lying just beneath everyday reality is a
breathtaking world where much of what we
perceive about the universe is wrong
physicist and best-selling author Brian
Greene takes you on a journey that bends
the rules of human experience why don't
we ever see events unfold in reverse
orders according to the laws of physics
this can happen it's a world that comes
to light as we probe the most extreme
realms of the cosmos from black holes to
the Big Bang to the very heart of matter
itself I'm gonna have what he said here
our universe may be one of numerous
parallel realities the three-dimensional
world may be just an illusion and
there's no distinction between past
present and future
but how could this be how could we be so
wrong about something so familiar
does it bother us absolutely there's no
principle built into the laws of nature
that say that theoretical physicists
have to be happy
it's a game-changing perspective that
opens up a whole new world of
possibilities coming up what if you took
all this stuff away we're left with
empty space but what seems like nothing
is actually teeming with ferocious
activity what is space it is one the
deepest mysteries in physics could its
elusive ingredients hold the key to the
fate of the universe the fabric of the
cosmos right now on Nova
major funding for Nova is provided by
the following
David H coke and discover new knowledge
h h mi and by the Corporation for Public
Broadcasting and by contributions to
your PBS station from viewers like you
thank you
major funding for the fabric of the
cosmos is provided by the National
Science Foundation where discoveries
begin
and
the Alfred P sloan Foundation supporting
original research and public
understanding of science technology
engineering and mathematics additional
funding is provided by the Arthur vining
Davis foundations dedicated to
strengthening America's future through
education the US Department of Energy's
Office of Science and the George D Smith
Fund
we think of our world as filled with
stuff like buildings and cars buses and
people and nor does that seem more
apparent than in a crowded city like New
York yet all around the stuff that makes
up our everyday world is something just
as important but far more mysterious
this space in which all this stuff
exists to get a feel for what I'm
talking about let's stop for a moment
and imagine what if you took all this
stuff away I mean all of it the people
the cars and buildings and not just the
stuff here on earth but the earth itself
what if you took away all the planets
stars and galaxies and not just the big
stuff but tiny things down to the very
last atoms of gas and dust what if you
took it all away what would be left most
of us would say nothing and we'd be
right but strangely we'd also be wrong
what's left is empty space and as it
turns out empty space is not nothing
it's something something with hidden
characteristics as real as all the stuff
in their everyday lives in fact space is
so real it can bend space can twist
and it can ripple so real that empty
space itself helps shape everything in
the world around us and forms the very
fabric of the cosmos but you can't
understand anything about the world
unless we understand space because
that's the world the world's space with
stuff in it we're not usually very
conscious of space but then again I tell
people fish are probably not conscious
of water either they're in it all the
time space is not really nothing
it actually has lot going on inside
when most of us picture space we think
of outer space a place that's far far
away but space is actually everywhere
you could say it's the most abundant
thing in the universe even the tiniest
of things like atoms the basic
ingredient in you and me and everything
else we see in the world around us even
they are almost entirely empty space in
fact if you removed all the space inside
all the atoms making up the stone glass
and steel of the Empire State Building
you'd be left with a little lump pop the
size of a grain of rice but weighing
hundreds of millions of pounds the rest
is only empty space but what exactly is
space I can show you a picture of Spain
of Napoleon
of my uncle Harold but space it looks
like this nothing so how do you make
sense of something that looks like
nothing why is this space rather than no
space why is space three-dimensional why
is space big we have a lot of room to
move around in how come it's not tiny
we have no consensus about these things
what is space we actually still don't
really know it is one of the deepest
mysteries in physics fortunately were
not completely in the dark
we've been gathering clues about space
for centuries some of the earliest came
from thinking about how objects move
through space to get a feel for this
take a look at that skater as she glides
across the rink she's moving in relation
to everything around her like the ice
and when she goes into a spin not only
can she see that she's spinning
she can also feel it because as she
spins she feels her arms pulled outward
but now let's imagine that you could
take away all the stuff around her from
the rink to the most distant galaxies
so the only thing left is the skater
spinning in completely empty space if
the skater still feels her arms pulled
outward she'll know she's spinning but
if empty space is nothing
what is she spinning in relation to
imagine you're that skater when you look
out you don't see anything
it's just uniform still blackness all
around you and yet your arms are being
pulled out words so you say to yourself
what could I be spinning with respect to
is there something out there that I'm
not seeing
trying to answer questions like these
scientists came up with a bold new
picture of space and the key was to make
something out of nothing
when you go to the theater you watch the
actors I do confess that I love nothing
in the world so well is the scenery the
story I protest I love and God forgive
me what offends the sweet beauty but
there's something important here that
you won't find mentioned in the play
though something we hardly ever noticed
the stage it's an absolutely vital part
of the show and yet most of us we don't
even give it a second thought but Isaac
Newton he did this is how the father of
modern science pictured space as an
empty stage to Newton space was the
framework for everything that happens in
the cosmos the arena within which the
drama of the universe plays out and
Newton's stage was passive absolute
eternal and unchanging the action
couldn't affect the stage and the stage
couldn't affect the action by picturing
space in this way Newton was able to
describe the world as no one had ever
done before his unchanging stage allowed
him to understand almost all motion we
can see around us yielding laws that can
predict everything from the way apples
fall from trees to the paths the earth
takes around the Sun
these laws worked so well that we still
use them for the things we do today from
launching satellites to landing
airplanes and the laws all hinge on one
radical idea space is real even though
you can't see it or smell it or touch it
space is enough of a real physical thing
to provide a benchmark for certain kinds
of motion like that skaters Newton would
say that when she spins her arms splay
out because she is spinning with respect
to something and that something is space
itself the lockers had been debating the
nature space for a very long time what
Newton does is change the terms of the
debate and with that essentially modern
science gets born Newton stage was a
huge hit it enjoyed the limelight for
over 200 years
but in the early decades of the 20th
century a new set of ideas emerged that
shook Newton's stage to it's very
foundation I just put forward by a young
clerk working in a Swiss Patent Office
his name Albert Einstein
Einstein grew up in the late 1800s at
the dawn of the age of electricity
electric power was lighting up cities
giving rise to all kinds of technologies
Newton could never have imagined all of
these developments tapped into something
that had captivated Einstein since he
was a child
light not lightbulbs and street lamps
but the very nature of light itself and
it was his fascination with one
particularly weird feature of light its
speed that would lead Einstein to
overturn Newton's picture of space to
see how let's take a ride
right now we're traveling at about 20
miles per hour
and to go faster all the driver needs to
do step on the gas
and the cab speed changes now you can
feel that change but you can also see it
on the cap speedometer or on one of
those radar speed signs okay you can
slow it down but now imagine that
instead of measuring the speed of the
cab you have a radar sign that measures
the speed of the light coming off its
headlights that sign would measure the
light traveling at an astounding 671
million miles an hour
now when the cab starts moving you'd
think that the speed of the light would
increase by the same amount as the car
after all you'd think that the moving
cab would give the light an extra push
but surprisingly that's not what happens
our radar sign or any measurement of
Lightspeed will always detect like
traveling at 671 million miles per hour
whether the cab is moving or not but how
could this be how could all measurements
of Lightspeed always come out the same
if you're running at a wall it's coming
at you faster than if you're standing
still with respect to that wall but
that's not true with light the speed of
light is the same for everybody that's
really extraordinary so here's how I'm
Stein made sense of this extraordinary
puzzle knowing that speed is just a
measure of the space that something
travels over time Einstein proposed a
truly stunning idea that space and time
could work together constantly adjusting
by exactly the right amount so that no
matter how fast you might be moving when
you measure the speed of light it always
comes out to be 671 million miles per
hour
to respect that absolute quality about
light time had to cease to be absolute
space had to cease to be absolute and
those two had to become relative in such
a way that they sloshed between each
other if space and time being flexible
sounds unfamiliar it's only because we
don't move fast enough in everyday life
to see it in action
but if this cab could move near the
speed of light the effects would no
longer be hidden
for example if you were on a street
corners I went by close to the speed of
light you see space adjusting so that my
cab
it would appear just inches long
and you know also here my watch ticking
off time or very slowly but from my
perspective inside the cab my watch
would be ticking normally and space in
here would appear as it always does
but when I look outside the cab I'd see
space wildly adjusting all to keep the
speed of light constant
so with Einstein time and space are no
longer rigid and absolute instead they
meld together with motion forming a
single entity that came to be called
space-time
I think as we live our life every day we
live with the Newtonian picture of space
and time it's something that we are
comfortable with but Einstein was able
to make reason conquer sense that really
was the genius of Einstein this notion
that space a time our unity to me is one
of the greatest insights that has ever
occurred in science it's so
counterintuitive to everything we've
ever experienced as human beings and in
the hands of Albert Einstein this new
picture of space would solve a deep
mystery having to do with the most
familiar force in the cosmos gravity
Newton knew that gravity is a force that
attracts objects to each other and as
laws predicted a strength of his force
with fantastic precision but how does
gravity actually work how does the earth
pull on the moon across hundreds of
thousands of miles of empty space they
behave as if they're connected by some
kind of invisible rope but everyone knew
that wasn't true and Newton's laws
provided no explanation
Einstein found that no band-aid patches
would fix Newtonian gravity he had to
invent a mechanism for it he had to
understand it after puzzling over this
problem for more than ten years
Einstein reached a startling conclusion
the secret to gravity lay in the nature
of space-time it was even more flexible
than he had previously realized it could
stretch like an actual fabric
this was a truly radical break from
Newton think of this table of space-time
and think of these balls as objects in
space
now if space-time were nice and flat
like the surface of this table objects
would travel in straight lines but if
space is like a fabric that can stretch
and Bend well this may seem a little
strange but watch what happens if I put
something heavy on a stretchy space-time
fabric
now if I take my shot again the ball
travels along an indentation in the
fabric that the heavier object creates
and this Einstein realized is how
gravity actually works
it's the warping of space-time caused by
the objects within it
in other words gravity is the shape of
space-time itself the moon is kept in
orbit
not because it's pulled to the earth by
some mysterious force but rather because
it rolls along a curve in the space-time
fabric that the earth creates
Provine stein space became not only real
but flexible so suddenly space had
properties suddenly space had curvature
suddenly space had a flexible kind of
geometry almost like a rubber sheet
it opens up a whole new way of thinking
about reality
that describe the entire universe
Einstein becomes Einstein because of
that observation where Newton saw space
is passive Einstein saw it as dynamic
it's interwoven with time and it
dictates how things move so after
Einstein space can no longer be thought
of as a static stage it's an actor and
it plays a leading role in the cosmic
drama
now it's one thing to think of space as
dynamic active and flexible like a
fabric but is it really is this just a
metaphor or does it actually describe
what space is
well Einstein's theory predicts that one
way to find out would be to take the
little journey to the edge of a black
hole
black holes are collapsed stars massive
objects crushed to a fraction of their
original size gravity around them is so
strong that according to Einstein's men
a spinning black hole can literally drag
space along with it twisting it like an
actual piece of cloth the nearest black
hole is trillions of miles away making
it a challenge to test this prediction
but in the late 1950s a physicist named
Leonard shift began searching for a way
to test on Stein's ideas about space
much closer to home Schiff was inspired
by something we usually think of as a
child's toy a gyroscope he thought that
if space really twists like a fabric the
gyroscope might allow him to detect it
it was a strange idea and he chose a
strange place to share it with the world
the Faculty swimming pool at Stanford
here in 1959 shift met with two
colleagues William Fairbank and Bob
cannon he was excited about an ad he'd
seen for a high-tech gyroscope though it
looked different it basically worked the
same as the child's toy then in there
the three decided to launch a device
like this into orbit around the Earth
normally a gyroscopes access points in a
fixed direction but if earth is actually
dragging space then the gyroscopes axis
would be dragged along with it shifting
its orientation in a way that could be
measured it was a brilliantly simple
plan there was just one problem
Einstein's theories predict that the
Earth's rotation twists space by only a
tiny amount and amounts so small it
would be like trying to measure the
height of a penny from 62 miles away
the team spent more than two years
trying to figure out how to make such a
precise measurement
they finally devised a plan to attach
four freely floating gyroscopes to a
telescope aimed at a distant star space
twists then over time the gyroscopes
would no longer point at the star since
they'd get caught up in the swirl of
space and in 1962 they applied to NASA
for a grant requesting around a million
dollars for what would come to be called
gravity probe B members of the team
originally thought the project would
take about three years they were just a
little optimistic with an ever growing
team gravity probe B became one of the
longest-running experiments in history
decade after decade was spent trying to
realize the original vision which meant
launching a telescope into space and
building gyroscopes that were among the
smoothest objects ever created the
technology is just frightening was like
the carrot on the front of the mule it
was like it was always five to ten years
away when we can do this and it was five
to ten years away for about 35 years
consuming more than four decades and 750
million dollars the project was nearly
canceled by NASA nine times
finally in April of 2004 the team
gathered to witness the launch
of the three men who sat by the pool
back in 1959 only one was alive to see
it there we were watching it's a
terribly exciting moment in your life
just a thrilling experience it was
flawless ten thousand things did not go
wrong for over a year
gravity probe B orbited the earth while
the team nervously monitored its every
move
trying to see if the earth would
actually twist space finally the data
began to trickle in and there was a
problem the gyroscopes were experiencing
a tiny unexpected wobble and to clean up
the data would cost millions
with funds running out it looked like
nearly half a century of work was about
to go down the drain
then at almost the last possible moment
two sources of additional funding
emerged the son of original team leader
William Fairbank
who made a private donation and Turkey
Al Saud
a member of the Saudi royal family with
the degree in aeronautics from Stanford
who arranged for a large grant over the
next two years the problem with the data
was solved revealing that the axes of
the gyroscope shifted by almost exactly
the amount predicted by Einstein's
equations I think it's the first time
that you can actually see Einstein
affect his drift with the naked eye
this experiment provides the most direct
evidence ever found that space is
something real a physical entity like a
fabric after all if space were nothing
there would be nothing to twist but at
the same time that Albert Einstein was
investigating space on the largest of
scales another band of physicists was
probing the universe on extremely tiny
scales and there they found a completely
uncharted realm
Brian Stein's picture of space it was
nowhere to be found to see what I'm
talking about imagine you could shrink
billions of times smaller than your
current size this is the realm of atoms
and subatomic particles the fundamental
building blocks of everything we can see
and when you get down to this size the
world plays by a wildly different set of
rules called quantum mechanics according
to these rules even if you try to remove
every last atom and particle you'd find
that empty space is still far from empty
in fact it's teeming with activity
particles are constantly popping in and
out of existence they erupt out of
nothingness quickly annihilate each
other and disappear in quantum mechanics
empty space is not that empty it's full
of fluctuating fields full of all sorts
of jittery things going on it's a place
where particles are constantly
fluctuating and annihilating each other
and being created again and annihilating
the place of chaos and bubbling while
the theory predicted this
it wasn't until 1948 that a scientist
named Hendrik Casimir suggested that
even though we can't see these particles
they should cause empty space to do
something we can see he predicted that
if you take two ordinary metal plates
and place them extremely close together
take closer together than the thickness
of a sheet of paper then particles with
certain energies would be excluded
because in some sense they wouldn't fit
between the plates with more of this
phonetic activity outside the plates
than inside
Casimir thought the plates would be
pushed together by what we usually think
of as empty space and some years later
when the experiment was done
Kasmir proven right an empty space that
plates were pushed together so on atomic
skills for empty space is not empty it's
so flooded with activity that it can
force objects to move and today the
quest to understand space on the
smallest scale is continuing with one of
the most expensive science experiments
in history
this is CERN the European Organization
for Nuclear Research in Geneva and here
buried a few hundred feet below the
ground is the Large Hadron Collider the
world's most powerful accelerator with a
price tag of about 10 billion dollars it
accelerates subatomic particles to more
than 99.99% of the speed of light and
smashes them into each other in the
showers of debris produced by these
collisions scientists at places like
this
have discovered a whole zoo of strange
and exotic particles and right now
they're chasing one of the most elusive
a particle thought to be essential to
shaping everything from the atoms in our
bodies to the most distant stars if this
particle is found it will redefine our
picture of space and fulfill a quest
begun more than 40 years ago it all
started in 1964 when a young English
physicist named Peter Higgs suggested
something about space that was so
radical and nearly ruined him
I was told that I was talking nonsence
but I couldn't be right
so they clearly hadn't understood what I
what I was saying
Higgs and a few others were wrestling
with a puzzle which comes down to this
the fundamental particles in the
universe all contain different amounts
of mass which we usually think of as
weight without mass these particles
would never combine to form the familiar
atoms and make up all the stuff we see
in the world around us but what creates
mass and why do different particles have
different masses try as they might no
one had been able to answer this
perplexing question then one weekend
after a walk outside Edinburgh Higgs had
a peculiar idea using mathematics he
imagined space in a new way as something
like an ocean particles are immersed in
this ocean and gain mass as they move
through it to see how this works
think of a particles mass like an
actor's fame and the Higgs ocean is like
the paparazzi some particles like
unknown actors pass through with ease
the paparazzi simply aren't interested
in them but other particles like
superstars captives push and press
and the more those particles struggled
to get through the more they interact
with the ocean and the more mass they
gain Higgs was convinced he'd made a
great discovery but when he submitted
his idea to a journalist earn it was
rejected undaunted kake's honed his
theory further until he was offered the
chance to present it at Einsteins old
haunt the Institute for Advanced Study
in Princeton there he expected his new
idea would meet some of its toughest
critics I was happily driving up the
freeway and then there was a sign to
turn off for Princeton and that really
confronted me with what I was going into
I broke out in a cold sweat and and
started trembling and I had to pull off
the road to recover but he expresser
beard it was the first in a series of
talks that would convince colleagues far
and wide
that he was onto something profound
eventually I sort of wore them down I
felt I'd sort of triumphed so I enjoyed
the parties which followed today the
idea Higgs pioneered called the Higgs
field is crucial to our understanding of
space the Higgs field is everywhere it's
something that even in the emptiest
vacuum of space has an effect it gives
you mass so I think Higgs actually
deserves credit for being one of the
people that said space is stuff it has
properties in it that are intrinsic that
you can't get rid of you can't turn them
off
the only problem there's no physical
proof that the Higgs field exists at
least not yet but here at CERN
scientists are attempting to smash
particles together with so much energy
that they will knock loose a piece of
the Higgs field
producing a tiny particle of its own
it's as if they're trying to chip off a
piece of space we think that if we knock
into space hard enough with particle
accelerator collisions that we can
actually actually make a Higgs particle
come out of empty space a whole
understanding of matter as we now have
it we just fall apart if the Higgs field
didn't exist I don't think anybody
seriously doubts that we will see it
certainly if we don't that would be an
extremely bizarre outcome finding the
Higgs particle would be a major
milestone establishing that the emptiest
of empty space has an impact on all of
matter but it turns out that space
contains an ingredient far more elusive
than anything Higgs ever imagined an
ingredient that may hold the key to the
greatest of all mysteries the very fate
of the cosmos
it's a mystery that began some 14
billion years ago and what we call the
Big Bang in a fraction of a second the
universe underwent a violent expansion
sending space hurtling outward
space has been expanding ever since
for decades most scientists thought that
expansion must be slowing down thanks to
the pull of gravity when I toss a an
apple up the gravity of the earth
eventually stops it and brings it back
and just like the Apple slows down with
time so too
the universe should have been slowing
down in its expansion because of the
gravitational attraction of all matter
and energy for all other matter and
energy but that raised the question what
is the ultimate fate of the cosmos would
space go on expanding forever or would
gravity eventually stop space from
expanding causing it to collapse back on
itself and a Big Crunch
to solve this mystery two teams of
astronomers set out to measure the
slowing of the expansion using a novel
tool exploding stars both supernovas so
a supernova is a star that ends its life
in a massive explosion they're extremely
luminous that can be as bright as a
billion suns
what makes soup another great is that
they're very similar when they explode
they all gets about the same brightness
and then they fade away in just about
the same way because the explosions are
so bright in uniform the teams reasoned
that these supernovas would act as very
precise cosmic beacons allowing them to
track how the expansion of space has
slowed over time
the trouble is supernovas are extremely
rare to find enough of them promotors
spent years calling astronomers around
the globe begging for time on their
telescopes we needed the biggest
telescopes in the world we needed
perfect conditions and in those perfect
conditions that would be calling people
I bet the middle of their night when
they're trying to do some serious work
and I'd be saying I know that you have a
very busy schedule but by any chance if
you could just squeeze end this half
hour observation it would really I'd be
very interesting to us when they finally
had enough data to chart how much the
pull of gravity was slowing the
expansion of the universe they were in
for a surprise
the results distraint they didn't Bush
show any slowing of the universe at all
very surprising actually the universe
that's actually speeding up it was as
though space which we really thought was
nothing actually had an inherent
springiness to it and so space did not
want to be compressed space actually
wants to push the universe apart that
looked like the universe was expanding
faster and faster with time accelerating
rather than decelerating my immediate
response was I have to figure out why
this is wrong this can't be right but it
was right and most scientists converged
on one explanation there's something
that fills space and counteracts the
pull of ordinary attractive gravity
pushing galaxies apart and stretching
the very fabric of the cause
this mysterious substance filling space
has been dubbed dark energy and it's
turned our picture of the universe
upside down over the largest distances
dark energy dominates the contents of
the universe and we don't know what it
is if you do sort of a survey a census
of all the energy in the universe dark
energy turns out to be about 70% of the
universe and up until a decade ago
nobody imagined such stuff even existed
so in essence the weight of empty space
itself is 70% of the weight of the
entire universe that's roughly the same
percentage of Earth's surface that's
covered by water imagine we didn't know
what water is that's where we stand the
dark energy we're really clueless about
how to explain it we have all of this
fancy scientific apparatus of quantum
mechanics and relativity and particle
physics that we have developed in the
last hundred years and none of that
works to explain dark energy
and the discovery of dark energy held
another surprise the idea that the
universe contains such an ingredient had
actually been cooked up eighty years
earlier I'll let you in on a little
secret
although he didn't call it dark energy
long ago Albert Einstein predicted that
space itself could exert a force that
would drive galaxies apart you see
shortly after discovering his general
theory of relativity his theory of
gravity
Einstein found that according to the
mathematics the universe would either be
expanding or contracting but it couldn't
hover at a fixed size this was puzzling
because before they knew about the Big
Bang most scientists including Einstein
pictured the universe as static eternal
and unchanging when Einstein's equations
suggested an expanding or contracting
universe not the static universe
everyone believed in he had a problem so
I said went back to his equations and
modified them to allow for kind of
anti-gravity that would infuse space
with an outward push counteracting usual
inward pull of gravity allowing the
universe to stand still he called the
modification the cosmological constant
adding the cosmological constant rescued
his equations but the truth is Einstein
had no idea if his outward push or
anti-gravity really existed
the introduction of the cosmological
constant by Einstein was not a very
elegant solution to try to find what he
was looking for stationary universe
it achieves this effect of anti-gravity
it it says that gravity sometimes can
behave in such a way is not to pull
things together but to push things apart
like the clash of two titans the Cosmo
chill constant and the pull of ordinary
matter could hold the universe in check
and keep it static but about a dozen
years later the astronomer Edwin Hubble
discovered the universe is not static
it's expanding due to the explosive
force of the Big Bang fourteen billion
years ago that meant Einsteins original
equations no longer had to be altered so
suddenly the need for a cosmological
constant went right out the window
thank you Einstein is said to have
called this his biggest blunder but
here's the thing
with the recent discovery that the
expansion of the universe is
accelerating scientists are convinced
that there is something in space that is
pushing things apart so 70 years later
Einsteins biggest blunder may rank among
his greatest insights it was something
that nobody else was thinking about but
it might be that Einsteins cosmological
constant is the key to understanding the
expansion of the universe as we see it
today though no one knows what dark
energy actually is it raises an
astounding and troubling possibility
Einstein pictured the strength of his
anti gravity is constant but is the
strength of dark energy constant and
what if it changes over time the answer
could overturn everything we thought we
knew about the fate of the cosmos
at the moment everything in our world
from the molecules makeup my body to the
molecules making up the moon is held
together by forces that overwhelm the
outward push of dark energy and that's
why we don't see things expanding in our
everyday lives but that situation might
not last forever in one scenario dark
energy will continue to push the
galaxies farther and farther apart until
ultimately they be pushed so far apart
at the universe we become a cold dark
and lonely place in another scenario the
strength of dark energy might increase
over time becoming so strong that it
would tear apart everything within the
galaxies from stars
to planets to matter of all kind
if the dark energy grows with time then
ultimately even atoms will get ripped
apart when there's enough dark energy
between the nuclei and the electrons to
rip space apart a big rip
our pictures face has gone through a
remarkable transformation back in
Newton's time space was just the
container didn't do anything at all then
through Einstein space begins to affect
how objects move then with Casimir
literally objects can be pushed by the
activity even in empty space now through
the ideas of Higgs and dark energy the
very expansion of the universe may be
coming from the energy of empty space
itself I don't think anybody would have
thought that space would have this kind
of rich and profound impact on the
nature of reality
but as far as we've come the journey
that began with Isaac Newton's pictures
space as something like a stage has not
yet finished
as we examine the fabric of the cosmos
ever more closely we may well find far
more surprises than anyone ever imagined
take me for example I seem real enough
don't I well yes but surprising new
clues are emerging that everything you
and I and even space itself may actually
be a kind of hologram that is everything
we see and experience everything we call
our familiar three-dimensional reality
maybe a projection of information that's
stored on a thin distant two-dimensional
surface sort of the way the information
for this hologram is stored on this thin
piece of plastic
now Holograms are something we're all
familiar with from the security symbol
you find the most credit cards
but the universe is a hologram that's
one of the most drastic revisions to our
picture of space and reality ever
proposed and the evidence for it comes
from some of the strangest realms of
space black holes this is a real
disconnect and it's very hard to get
your head around
modern ideas coming from black holes
tell us that reality is two-dimensional
that the three-dimensional world the
full-bodied three-dimensional world is a
kind of image of a hologram on the
boundary of the region of space this is
a very strange thing
when I was a younger physicist I would
have thought any physicists who said
that was absolutely crazy here's a way
to think about this imagine I took my
wallet and threw it into a black hole
what would happen
we used to think that since nothing not
even light can escape the immense
gravity of a black hole my wallet would
be lost forever but it now seems that
may not be the whole story recently
scientists exploring the math describing
black holes made a curious discovery
even as my wallet disappears into the
black hole a copy of all the information
it contains seems to get smeared out and
stored on the surface of the black hole
in much the same way that information is
stored in a computer so in the end my
wallet exists in two places there's a
three-dimensional version that's lost
forever inside the black hole and a
two-dimensional version that remains on
the surface as information the
information content of all the stuff
that fell into that black hole can be
expressed entirely in terms of just the
outside of the black hole the idea then
is that you can capture what's going on
inside the black hole by referring only
to the outside and in theory I could use
the information on the outside of the
black hole to reconstruct my wallet
and here's the truly mind-blowing part
space within a black hole plays by the
same rules a space outside a black hole
or anywhere else so if an object inside
a black hole can be described by
information on the black hole surface
then it might be that everything in the
universe from galaxies and stars to you
and me even space itself is just a
projection of information stored on some
distant two-dimensional surface that
surrounds us in other words what we
experience as reality may be something
like a hologram is the three-dimensional
world an illusion
in the same sense that a hologram is an
illusion perhaps I think I'm inclined to
think yes that the three-dimensional
world is a kind of illusion and that the
ultimate precise reality is the
2-dimensional reality at the surface of
the universe this idea is so new that
physicists are still struggling to
understand it but if it's right just as
Newton and Einstein completely changed
our picture of space we may be on the
verge of an even more dramatic
revolution
for something that's such a vital part
of our everyday lives space remains kind
of like a familiar stranger it's all
around us but we're still far from
having a mast its true identity that may
take a hundred years it may take a
thousand years or it may happen tomorrow
but when we solve that mystery we'll
take a giant step toward fully
understanding the fabric of the cosmos
major funding for Nova is provided by
David H coke and discover new knowledge
HH Li
and by the Corporation for Public
Broadcasting and by contributions to
your PBS station from viewers like you
thank you
major funding for the fabric of the
cosmos is provided by the National
Science Foundation where discoveries
begin
and
the Alfred P sloan Foundation supporting
original research and public
understanding of science technology
engineering and mathematics additional
funding is provided by the Arthur vining
Davis foundations dedicated to
strengthening America's future through
education the US Department of Energy's
Office of Science and the George D Smith
Fund
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