All language subtitles for Through the Wormhole s06e06 Why Do We Lie.eng

Did you do this?
I didn't do that.

You realize it's $400.
No.

Dude, it wasn't me.
Come in. Come on.

You ever tell a lie...
Even a little one?

[ Cellphone chimes ]

Is technology making it easier
for us to lie?

Or maybe nothing ever changes,

and dishonesty is just
a timeless part of human nature.

Dion.
Oh.

What are you doing?
Who is that?

Could society function
in a world

without lying or secrets?

No, I do not
have another girlfriend.

[ Buzzer ]

Mm.

Well,
you're a liar.

Dishonesty
might be so widespread

because we're so easily fooled,

and our memories are fallible.

Can we ever see the true nature
of reality?

Or is truth just a lie?

Space, time, life itself.

The secrets of the cosmos
lie through the wormhole.

Captions by vitac
www.Vitac.Com

captions paid for by
discovery communications

I'm going to let you in
on a little secret.

I have never told a lie.

Not once in my long career
has an untruth crossed my lips,

honest.

[ Chuckles ]

We all agree
that lying is shameful,

yet we still deliberately
deceive each other all the time.

Perhaps we lie
because we just can't help it.

When did you tell
your first lie?

Perhaps it was soon after
you were first lied to.

I told my son
if he didn't eat his broccoli,

he would be under 4 feet
the rest of his life.

I told my son his blanket
would protect him from monsters

in the closet.

I told my daughter if she didn't
keep her room clean,

she would never find a man
that would want to marry her.

Freeman: Kang Lee
is a developmental psychologist

at the university of Toronto.

As a father, he understands
why we lie to our kids.

Sometimes, you have exhausted
all the other better methods,

and the lying
sometimes becomes the only way

you can deal
with the situation on hand.

Freeman: In fact, Kang is
as guilty as the rest of us.

I used to drive my son Nathan
to his school every morning.

[ Indistinct shouting ]

And sometimes, in the backseat,

and he would be acting up
and screaming, yelling,

and I pointed
to the hazard light

and I said, "that actually
is an eject button.

If I push that button,
your car seat

is going to blow off
and go through the roof,

and you're going to fly
out of the car."

And immediately,
he became very quiet.

Freeman: Would children remain
honest and pure

if we grown ups didn't
corrupt them with our lies?

Kang believes
something deeper is going on.

He and his colleagues
have run an experiment

with thousands of kids
of various ages.

[ Barking ]

What do you think
it is?

A dog.
A dog.

Come around.
Yes, it is a dog.

Doggy.

[ Chuckles ]

It starts as a game...

Guess the animal
from just the sound it makes.

[ Neighing ]

A horse?
Yes.

Turn around.
Take a look.

Yeah.

Kids are promised a prize

if they can guess
the third animal correctly.

Turn around.

Then,
the grown ups leave the room.

And I'm gonna
play the sound...

All right.
So I'll be right back, okay?

[ Door opens, closes ]

[ Door closes ]

You can guess
how well that worked.

Hidden cameras revealed

that for many children,
the temptation was too great.

[ Door opens, closes ]

Sorry.

You can
turn around now.

When I was gone,

did you turn around to peek
to see what it is?

No? Okay.

Now, what do you
think it is?

Cow.

It's a cow?

If they later identified the
animal without ever hearing it,

the experimenters knew
those children lied.

Lee:
That's basically the procedure

we have been using with kids
in the U.S., in Canada,

in China, in Africa.

And it works very, very well
with kids all over the world.

Freeman:
Researchers used to believe

that children
start lying around age 5,

after more exposure
to the adult world.

But Kang has shown
that lying starts much earlier.

What do you think it is?

Cow.

[ Laughing ]
It's a cow. Okay.

How do you know
it's a cow?

Kids actually start to tell lies
at 2 years of age,

so that is very surprising.

At 2 years of age,

about 30% of kids
would tell lies,

and at 3 years of age,

about 50% of the kids
would tell a lie.

By 7 and 8 years of age,
100% of kids will lie.

Did you
turn around to peek?

No.

Freeman: Kang's revelation is
enough to send worried parents

into a tizzy,

except there is a bright side
to early lying.

Lee: Those kids who lie earlier
than the other kids

are actually those kids

who have better cognitive
development abilities.

So they seem to be more advanced

than those kids
who are telling the truth,

which is totally
surprising to us.

Freeman: A good lie requires
forethought and self control.

Lee: You have to be able to plan
ahead what you are going to say

and how you are going to say it.

Freeman: In other words,
the onset of lying

is an important stage
in brain development.

But why do we start lying as
soon as our brains are able to?

Would we be better off
always telling the truth?

Lee: Some of them are actually
very good... prosocial lies.

The reason
we tell white lies is because

we do not want
to hurt other people's feelings.

Imagine I'm playing cards
with my friends.

At the same time, I really want
to watch my favorite TV show.

What do I do?

One way I can do it
is do it bluntly.

My favorite TV show just came on
and, uh, so I have to go.

Uh, thank...
Thank you, guys.

Bye bye.

Nobody's gonna like you.

Or you can do it differently.

You basically tell a white lie
by saying, "oh, you know,

I don't feel very good.
I have to lie down."

Sorry, guys.

I suddenly
don't feel very well.

I probably have to go in
and lie down.

Uh...
Oh, do you need water?

So you really have to be able
to know when is the time

to tell the truth

and when is not a good time
to tell the truth.

A little white lie
doesn't hurt anyone.

But some people can't stop
twisting the truth, no matter

how damaging the consequences
to others or themselves.

For them,
dishonesty is a disease.

What separates
these pathological liars

from the rest of us?

Charles Ponzi began lying
to his investment clients

in the early 1900s,
and he couldn't stop,

even after he'd been to prison
three times for fraud.

18th century journalist
Daniel defoe

invented as many facts
as he reported

and did time for slander.

What drives some liars to reach
pathological levels of deceit?

That's what Yaling Yang,
a psychologist

at children's hospital
Los Angeles, wants to find out.

We start to spot inconsistency
between their statement.

Even when they know
that we have other data,

including
official criminal records,

they still lie.

Freeman:
Yaling and her colleagues

wondered if there might be
physical differences

between the brains
of pathological liars

and the brains
of average people.

The brain stores
our memories and knowledge

in gray matter cells,

but another type of neuron,
the white matter cell,

creates connections
between all that information.

Whenever we tell a story,
whether it's true or not,

we have to gather details
from gray matter cells

in different parts of the brain.

It's like gleaning information
from a series of books.

The books are the gray matter,
filled with the knowledge

that you need to fit together
into a compelling narrative.

The aisles that lead from book
to book are the white matter.

Imagine going to a bookstore
to get 10 different books

that are scattered

across different areas
of the bookstore.

Having multiple pathways
that lead you to the books

will help you get to the books
more easily and quickly.

The human brain
works in a very similar fashion.

When you have more connections

between various parts
of the brain, that will make it

easier for you to retrieve
important information.

Freeman:
For example, let's say a friend

asks Yaling what she
had for dinner yesterday.

To tell the truth,

she only has to gather
a few pieces of information.

She ate spaghetti
and a salad at home.

But lying is harder.

Yaling would have to
ignore the truth

and cook up a story
about a five star restaurant

and a six course meal,

a special occasion
and expensive champagne.

If she hesitates at any point,
her lie will be discovered.

She needs good pathways so she
can race from topic to topic,

grabbing the information
she needs.

Since lying requires
a lot more information gathering

than telling the truth,

Yaling and her colleagues
conjectured that the brains

of pathological liars might have
more white matter pathways.

Brain scans proved them right.

Liars have about 25% increase
in white matter

compared to healthy individuals.

So having more white matter
allows all this information

to be retrieved and be used
in a much faster way.

Freeman: Yaling also found
that pathological liars

have 14% less gray matter
than average people.

Gray matter stores our memories,

but it also
has another function...

It controls
our reckless impulses.

Yang: Gray matter
plays a very important role

in impulse control.

So this kind of reduction
in gray matter

is likely to contribute
to the lack of impulse control

in pathological liars.

Freeman: Pathological liars
can easily ruin their own lives,

as well as others'.

Perhaps now that we know more
about what makes them lie,

we can develop therapies
to help them stop.

Yang:
Without that information,

it will be very difficult
to develop any kind

of intervention or treatment
for this very damaging behavior.

Freeman:
But isn't technology

making it easier
for us to deceive one another?

Is there a way
to tell what's true

and what's not online?

This information scientist
has developed a way to find out.

Our modern devices appear
to make lying easier than ever.

After all, no one can see us
behind a screen.

Today's technology has
ushered in a new breed of lie.

It's called digital deception.

Is the information age
really the disinformation age?

[ Keypad clicking ]

Information scientist Jeff
Hancock at Cornell university

is examining the differences
between high tech lies

and the old standbys.

If I wanted to call in sick,
in the old days,

I'd need to psych myself up
and get my sick voice on.

[ Telephone rings ]

Yeah, hi.
[ Coughs ]

I'm really sorry.
[ Coughs ]

I'm...
I'm too sick to come in today.

Yeah. [ Coughs ]

Nowadays, we can type a message
about feeling sick,

no voice, no vocal cues,
no nonverbal cues.

Hit send, and my lie's done.

Freeman: Some digital deceptions
have become so common

that Jeff and his team
gave them names.

Hancock: One of the things
we saw on text messages

all the time was a lie
we call the Butler lie.

[ Doorbell rings ]

We used to have people
that would act as that buffer,

and they would provide
that physical buffer

between you and the world trying
to get in and talk to you.

[ Cellphone chimes ]

Freeman: Now we all
have digital butlers.

Hancock: People say, "well,
I'm on my way," when, in fact,

they're not, or, "my battery was
dead," because what we realized

is they're providing a buffer
between that person

and the fact that the world can
contact them pretty much 24/7.

Freeman: Even though it makes us
easier to reach,

the online world also
offers unprecedented anonymity.

A new identity
is just a few keystrokes away.

This leads
to a digital deception

known as the sock puppet lie.

Hancock: Sock puppet
is identity deception,

where you have an alter ego

that can say things
on your behalf

without appearing like you.

You're not Jeff Hancock,
are you?

No.
Not me.

Perfect, because I've got
this new book coming out,

and I really
need a positive review.

Could you help me out?

Yeah.
Great, thanks.

Freeman: It's no wonder
we have a hard time

deciding what to believe
of all that we read online.

Is it possible
to sort truth from lie?

That's what Jeff
decided to find out.

He started
by looking at something

we've all wondered about...

Those consumer reviews we see
when we shop online.

Who writes those,
and can we trust them?

The stakes are huge.

Together, we spend
trillions of dollars worldwide

on online sales every year.

Jeff examined the hotel reviews
we use to plan our vacations.

Should we really be relying
on the opinions of strangers?

We had people write fake reviews
for us,

and we paid for them.

We knew they were fake.

We compared them to ones
that were real.

So we took them
from the verified sites,

and we looked at linguistic
patterns and how they differed.

Freeman:
If he'd actually been there,

Jeff would write about the hotel
in a certain way.

He would know about every detail
of the room.

Hancock: A real reviewer
will have a sense

of what the beds are like
and the bathroom.

Is it clean,
is the shower small or not?

That sort of thing, since
they've experienced the space,

their bodies moved through it.

Freeman: But if Jeff
had never been to the hotel...

He wouldn't know
if there was mold in the shower

or if the Internet service
was slow.

So he'd have to write
about something else,

something made up.

Hancock:
Now, me writing a fake review here in my home with my computer

is completely different.

When a fake reviewer
has to write about something,

they're going into storytelling.

We were on business.

So they'll tell stories
about who they were with,

what they were
supposed to be doing.

They're trying
to convince people.

Freeman: Jeff and his team
compared the fake reviews

they had paid for
with the verified truthful ones.

Then, they developed
a truth or lie algorithm

that zeroes in on telltale words
and phrases.

Hancock:
See here that ones that are true

are things like,
"rooms were large,"

and, "they were more expensive,"
whereas,

over on the deceptive one,

we can see people
talking about themselves.

"I had a reservation."

Lot of instances of "i."

Freeman:
Jeff has developed

keyword algorithms
for other products and services

and discovered
some surprising results.

People tend to think
most reviews are fake,

and our estimation is
that it's much lower than that.

Like,
maybe 5% to 10% are fake.

Freeman: So online reviews
are pretty reliable.

What about digital
communications in general?

Do we use our gadgets
to lie more or less

than in old fashioned
face to face talks?

Things like e mail,

there's actually a lot
less lying than people expect.

The main reason, I think,
is that there's a record.

We evolved to talk
and have it disappear,

and now
we're in a radically new era.

If I write you an e mail,

not only have I created
a record for myself,

I've given you a record.

That record can be copied.

It can be searched.
It can be shared.

And so telling a lie
in a digital format

comes with substantial risks
that we've never,

as a set of communicators,
ever had to worry about before.

Freeman: Jeff found
a little more lying in texting,

which we use for more informal
communication than e mail.

And as soon
as the written words disappear,

more lies reappear.

What we find is that
it's the phone

where people lie a lot.

That's... every study,

it's always on the phone
where you see the most lies.

Freeman:
According to Jeff,

we lie the most when we ditch
our gadgets altogether

and talk to each other
face to face.

Why?

Perhaps because we are
really bad at spotting lies.

But a new device may help us
catch a liar every time.

Think you can spot a liar?

Oh, you may look
for certain tells,

facial expression, unusual tone
of voice, awkward body language.

But let's not kid ourselves,
folks.

It can be hard to tell
if someone is lying.

Could technology restore truth
to the expression,

"the eyes
are the window to the soul"?

This university of Utah student
is looking to swipe some money

from a campus office.

And he just found his chance.

He's not worried
about throwing away his future

for a measly 20 bucks...

...because it's all part of a
"mission: Impossible" experiment

dreamed up by
psychophysiologist John Kircher.

John has spent the last 30 years
studying lies,

and this experiment
is designed to test a device

that may one day
make lying impossible.

Today,
there are two test subjects.

John doesn't know if one,

both, or neither of them
will steal any money.

The subject receives
secret agent style instructions,

a mysterious envelope,

and directions
from a computerized voice.

You are an innocent participant
in this experiment.

Please wait outside
the building for 20 minutes

before returning to the lab.

The other student receives
a diabolical assignment.

You must steal $20
from the purse.

You must have
an alibi prepared.

You will not receive
full credit if you are caught.

They get instructions
to go to a different building,

to go to a secretary's office

and ask her
where Dr. Mitchell's office is,

and she'll reply
that there's no Dr. Mitchell

or that they should
check with the Dean's office.

Freeman: The secretary
is in on the caper.

She's been instructed
to leave her office unattended

for a few minutes

after the student
asks for Dr. Mitchell.

Kircher: We tried to set this up
like a "mission: Impossible"

scenario
to get the subject engaged

and apprehensive
about what they're doing.

Those effects reproduce
the kinds of things that we see

in field situations
with actual criminal suspects.

Take a seat
right over here.

Freeman: Now for the moment
of truth or lies.

The ocular deception test
begins.

The subjects answer

identical true or false
questions about general topics

and about the crime.

Below the screen
is John's device...

An infrared eye tracker able
to spot microscopic dilations

and contractions of the pupils.

The changes that we're seeing
in the size of the pupil

are very tiny.

They're less than
1/10 of a millimeter,

but with a computer,
we can get a clear indication

that the pupil is dilating
when a person is deceptive.

The subject looks like they
didn't have a difficult time

answering these questions,

and the pupil data

look like we would expect
from a truthful individual.

Freeman:
Did the thief's pupils dilate

when answering
the same questions?

Kircher: They're showing
stronger reactions

to the questions about the $20,

so I'd say there's a good chance
the subject's in a guilty group.

Freeman:
Sure enough, John is right.

The female subject was innocent

and the male subject
had to give back the 20 bucks.

But how did pupil dilation
help John catch the thief?

John knows that when our brains

go into overdrive
with mental effort,

our pupils dilate involuntarily.

And since deception

is more complicated
than telling the truth,

the male student's brain
had to work harder.

He couldn't hide his lying eyes.

John's ocular deception device
is already 85% accurate.

That's as good
as the best polygraph results.

But while people can be trained
to beat polygraph tests,

pupil dilation is involuntary.

And as technology improves,

the accuracy of John's
lie detector will, too.

Kircher: With better
eye tracking technology,

we'll get better measures
of pupil change.

Freeman: That means the accuracy
of John's device

could one day reach 100%.

Imagine a future
where a person with a cellphone

or smart eyewear
could use a miniaturized version

of John's device
on anyone they're talking to...

Husband and wife,
parent and child,

worker and boss.

Would the whole truth
and nothing but the truth

bring us closer together
or tear us apart?

According to
this cognitive scientist,

knowing the real truth
about the world around us

would simply blow our minds.

What we think of as reality
is just a series of illusions.

Why are our brains
and senses so easily fooled?

Wow.

We rely on our senses
to make sense of our world.

That's why it's so unsettling
when they fail us.

We can't trust our ability
to see the truth.

And even if we could...

[ Telephone rings ]

...could we handle it?

Hello?

Hello?

Hello?

I'm Don Hoffman...
As far as I can tell.

Freeman: UC Irvine
cognitive scientist Don Hoffman

thinks that anyone
who believes our senses

are designed to show what's
the truth has got it all wrong.

He enjoys proving his point

by finding new ways
to fool the senses.

I'm about to eat
this very tart lemon,

which normally doesn't sound
like a good idea,

but before I do, I'm going
to first eat this miracle berry

from west Africa.

It releases something
called miraculin,

a chemical that binds to the
sweet receptors on my tongue.

And what it's supposed to do is,
when the acid from the lemon

binds to the miraculin,
it triggers my sweet receptors

to give me an illusion
of a sweet taste.

Let's see it really works.

So I'll take the berry out,
and we'll cut this lemon.

And the moment of truth.

Wow.

That does taste sweet.

I've never tasted a lemon
like that before.

That is really good.
[ Chuckles ]

Freeman: don has identified
plenty of ways our senses

and brains
misconstrue the world around us.

Surely, we think, our sense
of touch could never be wrong.

With touch, we feel like we're
in direct contact with reality

as it really is.

Well, if you tap the shoulder
and then tap the elbow

and then tap the wrist and you
do the timing just right,

what a person will feel
is tapping between.

So you feel a tap here and a tap
here, tap there, a tap there.

And it'll feel like there's some
animal running down your arm.

The brain is saying,
"what is the best story

about the world
that I could come up with?"

And the best story
that it comes up with is, "well,

there's probably something
crawling down my arm."

Freeman:
With such limited senses,

the unfiltered truth
of the world

never reaches our brains,
so we're forced to use stories

or preconceived rules
about how reality should be.

But once you're constructing
reality based on rules,

if something
doesn't match your assumptions,

we construct things
that aren't really there.

Freeman: Each of our eyes
can only take in a 2 d image.

It's our brains that create
a 3 d view of the world.

There's gradients and shading,

so as you go from light
to dark and dark to light,

the visual system
automatically interprets that

in terms
of three dimensional shapes.

As you see things
like railroad tracks

converging in the distance,

you'll actually give
a depth interpretation to that.

Ah!

Freeman: don's radical
conclusion is that our senses

aren't intended
to see the truth of reality.

Our senses do just enough to
help us find mates, find food,

and avoid becoming
someone else's food.

Hoffman:
It's the perceptual systems

that allow you to stay alive
long enough to reproduce.

Those are the ones
whose genes get passed on

to the next generation.

So, in that sense,
it's quite clear.

Perception
and evolution of perception

is about having kids,
not about the truth.

Freeman: Every creature on earth
develops only the senses

it needs to survive
and reproduce.

This region used to be
a much bigger wetland

with millions of frogs.

Freeman:
This is how researchers believe the world looks to a frog.

If things aren't moving,

the frog pretty much
either doesn't see them

or is programmed to ignore them.

Freeman:
Luckily for the frog, it's great at detecting small objects

flying around close enough
to its tongue

to become a tasty meal.

We can see stationary objects
that a frog can't,

but we don't see all the colors
that a butterfly does,

and we can't hear
every frequency of sound

that a bat can,

which begs the question,
what is the world really like?

What are we not seeing?

Imagine a color
you've never experienced before.

Nothing happens.

If we can't even do that,

just one new color that
you've never experienced before,

we're really in the dark

about what the full complexity
of objective reality might be.

So our senses are this wonderful
window on the world,

but they're also a prison that
we really can't see outside of.

We can't necessarily
trust our senses,

but even if we only grasp
a simplified version of reality,

surely, our memories

can keep track
of where and when things happen.

Or that's what we thought.

New research suggests

that our brains trick us
into misremembering the truth.

We can't possibly
remember every single thing

that happens to us,

but we trust the memories
we do retain.

We remember every detail
about the birth of a child.

We know where we had a special
meal and whom we were with.

But what if some
of those memories aren't real?

What if we invented them?

Or...
Someone else implanted them?

This is Susumu Tonegawa's
favorite spot

to enjoy a cup of coffee.

And sitting here also reminds
the M.I.T. scientist of the time

two cars slammed into each other
just a few feet away.

He mentions the accident
to his friend,

but his friend
remembers it differently.

I had an argument
with my friend,

that he said, "no, no, no.

Actually, car accident
happened in front of our lab."

[ Crash ]

Freeman: Susumu thought,
"no, that can't be right."

But I insisted accident happened
in front of coffee shop.

Freeman: And then,
he realized his mistake.

I was thinking
of the conversation

I was having with my friend,
drinking a coffee,

when actually, car accident
happened in front of our lab.

[ Crash ]

Freeman: He and his friend
were in front of the lab

when the cars collided,

but his mind was on one
of their previous conversations

at the coffee shop.

Susumu's brain mistakenly
combined the two locations

and created a new memory
that is actually false.

As a Nobel laureate
and a scientist

who's devoted three decades
to understanding memory,

Susumu wanted to know
how this could happen.

He and his team decided to look
for physical evidence

of false memories being formed.

In the brain,
the area called the hippocampus

plays a very crucial role
in these types of memory.

If you have impairment
in the hippocampus,

then you cannot form memory
of episode very well.

Freeman: Susumu's research
centers on the physical changes

in the hippocampus
when an episodic memory forms.

When we experience something,
like witnessing a car accident,

it biochemically changes
a small group of neurons

in the hippocampus.

Neuroscientists call
that changed group an engram.

It is a physical trace
of the stored memory.

That stored memory is sometimes
triggered when we see something

that's new but similar.

A lone, majestic pine tree may
remind us of our first glimpse

of the Eiffel Tower
during a vacation years ago.

Susumu found
that when old memories

are activated
by new experiences,

both can become confused.

Sometimes, the neurons
of the old memory engram

become physically linked
to the recently formed engram.

The result is a false memory

that mistakenly combines
two events.

That got Susumu
and his colleagues wondering,

is it possible to intentionally
create false memories?

They devised an experiment
with a mouse and two chambers.

Freeman:
The mouse forms separate memories for each location.

For example,
chamber b has a wire floor,

and chamber a does not.

Susumu then sets about
locating each memory

in the mouse's brain.

The mouse has a series

of tiny wires monitoring
activity in its brain.

When he places the mouse
in chamber a,

Susumu can pinpoint the location
of the chamber a memory.

But the wires
can also stimulate neurons

to respond by emitting
small pulses of light.

So whenever Susumu shines
a light on those same neurons,

he can activate the mouse's
memory of being in chamber a.

Once the mouse has formed
a memory of chamber a,

it's placed
in the wire floored chamber b.

Susumu is ready
to create the false memory.

The shock is harmless
but startling.

Since the chamber a memory

is activated while the mouse
receives the shock in chamber b,

it creates an association
between chamber a and the shock.

And sure enough,

when Susumu places the mouse
back in chamber a,

it suddenly freezes in fear.

Even with no wire floor,

the mouse
acts like it might get a shock.

It now possesses a false memory

of being shocked in the chamber
where no shock ever happened.

Susumu and his colleagues

have successfully inserted
false memories into mice.

Does this mean the same thing
could be done to people?

What is science fiction today

may not be science fiction
in 50 years.

Human brain much bigger
than mouse brain,

but theoretically,
it's possible.

Freeman: So if we can't trust
our memories, our senses,

or each other,

is there any such thing
as an ultimate truth?

This physicist is looking for
answers in the quantum world.

He is finding that the notion
of truth keeps getting curiouser

and curiouser.

Truth is hard to find
in the human world.

Our brains are wired for lying.

We remember events
that never happened.

And our senses

don't perceive the reality
of the world around us.

But surely if we use the tools
of science

to examine the fundamental
nature of reality,

we can see the ultimate truth.

Unless the universe itself
lies to us.

I am Jeff Tollaksen,
and that's the truth.

Freeman:
Jeff Tollaksen, a physicist

at Chapman university
in Southern California,

has taken many trips
into the quantum world.

There are a million,
million, billion atoms

in each individual
grain of sand.

But when we are talking about
the quantum world,

we mean even smaller pieces of
matter that make up the atoms.

The protons, the neutrons,
and the electrons...

They make up everything
in the entire universe,

including us.

Freeman:
Jeff knows that the basic building blocks of existence

don't follow basic rules.

Tollaksen: Take,
for instance, the electron.

The laws of the quantum world

suggest that things can be
at many different places

at the same time.

They also forbid us from knowing
everything about the electron.

It's a bit like
looking at a hummingbird.

Its wings are moving so fast
that they appear as just a blur.

But if I take a photo
of the hummingbird,

I can learn one of two things.

If I set it
to a high shutter speed...

...i can clearly see
the location of the wings,

but I can't tell anything
about velocity.

So now I'll set it
to a low shutter speed.

And now it's just a blur.

I can't tell anything
about the location of the wings,

but I can clearly see
that they have a velocity.

Freeman: Similarly, we can never
know the true position

and velocity of an electron.

So the notion of truth
at the quantum level

is very different from our usual
human understanding of truth.

Freeman: But as strange
as these particles are,

we still know
they are bits of matter

and they have
certain defining properties,

such as spin direction
and electrical charge.

Matter and its properties
go together like rock and hard.

You can't have one
without the other.

Or can you?

The more Jeff and his colleagues

study the building blocks
of the universe,

the curiouser and curiouser
it all becomes.

Tollaksen:
If you've ever read Lewis carroll's "Alice in wonderland,"

you know
that there is a cheshire cat.

Now, the cheshire cat
has a grin.

And it's a remarkable grin.

So you can't have the
cheshire cat without the grin.

The grin belongs to the cat.

But one day, Alice is having
a conversation with the cat,

and suddenly,
the body disappears,

leaving just the grin.

To which Alice said,

"well, I've often seen a cat
without a grin.

But a grin without a cat?

It's the most curious thing
I've ever seen."

Now, it seems
physically impossible,

even in your wildest dreams,
that such a thing could happen.

But what's remarkable is we've
predicted how you could do this,

namely separate properties
from matter.

Freeman:
In July 2014,

Jeff and colleagues at the
Vienna institute of technology

put that prediction to the test.

Could they actually
create a quantum cheshire cat?

They split a stream of neutrons
into two beams.

Then, they used magnetic fields
to give the neutrons

in each beam
opposite spin direction.

Using other magnetic fields
and filters,

they manipulated the system

until something very curious
happened.

The mass of the neutrons went
entirely through the upper beam,

while the neutrons'
spin properties

traveled exclusively
through the lower beam.

Like a cat and its grin,

matter and its properties
were separated.

If it's possible
to separate an object

from the properties
that we use to describe it,

is truth itself

just another property
that can be stripped away?

Are we closer to finding
the truth about the universe,

or closer to dismissing it
as nothing more than a phantom?

Tollaksen:
Every time we peel back a little bit more of that veil,

we discover incredibly beautiful
and awe inspiring new truths.

Whether or not scientists
will ever be able to discover

absolute truth,
deep nature of everything,

we don't know.

But it is in the spirit
of science to keep trying.

Will we continue to peel back
layer after layer

of new truths forever?

Could we even comprehend the
truth with our limited senses

and our faulty,
selective memories?

There's only one thing
we can be sure of...

Anyone who claims
to know the ultimate truth...

...is probably just
telling you another lie.

[ Chuckles ]

Repair and Synchronization by
Easy Subtitles Synchronizer 1.0.0.0