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The universe is falling apart.
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Something is forcing galaxies
to rush away from each other
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at ever-increasing speeds.
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Ever since
this alarming discovery,
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physicists have struggled
to understand
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what might be causing it.
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So far,
they've come up with a name.
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They've called it dark energy.
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Dark energy is basically
our name for that thing
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that we don't understand.
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It's not the color dark.
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It's just an expression
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of our ignorance
as to what is the stuff.
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The discovery of dark energy
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really surprised
theoretical physicists
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and remains
a deep mystery of nature.
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We are absolutely
still lacking great ideas.
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So, it is crying out
for some new breakthrough,
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new thinking.
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Scientists all over the world
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are on the hunt for answers
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to modern science's
most enduring problem...
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to paint the biggest
picture of all,
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to finally solve the mystery
of dark energy.
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Captions by vitac
www.Vitac.Com
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captions paid for by
Discovery communications
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Energy is all around us.
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It comes from the sun,
from chemical reactions,
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from electricity.
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Energy powers our vehicles,
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heats our homes,
lights our nights.
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Understanding energy
has transformed our planet
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and our lives.
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Dark energy is something
altogether different.
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It seems to serve
no useful purpose at all
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except to show us
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that we understand less
than we thought we did.
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Dark energy
arrived entirely unexpectedly
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at the very end
of the 20th century.
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In 1998,
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a young scientist
named Saul Perlmutter
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was thinking
some very big thoughts indeed.
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As a graduate student,
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I really wanted
to find a project
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that would answer some...
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or at least be looking at some
very philosophical questions,
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something that felt
like it was meaningful
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about the world we live in
in some, you know, deep way.
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The question
that's been really exciting me
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is whether the universe
will last forever.
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Do we live in a universe
that is infinite
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or, some day,
will it come to an end?
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The two big options at the time
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were that the universe
could expand forever
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but just slow and slow and slow
but forever be expanding.
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Or if there was enough stuff
in the universe
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to gravitationally attract it,
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it could slow to a halt
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and then collapse
and come to an end.
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Perlmutter was measuring
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the way the universe
was expanding
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by observing exploding stars
called supernovae.
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One particular kind of supernova
always explodes the same way
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because it waits
until just a critical amount
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of mass has fallen on it,
and then it explodes.
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So, they all look very similar
to each other.
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They brighten as a firework,
then fade away,
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and they reach
the same brightness.
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And you can then use that
as an indicator
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of how far away it is
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by just looking to see
how bright it appears to you.
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Because they explode
with exactly the same intensity,
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these supernovae
are known as standard candles.
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By comparing
their relative brightnesses,
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relative distances
can be calculated.
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Perlmutter expected the stars
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to show what everyone
thought at the time...
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that the universe
was slowing down.
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Fainter ones are further,
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just like when you watch,
you know,
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a car recede into the distance,
you can tell
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how far away it is by
how faint the taillights look.
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If you can use the brightness
of a supernova
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to tell you how far away it is,
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that's really telling you how
long ago the explosion occurred,
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because you know
how long it takes
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for light to travel
that great distance.
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So, now we have an object
where it explodes,
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and its brightness
tells you when it exploded,
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how far back in time
it exploded.
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No matter how good the theory,
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the practical problem
of catching an exploding star
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at just the right time
is immense.
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But Perlmutter and his team
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applied the very latest computer
technology to the problem.
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Finally,
we have the analysis completed,
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at least the computer's part
of the analysis,
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and it's beginning
to show us on the screen
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what it thinks might
be a supernova.
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Eventually,
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after the team had identified
42 such dying stars,
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the calculations began.
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What Perlmutter discovered
shocked him.
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The data was telling
the wrong story.
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The universe didn't appear
to be slowing down.
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We... we thought
that that's what we would see,
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and it looked like the opposite
was taking place,
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and, in fact, the universe
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was speeding up
in its expansion.
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These distant supernova
were fainter
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than you would have thought,
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and very significantly fainter.
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They were, you know,
probably 20% or more.
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And that's the hallmark
of a universe
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that's actually speeding up
in its expansion.
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To say
that this result was a surprise
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would be a major understatement.
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It was so unexpected
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that the initial reaction
was disbelief.
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Everybody knew Saul,
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and everybody knew
the experiment he was doing.
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And I remember sitting in
the audience and Saul getting up
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and expecting him
to present an update
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on the results he'd given
a year ago
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that actually the universe
was slowing down.
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And so, I was absolutely amazed
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that, based on
only twice as many objects
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as he had the year before,
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that suddenly, he was saying
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that we lived in a universe
that was accelerating.
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I remember it just
being just incredible.
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I mean, all the astronomers
walking around,
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scratching their heads,
saying, "this can't be right."
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Surely it can't be right."
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It was not the result
that people had been expecting.
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And such an extraordinary claim
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demands extraordinary
evidence...
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more than a few data
from a handful of stars.
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So, here we are on a beach
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where there's
about a billion pebbles.
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And if you think you're trying
to understand this beach,
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you wouldn't think you could
understand it from 42 pebbles.
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But Saul was right.
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He was able to work out
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that the universe
was accelerating
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just from 42 supernovae,
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which is quite incredible
when you think about it.
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On the one hand,
this was a good result.
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It was new science
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and produced a nobel prize
for Saul Perlmutter.
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On the other,
it raised an obvious question.
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Once you know that the universe
is actually speeding up,
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then you're faced
with the question of,
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"Well,
what could make it speed up?"
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So far, the only
real progress on that question
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has been to give
the phenomenon a name.
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It's become known
as dark energy.
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Dark energy
is just the term we use
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to describe whatever it is
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that makes the universe
accelerate in its expansion,
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what makes it expand
faster and faster.
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We don't know what that is.
It's a mystery.
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And so, we call it dark
to reflect our ignorance,
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not because the color is dark.
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The mystery
is so deep, so beguiling,
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that wherever
there are physicists,
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there are people hoping
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that they will solve
the mystery of dark energy.
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People safe
in the infuriating knowledge
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of what they're looking for,
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if it's there at all,
is all around them.
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But the fact that no one
has yet been able to identify
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what the dark energy
might actually be
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has opened a can of worms
not seen in science
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since the last time a physicist
got involved in cosmology.
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In 1915,
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it seemed that the work
of physics was nearly at an end.
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Everything made sense.
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Newton had explained the heavens
by invoking gravity.
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And atoms had been identified
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as the smallest
invisible units of matter.
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Job done.
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But then a German man
who liked to muse on trains
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turned up with
a totally new set of ideas.
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I very rarely think in words
at all.
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A thought comes.
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And I might try to express it
in words afterwards.
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Einstein called
these little flights of fancy
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his thought experiments.
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And they would lead him
to develop his theory
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of general relativity,
which totally changed
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how the workings
of the universe were understood.
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According to Einstein,
space isn't simply a void.
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It's more
like a four-dimensional fabric,
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woven from both space and time.
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The mass of planets
can warp and distort the fabric,
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gathering
other celestial objects,
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like moons, around them.
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And it's this bending
of space-time
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that creates the effect
we experience as gravity.
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So, Einstein's theory
of general relativity
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is a beautiful theory.
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It's incredibly elegant,
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and it's been, now,
around for 100 years.
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It's very predictable.
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You can write things,
make predictions
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of what the universe
should look like
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and what objects should
look like in the universe,
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and we can test those.
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And as far as we can tell,
it's passed every test.
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The power
of general relativity is that,
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like Newton's version
of gravity before it,
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it's predictive.
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Bizarre as the curvature
of space-time may sound,
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it's eminently testable.
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In 1919, British astronomer
Arthur Eddington
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pointed his telescope
at a patch of sky near the sun
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during an eclipse
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and observed a star known
to be actually out of view,
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behind the sun.
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Its rays of light had been bent
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by the distorted space-time
created by the sun's mass.
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Einstein's theory had held up.
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A paradigm had shifted,
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and the crowd went wild.
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00:11:34,400 --> 00:11:39,269
Einstein was suddenly famous,
undoubtedly the cleverest
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yet most incomprehensible man
on earth.
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This is what all
the fuss was about.
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This is the equation
that the porters
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and waiters were discussing.
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On the one side,
the geometry of space-time.
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On the other, the mass
and energy of the universe,
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which acts on it.
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Not incomprehensible at all,
at least not to its author.
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00:12:11,170 --> 00:12:13,939
But there was one aspect
of general relativity
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that Einstein himself
didn't understand.
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00:12:22,780 --> 00:12:24,779
The problem that Einstein had
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00:12:24,780 --> 00:12:28,980
is when he solved his equations
of general relativity,
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what he found was
that he predicted
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that the universe
should actually be expanding,
241
00:12:36,200 --> 00:12:38,129
and that was radically different
242
00:12:38,130 --> 00:12:39,929
from the perceived wisdom
at the time,
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which is that we lived
in a static universe...
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both static in time
and in space.
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So, he put in
an extra term into the equation.
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He called it
the cosmological constant.
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00:12:54,116 --> 00:12:55,670
He used the Greek
variable lambda.
248
00:12:55,680 --> 00:12:58,400
But effectively,
it was really just what,
249
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you know,
a physics undergraduate
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would call a fudge factor
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00:13:01,156 --> 00:13:03,710
that was just designed to make
the equations come out right.
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And it would just make the
universe sort of stand still.
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When you add the lambda term,
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it means that the equation
is not quite as simple
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as it was before.
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00:13:17,670 --> 00:13:21,510
So, in that sense, it's not
as beautiful as an equation.
257
00:13:23,880 --> 00:13:27,149
The static universe
was restored,
258
00:13:27,150 --> 00:13:29,900
but Einstein always felt
259
00:13:29,100 --> 00:13:33,980
he'd added lambda
against his better judgment.
260
00:13:33,990 --> 00:13:35,760
Despite the fudge factor...
261
00:13:35,761 --> 00:13:38,519
lambda, the cosmological
constant...
262
00:13:38,520 --> 00:13:40,750
Einstein continued
to be celebrated
263
00:13:40,760 --> 00:13:43,959
as the world's cleverest man...
264
00:13:43,960 --> 00:13:48,930
Until, in 1929,
he became even more clever.
265
00:13:52,600 --> 00:13:55,369
In the U.S., an astronomer,
Edwin Hubble,
266
00:13:55,370 --> 00:13:57,100
was about to get a reputation
267
00:13:57,110 --> 00:14:00,579
for scientific cleverness
himself.
268
00:14:00,580 --> 00:14:03,149
He'd been using the world's
largest telescope
269
00:14:03,150 --> 00:14:07,119
at Mt. Wilson in California
to peer deeper into space
270
00:14:07,120 --> 00:14:09,760
than anyone had ever
looked before.
271
00:14:11,860 --> 00:14:15,259
What he discovered completely
changed the meaning
272
00:14:15,260 --> 00:14:18,529
of the word "universe."
273
00:14:18,530 --> 00:14:20,469
Until Hubble,
it had been thought
274
00:14:20,470 --> 00:14:23,869
that the universe
was our galaxy.
275
00:14:23,870 --> 00:14:27,769
What Hubble saw was that,
in fact, our galaxy
276
00:14:27,770 --> 00:14:30,430
is just one
of countless millions
277
00:14:30,440 --> 00:14:33,609
but, more importantly,
that all these galaxies
278
00:14:33,610 --> 00:14:36,140
were moving apart
from each other.
279
00:14:36,150 --> 00:14:40,419
The universe wasn't static
after all.
280
00:14:40,420 --> 00:14:43,659
This had huge implications.
281
00:14:43,660 --> 00:14:46,130
It introduced the notion
of a beginning
282
00:14:46,131 --> 00:14:49,120
and an age for the universe.
283
00:14:49,130 --> 00:14:51,599
But more importantly
for Einstein,
284
00:14:51,600 --> 00:14:54,469
it meant that he could ditch
his fudge factor,
285
00:14:54,470 --> 00:14:56,699
the cosmological constant,
286
00:14:56,700 --> 00:15:00,700
and return general relativity
to its former glory.
287
00:15:04,310 --> 00:15:07,149
Einstein was over the moon.
288
00:15:07,150 --> 00:15:11,479
In 1931, he went to Mt. Wilson
to shake Hubble's hand
289
00:15:11,480 --> 00:15:16,280
and thank him for putting beauty
back into his equation.
290
00:15:16,290 --> 00:15:18,289
Lambda, he later confessed,
291
00:15:18,290 --> 00:15:22,629
was the biggest blunder
in his career.
292
00:15:22,630 --> 00:15:26,369
I think that the reason
that he said that...
293
00:15:26,370 --> 00:15:27,829
that it was a blunder
294
00:15:27,830 --> 00:15:32,560
was because if he had just
not introduced that term,
295
00:15:32,570 --> 00:15:34,800
then he would have said that,
296
00:15:34,810 --> 00:15:37,209
you know, the universe
must be expanding
297
00:15:37,210 --> 00:15:41,509
and done that 14 years
before the discovery
298
00:15:41,510 --> 00:15:44,100
of the expansion
of the universe by Edwin Hubble,
299
00:15:44,200 --> 00:15:46,689
which would have been
a great achievement.
300
00:15:46,690 --> 00:15:48,989
But despite Einstein's blunder,
301
00:15:48,990 --> 00:15:52,789
general relativity
has stood the test of time.
302
00:15:52,790 --> 00:15:54,500
It is perhaps
303
00:15:54,600 --> 00:15:58,359
the single most successful
scientific theory yet.
304
00:15:58,360 --> 00:16:01,900
Every observation
we make of gravity,
305
00:16:01,100 --> 00:16:04,769
from the smallest scales
306
00:16:04,770 --> 00:16:07,569
to solar-system scales
307
00:16:07,570 --> 00:16:10,600
to galactic scales
all the way to the universe...
308
00:16:10,610 --> 00:16:13,979
all of that can be described
using the single theory
309
00:16:13,980 --> 00:16:16,719
that Einstein created.
310
00:16:16,720 --> 00:16:20,919
So, it's the most successful
and beautiful theory
311
00:16:20,920 --> 00:16:24,919
we have of our universe.
312
00:16:24,920 --> 00:16:27,450
Or at least it was.
313
00:16:27,460 --> 00:16:29,759
For all its beauty
and simplicity,
314
00:16:29,760 --> 00:16:31,259
general relativity
315
00:16:31,260 --> 00:16:35,160
doesn't account for the effects
of dark energy.
316
00:16:35,170 --> 00:16:38,599
Expansion as reported
by Hubble works fine,
317
00:16:38,600 --> 00:16:41,330
but the accelerated expansion
of the universe
318
00:16:41,340 --> 00:16:46,779
that Saul Perlmutter found
isn't part of the deal.
319
00:16:46,780 --> 00:16:49,320
That it's there at all
is bad enough,
320
00:16:49,321 --> 00:16:53,210
but worse, the way that
dark energy seems to work
321
00:16:53,220 --> 00:16:57,119
is unlike anything
that's been observed before.
322
00:16:57,120 --> 00:16:58,780
The density of anything
323
00:16:58,790 --> 00:17:03,659
is the amount of stuff
you have within a given volume.
324
00:17:03,660 --> 00:17:06,490
And dark energy
is an usual phenomenon
325
00:17:06,500 --> 00:17:09,169
in that even though the volume
of the universe
326
00:17:09,170 --> 00:17:11,499
is increasing as it expands,
327
00:17:11,500 --> 00:17:13,530
the density is staying the same.
328
00:17:13,540 --> 00:17:16,309
So, it's almost as if
there's new dark energy
329
00:17:16,310 --> 00:17:19,949
being created all the time
as the universe expands,
330
00:17:19,950 --> 00:17:25,279
meaning that its density
remains the same, constant.
331
00:17:25,280 --> 00:17:28,100
So, you can think of it
as you get more space,
332
00:17:28,200 --> 00:17:30,890
you actually get more
dark energy,
333
00:17:30,900 --> 00:17:32,125
which is like getting something
for nothing,
334
00:17:32,126 --> 00:17:33,550
which is clearly ridiculous.
335
00:17:33,560 --> 00:17:38,290
I mean, it's clearly
against all our training
336
00:17:38,300 --> 00:17:39,600
as physicists.
337
00:17:41,870 --> 00:17:44,969
There is one way
to adapt general relativity
338
00:17:44,970 --> 00:17:46,739
to cope with this magically
339
00:17:46,740 --> 00:17:49,139
constantly
self-replenishing force,
340
00:17:49,140 --> 00:17:53,770
and that is to simply
add it to the equation.
341
00:17:53,780 --> 00:17:57,349
100 years after Einstein's
biggest blunder,
342
00:17:57,350 --> 00:18:00,949
the cosmological constant
is back.
343
00:18:00,950 --> 00:18:03,650
Lambda
is being written once more,
344
00:18:03,660 --> 00:18:06,629
this time not to keep
the universe still,
345
00:18:06,630 --> 00:18:08,859
but to account
for its unexplained
346
00:18:08,860 --> 00:18:11,399
accelerating expansion.
347
00:18:11,400 --> 00:18:12,629
The values are different,
348
00:18:12,630 --> 00:18:17,230
but the concept
is exactly the same.
349
00:18:17,240 --> 00:18:22,939
All this leads to one of two
equally alarming conclusions.
350
00:18:22,940 --> 00:18:28,670
Either we need another Hubble
or we need another Einstein.
351
00:18:28,680 --> 00:18:32,585
But before we consign Albert
to the scientific scrap heap,
352
00:18:32,586 --> 00:18:35,449
there is a branch of physics
which might help,
353
00:18:35,450 --> 00:18:38,719
an area where things popping in
and out of existence
354
00:18:38,720 --> 00:18:40,150
is quite normal.
355
00:18:49,760 --> 00:18:52,990
Welcome to the strange
and wonderful world
356
00:18:52,100 --> 00:18:56,529
of Clare Burrage
and of quantum mechanics.
357
00:18:56,530 --> 00:18:59,199
Quantum mechanics
is the theory of what happens
358
00:18:59,200 --> 00:19:01,160
to really, really small things.
359
00:19:01,170 --> 00:19:04,300
It's the theory
of how the fundamental particles
360
00:19:04,400 --> 00:19:05,439
in the universe work...
361
00:19:05,440 --> 00:19:08,909
atoms, electrons, protons.
362
00:19:08,910 --> 00:19:13,140
And quantum mechanics
is intrinsically uncertain.
363
00:19:14,990 --> 00:19:19,189
Einstein hated
quantum mechanics.
364
00:19:19,190 --> 00:19:22,159
But even though Einstein
didn't like it,
365
00:19:22,160 --> 00:19:25,799
quantum mechanics could
shed light on dark energy
366
00:19:25,800 --> 00:19:30,769
and come to the aid of
his once-more-under-fire theory,
367
00:19:30,770 --> 00:19:32,310
in theory.
368
00:19:34,610 --> 00:19:36,709
Quantum mechanics
tells us that particles
369
00:19:36,710 --> 00:19:39,245
can come in and out of existence
in the vacuum.
370
00:19:39,246 --> 00:19:41,340
And the fact
that those particles have mass
371
00:19:41,350 --> 00:19:42,720
and potentially
are moving around...
372
00:19:42,721 --> 00:19:44,470
they have a little bit
of energy.
373
00:19:47,620 --> 00:19:49,489
And so,
when they pop into existence,
374
00:19:49,490 --> 00:19:51,589
they give a little bit
of energy to the vacuum.
375
00:19:51,590 --> 00:19:53,159
And, yes, they disappear again,
376
00:19:53,160 --> 00:19:56,590
but the fact that that process
is going on all of the time
377
00:19:56,600 --> 00:19:59,929
means that there's some energy
stored in the vacuum.
378
00:19:59,930 --> 00:20:01,420
And because Einstein told us
379
00:20:01,430 --> 00:20:04,430
that energy and mass
are the same thing,
380
00:20:04,440 --> 00:20:08,690
having lots of energy stored
in space affects space-time
381
00:20:08,700 --> 00:20:12,500
that caused the expansion
of the universe to accelerate.
382
00:20:12,510 --> 00:20:15,209
So, it seems
that quantum mechanics should,
383
00:20:15,210 --> 00:20:17,270
in theory, be able to explain
384
00:20:17,280 --> 00:20:20,610
how the cosmological
constant works
385
00:20:20,620 --> 00:20:24,890
and how dark energy appears
in the vacuum of space
386
00:20:24,900 --> 00:20:28,559
and is driving the acceleration
of the universe.
387
00:20:28,560 --> 00:20:30,999
But there's a problem.
388
00:20:31,000 --> 00:20:34,990
When they came
to calculate this vacuum energy,
389
00:20:34,100 --> 00:20:37,699
they discovered how
spectacularly wrong they were.
390
00:20:37,700 --> 00:20:41,300
If you were to say there was
one pebble on this beach,
391
00:20:41,400 --> 00:20:44,339
you'd be wrong
by one part in a billion.
392
00:20:44,340 --> 00:20:46,539
If you were to say
there was one particle
393
00:20:46,540 --> 00:20:50,679
in the universe, you'd
be off by 10 to the 80.
394
00:20:50,680 --> 00:20:53,100
But the vacuum energy
was calculated
395
00:20:53,200 --> 00:20:57,119
to be off by 10 to the 120.
396
00:20:57,120 --> 00:20:59,119
That is a googol.
397
00:20:59,120 --> 00:21:01,820
That is spectacularly wrong.
398
00:21:05,630 --> 00:21:08,499
The fact that our predictions
are so far off from what we see
399
00:21:08,500 --> 00:21:11,990
tells us that there's
something fundamentally missing
400
00:21:11,100 --> 00:21:13,600
in the way that we
understand physics,
401
00:21:13,700 --> 00:21:14,809
that we understand
the world around us.
402
00:21:14,810 --> 00:21:17,310
So, there's still a mystery,
still a puzzle there.
403
00:21:19,310 --> 00:21:23,549
It might be tempting
to simply ignore dark energy.
404
00:21:23,550 --> 00:21:26,319
You could argue that the
apparent accelerated expansion
405
00:21:26,320 --> 00:21:29,449
is, in fact,
a trick of the light,
406
00:21:29,450 --> 00:21:30,610
that it may be a function
407
00:21:30,620 --> 00:21:34,800
of other, inaccessible
dimensions at play,
408
00:21:34,900 --> 00:21:36,489
that it just
looks like dark energy
409
00:21:36,490 --> 00:21:40,290
but is actually something else.
410
00:21:40,300 --> 00:21:43,369
But dark energy
isn't just an irritating threat
411
00:21:43,370 --> 00:21:46,769
to Einstein's
beautiful equations.
412
00:21:46,770 --> 00:21:49,400
It's also a very
practical solution
413
00:21:49,410 --> 00:21:52,339
to a fundamental question
in cosmology,
414
00:21:52,340 --> 00:21:56,509
namely, what is the universe
made of?
415
00:21:56,510 --> 00:21:59,879
When Einstein was busy thinking
about gravity on trains,
416
00:21:59,880 --> 00:22:01,910
the answer was simple.
417
00:22:01,920 --> 00:22:03,989
The universe
was made of the same stuff
418
00:22:03,990 --> 00:22:06,219
that you and I are made of,
419
00:22:06,220 --> 00:22:09,200
the stuff of stars, planets,
420
00:22:09,300 --> 00:22:12,299
coke cans, tennis rackets...
421
00:22:12,300 --> 00:22:16,769
atoms, made from electrons,
protons, and neutrons.
422
00:22:16,770 --> 00:22:20,739
But physics
was about to get a surprise.
423
00:22:20,740 --> 00:22:23,980
It turned out there was
something else out there
424
00:22:23,981 --> 00:22:26,839
that the universe
was also made of...
425
00:22:26,840 --> 00:22:30,709
matter of a different kind.
426
00:22:30,710 --> 00:22:32,340
In 1975,
427
00:22:32,350 --> 00:22:37,249
astronomer Vera Rubin
made an unexpected discovery.
428
00:22:37,250 --> 00:22:42,950
If we plot
the velocity of the planets
429
00:22:42,960 --> 00:22:46,799
as a function of distance
from the sun...
430
00:22:46,800 --> 00:22:54,139
Mercury, Venus, earth,
Mars, Jupiter, Saturn,
431
00:22:54,140 --> 00:22:57,879
Uranus, Neptune, Pluto...
432
00:22:57,880 --> 00:23:00,809
and you can see
that Mercury orbits
433
00:23:00,810 --> 00:23:04,440
much more rapidly than pluto.
434
00:23:06,520 --> 00:23:09,589
The graph is called
a rotation curve.
435
00:23:09,590 --> 00:23:12,689
It is the embodiment
of the law of gravity.
436
00:23:12,690 --> 00:23:15,890
The further away
you travel from the sun,
437
00:23:15,900 --> 00:23:18,750
the weaker
its gravitational force.
438
00:23:18,760 --> 00:23:22,200
Galaxies work in the same way
as our solar system
439
00:23:22,300 --> 00:23:27,130
except that, instead of planets
orbiting a central sun,
440
00:23:27,140 --> 00:23:30,739
in a spiral galaxy,
stars are held in orbit
441
00:23:30,740 --> 00:23:34,140
by a gravity-providing
black hole.
442
00:23:34,150 --> 00:23:39,179
Vera Rubin decided to plot
the rotation curves in galaxies.
443
00:23:39,180 --> 00:23:41,680
She focused her telescopes
on Andromeda,
444
00:23:41,690 --> 00:23:44,819
the galaxy closest to our own.
445
00:23:44,820 --> 00:23:46,450
I came out with sets of numbers,
446
00:23:46,460 --> 00:23:48,789
and I plotted them
on pieces of paper,
447
00:23:48,790 --> 00:23:51,120
and I discovered that the stars,
448
00:23:51,130 --> 00:23:52,970
as you went further
and further out,
449
00:23:52,971 --> 00:23:54,660
did not slow down.
450
00:23:54,670 --> 00:23:59,839
They were moving just as fast
as the stars near the center.
451
00:23:59,840 --> 00:24:04,279
We find that their velocities
remain flat all the way
452
00:24:04,280 --> 00:24:07,509
to the edge of our observations.
453
00:24:07,510 --> 00:24:09,940
And that was a surprise,
454
00:24:09,950 --> 00:24:13,449
and a surprise
that had to be explained.
455
00:24:13,450 --> 00:24:14,649
By all accounts,
456
00:24:14,650 --> 00:24:17,210
the stars should have flown off
into space.
457
00:24:17,220 --> 00:24:18,550
But they didn't.
458
00:24:18,560 --> 00:24:21,429
And wherever spiral galaxies
were measured,
459
00:24:21,430 --> 00:24:24,359
the same flat curves appeared.
460
00:24:24,360 --> 00:24:27,159
It was decided
that the only explanation
461
00:24:27,160 --> 00:24:29,560
was that their must be
more stuff out there
462
00:24:29,570 --> 00:24:33,439
that we couldn't see
providing the extra gravity,
463
00:24:33,440 --> 00:24:35,569
holding the galaxies together,
464
00:24:35,570 --> 00:24:37,530
and flattening the curves.
465
00:24:42,780 --> 00:24:46,590
They called this stuff
dark matter.
466
00:24:51,790 --> 00:24:56,629
The new dark matter was a
surprise in more ways than one.
467
00:24:56,630 --> 00:24:58,359
The very fact of its existence
468
00:24:58,360 --> 00:25:00,859
was almost overshadowed
by the fact
469
00:25:00,860 --> 00:25:02,860
that when
the calculations were made,
470
00:25:02,870 --> 00:25:04,839
this new form of matter
471
00:25:04,840 --> 00:25:09,210
outweighed the atomic form
of stuff by about 90 to 1.
472
00:25:13,410 --> 00:25:14,779
In the 1980s,
473
00:25:14,780 --> 00:25:18,119
when new ways of measuring
dark matter were developed,
474
00:25:18,120 --> 00:25:21,119
it was discovered that there
simply wasn't enough of it
475
00:25:21,120 --> 00:25:25,419
to make the universe work
as it clearly does.
476
00:25:25,420 --> 00:25:27,280
The universe was short on stuff
477
00:25:27,290 --> 00:25:31,620
to the tune of about 70%.
478
00:25:31,630 --> 00:25:34,200
Cosmology scratched its head.
479
00:25:36,830 --> 00:25:39,730
Then, in 1998,
a young scientist,
480
00:25:39,740 --> 00:25:44,239
Saul Perlmutter, was thinking
some very big thoughts indeed.
481
00:25:44,240 --> 00:25:46,700
Something that felt
like it was meaningful
482
00:25:46,710 --> 00:25:50,679
about the world we live in
in some deep way.
483
00:25:50,680 --> 00:25:54,400
The universe was speeding up
in its expansion.
484
00:25:54,500 --> 00:25:55,240
The dark energy
485
00:25:55,250 --> 00:25:57,610
that earned Perlmutter
his Nobel prize
486
00:25:57,620 --> 00:26:00,219
was an interesting
and troubling concept,
487
00:26:00,220 --> 00:26:02,550
but it also had a number,
488
00:26:02,560 --> 00:26:07,299
and that number
was very significant.
489
00:26:07,300 --> 00:26:10,799
We know from Einstein that
energy and mass are related...
490
00:26:10,800 --> 00:26:12,299
that energy, "e,"
491
00:26:12,300 --> 00:26:15,560
equals mass times
the speed of light squared.
492
00:26:15,570 --> 00:26:18,730
"E" equals m-c squared.
493
00:26:18,740 --> 00:26:21,900
Plug dark energy
into that equation
494
00:26:21,910 --> 00:26:23,440
and you get the missing mass
495
00:26:23,450 --> 00:26:26,919
that dark matter
couldn't account for.
496
00:26:26,920 --> 00:26:29,519
The universe was complete.
497
00:26:29,520 --> 00:26:33,419
It was made up of about 4%
baryonic matter,
498
00:26:33,420 --> 00:26:35,650
the stuff that we're made from,
499
00:26:35,660 --> 00:26:41,229
26% dark matter, and the
gaping 70%-sized hole
500
00:26:41,230 --> 00:26:44,390
was filled with dark energy.
501
00:26:57,740 --> 00:26:59,970
Despite heroic efforts
to find it
502
00:26:59,980 --> 00:27:03,309
and overwhelming evidence
that it exists,
503
00:27:03,310 --> 00:27:07,400
no one has identified
what dark matter is.
504
00:27:12,390 --> 00:27:16,290
And, of course, dark energy,
both useful and confounding,
505
00:27:16,300 --> 00:27:17,829
is barely in its infancy
506
00:27:17,830 --> 00:27:21,229
when it comes
to a convincing explanation.
507
00:27:21,230 --> 00:27:23,490
But there is an idea
in cosmology
508
00:27:23,500 --> 00:27:26,300
that dark matter and dark energy
509
00:27:26,400 --> 00:27:29,480
may be linked by more
than just a common adjective.
510
00:27:29,481 --> 00:27:30,630
And if they are,
511
00:27:30,640 --> 00:27:34,240
a new European spacecraft
called the Euclid
512
00:27:34,250 --> 00:27:38,490
may shed light
on what that link might be.
513
00:27:38,500 --> 00:27:42,890
The Euclid consortium
is staffed by 1,200 scientists
514
00:27:42,900 --> 00:27:44,959
from 14 countries.
515
00:27:44,960 --> 00:27:47,289
Here are some of them having
their picture taken
516
00:27:47,290 --> 00:27:51,520
at their annual conference
in lausanne.
517
00:27:51,530 --> 00:27:54,799
They're hoping that by taking
pictures of the universe,
518
00:27:54,800 --> 00:27:56,299
they will be able to figure out
519
00:27:56,300 --> 00:27:59,339
how it's expanded
over its lifetime
520
00:27:59,340 --> 00:28:01,690
and, by determining that,
521
00:28:01,700 --> 00:28:05,839
the nature of dark energy
will become clearer.
522
00:28:05,840 --> 00:28:07,600
The way we think about it
523
00:28:07,610 --> 00:28:11,210
is that it's either some
new stuff in the universe,
524
00:28:11,220 --> 00:28:15,649
some particle
or even just a new field
525
00:28:15,650 --> 00:28:17,380
that you put into the universe
526
00:28:17,390 --> 00:28:20,660
to explain the properties
of the universe.
527
00:28:23,330 --> 00:28:24,859
Alternatively, you could say
528
00:28:24,860 --> 00:28:28,829
that the equation
you wrote down is not correct.
529
00:28:28,830 --> 00:28:30,590
It's not wrong,
but it's sort of...
530
00:28:30,600 --> 00:28:32,330
we like to say it's incomplete.
531
00:28:32,340 --> 00:28:33,639
So, you could sort of fiddle
532
00:28:33,640 --> 00:28:35,475
with the mathematics
of the equation.
533
00:28:35,476 --> 00:28:36,930
So, actually, what you could do
534
00:28:36,940 --> 00:28:41,470
is maybe come up with
a natural explanation for it.
535
00:28:41,480 --> 00:28:43,579
So, Euclid should be able
536
00:28:43,580 --> 00:28:48,540
to tell us which of
those alternatives it is.
537
00:28:48,550 --> 00:28:49,910
The satellite will launch
538
00:28:49,920 --> 00:28:53,300
and start sending data
back to earth in 2020.
539
00:28:57,630 --> 00:29:00,669
The all-important camera
for the Euclid space telescope
540
00:29:00,670 --> 00:29:03,629
is being built and tested
in the u.K.
541
00:29:03,630 --> 00:29:06,200
In this country house
in the surrey hills.
542
00:29:08,710 --> 00:29:09,909
Not only will Euclid
543
00:29:09,910 --> 00:29:12,209
be able to measure
the historic acceleration
544
00:29:12,210 --> 00:29:15,279
of stars and galaxies
in all directions,
545
00:29:15,280 --> 00:29:17,919
it's hoped that it will also
provide data
546
00:29:17,920 --> 00:29:20,719
about how dark matter
around galaxies
547
00:29:20,720 --> 00:29:23,589
has expanded over time.
548
00:29:23,590 --> 00:29:24,889
This is possible
549
00:29:24,890 --> 00:29:29,829
because of an effect
called gravitational lensing.
550
00:29:29,830 --> 00:29:34,290
So, in general relativity,
mass bends space and time,
551
00:29:34,300 --> 00:29:38,230
and then light is bent
around large, massive objects,
552
00:29:38,240 --> 00:29:41,709
just like Eddington measuring
the star behind the sun.
553
00:29:41,710 --> 00:29:45,790
And so, we use the same
technique for Euclid.
554
00:29:45,800 --> 00:29:47,409
I can illustrate it
using this wine glass
555
00:29:47,410 --> 00:29:49,109
and this image of the universe.
556
00:29:49,110 --> 00:29:53,810
So, as we draw the wine glass
across the image,
557
00:29:53,820 --> 00:29:58,259
what you see is that the
galaxies behind the wine glass
558
00:29:58,260 --> 00:29:59,919
get distorted,
559
00:29:59,920 --> 00:30:03,789
and that distortion
is caused by the lens.
560
00:30:03,790 --> 00:30:07,220
In general relativity,
the lens is mass,
561
00:30:07,230 --> 00:30:09,590
because it bends the light.
562
00:30:09,600 --> 00:30:11,469
And that can be shown
in this picture.
563
00:30:11,470 --> 00:30:13,805
You have a large clump
of mass here,
564
00:30:13,806 --> 00:30:15,600
which is like the lens,
565
00:30:15,700 --> 00:30:17,800
like our bottom
of the wine glass.
566
00:30:17,810 --> 00:30:20,650
And what you can see are all
the distorted galaxies
567
00:30:20,651 --> 00:30:22,509
behind that lens.
568
00:30:22,510 --> 00:30:24,770
And what you can do
with an image like this
569
00:30:24,780 --> 00:30:26,340
is you can calculate
570
00:30:26,350 --> 00:30:29,789
how much mass would I need
within the lens
571
00:30:29,790 --> 00:30:32,189
to create the distortions
that I see.
572
00:30:32,190 --> 00:30:33,830
And what you find
is quite remarkable.
573
00:30:33,831 --> 00:30:38,290
What you find is there is
about 100 times more mass here
574
00:30:38,300 --> 00:30:40,969
than you see from the light
in the image.
575
00:30:40,970 --> 00:30:42,799
And that missing mass,
576
00:30:42,800 --> 00:30:46,770
that mass you cannot see
is what we call dark matter.
577
00:30:49,270 --> 00:30:51,600
So, Euclid will make an image
578
00:30:51,610 --> 00:30:54,709
of the whole sky
at this resolution,
579
00:30:54,710 --> 00:30:59,840
and it will find all these
distorted background galaxies.
580
00:30:59,850 --> 00:31:01,349
And from that,
581
00:31:01,350 --> 00:31:05,680
it can infer the distribution
of dark matter in the universe.
582
00:31:05,690 --> 00:31:09,290
Euclid will compare
lensing all over the universe
583
00:31:09,300 --> 00:31:12,729
and, by doing so, will help
paint an accurate picture
584
00:31:12,730 --> 00:31:15,469
of how the universe
is tearing itself apart
585
00:31:15,470 --> 00:31:18,499
under the influence
of dark energy.
586
00:31:18,500 --> 00:31:20,660
So, Euclid may tell us
587
00:31:20,670 --> 00:31:23,700
that it's
the cosmological constant,
588
00:31:23,710 --> 00:31:27,379
and then we have to
explain that.
589
00:31:27,380 --> 00:31:35,190
It might tell us that our theory
of gravity is not complete,
590
00:31:35,200 --> 00:31:37,789
and we'd have to explain that.
591
00:31:37,790 --> 00:31:40,859
It could tell us
that actually the dark matter
592
00:31:40,860 --> 00:31:44,799
and dark energy are two sides
of the same coin
593
00:31:44,800 --> 00:31:48,899
and that actually there might be
a unified dark sector.
594
00:31:48,900 --> 00:31:50,899
But we'd have to explain that.
595
00:31:50,900 --> 00:31:53,330
Uh, it could be another theory
596
00:31:53,340 --> 00:31:56,690
that we haven't even
come up with yet.
597
00:31:56,700 --> 00:32:00,270
And so, Euclid
will give us a coherent data set
598
00:32:00,280 --> 00:32:02,880
that we can test
all these theories against.
599
00:32:05,780 --> 00:32:08,540
Whatever the case,
the devil's in the details,
600
00:32:08,550 --> 00:32:11,610
and these days, the details
can be interrogated
601
00:32:11,620 --> 00:32:13,850
to degrees not thought possible
602
00:32:13,860 --> 00:32:16,959
when Einstein first
reluctantly inserted
603
00:32:16,960 --> 00:32:22,160
his cosmological constant
into general relativity.
604
00:32:22,170 --> 00:32:24,350
Cosmology is one of the fields
605
00:32:24,360 --> 00:32:26,130
that is actually
pushing the boundaries
606
00:32:26,140 --> 00:32:30,879
of cosmology itself but also
statistics and computing.
607
00:32:30,880 --> 00:32:32,879
It is the frontier, I think.
608
00:32:32,880 --> 00:32:34,849
Euclid will be pushing
the boundaries
609
00:32:34,850 --> 00:32:36,779
like never before.
610
00:32:36,780 --> 00:32:39,850
It will stream more data
from space
611
00:32:39,860 --> 00:32:41,840
than has ever been
processed in the past.
612
00:32:41,850 --> 00:32:45,619
At the end, it will
have about 1.5 billion galaxies.
613
00:32:45,620 --> 00:32:49,289
It will observe 1.5 billion
galaxies, so it's huge.
614
00:32:49,290 --> 00:32:50,520
And a lot of the times,
615
00:32:50,530 --> 00:32:53,129
your eyes cannot just pick up
patterns, okay?
616
00:32:53,130 --> 00:32:54,899
So, this cannot be possible
617
00:32:54,900 --> 00:32:57,399
without computers
and statistics.
618
00:32:57,400 --> 00:32:59,530
The computer-aided searches
619
00:32:59,540 --> 00:33:01,939
should give
unprecedented clarity
620
00:33:01,940 --> 00:33:05,209
on how science should be
thinking about dark energy.
621
00:33:05,210 --> 00:33:08,279
There will be winners
and losers.
622
00:33:08,280 --> 00:33:10,549
The amount of data
that we have on dark energy
623
00:33:10,550 --> 00:33:13,649
hasn't been enough
to be able to tell us
624
00:33:13,650 --> 00:33:15,510
which path
we have to go down to.
625
00:33:15,520 --> 00:33:18,189
So, we have, like,
lots of theories and a lot of...
626
00:33:18,190 --> 00:33:21,590
hundreds of models
that could still fit our data.
627
00:33:21,600 --> 00:33:24,329
When Euclid comes, lots of these
can be thrown away,
628
00:33:24,330 --> 00:33:26,970
and it could, like, you know,
narrow down the possibilities
629
00:33:26,971 --> 00:33:29,260
of what this dark energy is.
630
00:33:43,100 --> 00:33:45,979
The Euclid telescope
is not the only show in town
631
00:33:45,980 --> 00:33:50,509
when it comes to mapping
the expansion of the universe.
632
00:33:50,510 --> 00:33:54,679
And kitt peak in Arizona,
risa wechsler is hoping to use
633
00:33:54,680 --> 00:33:58,410
the proposed dark energy
spectroscopic instrument, desi,
634
00:33:58,420 --> 00:34:00,719
to make a map
of part of the universe,
635
00:34:00,720 --> 00:34:02,450
like this one...
636
00:34:06,160 --> 00:34:08,720
...but 100 times more accurate
637
00:34:08,730 --> 00:34:10,429
so that she can check
the validity
638
00:34:10,430 --> 00:34:13,130
of computer simulations
of the universe
639
00:34:13,140 --> 00:34:16,769
that she's created.
640
00:34:16,770 --> 00:34:18,300
One of the things that I do
641
00:34:18,400 --> 00:34:21,670
is try to simulate
the entire universe
642
00:34:21,680 --> 00:34:25,979
and tie what we think about the
physics of the evolving universe
643
00:34:25,980 --> 00:34:29,410
to what we actually see
with surveys like desi.
644
00:34:32,290 --> 00:34:34,230
What we're trying to do
in these simulations
645
00:34:34,231 --> 00:34:38,389
is take a whole bunch
of hypothetical universes.
646
00:34:38,390 --> 00:34:40,920
Some of them will have
a cosmological constant.
647
00:34:40,930 --> 00:34:42,399
Some of them will have
a different,
648
00:34:42,400 --> 00:34:43,869
time-evolving dark energy.
649
00:34:43,870 --> 00:34:47,539
Some of them will have more
or less amount of dark matter.
650
00:34:47,540 --> 00:34:50,809
And then, when we compare that
to what we actually see,
651
00:34:50,810 --> 00:34:53,309
we can rule out
a lot of these ideas.
652
00:34:53,310 --> 00:34:56,279
So, some of them will not be
consistent with what we measure,
653
00:34:56,280 --> 00:34:58,620
and then we can determine
that that's not the universe
654
00:34:58,621 --> 00:35:01,240
we live in.
655
00:35:01,250 --> 00:35:04,890
When desi starts
producing data in 2020,
656
00:35:04,900 --> 00:35:07,159
it might be that one
of risa wechsler's simulations
657
00:35:07,160 --> 00:35:09,689
strikes gold.
658
00:35:09,690 --> 00:35:13,150
It'll be up against a lot
of competition.
659
00:35:13,160 --> 00:35:18,360
In the absence of hard data,
this is boom time for theories.
660
00:35:18,370 --> 00:35:21,439
Multi-galileons,
ghost condensates,
661
00:35:21,440 --> 00:35:24,609
and the higher co-dimensional
branes worlds theory
662
00:35:24,610 --> 00:35:29,649
jostle for attention in the race
to explain dark energy.
663
00:35:29,650 --> 00:35:30,979
Many of these theories
664
00:35:30,980 --> 00:35:33,619
usually try to provide
a global solution
665
00:35:33,620 --> 00:35:35,589
to the dark energy problem,
666
00:35:35,590 --> 00:35:38,959
a fix to general relativity.
667
00:35:38,960 --> 00:35:42,590
But Clare Burrage
is working on an idea
668
00:35:42,600 --> 00:35:44,229
that suggests Einstein
669
00:35:44,230 --> 00:35:48,129
may have been both right
and wrong at the same time,
670
00:35:48,130 --> 00:35:50,260
depending on where you are.
671
00:35:50,270 --> 00:35:52,939
We know that Einstein's
theory works very well
672
00:35:52,940 --> 00:35:54,269
on earth
and in the solar system.
673
00:35:54,270 --> 00:35:57,609
We've tested it,
and it works phenomenally well.
674
00:35:57,610 --> 00:36:00,809
But we don't have ways
of testing that theory
675
00:36:00,810 --> 00:36:02,849
on the kinds of distance scales
676
00:36:02,850 --> 00:36:04,949
that are relevant to cosmology.
677
00:36:04,950 --> 00:36:06,149
And so, it could be
678
00:36:06,150 --> 00:36:08,219
that whilst relativity's
a good description
679
00:36:08,220 --> 00:36:10,389
of what's happening around us,
680
00:36:10,390 --> 00:36:12,859
it doesn't work
as a description of the universe
681
00:36:12,860 --> 00:36:13,989
as a whole system,
682
00:36:13,990 --> 00:36:16,330
and maybe you need
to change the theory.
683
00:36:19,000 --> 00:36:20,229
Clare's solution
684
00:36:20,230 --> 00:36:22,870
involves something
called a chameleon...
685
00:36:24,900 --> 00:36:28,800
...a particle that tries to
blend in not by changing color,
686
00:36:28,810 --> 00:36:32,809
but by changing
how it exerts its force.
687
00:36:32,810 --> 00:36:34,650
There are two types
of particles in the universe.
688
00:36:34,651 --> 00:36:36,440
There are the ones
that make up matter,
689
00:36:36,450 --> 00:36:39,519
like electrons and protons
and neutrons and quarks.
690
00:36:39,520 --> 00:36:41,449
And then there's another set
of particles,
691
00:36:41,450 --> 00:36:43,949
and those are the ones
that transmit forces.
692
00:36:43,950 --> 00:36:46,750
So, for example, the photon,
which makes up light,
693
00:36:46,760 --> 00:36:50,529
also carries
the electromagnetic forces.
694
00:36:50,530 --> 00:36:51,995
It's exactly like
what we're doing
695
00:36:51,996 --> 00:36:53,250
with the ball and the magnet.
696
00:36:53,260 --> 00:36:55,520
We don't see the photons
transmitting the force directly,
697
00:36:55,530 --> 00:36:59,260
but we see the fact that
the magnet makes the ball move.
698
00:36:59,270 --> 00:37:02,500
In physics,
the greater a particle's mass,
699
00:37:02,600 --> 00:37:03,430
the smaller the distance
700
00:37:03,440 --> 00:37:08,849
over which its able to exert any
force or field it might have.
701
00:37:08,850 --> 00:37:10,279
The mass of a particle
702
00:37:10,280 --> 00:37:13,519
tells you how far
it can carry information.
703
00:37:13,520 --> 00:37:16,389
If a particle that's
transmitting a force is heavier,
704
00:37:16,390 --> 00:37:18,560
it only transmits the force
over a shorter distance scale.
705
00:37:18,561 --> 00:37:21,750
So, the range that you can
transmit the force over
706
00:37:21,760 --> 00:37:25,499
changes depending
on where you're looking.
707
00:37:25,500 --> 00:37:27,729
The idea here
is that when the chameleon
708
00:37:27,730 --> 00:37:30,429
comes into contact
with other stuff,
709
00:37:30,430 --> 00:37:32,690
it interacts with it
and becomes heavy,
710
00:37:32,700 --> 00:37:36,600
and its force-transmitting
capability all but disappears.
711
00:37:36,610 --> 00:37:38,609
But in regions of deep space,
712
00:37:38,610 --> 00:37:40,779
where there's very little
in the way of anything,
713
00:37:40,780 --> 00:37:43,920
the chameleon has no stuff
with which to interact
714
00:37:43,921 --> 00:37:45,710
and so is very light
715
00:37:45,720 --> 00:37:49,950
and can transmit its force
over vast distances.
716
00:38:01,400 --> 00:38:04,530
We're looking for this simple,
elegant solution
717
00:38:04,540 --> 00:38:07,839
to this strange
accelerated universe,
718
00:38:07,840 --> 00:38:10,270
and nothing yet
has given us that.
719
00:38:12,550 --> 00:38:14,149
Where that simple solution
720
00:38:14,150 --> 00:38:18,919
will eventually come
from is anyone's guess.
721
00:38:18,920 --> 00:38:22,359
That is one of the infuriating
things about science.
722
00:38:22,360 --> 00:38:24,659
It can't always produce
the rabbit out of the hat
723
00:38:24,660 --> 00:38:27,630
on time and on budget.
724
00:38:31,370 --> 00:38:34,669
Sometimes, it takes
an unexpected turn of events
725
00:38:34,670 --> 00:38:38,839
or what the media
like to call a genius,
726
00:38:38,840 --> 00:38:40,839
though the geniuses themselves
727
00:38:40,840 --> 00:38:43,670
have a rather different take
on their exploits.
728
00:38:46,910 --> 00:38:49,740
I'm not more gifted
than anybody else.
729
00:38:49,750 --> 00:38:52,755
I'm just more curious
than your average person.
730
00:38:52,756 --> 00:38:54,750
And I will not give up
on a problem
731
00:38:54,760 --> 00:38:57,719
until I have found
the proper solution.
732
00:38:57,720 --> 00:39:01,990
I think that curiosity
is what drives most cosmologists
733
00:39:02,000 --> 00:39:06,229
and physicists...
a curiosity about the universe.
734
00:39:06,230 --> 00:39:08,300
What is the universe
made out of?
735
00:39:08,400 --> 00:39:09,269
Why are we here?
736
00:39:09,270 --> 00:39:10,639
How did the universe begin?
737
00:39:10,640 --> 00:39:13,209
What will happen to the universe
in the future?
738
00:39:13,210 --> 00:39:16,550
All of these are questions
which are driven by curiosity.
739
00:39:21,420 --> 00:39:23,749
I have no special talent.
740
00:39:23,750 --> 00:39:27,219
I am only passionately curious.
741
00:39:27,220 --> 00:39:30,559
Curiosity, I think, is...
742
00:39:30,560 --> 00:39:34,159
well, it's the best
motivating force, okay?
743
00:39:34,160 --> 00:39:38,990
Working hard doesn't necessarily
get you to an answer.
744
00:39:39,000 --> 00:39:43,939
Working too hard
can actually stifle creativity.
745
00:39:43,940 --> 00:39:45,690
With our work, you know,
746
00:39:45,700 --> 00:39:47,169
it's a mixture of inventiveness
747
00:39:47,170 --> 00:39:49,270
and persistence
and the hard work.
748
00:39:49,280 --> 00:39:51,100
It's a combination.
749
00:39:55,450 --> 00:39:59,190
It's the end of the
Euclid conference in lausanne.
750
00:39:59,200 --> 00:40:02,389
The conference organizers
have arranged a social evening,
751
00:40:02,390 --> 00:40:05,890
cruising around lake Geneva.
752
00:40:05,900 --> 00:40:07,450
It's a chance for the delegates
to unwind
753
00:40:07,460 --> 00:40:09,200
and maybe even think a little
754
00:40:09,300 --> 00:40:12,199
about the biggest picture
of all.
755
00:40:12,200 --> 00:40:14,399
Yeah, so, Einstein's theory
756
00:40:14,400 --> 00:40:15,790
was motivated for a reason,
right?
757
00:40:15,800 --> 00:40:17,600
He had an equivalent...
758
00:40:17,700 --> 00:40:18,609
Yeah, and, I mean,
we're gonna measure a lot
759
00:40:18,610 --> 00:40:21,379
of things about the nature
by looking at how it evolves...
760
00:40:21,380 --> 00:40:23,379
how dark energy actually
evolves with red shift.
761
00:40:23,380 --> 00:40:25,449
The problem is
the zero-point energy,
762
00:40:25,450 --> 00:40:26,849
the vacuum energy,
763
00:40:26,850 --> 00:40:29,190
the quantum mechanical part
that you add there.
764
00:40:29,200 --> 00:40:31,285
Try and study the nature
of dark energy,
765
00:40:31,286 --> 00:40:32,510
and at the same time,
766
00:40:32,520 --> 00:40:34,489
try and test
if general relativity works.
767
00:40:34,490 --> 00:40:36,689
So, there's, like, a lot of work
and a lot of discoveries
768
00:40:36,690 --> 00:40:38,189
that are gonna
happen down the road.
769
00:40:38,190 --> 00:40:41,490
- Exactly.
- And I'll drink to that.
770
00:40:41,500 --> 00:40:43,000
- Exactly.
- Yeah.
771
00:40:45,500 --> 00:40:47,899
The process
of scientific discovery
772
00:40:47,900 --> 00:40:51,500
sometimes makes progress
through sheer hard work,
773
00:40:51,510 --> 00:40:53,209
and sometimes it needs someone
774
00:40:53,210 --> 00:40:57,900
to take an inspired
alternative view.
775
00:40:57,100 --> 00:41:00,279
We learned an awful lot
about animals and plants
776
00:41:00,280 --> 00:41:02,219
by simply observing them.
777
00:41:02,220 --> 00:41:05,289
But it took Darwin
with a radical idea
778
00:41:05,290 --> 00:41:09,719
to give us a context
to understand life itself.
779
00:41:09,720 --> 00:41:12,750
And in our efforts
to understand the wider world
780
00:41:12,760 --> 00:41:17,299
and even the universe,
observations are critical.
781
00:41:17,300 --> 00:41:20,399
The ideas of dark matter
and dark energy
782
00:41:20,400 --> 00:41:23,839
come courtesy
of people watching stars.
783
00:41:23,840 --> 00:41:26,669
But just as Einstein musing
on his train
784
00:41:26,670 --> 00:41:29,700
managed to take
all the known science
785
00:41:29,800 --> 00:41:32,179
and see it from a different,
more useful angle,
786
00:41:32,180 --> 00:41:35,449
it might be that to solve
the dark energy problem,
787
00:41:35,450 --> 00:41:38,619
someone needs to pull off
a similar trick
788
00:41:38,620 --> 00:41:41,390
and come up
with an even better idea.
789
00:41:43,460 --> 00:41:45,729
There are an awful lot of
very smart people in the world.
790
00:41:45,730 --> 00:41:48,290
I wouldn't be surprised
if we end up
791
00:41:48,300 --> 00:41:51,265
with another Einstein
somewhere along the line here.
792
00:41:51,266 --> 00:41:53,790
I don't know whether
it will be in our lifetime,
793
00:41:53,800 --> 00:41:57,239
but we... i think we have
a good shot at it.
794
00:41:57,240 --> 00:41:58,769
We need teams like Euclid.
795
00:41:58,770 --> 00:42:01,800
That's the only way you can
get the data that you need.
796
00:42:01,810 --> 00:42:03,839
But to understand that data,
797
00:42:03,840 --> 00:42:05,770
to give it some interpretation,
798
00:42:05,780 --> 00:42:09,879
to give it an idea could
come from one person.
799
00:42:09,880 --> 00:42:13,249
That could be the next Einstein.
800
00:42:13,250 --> 00:42:14,649
A genius could come up
801
00:42:14,650 --> 00:42:16,850
and put all the observations
that we have so far...
802
00:42:16,860 --> 00:42:19,359
put it together and come up
with a new theory.
803
00:42:19,360 --> 00:42:21,799
Yeah.
It is quite possible.
804
00:42:21,800 --> 00:42:23,700
I'm kind of hoping it's me.
805
00:42:31,570 --> 00:42:34,469
The tantalizing truth
is that all it might take
806
00:42:34,470 --> 00:42:37,139
to solve the mystery
of the dark energy
807
00:42:37,140 --> 00:42:39,840
is one big idea,
808
00:42:39,850 --> 00:42:42,749
for someone out there
to see things differently,
809
00:42:42,750 --> 00:42:46,319
someone perhaps like you.
810
00:42:46,320 --> 00:42:48,889
And if that new Einstein is you,
811
00:42:48,890 --> 00:42:52,559
if you manage to solve
the mystery of dark energy,
812
00:42:52,560 --> 00:42:55,829
you're likely to become
very famous indeed...
813
00:42:55,830 --> 00:42:59,400
as famous
as the original Einstein.
60401
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