[Music]
the holocene has ended what we do now
and in the next few years will
profoundly affect the next few thousand
year
the only conditions modern humans have
ever known so far
and changing fast
day is the same on this planet
everything changes the earth is going
into one of these jumps and you don't
know what is gonna be on the other side
of those jumps
the earth is always jumping
warmest planet
things are not still
everything is turning
[Music]
as he begins to run out of fuel the Sun
won't simply fade away to nothing its
core will collapse and the extra heat
this generates will cause its outer
layers to expand
the Sun is now dead
it remains slowly cooling in the
freezing temperatures of deep space
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the fate of the Sun is the same as for
all stars one day they must all
eventually die in the cosmos will be
plunged into eternal night all stars
eventually will run out of fuel the
temperature of the universe drops the
stars one by one to the night sky
and there'd be no more new stars created
and so that the universe will end not
with a bang but
and not in fire nice
[Music]
with no fuel left to burn a white
dwarves faint glow comes from the last
residual heat from its extinguished
furnace
[Music]
looking at it from where the earth is
now it would only generate the same
amount of light as the full moon on a
clear night
[Music]
the faint glow of whitewalls will
provide the only illumination in a dark
and empty void littered with dead stars
and black holes
[Music]
in some ways it's kind of a ghost
universe it's the corpses the zombie
stars that will take us into the future
[Music]
a black dwarf will be the final fate of
those last stars white dwarves that have
become so cold that they barely emit any
more heat or light
black dwarves a dark dense decaying
balls of degenerate matter
more than the ashes of stars their
constituent atoms are so severely
crushed that black dwarves are a million
times denser than our Sun
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stars take so long to reach this point
we believe there are currently no black
dwarves in the universe
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we have a pace of life that's based on
really the energy available to us now
you could imagine living conscious
systems which have a very different pace
and therefore can extend out at least a
lot farther than you'd imagine otherwise
[Music]
you could have a living system where if
it had a thought every 10 trillion years
that would seem normal
even if our life dies out one could
imagine at some time arbitrarily far in
the future a fluctuation occurs
intelligent life to exist began for the
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a proton or one of the fundamental
building blocks of atomic matter what
makes us up can just spontaneously fall
apart any material that evades the pull
of a black hole eventually dies away as
its protons disintegrate
[Music]
the matter inside black dwarves the last
matter in the universe will eventually
evaporate away
carried off into the void as radiation
leaving absolutely
behind
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with the black dwarves gone
there won't be a single atom of matter
left all that will remain of our once
rich cosmos will be particles of light
and black holes
[Music]
Oh
[Music]
the arrow of time
creates a bright window in the
universe's adolescence during which life
is possible
but it's a window that doesn't stay open
for long
as a fraction of the lifespan of the
universe as measured from its beginning
to the evaporation of the last black
hole life as we know it is only possible
for one thousandth of a billion billion
billionth billion billion billionth
billion billion billionth of a percent
black holes become the fundamental
building block of the universe
[Music]
a galaxy will basically be a
supermassive black hole in the center
with smaller black holes orbiting
[Music]
zombie galaxies filled with black holes
continued to evolve
[Music]
they'll lead each other and they'll get
maybe they'll fall into the supermassive
black hole and it'll get bigger the
universe will still be an exciting
dynamic place it's just that the time
scales you're talking about are now
trillions of years instead of thousands
or millions of years
[Music]
black holes can bang on space-time like
mallets on a drum
and have a very characteristic song
[Music]
magic to black holes that have lived a
long life together
at the end of their lives are going
around each other crossing thousands of
kilometers in a fraction of a second
as they do so they leave behind in there
a ringing of space an actual wave on
space-time
[Music]
space squeezes and stretches as it
emanates out from these black holes
banging on the universe
[Music]
those are the gravitational waves are
literally the sounds of space ringing
and they will travel out from these
black holes at the speed of light as
they were
- one spinning flying black hole if you
were standing near enough your ear would
resonate with the squeezing and
stretching of space
[Music]
imagine a lighter black hole falling
into a very heavy blackboard
the sounds are hearing
[Music]
each time it gets closed
[Music]
Falls in it gets faster and it gets
louder
scientists used to think black holes
were immortal but even these one day die
now we're talking about timescales of
unimaginable length but trillions of
years into the future on that time scale
even the black holes begin to evaporate
[Music]
according to quantum mechanics space is
filled with virtual particles and
antiparticles that are constantly
materializing in pairs separating coming
together again and annihilating each
other in the presence of a black hole
one member of a pair of virtual
particles may fall into the hole leaving
the other member without a partner with
which to annihilate the physical
particle appears to be radiation emitted
by the black hole and so black holes are
not internal they evaporate away at an
increasing rate until they vanish in a
gigantic explosion mechanics has allowed
particles and radiation to escape from
the ultimate prison a black hole
[Music]
philosophers and poets have asked the
question will the world end and fire or
ice we can now give an answer the latest
evidence shows that the universe is not
slowing down but it's speeding up
[Applause]
the universe we think will
in ice trillions upon trillions of years
[Applause]
empty space itself has energy in every
little cubic centimeter of space whether
or not their stuff whether or not
there's particles matter radiation or
whatever there is still energy even in
the space itself
and this energy according to Einstein
exerts a push on the universe
what is the weird stuff that's
accelerating the universe we call it
dark energy
and this stuff is the dominant stuff of
the universe almost 3/4 of the matter
energy content of the universe is this
dark energy and we don't know what it is
the arc energy unlike matter irradiation
does not dilute away as the universe
expands this has crucial implications
for what the universe is going to do in
the future
so what will be the future of the
universe
well if the dark energy remains dominant
and repulsive the universe will expand
forever
faster and faster and faster
a runaway universe
[Music]
percent of the energy of the universe
resides an empty space and we
understand why
but we do know what will happen
if that energy continues to be there the
universe has become cold and dark and
empty
that's the future as it might be we
don't know because we don't yet
understand the nature of dark energy
until we do we won't know the future we
won't even understand the our own
origins and that's why we want to know
and study this subject
[Music]
forecast does seem to be for
colder at the empty universe
but then of course we have to ask could
that end lead to a new beginning
and there are ideas whereby what
actually is the end of our universe
could in some sense beating into the
beginning of a new one
[Music]
we've worked out the mathematics the
equations they seem to say that if you
have an atom smasher that can
concentrate tremendous amounts of energy
at a single point you can perhaps open
up a gateway a baby universe
[Music]
facing the death of everything there is
this perhaps is their only possibility
of escape and this also raises a very
intriguing possibility sheer speculation
of course that perhaps any universe that
has intelligent life in it will create
baby universes will create lifeboats and
proliferate child universals
[Music]
so an evolution may pay
in the multiverse survival of the
fittest may take place so those
universes which do not have intelligent
life are infertile
have no children but those universes
that have mild temperatures stars like
us would create civilizations that could
open up child universes and they would
then proliferate
[Music]
after an unimaginable length of time
even the black holes will have
evaporated and the universe will be
nothing but a sea of photons gradually
tending towards the same temperature as
the expansion of the universe cools them
towards absolute zero
[Music]
once the very last remnants of the very
last stars and finally decayed away to
nothing but everything reaches the same
temperature the story of the universe
finally comes to an end
for the first time in its life the
universe will be permanent and
unchanging entropy finally stops
increasing because the cosmos cannot get
any more disordered nothing happens and
it keeps not happening forever
[Music]
you