,
that doesn't solve anything.
The combination of all those universes,
you can call the universe.
So you are back to square one.
It's like the turtle.
The world supported by elephants,
elephants by turtle,
what is supporting the turtle?
It's turtles all the way down.
That's the question.
Infinite regression
is impossible.
You have to be very careful.
Philosophers went very seriously
into these depths.
They became mad.
So you have to be careful.
Let me have just one minute
because I forgot to do this.
Look at the amount of water here.
There it is.
This globe is 30 million times smaller
than the Earth.
At this scale, Mount Everest will be
a quarter of a millimetre high.
The atmosphere will be
two millimetres thick,
and the oceans will be paper thin, deep.
The amount of water in all the oceans
on Earth will be this here.
That's all the water we have on Earth
at this scale.
When we say there is a lot of water
in the oceans, think about that.
This is how easy it is to destroy
the environment
and we are doing it very well,
very efficiently.
We have to bear this in mind,
the amount of water
we have in the ocean.
We have to stop there, because there is
another lecture coming in afterwards.
So thank you very much for coming.
Thank you Francisco Diego.
