0:07
ANNOUNCER:
The following "NOVA" program
contains scenes
0:09
of quantum physics,
which is known to cause
0:12
confusion, anxiety,
and even heartbreak.
0:15
Please see your physicist
0:21
NARRATOR:
Quantum physics.
0:23
It's the science
of the very small,
0:25
but it punches
far above its weight.
0:26
but it punches
far above its weight.
0:29
Quantum physics has not just
been important,
0:32
it's been revolutionary.
0:34
NARRATOR:
It's the most successful
scientific theory
0:36
of the last 100 years.
0:38
Quantum mechanics already
permeates everything we do.
0:40
NARRATOR:
Everything from your computer
or cellphone
0:42
NARRATOR:
Everything from your computer
or cellphone
0:48
depends on our understanding
of the quantum world.
0:51
DAVID KAISER:
We can say now that
we live in a quantum age.
0:53
NARRATOR:
And it's behind one of
the greatest discoveries
0:56
in the history of science:
1:02
tiny ripples in the fabric
of space-time itself.
1:03
tiny ripples in the fabric
of space-time itself.
1:07
SEAN CARROLL:
Gravitational waves
give us a whole new way
1:09
to look at the universe.
1:10
NARRATOR:
And yet, beyond the mathematics,
1:11
NARRATOR:
And yet, beyond the mathematics,
1:14
quantum physics
makes a shocking claim:
1:18
that at its deepest level,
1:22
reality plays like a game
of chance...
1:24
ELBA ALONSO-MONSALVE:
Probabilities are not
1:27
a measure of what we don't know.
1:30
They're just intrinsic
to the quantum theory.
1:31
NARRATOR:
...with mind-boggling behaviors
like superposition
1:32
NARRATOR:
...with mind-boggling behaviors
like superposition
1:38
This is weird-- it's strange.
1:39
NARRATOR:
What quantum physics
really means
1:42
remains deeply mysterious.
1:45
But it's created
the world we live in today.
1:48
Quantum physics actually
governs everything around us.
1:50
TARA FORTIER:
It's not some weird outpost
of physics that's far away.
1:53
It's completely changed
1:55
the way we used to live
into the way we live now.
1:56
NARRATOR:
"Decoding the Universe:
Quantum."
1:58
NARRATOR:
"Decoding the Universe:
Quantum."
2:01
Right now, on "NOVA."
2:19
ANNOUNCER:
As an American-based supplier
2:21
to the construction industry,
2:22
Carlisle is committed to
developing a diverse workplace
2:25
that supports
our employees' advancement
2:27
into the next generation
of leaders,
2:29
from the manufacturing floor
to the front office.
2:30
Learn more at Carlisle.com.
2:41
NARRATOR:
December 12, 1970.
2:44
NASA launches a Scout B rocket
2:47
from a former oil-drilling
platform off Kenya's coast.
2:49
from a former oil-drilling
platform off Kenya's coast.
2:54
Its payload is a small satellite
named Uhuru,
2:55
Its payload is a small satellite
named Uhuru,
2:59
a Swahili word
meaning "freedom."
3:02
Uhuru is the first space
telescope
3:05
dedicated to observing X-rays,
3:07
high-energy light waves
invisible to our eyes.
3:09
high-energy light waves
invisible to our eyes.
3:12
Powerful sources of X-rays
constantly bombard Earth,
3:13
Powerful sources of X-rays
constantly bombard Earth,
3:16
but our atmosphere blocks them.
3:18
but our atmosphere blocks them.
3:22
With this
groundbreaking telescope,
3:24
a new vista for exploration
opens.
3:26
a new vista for exploration
opens.
3:29
But buried in the data collected
from Uhuru
3:30
But buried in the data collected
from Uhuru
3:33
is something ominous.
3:39
scientists reveal
that the constellation Cygnus,
3:40
scientists reveal
that the constellation Cygnus,
3:45
contains what until then
3:47
was more of a
mythical mathematical beast.
3:52
was more of a
mythical mathematical beast.
3:59
ALONSO-MONSALVE:
Black holes are
4:00
the most mysterious objects
in the universe.
4:01
Also the most violent.
4:03
Also the most violent.
4:07
JANNA LEVIN:
Even Einstein didn't think
nature would allow
4:11
NARRATOR:
Black holes are
fearsome monsters,
4:13
NARRATOR:
Black holes are
fearsome monsters,
4:16
capable of devouring
whole planets...
4:19
capable of devouring
whole planets...
4:27
...and even each other.
4:30
A black hole is created
when gravitational forces
4:31
A black hole is created
when gravitational forces
4:34
bring together enough mass
4:37
to put a rip into the fabric
of space-time.
4:40
KAISER:
Some of them are genuinely
monstrous.
4:43
I mean, millions, billions,
4:45
maybe even ten billion times
4:46
the mass of our own sun.
4:47
ALONSO-MONSALVE:
We don't actually have
4:50
laws of physics to predict
4:51
what's going to happen to us
when we go in.
4:53
Hopefully, none of us will
experience it anytime soon.
(laughs)
5:02
NARRATOR:
In the decades
since the first sighting,
5:06
science has learned a lot about
5:07
these menacing and mysterious
objects of destruction.
5:09
these menacing and mysterious
objects of destruction.
5:12
They aren't that rare.
5:13
They aren't that rare.
5:16
Supermassive black holes
sit at the center
5:18
of most large galaxies.
5:19
of most large galaxies.
5:26
But it turns out
these cosmic behemoths
5:28
also may have an Achilles' heel,
5:31
also may have an Achilles' heel,
5:34
first predicted by
Stephen Hawking in 1974.
5:35
first predicted by
Stephen Hawking in 1974.
5:39
scientists thought
of a black hole
5:42
as a one-way trip to oblivion.
5:45
That past its event horizon,
nothing could escape.
5:48
That past its event horizon,
nothing could escape.
5:52
But Hawking disagreed.
5:54
He theorized something did
escape from these mighty giants:
5:55
He theorized something did
escape from these mighty giants:
6:02
Ironically, the end result
of physics
6:04
at the tiniest of scales:
quantum physics.
6:06
at the tiniest of scales:
quantum physics.
6:12
Clifford Johnson
is a nonfiction graphic author
6:15
and also a theoretical
physicist.
6:15
and also a theoretical
physicist.
6:19
JOHNSON:
One of the key things
6:21
that was discovered in quantum
physics
6:23
is that empty space itself
is not empty.
6:26
It's seething with possibility.
6:27
Instead of having empty space
here,
6:28
Instead of having empty space
here,
6:31
a particle and its antiparticle
can appear,
6:32
a particle and its antiparticle
can appear,
6:36
dance around a little bit,
6:40
and then annihilate
back into empty space.
6:42
Now, imagine that happening
near a black hole horizon,
6:43
Now, imagine that happening
near a black hole horizon,
6:47
which we're told
is a one-way door.
6:49
What if one of those particles
falls in?
6:51
What if one of those particles
falls in?
6:54
And now the partner doesn't have
anything to annihilate with.
6:57
So it will actually fly off,
7:01
and a distant observer
will see that particle
7:03
as radiation
coming from the black hole.
7:05
as radiation
coming from the black hole.
7:08
NARRATOR:
Without consuming more matter,
if it emits radiation,
7:10
NARRATOR:
Without consuming more matter,
if it emits radiation,
7:13
it will gradually shrink
in size.
7:14
it will gradually shrink
in size.
7:18
The black hole actually begins
to evaporate.
7:20
Now, this is a completely
stunning revelation.
7:22
Now, this is a completely
stunning revelation.
7:26
NARRATOR:
Known as Hawking Radiation,
7:28
its existence
is still only a theory.
7:32
But perhaps, given enough time--
7:33
and it is a very,
very, very long time...
7:36
and it is a very,
very, very long time...
7:39
For many black holes,
7:41
longer than the current age
of the universe.
7:44
NARRATOR:
...even a supermassive
black hole,
7:46
like the one at the heart
of the Milky Way,
7:47
like the one at the heart
of the Milky Way,
7:50
may evaporate and disappear,
7:53
may evaporate and disappear,
7:57
vanquished by the quantum world
7:59
and the physics
of the very small.
8:11
The quantum world is often cast
as weird,
8:14
and it sure can look that way
in the movies.
8:15
and it sure can look that way
in the movies.
8:18
JANET VAN DYNE:
You're sending a signal
8:19
down to the Quantum Realm.
8:27
(whispers):
Where are we?
8:29
NARRATOR:
But what is quantum physics?
8:32
NARRATOR:
But what is quantum physics?
8:35
It arose as the solution
to a problem.
8:36
It arose as the solution
to a problem.
8:40
Science during the 19th century
had investigated
8:43
smaller and smaller amounts
of matter and energy.
8:44
smaller and smaller amounts
of matter and energy.
8:48
But by the first two decades
of the 20th century,
8:51
the existing line
between the physics of particles
8:54
and the physics of waves
9:01
especially
when trying to understand
9:02
the fundamental nature of light.
9:05
the fundamental nature of light.
9:09
KAISER:
Sometimes it really is important
to describe light
9:11
as a wave, as an extended object
that sort of waves in space
9:12
as a wave, as an extended object
that sort of waves in space
9:16
and travels over time,
9:17
analogously to an ocean wave
in the water.
9:21
Other times, as people
like Albert Einstein and others
9:23
began to, to find, they really,
really had to describe
9:26
aspects of light as if
it was a collection of particles
9:30
that traveled almost
like miniature billiard balls.
9:33
NARRATOR:
Ultimately, the answer was
a new kind of physics,
9:34
NARRATOR:
Ultimately, the answer was
a new kind of physics,
9:40
which included
an amalgam of ideas
9:43
about both particles and waves.
9:45
Its earliest formulation
dates back roughly 100 years.
9:48
Its earliest formulation
dates back roughly 100 years.
9:52
This 1927 conference in Brussels
9:55
is where the world's leading
physicists met
9:58
to discuss
the newly formed theory.
10:02
(people talking in background)
10:03
NARRATOR:
And there was a lot to discuss.
10:05
Because quantum mechanics
represented a radical departure
10:06
Because quantum mechanics
represented a radical departure
10:10
from the previous paradigm
of physics--
10:11
what we call today
"classical physics."
10:12
what we call today
"classical physics."
10:16
CARROLL:
In classical physics,
10:18
handed down by Newton,
we had determinism.
10:21
We had the clockwork universe.
10:23
So if you throw a ball-- that's
a classical object--
10:26
with the same force,
the same speed,
10:29
it's always going to go
to the same place, right?
10:30
In principle,
if you knew exactly the state
10:31
In principle,
if you knew exactly the state
10:35
of the whole world all at once,
10:37
and you knew the laws
of physics,
10:39
you could exactly predict
what everything was going to do
10:41
arbitrarily far in the future
and into the past.
10:43
arbitrarily far in the future
and into the past.
10:47
NARRATOR:
In classical physics,
10:48
even events that we think of
as random aren't, really.
10:50
even events that we think of
as random aren't, really.
10:54
HAKEEM OLUSEYI:
There are things
10:55
that appear random in our
everyday lives,
10:59
It looks random, right?
11:01
But actually, it's a
deterministic
11:03
set of events which leads to
11:06
whatever outcome the dice shows.
11:09
If I told you exactly how
I was going to roll the dice...
11:11
OLUSEYI:
...you could predict,
based on that initial throw,
11:14
what the final outcome
is going to be.
11:16
It's a very hard
mathematical problem,
11:18
but it's not intractable.
11:20
Quantum mechanically,
that's not the case.
11:21
NARRATOR:
Quantum mechanics
tossed out the certainty
11:23
NARRATOR:
Quantum mechanics
tossed out the certainty
11:27
of the classical
clockwork universe
11:29
for one that only allowed
for probabilistic predictions
11:30
for one that only allowed
for probabilistic predictions
11:33
about potential observations.
11:34
about potential observations.
11:38
Probability in quantum physics
is different.
11:41
Because even if we have
11:43
the most complete description
11:46
that the laws of physics will
allow us to have,
11:50
typically,
we're unable to predict
11:53
precisely what we'll see when
we observe a quantum system.
11:55
CARROLL:
Quantum mechanics says we can
know everything there is to know
11:57
CARROLL:
Quantum mechanics says we can
know everything there is to know
12:00
about the setup right now.
12:02
And still, when we want to make
a measurement of it
12:05
in the future,
the best we can do is say,
12:07
"There's a 50% chance
of getting this outcome,
12:09
30% chance of that,
20% chance of that."
12:12
In the quantum theory,
12:13
probabilities are not
a measure of what we don't know.
12:14
probabilities are not
a measure of what we don't know.
12:17
They're just intrinsic
to the quantum theory.
12:20
We cannot get around them.
12:25
NARRATOR:
Some physicists,
raised on determinism,
12:27
had trouble accepting
this new probabilistic view.
12:29
had trouble accepting
this new probabilistic view.
12:32
Albert Einstein famously said
that he didn't believe
12:33
Albert Einstein famously said
that he didn't believe
12:36
God plays dice
with the universe.
12:39
God plays dice
with the universe.
12:42
But there is another related,
even stranger aspect
12:43
But there is another related,
even stranger aspect
12:46
to quantum mechanics.
12:46
to quantum mechanics.
12:50
In classical physics,
12:54
external reality
is independent of the observer.
12:55
Looking at the moon
doesn't change the moon.
12:57
Looking at the moon
doesn't change the moon.
13:01
And if you look away,
13:03
the deterministic laws
of physics
13:04
continue to guide the moon
on its path.
13:05
continue to guide the moon
on its path.
13:09
But in quantum mechanics,
things are weirder.
13:11
But in quantum mechanics,
things are weirder.
13:15
CARROLL:
The basic idea
of quantum mechanics,
13:17
the thing that we really
struggle with
13:20
to get our heads around,
even as professional physicists,
13:22
is that unlike any other version
of physics,
13:25
quantum mechanics separates
what happens in a system
13:26
quantum mechanics separates
what happens in a system
13:30
when we're not observing it
13:32
from what we see
when we measure it.
13:38
NARRATOR:
A few rare exceptions aside,
13:41
quantum mechanics says
that we can't know
13:44
the position of a particle
like an electron
13:46
when we're not observing it.
13:47
when we're not observing it.
13:50
At best, it can only
be described mathematically
13:55
its exact position
given in probabilities.
13:58
its exact position
given in probabilities.
14:02
But at the moment
that the particle is observed,
14:05
the probabilistic wave function
collapses
14:08
to one specific location.
14:10
to one specific location.
14:14
To the observer, who never
sees this wave-like quality,
14:17
it is like the particle
was a particle all along.
14:20
it is like the particle
was a particle all along.
14:24
That opens up a whole world
of questions, you know?
14:26
What happens to the
observational outcomes
14:30
that are not observed?
14:32
What picks out which outcome
is going to happen?
14:34
This is still what
we're thinking about today.
14:38
NARRATOR:
During that mysterious period,
14:40
when the particle is considered
neither here nor there,
14:42
it is said to be
in superposition--
14:44
it is said to be
in superposition--
14:47
in a sense, a combination
of all the possible outcomes.
14:50
in a sense, a combination
of all the possible outcomes.
14:54
But what does that really mean?
14:56
Is the electron everywhere
at the same time?
15:00
Is it nowhere at all?
15:01
Is it at one particular place
and we just don't know?
15:04
All of those questions
are actually outside
15:07
of what quantum theory itself
actually can answer.
15:10
It's not part of the theory
at all.
15:12
So if you ask me,
your guess is as good as mine.
15:13
(chuckles): Unfortunately,
that's the best I can do.
15:14
(chuckles): Unfortunately,
that's the best I can do.
15:20
NARRATOR:
For most people,
quantum mechanics remains
15:25
And yet it has proven itself
again and again
15:27
And yet it has proven itself
again and again
15:30
by making predictions
with uncanny accuracy.
15:35
it is the most successful theory
science has ever produced,
15:37
it is the most successful theory
science has ever produced,
15:40
and it has shaped
our modern life.
15:46
OLUSEYI:
Quantum physics has not just
15:48
been important,
it's been revolutionary.
15:50
It's completely changed
15:51
the way we used to live
into the way we live now.
15:56
NARRATOR:
Take our sense of time.
15:59
(tango music playing)
16:01
(tango music playing)
16:04
Perhaps there is no better
illustration
16:05
Perhaps there is no better
illustration
16:08
of our intimate relationship
with it
16:09
than music and dance.
16:16
FORTIER:
The underlying movement of tango
16:18
is reliant on the beat, which is
reliant on timing,
16:21
which creates synchronization.
16:23
To create a truly smooth dance,
16:27
it's not enough to just be
synchronized on the beat.
16:30
It's also the synchronicity
16:32
between the beats
that's important.
16:34
That's the real beauty in it,
16:36
in finding that connection
through,
16:37
stretching out that second.
16:48
NARRATOR:
Tara Fortier
is a tango professional
16:51
and a physicist deeply involved
16:51
and a physicist deeply involved
16:55
in the science of time.
16:57
So, we have a number of systems
in this lab.
16:59
NARRATOR:
She works here...
17:00
These systems are used
17:02
to characterize atomic clocks,
17:04
and also compare
atomic clocks.
17:06
NARRATOR:
...at the Boulder, Colorado,
laboratories
17:08
of the National Institute
of Standards and Technology,
17:14
home to some
of the atomic clocks
17:16
that help set the official time
for the country.
17:19
that help set the official time
for the country.
17:24
we've tracked time
a variety of ways:
17:26
by the sun's movement,
17:29
the swing of pendulums,
17:32
the oscillations of springs,
17:34
and, in the 20th century,
17:36
the vibrations
of quartz crystals.
17:39
But since the 1960s,
17:42
time has been officially
determined
17:48
and the quantum characteristics
of atoms.
17:52
And the idea is that the laws
of physics are unchanging,
17:54
unlike something like
the rotation of the Earth.
17:56
The rotation of the Earth itself
can change
17:59
because of plate tectonics,
18:00
because the moon is moving away
from the Earth.
18:03
Its physics
is not truly fundamental.
18:05
JUN YE:
The reason why we love
atomic clock,
18:08
it's a universally defined time.
18:11
No matter who does
the experiment,
18:12
no matter
where you do the experiment,
18:14
you know, in principle, once
you've corrected
18:16
for all the systematic effects,
18:17
you should produce the same time
no matter where.
18:20
you should produce the same time
no matter where.
18:24
NARRATOR:
The consistency
of atomic clocks arises
18:26
from the very nature of atoms.
18:27
from the very nature of atoms.
18:31
Atomic clocks depend crucially
18:33
on the quantum physics of atoms.
18:40
around which there are electrons
18:42
in certain energy levels.
18:45
And these energy levels
are possible energy states
18:48
that the electron can have
inside the atom.
18:50
NARRATOR:
Since an electron can only be
at certain energy levels
18:52
NARRATOR:
Since an electron can only be
at certain energy levels
18:56
and not in between,
to get to a higher level,
18:59
it needs to encounter
a very specific helping hand,
19:00
it needs to encounter
a very specific helping hand,
19:03
such as a particular photon.
19:06
such as a particular photon.
19:10
If it were to absorb
an incoming photon,
19:12
it would have to be
of just the right energy
19:14
to jump from one level
to a higher level.
19:15
to jump from one level
to a higher level.
19:19
NARRATOR:
That special relationship
19:21
between the electrons
of a particular atom
19:23
and a photon
of a specific energy level
19:26
is a unique signature
for that atom.
19:29
It's called
a "resonant frequency."
19:31
It's called
a "resonant frequency."
19:35
JOHNSON:
So this characteristic signature
of this atom
19:38
gives us a very specific
frequency standard
19:40
that we can use to build
a time-keeping device.
19:42
that we can use to build
a time-keeping device.
19:46
NARRATOR:
Atomic clocks
work in different ways,
19:49
but they all use
a specific type of atom
19:52
or molecule
as a reference to lock in
19:56
the frequency
of an electromagnetic wave,
19:58
whose oscillations provide
the "ticking" of the clock.
20:06
Today, a second
is officially defined
20:10
by counting the oscillations
20:12
of the primary
resonant frequency
20:14
of a cesium-133 atom.
20:16
of a cesium-133 atom.
20:19
That's over nine billion
oscillations per second.
20:22
That's over nine billion
oscillations per second.
20:26
And you interact
with that time reference
20:29
more than you might think.
20:30
For example, through
the Global Positioning System:
20:31
For example, through
the Global Positioning System:
20:41
FORTIER:
I think that GPS
20:43
is actually kind of crazy,
when you think about it.
20:45
How did we do anything
before GPS?
20:49
NARRATOR:
The U.S.-based GPS system
20:52
uses over 30 dedicated
orbiting satellites,
20:55
each with
multiple atomic clocks.
20:58
When you use the GPS
on your cell phone,
21:01
its receiver checks the signals
21:04
from four or more satellites.
21:08
The signal contains information
21:09
about the satellite's position
and the time it sent the signal.
21:11
about the satellite's position
and the time it sent the signal.
21:15
That time stamp is critical.
21:18
Your phone uses it to calculate
how long it took
21:21
to receive the signal,
and from that,
21:24
knows the distance
to the satellite.
21:27
With that information
from multiple satellites,
21:31
it is possible to triangulate
the phone's position
21:37
But the whole system depends
on knowing the time.
21:39
But the whole system depends
on knowing the time.
21:43
FORTIER:
In the end, I find it amazing,
21:46
how strongly we're committed
and tied to atomic clocks
21:49
and how much we take it
for granted.
21:51
Even though I build
atomic clocks,
21:53
but when I'm driving,
21:54
being guided
by this GPS service,
21:56
you don't really become aware
21:58
of how much atomic clock
technology has permeated
22:00
everywhere in modern life.
22:02
everywhere in modern life.
22:10
Have you had a chance to look
22:12
at more systematically
varying the V-Z?
22:14
NARRATOR:
Jun Ye is a physicist
with joint appointments:
22:20
the University of Colorado-
Boulder,
22:23
and their joint institute, JILA.
22:26
What if you locked exactly
on top of each other
22:28
and see whether
that peak disappears completely?
22:29
NARRATOR:
He works on the new generation
of atomic clocks,
22:31
NARRATOR:
He works on the new generation
of atomic clocks,
22:34
known as optical atomic clocks.
22:34
known as optical atomic clocks.
22:41
optical clocks use lasers,
22:43
which run at higher frequencies.
22:47
That also means
using a different atom.
22:50
Instead of cesium, Jun's work
mostly uses strontium atoms,
22:52
Instead of cesium, Jun's work
mostly uses strontium atoms,
22:56
along with a laser
carefully tuned
22:59
to one of strontium's
resonant frequencies.
23:02
It puts one of the strontium
electrons into superposition,
23:04
It puts one of the strontium
electrons into superposition,
23:08
so it is both excited
and unexcited at the same time,
23:10
so it is both excited
and unexcited at the same time,
23:13
creating what Jun calls
a quantum pendulum.
23:15
creating what Jun calls
a quantum pendulum.
23:19
This pendulum
is swinging at a speed
23:22
of nearly one million
billion cycles per second.
23:26
It's going back and forth,
back and forth.
23:28
And this superposition
creates this quantum pendulum.
23:32
NARRATOR:
And when it comes
to accuracy,
23:34
more swings or higher frequency
23:38
equals more precision.
23:40
If you think of swings
as marks on a ruler,
23:43
the more marks you have, the
more exactly you can measure.
23:45
the more marks you have, the
more exactly you can measure.
23:48
So, compared to a cesium clock,
Jun's strontium clock
23:49
So, compared to a cesium clock,
Jun's strontium clock
23:52
is around 100,000 times
more precise.
23:56
is around 100,000 times
more precise.
23:59
And that much sensitivity makes
all the more apparent
24:03
some of the stranger aspects
of time,
24:05
including one first predicted
by Einstein:
24:07
including one first predicted
by Einstein:
24:11
gravitational time dilation.
24:14
In the movie "Interstellar,"
24:17
part of the crew of a spaceship
24:19
descends in a shuttle
to a planet
24:21
orbiting
a supermassive black hole.
24:25
orbiting
a supermassive black hole.
24:28
When the shuttle returns,
24:30
those on the mission feel
24:32
they've only been gone for three
hours,
24:33
but not the crew member who
remained in orbit.
24:41
CASE: 23 years, four months,
eight days.
24:45
NARRATOR: The difference in time
is another effect
24:46
of the black hole's warping
of the fabric of space-time.
24:48
of the black hole's warping
of the fabric of space-time.
24:52
The warping not only means
gravity gets stronger
24:54
closer to the black hole,
but time gets slower, too.
24:56
closer to the black hole,
but time gets slower, too.
24:59
And you don't need a black hole
to be able to measure it.
25:01
And you don't need a black hole
to be able to measure it.
25:04
Even on Earth, gravity varies,
25:04
Even on Earth, gravity varies,
25:08
and so does time,
based on the distance
25:12
from the planet's center.
25:13
So a person at the top
of the Empire State Building
25:14
So a person at the top
of the Empire State Building
25:18
experiences weaker gravity
25:21
and time going faster
25:23
than a person at street level,
25:25
where gravity is stronger.
25:28
But all that happens
imperceptibly.
25:31
Our wristwatches
just aren't accurate enough
25:34
to show the difference.
25:39
But Jun's optical clocks
are so accurate
25:41
that even a small difference
in elevation between two clocks
25:43
that even a small difference
in elevation between two clocks
25:46
will reveal a discrepancy
in the passage of time.
25:49
will reveal a discrepancy
in the passage of time.
25:53
When the clock changes elevation
by a few hundred microns,
25:55
basically size of a human hair,
25:58
you will start to be able to see
26:00
that time is actually running
differently.
26:04
NARRATOR:
With that much accuracy,
a clock transforms
26:05
NARRATOR:
With that much accuracy,
a clock transforms
26:09
into something more
than a timepiece.
26:10
It becomes a new window
into the nature of the universe.
26:12
It becomes a new window
into the nature of the universe.
26:18
YE:
Making a clock is much more
than just a piece to keep time.
26:22
It is a sensor to explore
fundamental physics,
26:25
to expand our curiosity,
26:29
to build new technologies
that can connect
26:31
to quantum computing,
quantum information processing,
26:43
NARRATOR:
Central to making Jun's
precision atomic clocks work
26:45
NARRATOR:
Central to making Jun's
precision atomic clocks work
26:47
are ultra-stable lasers,
26:48
are ultra-stable lasers,
26:51
which themselves are also
a quantum technology.
26:53
which themselves are also
a quantum technology.
26:57
They date back to the 1960s.
27:00
GOLDFINGER:
You are looking
at an industrial laser,
27:02
which emits
an extraordinary light
27:04
not to be found in nature.
27:09
NARRATOR:
This scene from 1964's
"Goldfinger"
27:11
is said to be one of the first
popular depictions
27:15
of this new, cutting-edge tech.
27:18
I think you've made your point,
Goldfinger.
27:19
Thank you for the demonstration.
27:26
NARRATOR:
Today, lasers are everywhere.
27:30
NARRATOR:
Today, lasers are everywhere.
27:34
There are medical lasers
to correct vision,
27:36
lasers at the checkout counter,
27:45
and, of course, for light shows.
27:46
and, of course, for light shows.
27:52
NARRATOR:
Which encourage us all
to trip the light fantastic.
27:53
NARRATOR:
Which encourage us all
to trip the light fantastic.
28:13
NARRATOR:
Which may be why...
28:17
...experimental physicist
Rana Adhikari
28:20
is laser-focused on lasers.
28:21
is laser-focused on lasers.
28:25
When I talk about how,
28:26
how beautiful a laser
is as a instrument,
28:28
I don't want to gush about
it too much.
28:29
Like, I'm in love with lasers,
I don't know.
28:31
I feel like a weirdo fanatic
28:33
or something like that, but...
28:35
They're just,
there's something about them.
28:37
NARRATOR:
To understand what makes
laser light so special,
28:40
it makes sense to look
at an ordinary light bulb--
28:41
it makes sense to look
at an ordinary light bulb--
28:45
the old-fashioned kind,
with a tungsten filament.
28:47
It produces light through
thermal radiation--
28:49
It produces light through
thermal radiation--
28:52
an electric current
passing through the filament
28:57
Its tungsten atoms
become excited
29:01
and vibrate at different speeds,
29:04
which causes them
to emit photons
29:05
in all directions,
across a variety of wavelengths.
29:07
in all directions,
across a variety of wavelengths.
29:10
Compared to a laser,
this is chaos.
29:13
Compared to a laser,
this is chaos.
29:17
ADHIKARI:
The way you should think
about a light bulb
29:20
they're just a mob of people,
29:22
all singing at different pitch,
29:23
so it's like
a rock concert audience.
29:25
CROWD (singing):
♪ We will, we will rock you ♪
29:29
But a laser,
a laser is more like
29:31
if you go to Juilliard
or Berklee School of Music
29:34
and you go to a concert.
29:36
(singing on one pitch)
29:40
ADHIKARI:
It's like a choir of people
29:42
who have got perfect pitch,
29:43
but it's a choir
of something like
29:44
a million trillion people
29:46
singing at the same time,
the same tone.
29:49
NARRATOR: That's because
29:51
laser light is generated
29:53
in an entirely different way,
29:54
a fact hidden in its name:
29:57
stimulated emission.
30:00
Let's say we have,
inside an atom,
30:02
an electron that's
at some excited state,
30:05
some higher energy level,
30:07
and now a photon of
just the right frequency
30:13
It triggers the atom
to do something interesting.
30:15
The electron loses energy
and goes to a lower energy,
30:17
The electron loses energy
and goes to a lower energy,
30:21
and emits a photon of
precisely the same frequency
30:23
and emits a photon of
precisely the same frequency
30:27
as the one that came in.
30:28
It's going in the same direction
and it has the same phase.
30:31
So what we have there is
30:33
a quantum mechanical
amplification process.
30:35
NARRATOR:
If we place a group of
those same excited atoms
30:36
NARRATOR:
If we place a group of
those same excited atoms
30:40
inside a chamber
with mirrors at both ends,
30:42
the emitted photons
will bounce back and forth,
30:44
the emitted photons
will bounce back and forth,
30:47
continuing to stimulate
the emission of more photons,
30:49
continuing to stimulate
the emission of more photons,
30:52
which in turn stimulate
even more photons.
30:54
which in turn stimulate
even more photons.
30:57
One of the mirrors is only
partially reflective.
30:58
One of the mirrors is only
partially reflective.
31:01
It allows some of the light
to escape.
31:03
It allows some of the light
to escape.
31:06
Now, that light's very special.
31:08
It's composed of photons
31:11
that are all
the same frequency--
31:13
so, the same color--
and they're all the same phase,
31:16
and all going in
the same direction.
31:18
So you have this intense
pure beam of light,
31:20
and that's the laser.
31:24
NARRATOR:
Lasers have proven to be
an extremely versatile tool,
31:25
NARRATOR:
Lasers have proven to be
an extremely versatile tool,
31:28
including for
measuring distance.
31:30
including for
measuring distance.
31:34
Rana's work with
stable high-frequency lasers
31:36
takes that to an extreme.
31:42
you're in a whole different
realm of measurement
31:44
than anything else
that has to do with rulers
31:45
and any of that other stuff.
31:47
Anybody who is, like, a real pro
31:49
knows that the only thing
that you ever measure
31:52
If you're measuring
anything else,
31:53
you're kind of an amateur.
31:54
you're kind of an amateur.
31:58
NARRATOR:
Thanks to the fixed speed
of light,
32:00
the beam
of a high-frequency laser
32:03
has an incredibly short
wavelength,
32:05
perfect for measuring extremely
small changes in distance.
32:08
perfect for measuring extremely
small changes in distance.
32:11
Since 1996, Rana has been part
of a project
32:12
Since 1996, Rana has been part
of a project
32:16
that uses laser light
32:17
to measure something incredibly,
unimaginably small--
32:19
to measure something incredibly,
unimaginably small--
32:26
in the fabric of space and time
itself.
32:27
in the fabric of space and time
itself.
32:31
Space and time ripple.
32:33
They're not fixed things,
and so,
32:36
the distance
between my two hands
32:37
is not always going to be this
if I hold them steady.
32:40
NARRATOR:
The idea, like so many,
32:43
goes back to Einstein.
32:46
In the early 20th century,
his work led
32:48
to the merging of space and time
into one concept:
32:49
to the merging of space and time
into one concept:
32:55
And he theorized that gravity
32:58
was the warping
of that space-time fabric
33:01
by the mass of objects.
33:03
But that carried
a startling implication,
33:04
But that carried
a startling implication,
33:08
that the acceleration
of objects with mass
33:11
would create ripples
in space-time
33:14
that spread
at the speed of light:
33:18
gravitational waves.
33:21
TIFFANY NICHOLS:
Gravitational waves
33:23
were first predicted
by Einstein,
33:24
and he didn't believe it
at first.
33:27
So he went back and forth
33:28
through, I believe,
the mid-'30s.
33:31
But his first prediction was
33:32
they were too minute
to ever be detected.
33:37
NARRATOR:
By the 1980s, that
sentiment had changed,
33:39
NARRATOR:
By the 1980s, that
sentiment had changed,
33:42
and LIGO--
the Laser Interferometer
33:46
Gravitational Wave
Observatory--
33:47
was founded as a joint
Caltech and M.I.T. project.
33:51
was founded as a joint
Caltech and M.I.T. project.
33:55
Part of Rana's work at Caltech
has been
33:58
to continuously improve
the essential art of LIGO:
34:01
laser interferometry.
34:03
laser interferometry.
34:06
This is the,
where it all begins.
34:09
I'm going to show you
34:11
the whole laser interferometer
in here
34:13
that's a prototype
of the LIGO system.
34:14
NARRATOR:
The basic design
is easy to understand.
34:15
NARRATOR:
The basic design
is easy to understand.
34:19
The LIGO interferometer
has two arms
34:22
at right angles
to each other.
34:24
A very stable infrared laser
34:27
feeds into a beam splitter,
34:29
which directs half the beam
down each arm.
34:32
ADHIKARI:
Half of the light goes one way
and half goes the other way.
34:35
And then you have mirrors
at the ends,
34:38
and they reflect the light back.
34:39
NARRATOR:
The phase of one arm
of the laser
34:42
is the reverse of the other.
34:45
when recombined,
they will cancel each other out,
34:49
resulting in no signal.
34:52
But if a gravitational wave
passes through,
34:53
But if a gravitational wave
passes through,
34:56
distorting space-time,
34:58
the length of each arm
will change,
35:01
shifting the phase
of the two beams.
35:02
shifting the phase
of the two beams.
35:07
the equipment will register
a signal.
35:08
the equipment will register
a signal.
35:12
Instead of having exact
cancellation
35:14
and destructive interference,
35:16
you have a little bit of light
leaking out.
35:18
And that little bit of light
35:19
that leaks out
is what we detect.
35:22
NARRATOR:
But there is a key difference
35:24
between Rana's working testbed
35:31
This is one of
two LIGO installations
35:34
in the United States.
35:35
While the arms of
the Caltech instrument
35:39
are about 44 yards long,
35:41
the ones here cover about
two-and-a-half miles each.
35:45
the ones here cover about
two-and-a-half miles each.
35:49
Costing hundreds
of millions of dollars,
35:51
LIGO was a huge gamble
on an unproven idea...
35:54
LIGO was a huge gamble
on an unproven idea...
36:01
In 2015, a signal was detected.
36:04
In 2015, a signal was detected.
36:11
LEVIN:
The first event
that LIGO detected
36:14
was the most powerful event
human beings had recorded
36:15
was the most powerful event
human beings had recorded
36:18
since the Big Bang itself.
36:22
of that collision
of those two black holes
36:23
than was emanated by
36:25
all the stars in the universe
combined.
36:28
All of that power came out
36:31
in the ringing of the drum
of space time.
36:33
NARRATOR:
Since the original event,
36:35
LIGO has confirmed the detection
36:37
of more than 80 others.
36:38
of more than 80 others.
36:42
It is hard to overstate
36:43
the significance
of the discovery.
36:52
Albert Einstein predicted
36:54
that gravitational waves
should exist,
36:55
and now we measure them.
36:57
This is the most
direct observation
36:59
of black holes
that we've ever had.
37:00
This is a complete revolution
in science.
37:02
This is a complete revolution
in science.
37:06
NARRATOR:
And it's all possible
37:08
because of that
quantum technology
37:09
that has become completely
embedded in our lives:
37:10
that has become completely
embedded in our lives:
37:16
The more stable your laser is,
37:18
the more things in the universe
you can measure.
37:20
And there's no limit to it.
37:22
So every year, when we get
lasers
37:24
better and better, we'll be able
to see
37:25
further out into the universe
37:27
and see tinier things
37:29
in the microscopic nature
of reality, matter,
37:32
space and time--
anything like that.
37:33
You just have to keep working
on this one tool
37:35
and make it better and better.
37:39
NARRATOR:
Arguably, the most important
change in quantum physics
37:43
in recent decades
is a deeper understanding
37:46
of a special kind
of shared state
37:47
of a special kind
of shared state
37:51
called quantum entanglement.
37:53
Imagine a machine that spits out
pairs of coins,
37:55
Imagine a machine that spits out
pairs of coins,
37:59
which, on the surface,
look like ordinary coins.
38:02
If you flip one,
it comes up heads or tails
38:02
If you flip one,
it comes up heads or tails
38:06
about 50% of the time.
38:08
Nothing strange there.
38:10
But using a pair of coins
fresh out of the machine,
38:11
But using a pair of coins
fresh out of the machine,
38:14
you flip one, it comes up heads.
38:19
it also comes up heads.
38:22
That could just be luck.
38:24
(machine chirping,
crowd cheering)
38:25
NARRATOR:
So then you do the same thing
with another fresh pair.
38:28
This time,
the first coin is tails,
38:31
and so is the second--
38:35
So you flip another pair,
38:46
the two coins always agree
on the first flip.
38:48
the two coins always agree
on the first flip.
38:55
Maybe the first flipped coin,
38:58
once it comes up heads or tails,
38:59
is somehow telling
the other coin how to behave.
39:00
is somehow telling
the other coin how to behave.
39:04
To make sure that can't happen,
39:05
you separate the coins
by flying one to the moon
39:06
you separate the coins
by flying one to the moon
39:10
and flip them at the same time,
39:12
so no message could possibly
travel between them.
39:13
so no message could possibly
travel between them.
39:16
Still, they come up
in agreement.
39:17
Still, they come up
in agreement.
39:23
It all sounds too strange
to be true,
39:26
but particles really can behave
like those coins.
39:28
but particles really can behave
like those coins.
39:31
In quantum physics,
it's called "entanglement."
39:32
In quantum physics,
it's called "entanglement."
39:36
KAISER:
Entanglement is really just
a stubborn, stubborn,
39:39
exciting and/or frustrating
fact
39:42
that takes a long time
39:44
to try to get our heads around.
39:45
Entanglement is certainly
39:46
the most interesting and the
most confusing
39:51
It's one of these things
we don't see,
39:53
you know, naively
in the world around us,
39:55
but it is taking place deep
in the materials
39:58
that exist around us
every day.
39:59
NARRATOR:
And while you probably
won't come across
40:02
a coin entangler anytime soon,
40:03
a coin entangler anytime soon,
40:07
in the lab, scientists
routinely generate
40:11
pairs of entangled particles
40:14
that share a quantum state
so fully,
40:16
they can be thought of
as one quantum object.
40:18
they can be thought of
as one quantum object.
40:21
You simply can't differentiate
between them.
40:23
It's just one pure state.
40:26
It's as though
you have a single entity
40:28
that's spatially separated
without a physical connection.
40:31
NARRATOR:
Entangled particles
remain connected
40:34
even when they're separated
by hundreds of miles--
40:38
and likely far more.
40:41
KAISER:
So does that mean it can
go between here and Andromeda?
40:44
Probably-- the equations give us
no reason to think it wouldn't.
40:46
NARRATOR:
Entanglement sounds bizarre.
40:47
NARRATOR:
Entanglement sounds bizarre.
40:51
Einstein derided the idea
40:53
as "spooky action
at a distance."
40:57
But since the 1970s,
41:00
experiment after experiment
has confirmed
41:03
entanglement is a real
quantum phenomenon.
41:05
entanglement is a real
quantum phenomenon.
41:09
Now, of course, many,
many decades later,
41:12
we know that entanglement is
undeniably a part of the world.
41:14
It's how the world works at
the quantum mechanical level.
41:17
We better get used to that,
41:19
and now see,
what can we do with it?
41:20
Because it's powerful,
let's try to use it.
41:23
It's become this new tool.
41:25
Being able to
create and control it
41:27
might be arguably thought of
as one of the biggest
41:29
scientific and engineering
developments
41:31
of the 21st century.
41:34
NARRATOR:
And that's happening
on several fronts.
41:37
Entanglement
has been put to work
41:39
in quantum cryptography
41:41
and quantum communication,
41:46
and in continuing improvements
to LIGO,
41:49
but perhaps with
the greatest fanfare
41:53
in quantum computing.
41:56
And that starts with this:
42:04
The qubit gets its name
from its cousin
42:07
in classical computing,
the binary bit.
42:14
Like its name suggests,
42:15
a binary bit can only be set
to zero or one.
42:16
a binary bit can only be set
to zero or one.
42:20
But from such humble beginnings,
much has flowed--
42:22
But from such humble beginnings,
much has flowed--
42:25
more or less all the computing
that makes up the modern world.
42:27
more or less all the computing
that makes up the modern world.
42:30
All the calculations,
all emails.
42:33
Whether you're talking
to your friend
42:36
or whether you
are a NASA scientist
42:38
doing some rocket calculation,
42:40
all of that can boil down
to just zeros and ones
42:44
switching inside your computer,
42:45
which is kind of amazing,
that it's that universal.
42:46
which is kind of amazing,
that it's that universal.
42:50
NARRATOR:
Despite its many successes,
42:52
the binary bit
is the equivalent
42:59
The qubit is far more subtle.
43:02
ALONSO-MONSALVE:
The special thing about a qubit
43:04
is that it operates by the laws
of quantum mechanics.
43:07
It doesn't have to be
just in the zero state
43:09
It doesn't have to be
just in the zero state
43:12
or just in the one state.
43:14
It can be in a superposition
of both.
43:17
NARRATOR:
That superposition creates
43:20
a mathematical space
43:22
often represented by a sphere.
43:26
SOPHIE HERMANS:
Where a classical bit
43:27
can only sit at the South Pole
or the North Pole,
43:30
a quantum bit can be anywhere
43:32
on the surface of the sphere.
43:34
It opens up a whole new array
43:37
of possibilities
of mathematical operations.
43:40
NARRATOR:
But a single qubit will only
take you so far in computing.
43:41
NARRATOR:
But a single qubit will only
take you so far in computing.
43:46
LANES:
One qubit by itself
is not a computer,
43:47
or it would be the world's
smallest, most useless computer.
43:51
But when you combine them,
43:52
it can provide enough
computation and calculations
43:53
it can provide enough
computation and calculations
43:57
that you can get something
on the other end.
43:59
NARRATOR:
Using several qubits together
44:03
opens up the power
of entanglement
44:04
and unleashes mind-boggling
levels of complexity.
44:06
and unleashes mind-boggling
levels of complexity.
44:11
PRESKILL:
If I wanted to give
a complete description
44:14
of what's happening
with just a few hundred qubits,
44:15
very highly entangled
with one another,
44:18
I would have to write down
more bits
44:21
than the number of atoms in the
visible universe.
44:24
And it's that extravagance
of the quantum language
44:26
that we wish to exploit
in a quantum computer.
44:28
that we wish to exploit
in a quantum computer.
44:32
NARRATOR:
Beyond the work being done
at universities,
44:34
there are
about 100 companies
44:39
and quantum
computing hardware.
44:42
Major players
include Google,
44:52
Its hardware development effort
is centered here,
44:55
at the Thomas J. Watson
Research Center
44:57
in Yorktown Heights
outside New York City.
44:58
in Yorktown Heights
outside New York City.
45:02
Okay, let me introduce you
45:05
to our IBM Quantum System Two.
45:07
Actually, inside here
is three quantum processors,
45:10
and the team is working on how
you investigate algorithms
45:12
that use multiple
different processors.
45:18
NARRATOR:
IBM's qubits employ small loops
of superconducting metal.
45:21
NARRATOR:
IBM's qubits employ small loops
of superconducting metal.
45:25
Since superconductors
45:27
require cold temperatures
to operate,
45:29
the center section
of the computer
45:31
is a refrigeration unit.
45:36
the cooling unit
of a quantum computer
45:40
it's often confused
for the star of the show.
45:41
it's often confused
for the star of the show.
45:46
LANES:
So this is a dilution
refrigerator.
45:49
A lot of people think this
entire cool shiny machine here
45:52
is a quantum computer,
45:54
but that's actually
not the case.
45:55
This is not a quantum computer.
45:57
This is a quantum computer,
45:59
this tiny little chip down here.
46:01
(laughing):
This is a freezer, basically.
46:03
But you can't deny
that it is amazing-looking.
46:04
But you can't deny
that it is amazing-looking.
46:08
All of these fancy shiny parts
46:10
are just plumbing parts
and cables
46:12
designed to keep the quantum
computer insanely cold.
46:13
designed to keep the quantum
computer insanely cold.
46:17
minus-400-something degrees
Fahrenheit.
46:20
Like, there's absolute zero.
46:23
We are .015 above that.
46:27
It has to be so insanely cold
46:29
because we use superconductors
to make our qubits.
46:31
And then furthermore,
46:33
we want to remove
any type of noise
46:35
or thermal excitations,
which can disturb the qubits
46:38
and make them behave
in ways that we don't like.
46:42
NARRATOR:
Since 2016, IBM has made
its quantum computers
46:44
NARRATOR:
Since 2016, IBM has made
its quantum computers
46:48
accessible to the public
over the internet.
46:50
Anyone can come up
with a quantum algorithm,
46:54
akin to a classical
computer program,
46:57
and submit it to be run.
47:00
GAMBETTA:
Since we first put it
on the cloud,
47:01
people have run
over three trillion jobs
47:05
on the quantum computers.
47:06
NARRATOR:
Running an algorithm
on a quantum computer
47:07
NARRATOR:
Running an algorithm
on a quantum computer
47:10
involves setting the initial
state of the qubits,
47:13
and then manipulating them
in a series of steps.
47:15
and then manipulating them
in a series of steps.
47:18
To do that, on its systems,
IBM uses microwave pulses.
47:20
To do that, on its systems,
IBM uses microwave pulses.
47:24
GAMBETTA:
These microwave pulses
47:26
essentially either
flip the qubit,
47:27
create it in a superposition,
47:31
NARRATOR:
After all the manipulation,
the qubits are read,
47:32
NARRATOR:
After all the manipulation,
the qubits are read,
47:35
collapsing their quantum state
into either a zero or one.
47:37
collapsing their quantum state
into either a zero or one.
47:41
But there's a catch.
47:43
LANES:
On a quantum computer,
the chip can
47:46
spontaneously decay
from the excited state,
47:47
or the one state,
into the zero state
47:49
when we don't want it to.
47:51
And this can occur, you know,
47:53
about every millisecond or so.
47:54
These errors
are basically inherent
47:57
to the quantum nature
of the device.
47:58
NARRATOR:
Correcting these errors
48:00
is one of the
built-in challenges
48:02
of quantum computing.
48:04
The current generation
of quantum computers
48:06
are not yet able
to do it themselves.
48:10
So there's one final step.
48:12
GAMBETTA:
The information
then comes back out.
48:15
Then it gets sent over
to a computer
48:17
where we do things
like error mitigation,
48:19
post-process the results,
correct for any extra noise,
48:21
and then we send it back
through the cloud.
48:28
NARRATOR:
It is easy to imagine
that quantum computing
48:31
is the next phase
of classical computing.
48:34
That soon, you'll see
a box that says
48:36
"New Qubitium chip inside!"
48:37
"New Qubitium chip inside!"
48:41
The most common question
48:42
people always ask me,
which is, like,
48:44
"When will I be able
to play 'Minecraft,'
48:46
when will I be able to play
'Doom' on my quantum computer?"
48:49
Quantum computers
are not good for everything.
48:51
In the future, there won't
be quantum PowerPoint,
48:53
there won't be quantum Word.
48:55
We don't need to do that,
48:57
because we have
classical computers
48:58
and Xboxes that are
perfectly suitable
49:00
for those types of applications.
49:02
NARRATOR:
Quantum computers
function very differently
49:03
NARRATOR:
Quantum computers
function very differently
49:05
and are aimed
at very different tasks.
49:07
and are aimed
at very different tasks.
49:11
Experts see a role
for quantum computers in areas
49:14
like simulation
of quantum behaviors
49:17
in chemistry and materials,
49:19
or optimization
of complex systems
49:19
or optimization
of complex systems
49:23
ranging from energy distribution
49:26
to database searches.
49:28
In any case, the future
of quantum computing
49:29
In any case, the future
of quantum computing
49:34
is far from written.
49:37
GHOSE:
So because things are really
speeding up all over the world,
49:40
I think we're going to
very quickly see
49:43
a demonstration of a task
49:45
that's been done with
a quantum computer
49:47
that just is well,
well outside the capability
49:51
of current computers.
49:52
And that'll probably
happen within the next
49:54
five to ten years,
I would say.
49:56
The future of computing
49:57
is going to have
classical accelerators,
50:01
it's going to have
A.I. accelerators,
50:02
and it's going to have
quantum computing accelerators
50:04
all working together.
50:05
And for me, that's one
of the most exciting things,
50:08
is, how do we actually
take advantage
50:10
of all these different
accelerators?
50:12
CARROLL:
I think that a well-functioning
quantum computer
50:15
will be able to do certain
things much, much faster.
50:17
But number one, we don't know
for sure.
50:19
And number two, it might
turn out,
50:22
the pessimistic view of this,
50:24
that those problems
are kind of limited,
50:26
that they're very, very
specialized.
50:28
But that's all exciting,
fun work in progress.
50:30
That's what makes it
interesting.
50:38
NARRATOR:
The roots of quantum physics
go back 100 years.
50:40
NARRATOR:
The roots of quantum physics
go back 100 years.
50:44
But only in recent decades
50:46
have we started to gain control
over the quantum realm.
50:48
And that has already
transformed the way we live.
50:52
And that has already
transformed the way we live.
50:55
There has been
astonishing change
50:57
in the kinds of quantum systems
50:59
we can build and manipulate.
51:00
Quantum mechanics itself
51:02
already permeates
everything we do.
51:04
They're part of how
we manipulate the world.
51:08
They're part of every transistor
and every computer.
51:10
LANES:
It's about how things interact
on a fundamental level,
51:11
LANES:
It's about how things interact
on a fundamental level,
51:14
but it turns out we need
to know how things interact
51:17
on a fundamental level
to do big things, as well.
51:20
KAISER:
There are still deep mysteries
to puzzle with.
51:23
That part hasn't gone away.
51:24
What's increased, in a way
that I still find remarkable,
51:27
is that these same curious,
51:30
mind-boggling quantum features
51:32
are now built into how people
51:33
navigate the world
every single day.
51:34
navigate the world
every single day.
51:37
NARRATOR:
But what about the future?
51:39
What will quantum technology
offer
51:42
in the coming decades?
51:45
Just like we can tell
our kids, "Oh, yeah,"
51:46
you know, "I was born
before the internet,
51:48
I was born before
smartphones,"
51:52
people are going to be
telling stories
51:53
about technologies
that are normal
51:55
that today we can't even fathom.
51:58
I believe 50 years from now,
52:00
people growing up
won't think twice
52:03
about entanglement,
superposition...
52:05
I think that will be
commonplace.
52:07
One of the things I love
about quantum mechanics
52:09
is that it seems non-intuitive
to us.
52:12
It tells us
that there's something
52:14
beyond just what we think
we understand.
52:16
We can't always rely
on our intuition.
52:18
We have to rely
on our understanding
52:22
And quantum mechanics
just shows us that so clearly.
