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Neutron stars.
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Super heavy, super dense.
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Extreme.
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Gravitational, magnetic, hot.
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Scary.
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They destroy planets.
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They can even destroy stars.
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A cosmic conundrum.
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They're very, very massive,
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but they're also
really, really small.
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Tiny cosmic super powers
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long overshadowed by black holes...
Until now.
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Neutron stars have
been thrust very much
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to the forefront of
modern astrophysics.
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The world's astronomers know
that something is happening.
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Something's up, it's new,
and it's different.
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Neutron stars are
the most interesting
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astrophysical object
in the universe.
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Now firmly in the limelight,
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neutron stars, creators of
our most precious elements
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and life itself.
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Captions by vitac...
www.vitac.com
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captions paid for by
discovery communications
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130 million
light years form earth,
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a galaxy called
"NGC-4993."
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Two dead stars trapped in
a rapidly diminishing spiral.
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It's like listening to the
ringing of the cosmos itself.
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The sound of that collision,
if you will,
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imprinted on the fabric
of space and time itself.
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Livingston, Louisiana,
the advanced LiGO observatory.
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Its mission...
To detect gravitational waves
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generated in space.
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A gravitational wave is
a distortion of space time
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that's caused by, usually,
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some kind of very traumatic
gravitational event.
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Events such as a supernova,
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or the collision of black holes,
or massive stars.
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2015... LiGO makes history
by detecting gravitational waves
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for the first time,
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100 years after
Einstein's prediction.
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It's the signature of
the crash of black holes.
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It's almost like
listening to the sound
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of a distant car crash
that you didn't witness.
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But you're so clever,
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and the sound of this car crash
is such a unique signature,
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that you are able to use
your computers to model
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exactly the type of cars that
must have collided together.
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In 2017, LiGO picks up a
different kind of signal.
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The unfolding of
the August 2017 event
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was nothing short
of extraordinary.
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So, the signal comes in,
and the signal is strange.
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It has a long-lasting signal.
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It's over 100 seconds.
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Less than two seconds later,
a gamma-ray telescope
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detected a flash of gamma rays
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from that same part of the sky.
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And very quickly,
the world's astronomers
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know that something
is happening.
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Something's up, it's new,
and it's different.
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This combination of
a long gravitational wave signal
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and a blaze of gamma rays...
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Acts as a beacon
for astronomers.
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When they saw this event,
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they sent out a worldwide alert
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to astronomers
across the globe, saying,
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"hey, we saw
something interesting,
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and it came from
a particular patch of sky.
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Then, all the chatter started
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amongst the
astronomical community,
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and everyone starting
pointing their telescopes
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at this one part of the sky.
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Within hours,
thousands of astronomers
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and physicists across the globe
are frantically
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collecting data
on this mysterious event.
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There is not just
the gravitational waves,
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there is not just
the gamma rays.
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There's a visible light,
there's infrared light,
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there's ultraviolet light.
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And all these signals together
tell us a story.
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And this was the very first time
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we've seen these two
multiple messengers at once...
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Gravitational waves
and regular light.
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So, that was a groundbreaking
moment for astronomy.
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Scientists realize
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this isn't another
black-hole collision.
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This is something different.
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When you see an explosion
in the universe,
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there aren't exactly
a lot of candidates.
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There's not a lot of things
in the universe that blow up.
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But the length of
the signal is the smoking gun.
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The collision
of two black holes was quick.
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This one was the longer,
slower, death end-spiral
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of two neutron stars.
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Spiraling in,
closer and closer, speeding up.
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And then, when they
finally collide,
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when they finally touch,
releasing a tremendous
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amount of energy
into the surrounding system.
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The collision
throws up huge clouds of matter,
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which may have slowed down
the light very slightly.
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The light
and gravitational waves
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travel for 130 million years,
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arriving at earth
almost simultaneously.
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It's the first time astronomers
see neutron stars collide.
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They call it a "kilonova."
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And this spectacular
cosmic event
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doesn't just release energy.
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The aftermath of this
neutron-star collision,
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this kilonova, created
a tremendous amount of debris,
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which blasted out into space.
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And this may finally
have provided us
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the evidence of where
some very special
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heavy elements are created.
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Through the destruction of
a neutron star comes the seeds
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for the essential ingredients
of life itself.
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We breathe oxygen
molecules... O2.
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Water is hydrogen and oxygen.
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Most of our body is made up
of carbon compounds
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that include nitrogen,
phosphorus.
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One of the big questions
in science
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over the history of humanity
has been,
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"what are the origins
of these elements?"
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And it turns out that neutron
stars play a critical role
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in creating many of
the heavy elements.
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Most of the elements
on earth are made in stars.
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But how the heaviest
elements are made
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has been one of science's
longest-running mysteries.
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For a long time,
we knew there was a problem
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with making these
heavier atoms...
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Things like gold and platinum,
all the way out towards uranium.
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And really, the most
energetic thing we had
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in the universe
was supernova explosions.
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So, they had to be created
somehow in supernovas.
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But when scientists
ran computer simulations,
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virtual supernovas failed to
forge these oversized atoms.
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In 2016, astronomer
Edo Berger explained
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a potential solution
to the mystery.
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If you open
any one of these books,
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and flip to the page that
tells you where gold came from,
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it will tell you that gold
came from supernova explosions.
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But it was becoming clear that
the textbooks were out of date.
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To form heavy elements
requires a lot of neutrons,
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and so, another possible
theory was that
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the heaviest elements
were produced in the mergers
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of two neutron stars
in a binary system.
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But at the time,
no one had actually seen
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a neutron-star collision.
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It was difficult
to convince the community
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that this was
a potential channel
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for the production
of heavy elements.
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The proof is to actually
see this process
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happening in the universe.
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The 2017 kilonova
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provides the
perfect opportunity.
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It generates thousands
of hours of data.
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Scientists notice a pattern...
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Subtle changes in the color
of the kilonova remnants.
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In space, when you have
an event that is very bright,
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it emits a certain
amount of light,
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and it emits it at
certain wavelengths...
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What we think of as colors.
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Different colors
in a pyrotechnics display
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indicate the use of different
chemicals in fireworks.
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In the same way, scientists
can uncover the elements
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in the kilonova
by the colors in the explosion.
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As the kilonova turns red,
they realize it's the result
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of newly-created heavy elements
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starting to absorb blue light.
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As we watched
this remnant change...
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The explosion change in
color, expand and cool...
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We could estimate what sort of
elements were being produced.
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The light from the debris shifts
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from blue and Violet
to red and infrared.
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The color change provides clues
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about the presence
of certain heavy metals.
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Well, this neutron-star
collision, this kilonova,
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produced brightness
and a color spectrum
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that are consistent
with models of predictions
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that produce gold and platinum.
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This model
is called "The R-process,"
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short for
"rapid neutron capture."
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That is a bit of
a complicated term
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that describes how we make atoms
heavier than iron.
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You need a really
neutron-rich environment.
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And as you might imagine,
a neutron-star collision
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is a very neutron-rich
environment.
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If these models are correct...
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And this blows me away...
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This collision, this kilonova,
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produced several dozen times
the mass of the Earth
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in just gold.
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The 2017 kilonova
not only reveals
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the origin of key elements,
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it sheds light on
the neutron star's interior...
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The strongest material
in the universe
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creating a magnetic field
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a trillion times greater
than that of earth.
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Two neutron stars
caught in a death spiral.
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This massive kilonova explosion
not only sheds light
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on the creation
of heavy elements,
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such as gold and platinum,
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it also provides scientists
with a unique insight
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into one of the most mysterious
objects in the universe.
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Trying to imagine what
a neutron star is really like
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really challenges
our imagination.
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It also challenges
our theoretical physics.
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We have to go to our computer
models, our mathematics,
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to have some estimate
of what this might be like.
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Now,
scientists don't have to rely
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on their imaginations.
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They can use hard data
from the kilonova
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to work out what makes
neutron stars tick.
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There's so much information
we got from observing
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that one single event, that one
colliding neutron star pair.
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Now, for the first time,
we have an accurate estimate
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of the mass of a neutron star,
and the diameter.
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We can finally begin
to piece together
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how neutron stars really work.
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They calculate
the diameter is just 12.4 miles,
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1 mile less than
the length of Manhattan.
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Nailing down
any physical characteristic
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is really important.
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And if there's gonna be one,
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the radius is a big one,
because from there,
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if you know the mass,
you can get the density.
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And if you know
the overall density,
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you can start to figure out
what the layering
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inside of a neutron star
is like.
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For physicists,
the interior of a neutron star
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is one of the most intriguing
places in the universe.
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You have to realize
that the conditions
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inside a neutron star are very,
very different
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than the conditions
that exist here on earth.
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00:13:07,340 --> 00:13:09,400
We're talking about material
that's so dense
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that even the nuclei of atoms
can't hold together.
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With a neutron star,
you're taking something
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that weighs more than the sun,
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and compressing it down
to be smaller than a city.
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It's so dense that, if you
tried to put it on the ground,
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it would fall
right through the Earth.
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High density
means high gravity...
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Gravity 200 billion times
greater than on earth.
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Imagine climbing up on
a table on the surface
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of a neutron star
and jumping off.
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You're gonna just
get flattened instantly,
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and just spread out
on that surface.
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So, don't even think about
trying to do push-ups.
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Added to the intense gravity
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are hugely powerful
magnetic fields,
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awesome X-ray radiation,
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00:13:54,780 --> 00:13:58,550
electric fields 30 million times
more powerful
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00:13:58,550 --> 00:14:00,550
than lightning bolts,
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and blizzards of
high-energy particles.
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This isn't a good neighborhood
for a space traveler.
254
00:14:11,630 --> 00:14:14,540
If you were to
find yourself in the vicinity
255
00:14:14,540 --> 00:14:18,170
of a neutron star,
it's gonna be bad news.
256
00:14:18,170 --> 00:14:20,170
First, you would be torn apart
257
00:14:20,180 --> 00:14:22,840
by the incredibly strong
magnetic fields.
258
00:14:22,850 --> 00:14:27,720
Then, the X-ray radiation
would blast you to a crisp.
259
00:14:27,720 --> 00:14:29,550
And as it pulled you closer,
260
00:14:29,550 --> 00:14:31,950
its intense gravity
would stretch out
261
00:14:31,950 --> 00:14:35,520
your atoms and molecules
into a long, thin stream.
262
00:14:35,520 --> 00:14:38,390
You would build your speed
faster and faster,
263
00:14:38,390 --> 00:14:41,500
and then, you would finally
impact the surface,
264
00:14:41,500 --> 00:14:43,230
splatter across it.
265
00:14:43,230 --> 00:14:46,230
And that process would
release as much energy
266
00:14:46,240 --> 00:14:47,370
as a nuclear bomb.
267
00:14:50,440 --> 00:14:53,640
If I had the choice between
falling into a neutron star
268
00:14:53,640 --> 00:14:56,880
versus a black hole,
I think I'd pick the black hole.
269
00:14:56,880 --> 00:14:58,980
'Cause I don't really feel like
being torn apart
270
00:14:58,980 --> 00:15:01,620
by a magnetic field
and blasted with x-rays.
271
00:15:06,020 --> 00:15:10,560
On a cosmic scale,
neutron stars may be pint-sized,
272
00:15:10,560 --> 00:15:13,290
but they sure pack
a serious punch.
273
00:15:13,300 --> 00:15:15,800
The secret to
all this pent-up power
274
00:15:15,800 --> 00:15:20,330
is what's going on
below the surface.
275
00:15:20,340 --> 00:15:22,870
Armed with
the new kilonova data,
276
00:15:22,870 --> 00:15:24,610
we can now take
a virtual journey
277
00:15:24,610 --> 00:15:27,340
into the heart
of a neutron star.
278
00:15:27,340 --> 00:15:31,610
First, we must pass
through its atmosphere.
279
00:15:31,610 --> 00:15:32,950
Now, it's not like
the Earth's atmosphere,
280
00:15:32,950 --> 00:15:34,780
which goes up,
like, a 100 miles.
281
00:15:34,780 --> 00:15:38,220
On a neutron star, the
atmosphere is about this deep,
282
00:15:38,220 --> 00:15:43,390
and it's extremely dense
compared to the air around us.
283
00:15:43,390 --> 00:15:48,030
Below the compressed atmosphere
is a crust of ionized iron,
284
00:15:48,030 --> 00:15:50,430
a mixture of
crystal iron nuclei,
285
00:15:50,430 --> 00:15:53,770
and free-flowing iron electrons.
286
00:15:53,770 --> 00:15:55,740
Now, the gravity's so strong
287
00:15:55,740 --> 00:15:58,170
that it's almost
perfectly smooth.
288
00:15:58,170 --> 00:15:59,640
The biggest mountains
on the surface
289
00:15:59,640 --> 00:16:02,040
are gonna be less than
a quarter of an inch high.
290
00:16:02,040 --> 00:16:07,480
A quarter-inch
mountain range may sound odd...
291
00:16:07,480 --> 00:16:11,790
But things get even stranger
as we go below the surface.
292
00:16:13,890 --> 00:16:17,860
This is home to the strongest
material in the universe.
293
00:16:20,930 --> 00:16:27,100
It's so weird, scientists
liken it to nuclear pasta.
294
00:16:27,100 --> 00:16:30,070
As we dive beneath
the crust of a neutron star,
295
00:16:30,070 --> 00:16:33,340
the neutrons themselves start
to glue themselves together
296
00:16:33,340 --> 00:16:35,280
into exotic shapes.
297
00:16:35,280 --> 00:16:40,550
First, they form clumps that
look something like gnocchi,
298
00:16:40,550 --> 00:16:43,620
then, deeper, the gnocchi
glue themselves together
299
00:16:43,620 --> 00:16:47,590
to form long strands
that look like spaghetti.
300
00:16:47,590 --> 00:16:50,190
Even deeper,
the spaghetti fuse together
301
00:16:50,190 --> 00:16:53,660
to form sheets of lasagna.
302
00:16:53,660 --> 00:16:56,630
And then, finally,
the lasagna fuse together
303
00:16:56,630 --> 00:17:01,240
to become a uniform mass,
but with holes in it.
304
00:17:01,240 --> 00:17:03,670
So, it looks like penne.
305
00:17:03,670 --> 00:17:07,140
This is pasta, nuclear style,
306
00:17:07,140 --> 00:17:08,410
simmering at a temperature
307
00:17:08,410 --> 00:17:11,180
of over one million
degrees Fahrenheit.
308
00:17:11,180 --> 00:17:14,950
Extreme gravity bends,
squeezes, stretches,
309
00:17:14,950 --> 00:17:17,890
and buckles neutrons,
creating a material
310
00:17:17,890 --> 00:17:22,190
100,000 billion times
denser than iron.
311
00:17:22,190 --> 00:17:25,990
But the journey
gets even more extreme.
312
00:17:26,000 --> 00:17:29,830
Even deeper is more mysterious
and harder to understand.
313
00:17:29,830 --> 00:17:31,870
The core of a neutron star...
314
00:17:31,870 --> 00:17:34,600
Which is very far away
from these layers,
315
00:17:34,600 --> 00:17:36,700
which we call
the "nuclear pasta"...
316
00:17:36,710 --> 00:17:39,970
Is perhaps the most
exotic form of matter.
317
00:17:39,980 --> 00:17:44,140
So exotic it might be
the last bastion of matter
318
00:17:44,150 --> 00:17:48,480
before complete gravitational
collapse into a black hole.
319
00:17:50,490 --> 00:17:52,790
Data from NASA's
Chandra observatory
320
00:17:52,790 --> 00:17:56,160
suggests the core
is made up of a super fluid...
321
00:17:56,160 --> 00:17:59,960
A bizarre friction-free
state of matter.
322
00:17:59,960 --> 00:18:02,660
Similar super fluids
produced in the lab
323
00:18:02,670 --> 00:18:04,700
exhibit strange properties,
324
00:18:04,700 --> 00:18:07,330
such as the ability
to flow upwards
325
00:18:07,340 --> 00:18:11,270
and escape airtight containers.
326
00:18:11,270 --> 00:18:13,570
Although our knowledge
of the star's interior
327
00:18:13,580 --> 00:18:15,810
is still hazy,
there's not mystery
328
00:18:15,810 --> 00:18:17,950
about its dazzling birth.
329
00:18:17,950 --> 00:18:22,050
Forged into life during
the most spectacular event
330
00:18:22,050 --> 00:18:23,980
the universe has to offer...
331
00:18:23,990 --> 00:18:27,490
The explosive death
of a massive star.
332
00:18:38,270 --> 00:18:40,270
Neutron stars...
333
00:18:40,270 --> 00:18:46,840
Manhattan-sized, but with a mass
twice that of our sun.
334
00:18:46,840 --> 00:18:52,910
So dense a teaspoon of their
matter weighs a billion tons.
335
00:18:52,920 --> 00:18:57,250
Mind-blowing objects
that arrive with a bang.
336
00:18:57,250 --> 00:18:59,220
Neutron stars spark into life
337
00:18:59,220 --> 00:19:01,190
amid the death
of their parent star.
338
00:19:01,190 --> 00:19:03,890
They're the ultimate story
of resurrection,
339
00:19:03,890 --> 00:19:06,560
or of life from death.
340
00:19:06,560 --> 00:19:10,630
It's all part of a cosmic cycle.
341
00:19:10,630 --> 00:19:14,970
Stars are born from giant
clouds of very cold gas.
342
00:19:14,970 --> 00:19:18,010
Those clouds collapse
under their own gravity,
343
00:19:18,010 --> 00:19:21,140
and the density of the core
at the center of the collapse
344
00:19:21,140 --> 00:19:22,310
starts to increase.
345
00:19:27,420 --> 00:19:31,350
A star is a huge
nuclear fusion reactor.
346
00:19:31,350 --> 00:19:33,920
The force of its gravity
is so powerful
347
00:19:33,920 --> 00:19:35,690
that it fuses atoms together
348
00:19:35,690 --> 00:19:40,590
to make progressively
heavier and heavier elements.
349
00:19:40,600 --> 00:19:43,730
The star fuses hydrogen
into helium.
350
00:19:43,730 --> 00:19:46,930
Once it exhausts its hydrogen,
then, if it's massive enough,
351
00:19:46,940 --> 00:19:49,370
it can start fusing helium
at its core.
352
00:19:51,810 --> 00:19:54,470
Fusion continues,
forming carbon,
353
00:19:54,480 --> 00:20:00,450
oxygen, nitrogen,
all the way up to iron.
354
00:20:00,450 --> 00:20:02,780
Once a star
has iron in the core,
355
00:20:02,790 --> 00:20:04,750
it's almost like
you've poisoned it,
356
00:20:04,750 --> 00:20:08,420
because this extinguishes
the nuclear reactions
357
00:20:08,420 --> 00:20:09,760
in the core of the star.
358
00:20:09,760 --> 00:20:13,990
You fuse something into iron,
and you get no energy.
359
00:20:14,000 --> 00:20:15,830
All of a sudden,
there's nothing to support
360
00:20:15,830 --> 00:20:17,100
the crush of gravity.
361
00:20:17,100 --> 00:20:18,800
No radiation pressure
pushing out
362
00:20:18,800 --> 00:20:22,770
means no pressure keeping the
outer regions from falling in,
363
00:20:22,770 --> 00:20:24,640
and that's what they do.
364
00:20:24,640 --> 00:20:27,740
As the star collapses
in its death throes,
365
00:20:27,740 --> 00:20:31,180
its core becomes
the wildest, craziest,
366
00:20:31,180 --> 00:20:35,420
and freakiest pressure cooker
in the whole universe.
367
00:20:37,550 --> 00:20:40,020
The ingredients
are all in place.
368
00:20:40,020 --> 00:20:44,890
It's time to start cooking up
a neutron star.
369
00:20:44,890 --> 00:20:47,630
If we were to scale up
an atomic nucleus
370
00:20:47,630 --> 00:20:49,500
to be the size of a baseball,
371
00:20:49,500 --> 00:20:53,670
in a normal atom,
the nearest electron would be
372
00:20:53,670 --> 00:20:55,700
way over in those trees,
373
00:20:55,700 --> 00:20:57,800
but in the extreme
conditions that lead to
374
00:20:57,810 --> 00:20:59,970
the formation of a neutron star,
375
00:20:59,980 --> 00:21:04,010
those electrons can be pushed
closer to the nucleus.
376
00:21:04,010 --> 00:21:07,180
They can come zipping in
from any direction.
377
00:21:07,180 --> 00:21:10,080
And if the temperatures
and pressures are high enough,
378
00:21:10,090 --> 00:21:12,050
they can even strike the nucleus
379
00:21:12,050 --> 00:21:14,960
and enter it,
and they can hit a proton.
380
00:21:14,960 --> 00:21:19,490
And when they do, they become
converted into more neutrons.
381
00:21:19,500 --> 00:21:22,130
So, in the formation
of one of these objects,
382
00:21:22,130 --> 00:21:24,460
the protons and
electrons disappear,
383
00:21:24,470 --> 00:21:27,470
and you're left with
almost entirely pure neutrons,
384
00:21:27,470 --> 00:21:30,540
with nothing to stop them
from cramming together
385
00:21:30,540 --> 00:21:33,410
and filling up
this entire baseball
386
00:21:33,410 --> 00:21:38,950
with neutrons leading to
incredibly high densities.
387
00:21:38,950 --> 00:21:40,310
With the sea of electrons
388
00:21:40,320 --> 00:21:42,880
now absorbed
in the atomic nuclei,
389
00:21:42,890 --> 00:21:47,820
the matter in the stars can now
press together a lot tighter.
390
00:21:47,820 --> 00:21:51,020
It's like squeezing
300 million tons of mass
391
00:21:51,030 --> 00:21:54,360
into a single sugar cube.
392
00:21:54,360 --> 00:21:56,130
As the star collapses,
393
00:21:56,130 --> 00:21:59,300
enormous amounts of gas
fall towards the core.
394
00:22:01,970 --> 00:22:06,470
The core is small in size,
but huge in mass.
395
00:22:06,480 --> 00:22:09,280
Billions of tons of gas
bounce off of it,
396
00:22:09,280 --> 00:22:12,750
then erupt into
the biggest fireworks display
397
00:22:12,750 --> 00:22:18,220
in the cosmos... A supernova.
398
00:22:18,220 --> 00:22:19,520
It's massive.
399
00:22:19,520 --> 00:22:20,620
It's bright.
400
00:22:20,620 --> 00:22:21,920
It's imposing.
401
00:22:21,920 --> 00:22:25,030
Supernova are among
the most dramatic events
402
00:22:25,030 --> 00:22:26,490
to happen in the universe.
403
00:22:26,500 --> 00:22:28,130
A single star dying...
404
00:22:28,130 --> 00:22:33,200
One star dying...
Can outshine an entire galaxy.
405
00:22:37,040 --> 00:22:39,510
And arising
out of this cataclysm,
406
00:22:39,510 --> 00:22:42,940
a new and very strange
cosmic entity.
407
00:22:45,910 --> 00:22:48,780
When the smoke finally clears
from the supernova explosion,
408
00:22:48,780 --> 00:22:51,520
you're left with one of
the most real, fascinating,
409
00:22:51,520 --> 00:22:54,690
unbelievable monsters
of the entire universe.
410
00:22:54,690 --> 00:22:56,360
Humans have been
witnessing supernovas
411
00:22:56,360 --> 00:22:57,990
for thousands of years,
412
00:22:57,990 --> 00:23:00,730
but we're only now
just starting to understand
413
00:23:00,730 --> 00:23:03,530
what we've truly
been witnessing...
414
00:23:03,530 --> 00:23:07,470
The births of neutron stars.
415
00:23:07,470 --> 00:23:10,570
But while supernovas
are big and bright,
416
00:23:10,570 --> 00:23:13,110
neutron stars are small,
417
00:23:13,110 --> 00:23:16,280
and many don't even
give off light.
418
00:23:16,280 --> 00:23:20,250
So, how many neutron stars
are out there?
419
00:23:20,250 --> 00:23:23,820
We know of about 2,000
neutron stars in our galaxy,
420
00:23:23,820 --> 00:23:25,420
but there probably are many,
many, more.
421
00:23:25,420 --> 00:23:28,260
I'm talking about tens of
millions in the milky way alone,
422
00:23:28,260 --> 00:23:32,530
and certainly billions
throughout the universe.
423
00:23:32,530 --> 00:23:38,330
Neutron stars may be small,
but some give themselves away,
424
00:23:38,330 --> 00:23:41,800
shooting beams
across the universe...
425
00:23:41,800 --> 00:23:47,070
Unmistakable, pulsing strobes
of a cosmic lighthouse.
426
00:24:00,760 --> 00:24:05,260
Our knowledge of
neutron stars is expanding fast.
427
00:24:07,800 --> 00:24:09,900
But we didn't even know
they existed
428
00:24:09,900 --> 00:24:13,470
until a lucky discovery
just over 50 years ago.
429
00:24:15,500 --> 00:24:18,640
Cambridge,
the Mullard radio observatory,
430
00:24:18,640 --> 00:24:20,540
Jocelyn bell, grad student,
431
00:24:20,540 --> 00:24:24,110
operating the new
radio telescope.
432
00:24:24,110 --> 00:24:27,210
Scanning the sky, doing all
sorts of cool astronomy stuff,
433
00:24:27,220 --> 00:24:32,650
and sees what she calls
"a bit of scruff" in the data.
434
00:24:32,650 --> 00:24:34,090
This scruff is a short
435
00:24:34,090 --> 00:24:37,420
but constantly repeating
burst of radiation
436
00:24:37,430 --> 00:24:41,700
originating 1,000 light years
from earth.
437
00:24:41,700 --> 00:24:44,830
It's so stable and regular
that bell is convinced
438
00:24:44,830 --> 00:24:47,600
there's a fault
with her telescope.
439
00:24:47,600 --> 00:24:49,540
She returns to that spot,
440
00:24:49,540 --> 00:24:53,840
and finds a repeating,
regular signal...
441
00:24:53,840 --> 00:24:59,380
A single point in the sky that
is flashing at us continually,
442
00:24:59,380 --> 00:25:02,180
saying "Hi. Hi. Hi."
443
00:25:02,180 --> 00:25:03,880
Blip, blip, blip.
444
00:25:03,890 --> 00:25:06,250
Boom, boom, boom.
445
00:25:06,260 --> 00:25:08,150
Pulse, pulse, pulse.
446
00:25:08,160 --> 00:25:10,160
Nothing that we know of
in the universe,
447
00:25:10,160 --> 00:25:14,730
has such a steady,
perfectly-spaced in time, pulse.
448
00:25:14,730 --> 00:25:18,970
It seemed so perfect that
it must have been artificial.
449
00:25:18,970 --> 00:25:22,340
It looks like
someone is making that,
450
00:25:22,340 --> 00:25:26,310
but it turns out, it's not
a person, but a thing.
451
00:25:26,310 --> 00:25:29,180
What she discovered
was called a "pulsar."
452
00:25:32,010 --> 00:25:34,610
A pulsar is
a type of rapidly spinning
453
00:25:34,620 --> 00:25:35,980
neutron star.
454
00:25:38,790 --> 00:25:42,660
Neutron stars had been theorized
in the 1930s,
455
00:25:42,660 --> 00:25:46,560
but were thought to be
too faint to be detected.
456
00:25:46,560 --> 00:25:51,160
Neutron stars were
hypothesized to exist,
457
00:25:51,170 --> 00:25:54,070
but not really taken seriously.
458
00:25:54,070 --> 00:25:56,540
It was just a, "oh, that's cute.
459
00:25:56,540 --> 00:25:59,140
Maybe they're out there,
but probably not."
460
00:26:00,280 --> 00:26:02,110
The signal bell detected
461
00:26:02,110 --> 00:26:06,110
seemed like something
from science fiction.
462
00:26:06,110 --> 00:26:08,880
No one had ever seen this
in astronomy before,
463
00:26:08,880 --> 00:26:13,020
and some people even speculated
that it was an alien signal.
464
00:26:13,020 --> 00:26:15,360
She even called them
"LGM objects"...
465
00:26:15,360 --> 00:26:18,330
"little green men."
466
00:26:18,330 --> 00:26:20,830
But then,
bell found a second signal.
467
00:26:23,670 --> 00:26:26,830
Little green men
went back to being fiction,
468
00:26:26,840 --> 00:26:30,500
and pulsars became science fact.
469
00:26:30,510 --> 00:26:32,770
The discovery of pulsars
came out of the blue.
470
00:26:32,770 --> 00:26:34,370
Nobody was expecting this.
471
00:26:34,380 --> 00:26:36,580
So, it was
an amazing breakthrough...
472
00:26:36,580 --> 00:26:37,780
Really important.
473
00:26:40,950 --> 00:26:45,350
Pulsars pulse
because they are born to spin.
474
00:26:45,350 --> 00:26:49,590
They burst into life
as their parent star collapses
475
00:26:49,590 --> 00:26:51,120
during a supernova.
476
00:26:53,300 --> 00:26:55,660
Any object at all
that is undergoing
477
00:26:55,660 --> 00:26:57,800
any sort of compression event,
478
00:26:57,800 --> 00:27:01,030
if it has any initial
angular momentum at all,
479
00:27:01,040 --> 00:27:05,140
it will eventually
end up spinning.
480
00:27:05,140 --> 00:27:09,240
As the star shrinks,
it spins faster and faster.
481
00:27:11,210 --> 00:27:15,350
They spin so quickly
because the Earth-sized core
482
00:27:15,350 --> 00:27:16,720
of a massive star
483
00:27:16,720 --> 00:27:19,990
collapsed to something
as small as a city.
484
00:27:19,990 --> 00:27:24,090
So, because the size of the
object became so much smaller,
485
00:27:24,090 --> 00:27:28,830
the rate of spin had to increase
by a tremendous amount.
486
00:27:28,830 --> 00:27:32,100
Neutron stars can spin
really, really, fast.
487
00:27:32,100 --> 00:27:34,570
Their surface is moving so fast.
488
00:27:34,570 --> 00:27:38,370
It's moving at about 20% the
speed of light, in some cases.
489
00:27:38,370 --> 00:27:41,640
So, if you were to
get on the neutron star ride...
490
00:27:41,640 --> 00:27:45,610
No pregnant women, no bad backs,
no heart issues,
491
00:27:45,610 --> 00:27:48,380
keep your arms and legs
inside the ride at all times,
492
00:27:48,380 --> 00:27:50,720
because they are about
to be obliterated.
493
00:27:52,620 --> 00:27:57,890
And as they spin, they generate
flashing beams of energy.
494
00:27:57,890 --> 00:28:00,290
This beam is like
a lighthouse beam.
495
00:28:00,300 --> 00:28:03,700
You see these periodic flashes
many times per second.
496
00:28:03,700 --> 00:28:08,570
So, every time you see it...
Beam, beam, beam.
497
00:28:08,570 --> 00:28:11,570
These beams
are the pulsar's calling card.
498
00:28:11,570 --> 00:28:14,270
They're generated
by the elemental chaos
499
00:28:14,280 --> 00:28:16,910
raging inside a neutron star.
500
00:28:16,910 --> 00:28:18,780
Although the star
is predominantly
501
00:28:18,780 --> 00:28:20,650
a ball of neutrons,
502
00:28:20,650 --> 00:28:24,380
the crust is sprinkled
with protons and electrons,
503
00:28:24,390 --> 00:28:26,620
spinning hundreds
of times a second,
504
00:28:26,620 --> 00:28:29,360
generating an incredible
magnetic field.
505
00:28:31,060 --> 00:28:32,890
And with this strong
magnetic field,
506
00:28:32,890 --> 00:28:34,990
you can create strong
electric fields.
507
00:28:35,000 --> 00:28:36,660
And the electric
and magnetic fields
508
00:28:36,670 --> 00:28:40,270
can work off of each other
and become radiation.
509
00:28:40,270 --> 00:28:46,040
These neutron stars send jets...
Beams of radiation...
510
00:28:46,040 --> 00:28:48,140
Out of their spinning poles.
511
00:28:48,140 --> 00:28:50,610
And if their spinning pole
is misaligned,
512
00:28:50,610 --> 00:28:52,210
if they're a little bit tilted,
513
00:28:52,210 --> 00:28:56,480
this beam will make circles,
across the universe.
514
00:28:56,490 --> 00:28:59,250
And if we're in the path
of one of these circles,
515
00:28:59,250 --> 00:29:02,990
we'll see a flash... A flash.
516
00:29:02,990 --> 00:29:04,660
Just like if you're on a ship,
517
00:29:04,660 --> 00:29:07,330
and you observe a distant
lighthouse in a foggy night,
518
00:29:07,330 --> 00:29:11,300
you can see pulsars across
the vast expanse of space
519
00:29:11,300 --> 00:29:14,900
because they are immensely
powerful beams of light.
520
00:29:14,900 --> 00:29:18,200
But sometimes,
pulsars get an extra push
521
00:29:18,210 --> 00:29:21,980
that accelerates
the spin even more.
522
00:29:21,980 --> 00:29:24,110
The way you make it spin
even faster
523
00:29:24,110 --> 00:29:27,280
is by subsequently
dumping more material onto it.
524
00:29:27,280 --> 00:29:29,780
That's called "accretion,"
and you end up spinning it up
525
00:29:29,790 --> 00:29:31,890
even faster than it
was already spinning.
526
00:29:31,890 --> 00:29:33,990
Like stellar vampires,
527
00:29:33,990 --> 00:29:36,220
pulsars are ready
to suck the life
528
00:29:36,220 --> 00:29:39,630
out of any objects
that stray too close.
529
00:29:39,630 --> 00:29:42,060
Gravity is bringing
that material in,
530
00:29:42,060 --> 00:29:44,730
which means that any spin
it has is accelerated.
531
00:29:44,730 --> 00:29:46,530
It spins faster and faster.
532
00:29:46,540 --> 00:29:48,840
These millisecond pulsars
533
00:29:48,840 --> 00:29:53,040
spin at around
700 revolutions per second.
534
00:29:53,040 --> 00:29:55,140
They are the ultimate
kitchen blender...
535
00:29:55,140 --> 00:29:59,480
They will chop, they will slice,
they will even julienne fry.
536
00:30:02,180 --> 00:30:04,220
So, what stops neutron stars
537
00:30:04,220 --> 00:30:07,390
from simply tearing
themselves apart?
538
00:30:07,390 --> 00:30:10,690
Neutron stars are
incredibly exotic objects
539
00:30:10,690 --> 00:30:14,730
with immense, immense forces
that bind them together,
540
00:30:14,730 --> 00:30:16,930
and so, they can be
held rigid even against
541
00:30:16,930 --> 00:30:19,230
these incredibly fast
rotation speeds.
542
00:30:22,900 --> 00:30:24,770
They have
incredibly strong gravity,
543
00:30:24,770 --> 00:30:26,670
and this is what allows them
to hold together
544
00:30:26,680 --> 00:30:28,840
even though they're
spinning around so fast.
545
00:30:31,910 --> 00:30:37,280
The speed of the spin
is hard to imagine.
546
00:30:37,290 --> 00:30:39,450
On earth, a day
is 24 hours long.
547
00:30:39,450 --> 00:30:44,490
On a neutron star,
it's a 700th of a second long.
548
00:30:44,490 --> 00:30:48,530
Super-speeding pulsars are
not the only weird stars
549
00:30:48,530 --> 00:30:51,060
that scientists
are coming to grips with.
550
00:30:51,070 --> 00:30:53,430
There is one other type
of neutron star,
551
00:30:53,440 --> 00:30:57,340
that has the most powerful
magnetic field in the universe.
552
00:30:57,340 --> 00:31:01,740
This magnetic monster
is called a "magnetar."
553
00:31:11,850 --> 00:31:14,990
Astronomers monitoring
pulsing neutron stars
554
00:31:14,990 --> 00:31:17,960
have noticed something very odd.
555
00:31:17,960 --> 00:31:23,560
On very rare occasions,
they can suddenly speed up.
556
00:31:23,570 --> 00:31:24,760
That's amazing.
557
00:31:24,770 --> 00:31:26,770
I mean, you've got this
incredibly dense object,
558
00:31:26,770 --> 00:31:28,200
and suddenly,
it's spinning faster.
559
00:31:28,200 --> 00:31:30,270
It happens... Instantly.
560
00:31:30,270 --> 00:31:32,110
They'll suddenly
change frequency.
561
00:31:32,110 --> 00:31:35,380
It would take an amazing
amount of power to do that.
562
00:31:35,380 --> 00:31:36,980
What's doing it?
563
00:31:36,980 --> 00:31:41,680
These sudden changes
in speed are called "glitches."
564
00:31:41,680 --> 00:31:44,050
One leading idea for
what causes these glitches
565
00:31:44,050 --> 00:31:46,690
is that the core material
latches onto the crust,
566
00:31:46,690 --> 00:31:49,890
and this affects
the way it can spin around.
567
00:31:49,890 --> 00:31:53,760
Excess material beneath
the crust cracks it open,
568
00:31:53,760 --> 00:31:55,760
causing the glitch.
569
00:31:55,760 --> 00:31:59,670
This process releases a
tremendous amount of radiation,
570
00:31:59,670 --> 00:32:04,200
a blast of x-rays, causes
the face of the neutron star
571
00:32:04,210 --> 00:32:08,570
to rearrange itself, and for
the rotation speed to change.
572
00:32:08,580 --> 00:32:11,180
But there's another
possible explanation.
573
00:32:11,180 --> 00:32:15,520
Glitches could also be caused
by starquakes.
574
00:32:15,520 --> 00:32:17,980
Sometimes,
the crust gets ruptured.
575
00:32:17,990 --> 00:32:22,120
Anything that basically changes
the geometry of the pulsar
576
00:32:22,120 --> 00:32:25,090
can change the rate
at which it spins.
577
00:32:25,090 --> 00:32:26,590
So,
what could be powerful enough
578
00:32:26,590 --> 00:32:29,930
to cause these starquakes?
579
00:32:29,930 --> 00:32:30,960
It's hard to believe
580
00:32:30,970 --> 00:32:33,300
that there's any
force in the universe
581
00:32:33,300 --> 00:32:36,370
that could deform the matter
inside of a neutron star,
582
00:32:36,370 --> 00:32:39,140
which is undergoing
tremendous gravity.
583
00:32:39,140 --> 00:32:40,870
But when it comes to
a neutron star,
584
00:32:40,880 --> 00:32:44,080
if there's one thing that
can do it, it's magnetism.
585
00:32:44,080 --> 00:32:45,810
Extreme magnetic fields
586
00:32:45,810 --> 00:32:48,610
within the star
can get so twisted
587
00:32:48,620 --> 00:32:51,320
they can rip the crust
wide open.
588
00:32:51,320 --> 00:32:53,920
And so, the surface
can restructure itself,
589
00:32:53,920 --> 00:32:55,490
and constantly reshape.
590
00:32:55,490 --> 00:32:58,160
And just a tiny reconfiguration
591
00:32:58,160 --> 00:32:59,930
of the surface
of a neutron star,
592
00:32:59,930 --> 00:33:01,560
on the order of
a few millimeters,
593
00:33:01,560 --> 00:33:06,030
would be associated with
an enormous release of energy.
594
00:33:06,030 --> 00:33:08,200
The neutron star's
immense gravity
595
00:33:08,200 --> 00:33:13,340
smooths over the star's surface
almost instantaneously.
596
00:33:13,340 --> 00:33:15,880
It's like the glitch
never happened.
597
00:33:19,350 --> 00:33:21,450
When it comes to neutron stars,
598
00:33:21,450 --> 00:33:26,050
there is no end
to magnetic mayhem.
599
00:33:26,050 --> 00:33:28,020
Meet the reigning champion
600
00:33:28,020 --> 00:33:32,560
in the universal "strongest
magnetic field" competition...
601
00:33:32,560 --> 00:33:35,060
The magnetar.
602
00:33:35,060 --> 00:33:38,630
1 in 10 neutron stars
formed during a supernova
603
00:33:38,630 --> 00:33:41,130
becomes a magnetar.
604
00:33:41,140 --> 00:33:45,710
The thing about magnetars,
as is implied in their name...
605
00:33:45,710 --> 00:33:48,010
The magnetic field
on them is so strong,
606
00:33:48,010 --> 00:33:50,540
that even somebody who is
used to using big numbers...
607
00:33:50,550 --> 00:33:52,310
Like, say, an astronomer...
608
00:33:52,310 --> 00:33:55,380
Is still kind of in awe
of these things.
609
00:33:55,380 --> 00:33:57,750
Magnetars have a magnetic field
610
00:33:57,750 --> 00:34:01,920
one thousand trillion times
stronger than that of earth's.
611
00:34:01,920 --> 00:34:03,820
This amount of magnetism
612
00:34:03,830 --> 00:34:08,630
will seriously mess up
anything that comes close.
613
00:34:08,630 --> 00:34:11,130
Any normal object
that we are familiar with,
614
00:34:11,130 --> 00:34:14,770
if it got close to a magnetar,
it would just be shredded.
615
00:34:14,770 --> 00:34:17,070
Any charged particle
with any movement at all,
616
00:34:17,070 --> 00:34:18,910
would just be torn
from its atom.
617
00:34:18,910 --> 00:34:22,310
It would be just
an insane situation.
618
00:34:22,310 --> 00:34:26,710
Magnetars burn brightly,
but their lives are brief.
619
00:34:26,710 --> 00:34:27,980
We think magnetars...
620
00:34:27,980 --> 00:34:30,620
These intensely
magnetized neutron stars...
621
00:34:30,620 --> 00:34:32,550
Can only be really short-lived.
622
00:34:32,550 --> 00:34:34,820
Their magnetic field
is so powerful
623
00:34:34,820 --> 00:34:37,360
that it should decay
over very rapid time scales,
624
00:34:37,360 --> 00:34:39,890
only on the order of
a few ten thousand years.
625
00:34:39,890 --> 00:34:44,360
It seems their very strength
leads to their downfall.
626
00:34:44,370 --> 00:34:46,300
That magnetic field is so strong
627
00:34:46,300 --> 00:34:49,340
that it's picking up material
around it, and accelerating it.
628
00:34:49,340 --> 00:34:51,370
Well, that acts like a drag,
slowing it down.
629
00:34:51,370 --> 00:34:54,540
So, over time, the spin
of the neutron star slows,
630
00:34:54,540 --> 00:34:56,380
and the magnetic field
dies away.
631
00:34:58,680 --> 00:34:59,980
During their lives,
632
00:34:59,980 --> 00:35:03,580
magnetars operate very
differently than pulsars.
633
00:35:03,590 --> 00:35:05,220
They don't have beams.
634
00:35:05,220 --> 00:35:08,190
Their magnetic fields
shoot out gigantic bursts
635
00:35:08,190 --> 00:35:11,620
of high-intensity radiation.
636
00:35:11,630 --> 00:35:15,290
But recently, astronomers
have spotted one neutron star
637
00:35:15,300 --> 00:35:17,760
that's hard to classify.
638
00:35:17,770 --> 00:35:22,030
It behaves like a stellar
Jekyll and Hyde.
639
00:35:24,040 --> 00:35:27,940
So, this particular neutron star
is a really weird example.
640
00:35:27,940 --> 00:35:30,310
It behaves both like
a radio pulsar,
641
00:35:30,310 --> 00:35:33,250
and also a highly-magnetized
magnetar.
642
00:35:33,250 --> 00:35:35,580
It has the extreme
magnetic fields,
643
00:35:35,580 --> 00:35:38,320
it can have these
magnetic outbursts,
644
00:35:38,320 --> 00:35:41,050
but it also has
this strong jet of radiation
645
00:35:41,060 --> 00:35:42,320
coming out of its poles.
646
00:35:42,320 --> 00:35:46,360
It's almost like it has
a split personality.
647
00:35:46,360 --> 00:35:48,630
When first sighted in 2000,
648
00:35:48,630 --> 00:35:51,130
this star was emitting
radio waves...
649
00:35:51,130 --> 00:35:54,070
Typical pulsar behavior.
650
00:35:54,070 --> 00:35:58,070
Then, 16 years later,
it stopped pulsing,
651
00:35:58,070 --> 00:36:02,510
and suddenly started sending out
massive X-ray bursts...
652
00:36:02,510 --> 00:36:05,440
The actions of a magnetar.
653
00:36:05,450 --> 00:36:08,480
Scientists were baffled.
654
00:36:08,480 --> 00:36:11,680
We don't know if this thing is a
pulsar turning into a magnetar,
655
00:36:11,690 --> 00:36:14,250
or a magnetar turning
into a pulsar.
656
00:36:14,260 --> 00:36:17,190
One theory is that
these X-ray bursts happened
657
00:36:17,190 --> 00:36:21,260
because the star's magnetic
field suddenly twisted.
658
00:36:21,260 --> 00:36:25,700
The stress became so great,
the star cracked wide open,
659
00:36:25,700 --> 00:36:29,700
releasing the X-rays
from the fractured crust.
660
00:36:29,700 --> 00:36:31,970
A neutron star
is the densest material
661
00:36:31,970 --> 00:36:33,910
that we know of in the universe.
662
00:36:33,910 --> 00:36:35,140
And yet, we've seen things
663
00:36:35,140 --> 00:36:37,580
that actually make it shift
and pull apart.
664
00:36:37,580 --> 00:36:40,210
This neutron star is actually
ripping itself apart
665
00:36:40,220 --> 00:36:42,280
under the forces
of the magnetic field.
666
00:36:42,280 --> 00:36:43,780
If this is the case,
667
00:36:43,790 --> 00:36:48,350
placid neutron stars
turn into raging magnetars,
668
00:36:48,360 --> 00:36:51,790
growing old disgracefully.
669
00:36:51,790 --> 00:36:53,790
When you think about the
life cycle of a human being,
670
00:36:53,800 --> 00:36:55,630
we seem to kind of
slow down over age,
671
00:36:55,630 --> 00:36:57,100
become a little more calmer.
672
00:36:57,100 --> 00:36:58,760
Neutron stars do the opposite.
673
00:36:58,770 --> 00:37:00,570
They can be spinning
faster than they were
674
00:37:00,570 --> 00:37:01,870
when they were formed,
675
00:37:01,870 --> 00:37:04,200
and the magnetic field can
get stronger over time.
676
00:37:04,210 --> 00:37:07,370
It's sort of
a reverse aging process.
677
00:37:07,380 --> 00:37:10,640
But these strange
changes are extremely rare.
678
00:37:10,650 --> 00:37:15,720
Most pulsars
are as regular as clockwork.
679
00:37:15,720 --> 00:37:17,680
Pulsars are normally
incredibly regular.
680
00:37:17,690 --> 00:37:20,850
You can literally set your watch
to the timing of their pulse.
681
00:37:20,860 --> 00:37:23,420
And it's this
stability that we may use
682
00:37:23,420 --> 00:37:27,060
in our future exploration
of the universe.
683
00:37:27,060 --> 00:37:28,930
You know,
if you're a starship captain,
684
00:37:28,930 --> 00:37:32,100
what you need is
a galactic GPS system.
685
00:37:32,100 --> 00:37:35,230
Well it turns out,
neutron stars may be the answer.
686
00:37:45,310 --> 00:37:47,150
Astronomers often compare
687
00:37:47,150 --> 00:37:51,420
the steady flash of spinning
neutron stars, called "pulsars,"
688
00:37:51,420 --> 00:37:53,490
to cosmic lighthouses.
689
00:37:53,490 --> 00:37:57,260
These flashes are not only
remarkably reliable,
690
00:37:57,260 --> 00:38:02,800
each pulsar has its very own
distinct flickering beam.
691
00:38:02,800 --> 00:38:05,230
Each one has a slightly
different frequency.
692
00:38:05,230 --> 00:38:08,070
Each one has a slightly
different rate.
693
00:38:08,070 --> 00:38:11,440
Anyone in the galaxy,
no matter where you are,
694
00:38:11,440 --> 00:38:17,680
can all agree on the positions
of these pulsars.
695
00:38:17,680 --> 00:38:20,010
The unique signature of pulsars
696
00:38:20,010 --> 00:38:22,650
opens up intriguing
possibilities
697
00:38:22,650 --> 00:38:24,250
for the future of space travel.
698
00:38:29,690 --> 00:38:32,090
We would
basically be using pulsars
699
00:38:32,090 --> 00:38:34,990
to be able to sort of
triangulate where we're at.
700
00:38:35,000 --> 00:38:37,360
And because those pulses
are so precise,
701
00:38:37,370 --> 00:38:40,570
we can use that in a similar way
that we use GPS satellites
702
00:38:40,570 --> 00:38:42,100
that are stationed
above the Earth.
703
00:38:45,040 --> 00:38:47,910
Using pulsars
as navigational aids
704
00:38:47,910 --> 00:38:49,740
is not a new idea.
705
00:38:49,740 --> 00:38:53,110
It was recognized
by the NASA voyager mission
706
00:38:53,110 --> 00:38:56,120
in the 1970's.
707
00:38:56,120 --> 00:38:58,480
Affixed to the surface
of those spacecraft
708
00:38:58,490 --> 00:38:59,750
is a golden record.
709
00:38:59,750 --> 00:39:01,750
And on the plate
that covers that record
710
00:39:01,760 --> 00:39:05,190
is a pulsar map,
which in principle could tell
711
00:39:05,190 --> 00:39:08,590
an advanced alien civilization
how to find earth,
712
00:39:08,600 --> 00:39:11,100
because it uses
the position of earth
713
00:39:11,100 --> 00:39:13,270
relative to 14 known pulsars,
714
00:39:13,270 --> 00:39:15,430
as, effectively,
a way to triangulate
715
00:39:15,440 --> 00:39:16,970
the position of our planet
716
00:39:16,970 --> 00:39:19,910
relative to all
of these pulsars.
717
00:39:19,910 --> 00:39:25,910
Aliens haven't made contact,
but NASA still uses pulsar maps.
718
00:39:25,910 --> 00:39:27,810
NASA recently
launched a satellite
719
00:39:27,820 --> 00:39:29,450
called "nicer sextant"
720
00:39:29,450 --> 00:39:32,050
that exists on the
international space station,
721
00:39:32,050 --> 00:39:34,750
that is being used to test
these types of theories.
722
00:39:43,460 --> 00:39:45,930
They've used pulsars
to figure out the location
723
00:39:45,930 --> 00:39:47,930
of an object orbiting
around the Earth
724
00:39:47,940 --> 00:39:50,240
at 17,000 miles an hour,
725
00:39:50,240 --> 00:39:52,070
and they were able to
pinpoint its location
726
00:39:52,070 --> 00:39:53,570
to within three miles.
727
00:39:53,570 --> 00:39:55,640
That's pretty incredible.
728
00:39:55,640 --> 00:40:00,010
By recognizing their position
relative to known pulsars,
729
00:40:00,010 --> 00:40:03,720
future space missions
could navigate the universe.
730
00:40:10,260 --> 00:40:13,230
Neutron stars are gonna take us
on this incredible journey...
731
00:40:13,230 --> 00:40:14,660
Something as necessary
732
00:40:14,660 --> 00:40:16,530
as knowing where you are
in the galaxy.
733
00:40:16,530 --> 00:40:18,430
We could be many hundreds
of light years away,
734
00:40:18,430 --> 00:40:20,230
but neutron stars
can actually show us
735
00:40:20,230 --> 00:40:21,800
where in the milky way we are.
736
00:40:29,610 --> 00:40:30,910
I read a lot of science fiction,
737
00:40:30,910 --> 00:40:33,610
and I love the idea
of being able to go
738
00:40:33,610 --> 00:40:36,180
from star to star,
planet to planet.
739
00:40:36,180 --> 00:40:39,950
It's kind of weird to think
that, in the future,
740
00:40:39,950 --> 00:40:42,460
as a galactic coordinate grid,
741
00:40:42,460 --> 00:40:46,690
we might wind up using
these gigantic atomic nuclei,
742
00:40:46,690 --> 00:40:49,800
these rapidly spinning,
bizarrely-constructed,
743
00:40:49,800 --> 00:40:54,270
magnetic, fiercely gravitational
objects like neutron stars.
744
00:40:57,370 --> 00:41:00,210
Neutron stars
have come a long way
745
00:41:00,210 --> 00:41:04,910
since being mistaken
for little green men.
746
00:41:04,910 --> 00:41:09,450
Once overlooked
as astronomical oddities,
747
00:41:09,450 --> 00:41:16,890
they've now taken center stage
as genuine stellar superstars.
748
00:41:16,890 --> 00:41:19,330
What's really exciting
about neutron stars is that,
749
00:41:19,330 --> 00:41:21,630
we're at the beginning
of studying them.
750
00:41:21,630 --> 00:41:23,960
We're not at the conclusion.
We've learned a lot,
751
00:41:23,970 --> 00:41:25,800
but there's a lot more
to be learned.
752
00:41:25,800 --> 00:41:30,470
From the humble neutron
comes the most powerful,
753
00:41:30,470 --> 00:41:33,910
the most rapid,
the strongest magnetic field,
754
00:41:33,910 --> 00:41:37,740
the most exotic objects
in the cosmos.
755
00:41:37,750 --> 00:41:39,450
I love the idea of a Phoenix,
756
00:41:39,450 --> 00:41:41,980
something actually rising
from its own ashes.
757
00:41:41,980 --> 00:41:44,550
You think something dies,
and that's the end of the story,
758
00:41:44,550 --> 00:41:46,120
but something even
more beautiful,
759
00:41:46,120 --> 00:41:48,550
even more fascinating,
comes afterwards.
760
00:41:48,560 --> 00:41:50,790
I told you at the beginning,
and you didn't believe me,
761
00:41:50,790 --> 00:41:52,160
but now, I hope you do...
762
00:41:52,160 --> 00:41:54,760
Neutron stars
are the most fascinating
763
00:41:54,760 --> 00:41:57,400
astrophysical objects
in the universe.
61405
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