TYSON: Can we know the universe?
Are our brains capable of comprehending the cosmos in
all of its complexity and splendor?
We don't yet know the answer to that question because our
brain remains almost as much of a mystery
as the universe itself.
We think that the number of processing units in your brain
is roughly equal to all the stars in 1,000 galaxies.
At least 100 trillion.
And it's possible that the real number of processing units
is ten times larger.
We're inside a brain.
It's in the grip of a Category 5 hurricane of chemical and
electrical forces.
The storm came without warning,
spreading chaos and heartache far beyond its path...
But it also provided the first clues to the nature of this
little cosmos.
[theme music plays]
♪ ♪
TYSON: We are traveling 2,500 years back in time to the island
of Kos in the Aegean Sea.
This is the story of a giant leap in the
history of thought.
It was here that one of the most powerful spells
ever to cloud the mind was first broken.
Imagine you are the loving parents of a
precious only child.
The boy is given to moments of brilliance,
which charm and impress your friends.
But there's something wrong...
A storm is brewing inside his head...
GOVERNESS: Peleus! Peleus!
♪ ♪
TYSON: This was medicine 2,500 years ago in Greece.
The idea that the ritual appeasement of one of the gods
could bring about the cure for an epileptic seizure was
magical thinking.
When the Greeks and people of other cultures performed their rituals,
some of the afflicted recovered,
due to the finite course of the illness,
or to their own immune systems.
But to the patients and their loved ones,
it meant that the gods had been appeased.
And when the patient died?
That just meant the gods were so angry,
nothing could be done.
This way of thinking was a by-product of that great human strength, and weakness,
called pattern recognition.
In this case, false pattern recognition.
The belief that epilepsy was caused by the anger of the
gods was the confusion of correlation with causation,
and the wishful thinking that prevails when
people feel powerless.
That's not to say that the ancient Greeks didn't have
remedies, plants and minerals, they used as medicines.
But for a disease as mysterious as epilepsy,
they could only light their incense and pray.
They didn't even know it had anything to do with the brain.
And then came Hippocrates.
Hippocrates rejected the notion that angry gods were
the cause of disease and injury.
He wrote: "The physician must investigate the entire patient,
his diet and his environment...
The best physician is the one who is able
to prevent illness.
Nothing happens without a natural cause."
For this alone, he could be called the Father of Medicine.
He is credited with codifying an ethos for doctors.
The oath ascribed to him in the 3rd century BCE is still
taken today by those who would practice medicine.
And it was Hippocrates who was among the first
to declare the brain to be the seat of consciousness.
It's hard to believe,
but this was once a revolutionary concept.
The prevailing wisdom being that we actually
thought with our hearts.
And it may have been here where he made one of
the great prophecies in the history of science.
Hippocrates understood that he and his contemporaries
called epilepsy "“the sacred disease"”
because they didn't understand its physical cause.
He wrote, "When we do, we will no longer think it divine."
That little boy wasn't cursed.
There was a physical malfunction inside his brain.
As long as we searched for it in the whim of the gods,
we had no hope of helping him, or ourselves.
Yet thousands of years passed,
and the brain remained a mystery.
Between 420 BCE and the 19th century,
our understanding of the cosmos grew by leaps and bounds.
We discovered the speed of light,
the laws of gravity,
and we learned that our Sun is part of a greater galaxy
of stars and yet, 2,300 years after Hippocrates,
we still knew virtually nothing about the part of
ourselves that made it possible to make these discoveries:
our brains.
It could be said that we actually knew less.
The study of the brain had become stuck in a
pseudoscientific dead-end called "“phrenology,"”
which held that from the shape of a person's skull,
you could deduce their intelligence and
trustworthiness.
A frenzy of head-measuring ensued.
A gift for languages resided above the cheekbone,
and marital fidelity located behind the ears.
And not surprisingly,
European phrenologists discovered that their
particular heads represented the universal
standard of cerebral excellence.
The first real insight regarding the connection
between the mind and the brain was made in France in 1861.
And here again, epilepsy played a critical role...
The Bicêtre psychiatric hospital was state-of-the-art
in Paris back then.
In the previous century, it had been the first to
introduce humane practices in the treatment of the insane
and the mentally disabled.
And among the doctors there, surgeon Paul Broca was
especially admired for his enlightened treatment
of his patients.
TAN: Tan...
TYSON: The patient's name was Louis Leborgne.
TAN: Tan...
TYSON: But everyone called him "Tan" after the
only syllable that he had uttered since he was 30.
He was now 51.
Tan had been having epileptic seizures since childhood,
but he was committed to Bicêtre because he had lost
all powers of speech except for being able to say "“tan."”
Now, poor Tan lay dying.
His right side had become paralyzed,
and gangrene had set in.
Prior to Tan's medical crisis,
Broca had been speculating that specific regions
of the brain might be responsible for
the powers of speech and memory.
Broca wanted to know everything he possibly could
about the dying patient in expectation of what a
post-mortem might reveal.
We do not know if Tan's epilepsy caused the damage to his brain,
or whether an unreported childhood injury
caused his epilepsy and later loss of speech.
TAN: Tan...
TYSON: But because of Tan's fate,
Paul Broca was able to connect,
for the very first time, a part of the human brain,
in this case the region that was damaged,
and its specialized function: the ability to use language.
His reward...
that part of our brain has been known ever since
as "Broca's area."
Paul Broca's own brain ended up in a jar
like this one in a back storage room of the
anthropological museum he directed,
with shelf upon shelf of the brains of mass murderers and
other master criminals, as well as congenital
abnormalities that seemed to fascinate the public of the
19th century.
Broca was a humanist.
He concluded that there were deep connections in brain
physiology between non-human primates and us.
He founded a society of freethinkers in his youth,
and believed passionately in the importance
of unobstructed inquiry.
He lived his life in pursuit of that aim.
But he, too, was partly blinded by the prejudices that
permeated his society.
He thought men mentally superior to women,
and whites superior to everyone else.
His falling short of humanist ideals shows that even someone
as committed to the free pursuit of knowledge
as Broca could still be deceived by endemic bigotry.
Society corrupts the best of us.
It's a little unfair,
I think, to criticize a person for not sharing
the enlightenment of a later age,
but it is also profoundly saddening that such prejudices
were so pervasive.
The question raises nagging uncertainties about which of
the assumptions of our own age will be considered
unforgivable by the next...
Broca established for the first time that there were
physical correlations between anatomy and function,
but what of the crackling energy of consciousness?
What of the stuff that dreams are made of?
Can't put them in a jar...
♪ ♪
TYSON: When the ancient Egyptians looked up at night,
they saw the underbody of Nut,
Goddess of the Milky Way.
When they closed their eyes and began to dream,
they believed they were transiting to the afterlife.
And so, dreaming was ritualized into a form of
worship, a means to learn what their future held,
or to send a message to the gods, as they slumbered.
The faithful would make a pilgrimage to
a temple to dream.
To prepare themselves, they would withdraw to a
place of isolation,
and fast to cleanse their mind and body.
A prayer might be written to a particular god...
and burned.
It was hoped that its smoke would convey the contents to
the underworld.
If we could only materialize and decipher the dreaming that
went on at the Temple of Dendera so long ago.
And what of your dream just last night?
The ancient Egyptians were mystified by the boundary that
separates our waking and sleeping life.
They believed that we were actually transported to
another physical realm, and that dreams had
a material reality.
How else to explain the stunning detail of a
particularly vivid dream?
More than 1,000 years after the last dreamers awakened at
Dendera, there was a scientist who believed that conscious
and unconscious thoughts do have a material reality,
that dreams were actually physical phenomena
that could be recorded.
And he found a way to do it.
In a place of broken minds and shattered dreams...
This is the Manicomio di Collegno,
in Turin, Italy.
Built as a monastery in the 17th century,
it had become a psychiatric hospital by 1850.
It was abandoned decades ago, but it still reverberates with
centuries of human suffering and loneliness.
It was here that Angelo Mosso came to perform
experiments on dreams and thoughts.
Mosso was a child of the working class who
boot-strapped himself into becoming a scientist.
His primary research had been in
pharmacology and physiology.
And it was all focused on making life better
for the working poor.
He viewed science as a means to improve labor conditions.
In a time when people were literally worked to death,
without recourse or legal protection,
Mosso designed and built an ergograph,
or "“fatigue recorder,"” so that he could demonstrate
experimentally what the relentless stress of hard
labor did to the human body and mind.
To Mosso, exhaustion was both a physical and emotional state,
not a sign of human weakness or a character flaw.
And it was your body's way of telling you to stop
what you were doing to avoid injury.
Mosso reasoned that fatigue had an evolutionary advantage,
much like fear.
[screams]
[goats bleeting]
To demonstrate this, Mosso began thinking about designing
an apparatus that could record the body's blood flow.
The table that Mosso's assistant floated on was
exquisitely balanced, and was all attached to a rotating
drum with a stylus that recorded the blood flow.
It was the beginning of medical imaging,
a tool that had never existed before.
But if the actions of the heart could be recorded,
what about the brain?
How could you transcribe the brain's delicate murmurings
when they were housed in a protective skull?
There was no way to do that without harming a patient...
Or was there?
When he was not even two years old,
Giovanni Thron fell from a great height.
His skull had been so badly shattered it was necessary to
remove some of the pieces.
As a result of the blow, he began to have frequent
and violent epileptic seizures.
Fearing that they might be contagious,
his parents abandoned him at the mental hospital
in Turin by the time he was five.
And there he languished for six years.
The catastrophic injury that had ruined Giovanni's life had
left a doorway to his brain.
Mosso designed and built the machine so sensitive it could
register the blood coursing through his brain.
But Giovanni was so agitated during his waking hours,
Mosso could only study him while he slept.
Mosso needed Giovanni to be perfectly still in
order to record the faint signature of his thoughts.
GHOST: When I saw Giovanni in February, 1877,
he had a large opening in the skull covered with skin.
The terrible fall had forever arrested
his intellectual development.
It was a saddening circumstance,
that in the midst of the ruin of his mind, one single,
higher idea had remained, a remnant of his earlier
intellectual life, a motto which he constantly repeated:
'I want to go to school.' It was one of the most
interesting sights to observe in the stillness of night,
what was going on in his brain,
when there was no external cause to disturb this
mysterious life of sleep.
The brain-pulse remained for 10 or 20 minutes quite regular
and very weak...
and then began suddenly, without any apparent cause to
swell and beat more vigorously.
The dreams, perhaps,
come to cheer the repose of the unhappy boy?
That the face of his mother and the recollections of his
early childhood glow bright in his memory?
Lighting up the darkness of his intelligence,
and make his brain pulsate with excitement?
Or was it an unconscious agitation of matter,
like the ebb and flow of an unknown and solitary sea?
TYSON: On that snowy night, Angelo Mosso gave the brain
its first pen to write with.
He had invented neuroimaging,
and showed that even in sleep,
the brain is pulsing, throbbing,
flashing with the complex business of life...
dreaming, remembering, figuring things out.
Our thoughts, visions, fantasies and our dreams,
do have a material reality.
Three months after the night of dreams,
Giovanni died of anemia.
He was not yet 12.
Angelo Mosso's breakthrough in pioneering the field of
neuroscience inspired another man to take Mosso's
work one giant step further.
He wanted to demonstrate that psychic powers are real.
It all happened because of a freak accident...
[gunshots]
Hans Berger dreamed of becoming an astronomer,
but it was too hard, and so in 1892,
he enlisted in the German army.
Berger was shaken by his brush with death,
but something happened that night that shocked
him even more...
A telegram had arrived from his father,
a cold and distant man who had never sent him
a telegram before.
Berger's older sister had become panic-stricken with the
certainty that something terrible had happened
to her little brother.
Was it possible, Berger wondered,
that in the moment that he realized he was going to die,
his brain had somehow telepathically delivered a
message to the person he was closest to, his sister?
Berger became a physician and a professor at
the University of Jena.
By day, he worked with his students and colleagues,
who found him to be awkwardly formal,
and scientifically unadventurous.
But by night, he went to a secret laboratory where he
conducted experiments on the brain's activity.
Berger believed that this was his best chance of proving
that psychic energy was real.
He feared that if anyone were to discover his real
scientific objective, he'd be laughed out of the profession.
He kept his secret for 20 years.
Berger's electroencephalograph made it
possible to interpret the signals that the brain sends,
and to diagnose many neurological diseases,
including epilepsy.
He never did find any evidence for psychic energy,
or telepathic communication.
Berger sunk into a deep depression,
and hanged himself in his secret laboratory in 1941.
The EEG is still in use today, although we now have far more
accurate ways of seeing and recording what the brain does,
and we even have the ability to decrypt the electrochemical
language of thought.
Exactly 100 years after Angelo Mosso first recorded
the electrical whispers of Giovanni's dreams,
the brain waves of a woman newly fallen in love,
were included in the Voyager Interstellar Message,
destined to sail the Milky Way
for a billion years or more.
From horse-drawn carriage to interstellar craft,
in just a 100 years.
From telegrams to sending our thoughts hand-delivered to one
another at the speed of light,
and our deepest feelings to a billion years from now.
How did we make that leap?
And why us?
Of all the billions of species that have ever lived on Earth,
why us and no other?
♪ ♪
TYSON: Primates who descended from the African savannah have
sent their robot emissaries to explore the red deserts of
Mars, and ring that world with satellites.
We've only been at this since the mid-20th century,
not even a lifetime, yet look at how far beyond
our little world our robots have ventured.
One of our craft, Voyager 1,
has broken free of the Sun,
and now sails the deep ocean of interstellar space.
And every one of those odysseys of
discovery began here.
It's easy to see why the seat of all these mythic
achievements would itself seem beyond our
ability to understand.
It's hard to believe that our minds are made of
the same matter as our stomachs and our feet.
Consciousness seems supernatural.
Identity, awe...
Skepticism, imagination, love.
How do you assemble transcendence from the
periodic table of the elements?
We are at the bottom of the sea,
off the coast of Chile and Peru.
This is perhaps the largest living organism on Earth.
It's a community of microbes that is the size of a country...
Greece.
But there's something even more amazing about it than its immensity.
The ancient ancestors of these colonies represent an early step in
the development of brains.
When the microbes living at the center of this vast mat get hungry,
they dispatch electrochemical messages to
their fellow citizens at the outer-edge.
These communiqués travel through passages called ion channels.
A message goes out on amber waves of potassium from
"“Sparta to Athens"” saying,
"“Hey, guys, stop hogging all the food!"”
And the residents of the mat's outer edge respond
by reducing their intake of nutrients.
It's possible that their ancient ancestors evolved
cells called neurons that specialized in
this kind of messaging.
Neurons are the basic unit of nervous systems in almost
every life form in the animal kingdom, including us.
And they vary very little in nature, if at all,
from species to species,
but vary dramatically in number.
In fact, we now think that epilepsy,
that so-called "“sacred disease,"”
is a misfiring in the brain of our own ion channels.
Think of it: A microbial mat and Isaac Newton,
separated by hundreds of millions of years of evolution,
but sharing the same basic currency of thought.
The messaging system pioneered by the microbes
some four billion years ago,
is still inside us.
No one looking at a microbial mat three billion years ago
could have predicted that the one-celled organisms
of life on Earth would evolve into you.
That's what happens when living things and environments
interact over the eons.
New forms and ways of being alive and aware
come into existence.
When the whole becomes greater than the sum of its parts,
it's called emergence.
See the thing that looks like a shred of a ruffle
from a gaudy dress?
You might think it's kind of silly.
But, you would be so wrong.
Long, long ago, some 600 million years ago,
life first evolved something new to planet Earth,
a command center that could perceive and react
to its environment...
a brain.
Now, life inched closer to the stars.
We think it first happened inside a flatworm...
this little guy's ancestor, the first animal hunter.
A brain was just what a hunter would need to
seek out and plan a strategy for attack.
Binocular vision allowed the flatworm to perceive the
dimension of depth more sharply and objects with greater clarity,
all the better to triangulate on prey.
The flatworm brain had a pair of dense nerve clusters called "ganglia."
Cords extended from them,
carrying instructions and sensations to the rest of its
body via some 8,000 neurons.
Not many compared with the life forms that would come later,
but a momentous beginning.
Flatworms have something called auricles on the sides
of their heads where their ears should be,
but they're actually noses.
We may not look much alike, but we have a lot in common.
We share the same chemicals that control our nervous systems,
called "“neurotransmitters."”
We get addicted to the same drugs.
Flatworms can learn.
They process information about their environment
and act accordingly.
We think they're nature's first animals to have a front,
a back and a head,
a blueprint that remains state of the art,
600 million years later.
And they were the true pioneers in the deepest sense
of that word.
Unlike any life form before them,
they developed the habit of venturing into the unknown
territory in search of what they craved.
Okay, flatworms are cool, but there's a big difference
between a flatworm brain and ours.
How did we get from there to here?
We don't yet know.
That's mainly because brains tend to be squishy.
They don't leave distinct imprints in the fossil record.
But the brain preserves its evolutionary past...
Why?
Because our brains are a little like New York City...
[honking and sirens]
TYSON: Most of the world's great cities have grown haphazardly,
little by little,
in response to the needs of the moment;
very rarely is a city planned for
the remote future.
In New York City,
many of the streets date all the way back
to the 17th century...
the stock exchange to the 18th...
the waterworks and the electrical power system
to the 19th century.
And the communications bandwidth to the 20th.
A city is like a brain: it develops from a small center
and slowly grows and changes,
leaving many old parts still functioning.
New York can't afford to suspend its water supply,
or its transportation system,
while they're being replaced by something more efficient.
Changes have to happen piecemeal.
And that's how it is for the brain.
There is no way for evolution to rip out the ancient
interior of the brain because of its imperfections and
replace it with something of more modern manufacture.
The brain and the city both must function continuously
during the renovation.
That's why our limbic system is surrounded by
the cerebral cortex.
The old part is in charge of too many vital mechanisms for
it to be replaced altogether.
So, it's sometimes counterproductive.
But that's a necessary consequence of evolution.
The city is a gift of the cerebral cortex.
But the brain's language is not encoded in the DNA of
genes because the vocabulary of life is too small.
Our brains need a language with 10,000 times
as many words.
The information content of the human brain expressed
in bits is probably comparable to the total number of connections
among the neurons...
about a thousand trillion bits.
If all the contents of your brain were transcribed into
written language, it would amount to vastly more books
than are contained in the largest libraries on earth.
The equivalent of more than four billion books
are inside your head.
The brain is a very big place in a very small space.
It's written in those neurons pioneered by
the undersea microbial mats.
These are tiny electrochemical switching elements,
typically a few hundredths of a millimeter across.
Each of us has 86 billion neurons,
comparable to the number of stars in the Milky Way galaxy.
The neurons and their parts, axons, dendrites,
synapses and the cell bodies themselves make up
a network in the brain.
Many neurons have thousands of connections
with their neighbors.
Dendrites, those pathways sent out by neurons to connect with other neurons,
extend these nerve cells to synapses until
they create a full-blown network of consciousness.
The neurochemistry of the brain is astonishingly busy,
the circuitry of a machine more wonderful than any
devised by humans.
Your brain functions are due to those 100 trillion
neural connections that make you, you.
Your deepest feelings of love and awe...
those moments when we glimpse the grandeur of nature,
and all the elegant architecture of consciousness...
are made possible by those connections.
This is the essence of emergence:
tiny units of matter operating collectively
to become something much more
than themselves,
to enable the cosmos to know itself.
But there's a vision of emergence that takes it even higher.
Can we know the universe?
And will it ever come to know us?
TYSON: Can we know the universe?
All those galaxies, solar systems, numberless worlds,
moons, comets, beings, and their dreams...
everything that ever was, is, or will be?
Can we know the universe?
I'm not sure we can even know a grain of salt.
Consider one microgram of table salt,
a speck just barely large enough for someone with keen
eyesight to see without a microscope.
In that grain of salt there are about 10 to the power 16
sodium and chlorine atoms.
What does that mean?
It means that there are 10 million billion atoms in this
and every other single grain of salt.
To know the grain of salt deeply,
requires us to know at least the three-dimensional
positions of each of these atoms.
In fact, there's much more to be known...
for example, the nature of the forces between the atoms.
But okay, let's try to keep it simple,
we'll leave that aside.
Is the number of all the positions more or less than
the number of things which the brain can know?
How much can the brain know?
If you do the calculation, with all the neurons and their
dendrites, axons, synapses...
we can know 100 trillion things.
But this is only 1% of the number of atoms in
our grain of salt.
So in this sense, the universe is unmanageable,
astonishingly immune to any human attempt
at full knowledge.
We cannot, at this level, fully know a grain of salt,
much less the universe.
But let's look a little more deeply at our
microgram of salt.
Salt happens to be a crystal in which,
except for defects in the structure of its lattice,
the position of every sodium and chlorine
atom is predetermined.
If we shrink ourselves into this crystalline world,
we would see rank upon rank of atoms in an ordered array,
a regularly alternating structure...
sodium, chlorine, sodium, chlorine...
specifying the sheet of atoms we are flying through,
and all the sheets above us and below us.
An absolutely pure grain of salt could have the position
of every atom specified by something like
ten bits of information.
This wouldn't strain our brain's carrying capacity.
We'd still have plenty of room for other stuff.
Now, imagine a universe with natural laws that govern its
behavior to the same degree of regularity that's true
for a grain of salt.
That universe would be knowable.
Even if it had many complicated laws,
we'd still have a shot at knowing that cosmos.
It wouldn't matter if the reality of that universe
exceeded the information-carrying capacity
of one of our brains.
We'd just go outside our bodies and build a computer to
store the surplus information.
And we'd still, in some sense,
know the universe.
Now, imagine a universe with no such laws,
one that behaves in a completely unpredictable fashion.
That universe would contain something like 10 to the 80th
elementary particles.
The inhabitants would find everyday experience a muddled
jumble of events with no predictability, no regularity.
And if they ever came to exist,
they would be in grave peril.
Lucky for us, we live in a universe with important parts
that are knowable.
The universe belongs to those who,
at least to some degree, have figured it out.
It's an astonishing fact that there are laws of nature,
rules that summarize...
not just qualitatively but quantitatively,
how the cosmos works.
But what about the cosmos inside each of us...
That unknown and solitary sea?
There are something like 100 trillion...
that is, one-hundred thousand billion connections
in your cerebral cortex.
That's 100 times as many connections inside you as all
the galaxies of the visible universe.
We're just at the beginning of a great
journey of exploration.
Just as biologists succeeded in mapping the human genome,
neuroscientists are attempting to map something
far more complex and unique to each and every one of us.
It's called our connectome.
If we could truly know another person's connectome,
the singular wiring diagram of all their memories,
thoughts, fears, dreams...
How would we treat each other?
Could we heal the brain of its countless torments,
and free all the Giovanni's of the world?
Could we send one of our connectomes on a future interstellar probe,
or ever hope to receive one from the
being of another world?
Would that be the ultimate realization of emergence...
a cosmos interconnected by thoughts and dreams?
Captioned by Cotter Captioning Services.