Cosmos: Possible Worlds (2014–…): Season 1, Episode 3 - When Knowledge Conquered Fear - full transcript
Neil deGrasse Tyson sets off on the Ship of the Imagination to chase a single comet through its million-year plunge toward Sol. Later, Tyson visits the birth-place of Sir Isaac Newton and ...
"When Knowledge Conquered Fear"
TYSON:
We were born into a mystery...
...one that has haunted us since
at least as long as we've been human.
We awakened on this tiny world
beneath a blanket of stars...
...like an abandoned baby
left on a doorstep...
...without a note to explain
where we came from, who we are...
...how our universe came to be...
...and with no idea
how to end our cosmic isolation.
We've had to figure it
all out for ourselves.
Best thing we had going for us
was our intelligence...
...especially our gift for
pattern recognition...
...sharpened over eons of evolution.
The ones who were good
at spotting prey and predator...
...telling poisonous plants
from the nourishing ones...
...had a better chance
to live and reproduce.
They survived and passed on those genes
for pattern recognition...
...with its obvious advantages.
Cultures all over the planet
looked up at the same stars...
...and found different pictures there.
We used this gift
for recognizing patterns in nature...
...to read the calendar in the sky.
The messages written in the stars
told our forefathers and mothers...
...when to camp and when to move on...
...when the migratory herds and when
the rains and the cold would come...
...and when they would cease for a time.
When they observed the connection
between the motions of the stars...
...and the seasonal cycles
of life on Earth...
...they concluded, naturally,
that what happens up there...
...must be directed at us down here.
It makes sense, right?
If the sky was a calendar and somebody
stuck a Post-it note on top of it...
...what else could it be but a message?
And so when the heavenly order
was suddenly violated...
...by the apparition of a comet in the sky,
they took it personally.
Can we really blame them?
Back then, they had no other logical
explanation for what was happening.
This was long before
anyone had yet to imagine Earth...
...as a spinning planet with a tilted axis,
revolving around the sun.
Every ancient human culture
made the same mistake:
The comet must be a message
sent by the gods, or one particular god.
And almost invariably our ancestors
concluded the news was not good.
It didn't matter if you were an ancient
Aztec, Anglo-Saxon, Babylonian, Hindu.
Comets were portents of doom.
The only difference among them was the
precise nature of the coming disaster.
"Disaster," as in the
Greek word for "bad star."
To the Masai of East Africa,
a comet meant famine.
To the Zulu in the south, it meant war.
To the Eghap people of the west,
it meant disease.
To the Djaga of Zaire,
specifically smallpox.
To their neighbors, the Lube,
a comet foretold the death of a leader.
The ancient Chinese
were remarkably systematic.
Starting in roughly 1400 BC...
...they began recording and cataloging
the apparitions of comets.
A three-tailed comet
meant calamity for the state.
A four-tailed comet
signified an epidemic was coming.
The human talent for pattern recognition
is a two-edged sword.
We're especially good at finding patterns
even when they aren't really there...
...something known as
"false pattern recognition."
We hunger for significance...
...for signs that our personal existence
is of special meaning to the universe.
To that end, we're all too eager
to deceive ourselves and others...
...to discern a sacred image
in a grilled cheese sandwich...
...or find a divine warning in a comet.
Today we know exactly
where comets come from...
...and what they're made of.
TYSON".
Our Ship of the Imagination...
...fueled by equal parts
of science and wonder...
...can take us anywhere in space and time.
It can travel faster than light...
...and render visible those things
that cannot be seen.
It's carrying us to a mysterious realm
that lies one light-year from the sun.
What is this swarm of worlds?
Was it organized by alien beings?
No, just gravity.
These are the snows of yesteryear.
Drifting mountains of ice and rock.
The preserved remnants
of the birth of the solar system.
It's called the Oort
cloud, after Jan Oort...
...the Dutch astronomer who
foretold its existence back in 1950.
He was trying to solve a paradox.
There's so many ways for comets to die.
Because they cross the orbits of planets,
comets frequently collide with them.
Comets are largely made of ice,
so every time they come near the sun...
...they lose a part of themselves
through evaporation.
And after several thousand trips,
their ice is all gone...
...and what remains of the comet
is now an asteroid.
Comets can be gravitationally
ejected from the solar system...
...and exiled into space.
And yet somehow the comets keep coming.
Oort and other astronomers wondered,
"Where do all the comets come from?"
Oort calculated the rate
at which new comets appear...
...and concluded that there must
be a vast spherical swarm of them...
...a few light-years across,
surrounding the sun.
Oort's logic still holds up...
...even after all the discoveries
we've made about comets...
...and the solar system
in the many decades since.
And yet the Oort cloud is a sight
that no one has ever seen.
Nor could we. It's dark out here.
And each comet is about as far
from its closest neighbor...
...as the Earth is from Saturn.
But science gives us
special powers of our own.
It gave Jan Oort the gift of prophecy.
Oort was also the first
to correctly estimate...
...the distance between the sun
and the center of our galaxy.
That's a big deal, finding out
where we are in the Milky Way.
Our star is about
30,000 light-years from the center.
Oort was also the first guy
to use a radio telescope...
...to map the galaxy's spiral structure.
And he discovered that the center of our
galaxy was a place of titanic explosions...
...the first indication
that there might have
been a supermassive black
hole lurking there.
Does the fact that most of us know
the names of mass murderers...
...but have never heard of Jan Oort,
say anything about us?
The Oort cloud is so enormous...
...that it takes one of its comets
about a million years...
...to complete a single
trip around the sun.
Out here at the far edge
of the solar system...
...even a little tug from
the gravity of a passing star...
...can liberate some of these comets from
their gravitational bondage to the sun.
Some comets are flung out of the solar
system to wander interstellar space.
But for others there's a different fate.
This one is plunging towards the sun,
gaining speed in an unbroken free fall...
...that lasts hundreds
of thousands of years.
When Neptune's gravity gives it another
tug, there's a small change in course.
Mighty Jupiter, the most massive object
in our solar system other than the sun...
...attracts the comet
with its powerful gravitational pull...
...bending its path.
When our comet reaches
the inner solar system...
...heat from the sun bakes it.
A beautiful transformation begins.
The barren, sooty iceberg
now sports a glowing halo...
...and a tail.
These layers tell the story
of how the comet was made...
...some 4 billion years ago.
During the 40,000
generations of humanity...
...there must have been roughly
100,000 apparitions of a bright comet.
For all that time, the best we could do
was look up in helpless wonder...
...prisoners of Earth with nowhere to turn
for an explanation...
...beyond our guilt and our fears.
But then a friendship began
between two men...
...that led to a permanent revolution
in human thought.
Isaac Newton and Edmond Halley
could not know it...
...but their collaboration
would ultimately set us free...
...from our long confinement
on this tiny world.
TYSON: The comet of 1664
sent shivers of dread throughout Europe.
And the terror seemed justified...
...when the plague and the Great
Fire of London followed soon after.
WOMAN:
There, with long bloody hair...
...a blazing star threatens the world...
...with famine, plague and war.
To princes, it spells death.
To kingdoms, many crosses.
To all estates, inevitable losses.
To herdsmen, rot.
To plowmen, hapless seasons.
To sailors, it brings storms.
To cities, civil treasons.
TYSON".
But for one child...
...the comet was not the
least bit frightening.
For him, it was a thing of wonder.
Like all of us,
Edmond Halley was born curious.
Hell's bells.
TYSON: He was lucky to have a father who
encouraged and nurtured his curiosity...
...buying him the best
scientific instruments,
and even funding
his expedition...
...to make the first accurate star map
of the Southern Hemisphere.
Halley dropped out of Oxford when he was 20
and sailed to St. Helena...
...an island below the equator,
off the west coast of Africa.
Hell's bells.
TYSON: Problem was, nobody told Halley
that the weather on St. Helena...
...was generally lousy.
It took him 12 frustrating months...
...to observe enough southern stars
to make a complete map.
The gods and heroes of ancient Greece...
...were now joined by the mythic figures
of a new world and age:
a toucan, a compass, a bird of paradise.
When Halley came home
with the other half of the sky...
...his map created a sensation.
Now merchants and explorers
could navigate by the stars...
...visible anywhere on Earth.
At the time,
the Royal Society of London...
...was the world's clearinghouse
of scientific discovery.
Its motto, "Nullius in verba,"
sums up the heart of the scientific method.
It's Latin for "see for yourself."
In other words, question authority.
Halley's star maps caught the attention
of the Society's curator of experiments.
I'd show him to you if I
could, but no portrait
of Robert Hooke exists
from his time...
...only the verbal descriptions
of his contemporaries.
They called him "lean, bent, ugly."
He was possibly the most
inventive person who ever lived.
And despite his appearance, he was the most
sought-after party guest in all of London.
Why? Hooke's insatiable curiosity
encompassed absolutely everything.
Hooke discovered a little cosmos...
...and we still call it
by the name he gave it: the cell.
Hooke discovered the
cell by looking at a
piece of cork with one
of his own inventions:
the compound microscope.
He anticipated aspects of Darwin's
theory of evolution by almost 200 years.
Hooke also improved the telescope.
The drawings he made of the
astronomical bodies he observed...
...attest to his uncanny precision.
After the Great Fire
destroyed central London in 1666...
...Hooke partnered with the architect
Christopher Wren...
...to redesign and rebuild the city.
Hooke was the foremost
experimentalist of his age.
Using coiled springs,
he derived the law of elasticity...
...known today as Hooke's law.
He perfected the air pump,
the height of technology in its time...
...and used it to experiment
on respiration and sound.
And he experimented with cannabis.
He reported to a meeting
of the Royal Society...
...that a sea captain friend of his, quote,
"had so often experimented with it...
...that there is no cause of fear,
though possibly there may be of laughter."
But coffee was the drug of choice
for England in the 17th century.
Coffeehouses sprang up
all over London.
[INAUDIBLE DIALOGUE]
This is where people came to get news...
...to launch new ventures,
and to debate ideas.
The coffeehouse was an oasis of equality
in a class-obsessed society.
Here a poor man needn't give up his seat
to a rich man, nor submit to his opinion.
It was a kind of laboratory of democracy.
In this highly caffeinated atmosphere...
...Halley and Hooke met Christopher Wren
to discuss a deep mystery:
Why do the planets move as they do?
The astronomer Johannes Kepler
had demonstrated some 80 years before...
...that the orbits of the planets
around the sun...
...were not perfect circles,
but actually ellipses...
...and that the closer a planet
was to the sun, the faster it moved.
Why? Could some invisible
force from the sun
be responsible for
this change in motion?
If so, how did it work?
Could there be a simple
mathematical law to describe it?
Maybe something like
Hooke's law of elasticity?
Perhaps.
But try as he might,
Christopher Wren couldn't figure it out.
Damned if I haven't tried. It's beyond me.
I'll wager a book worth 40 shillings
to the man who can solve it.
HOOKE: That book is mine, Mr. Wren.
I've already done the calculation.
TYSON".
Halley was delighted.
Show us, Mr. Hooke.
TYSON". But months passed,
and Hooke failed to deliver.
He couldn't do the math.
None of them could.
Finally Halley had enough
of Hooke's excuses.
Halley knew there must be someone,
somewhere, up to the challenge.
What about that mathematician
at Cambridge?
He was a clever fellow.
He had solved central questions
about the nature of light years before...
...when he was still only 22.
And he invented the reflecting telescope.
Odd bird.
Dropped out of sight a while back.
Some squabble over Hooke
and his discovery about light.
Went completely to pieces over it, has
been hiding out in Cambridge ever since.
Halley wondered if this strange and, by all
accounts, exceedingly difficult man...
...might succeed where Hooke
and others had failed.
What he couldn't know, what no one
could possibly imagine at the time...
...were the countless ways the world
would be forever changed by this meeting...
...on an August day in 1684.
TYSON: Isaac Newton was born in England
on Christmas Day in 1642.
[PANTING]
TYSON: Before he even opened his eyes,
his father was already dead.
His mother left him when he was only 3
and did not return until he was 11 .
[CHILDREN CHATTERING]
TYSON: When she did,
it was with a new family and husband...
...a stepfather who Isaac Newton despised.
Newton's refuge
from his miserable family life...
...was his passion
to understand how things worked...
...especially nature itself.
In 1661 the talented young Isaac entered
Trinity College at Cambridge University...
...where he was a consistently
lousy student...
...one without friends or a loving family
to provide any warmth or encouragement.
Newton mostly kept to himself,
sequestered in his room...
...studying ancient Greek philosophers,
geometry and languages...
...and pondering deep questions on the
nature of matter, space, time and motion.
This budding scientist
was also a passionate mystic.
Newton believed that a secret knowledge
called alchemy...
...known only to a small group
of ancient philosophers...
...was waiting to be rediscovered.
He hoped to learn how to change
ordinary metals into silver and gold...
...and maybe even cook up the elixir
of life, the key to immortality.
He was also obsessed with finding
hidden messages in the words of the Bible.
He combed through translations
in several different languages...
...hoping to decipher
coded instructions from God.
He made elaborate calculations in an effort
to discover the date of the Second Coming.
His lifelong research in alchemy
and biblical chronology never led anywhere.
When Halley found Newton that fateful day,
he was living as a virtual recluse.
Newton had gone into hiding
13 years earlier...
...after Robert Hooke had publicly
accused Newton...
...of stealing his groundbreaking work
on light and color.
In fact, it was Isaac Newton who solved
the mystery of the spectrum of light...
...not Robert Hooke.
The wound was painful and deep...
...and Newton resolved to never
expose himself...
...to that kind of public humiliation
ever again.
Sir, I don't suppose you recall
our meeting a few years ago?
Yes, Mr. Halley.
I'm sorry to bother you.
Never mind the formalities.
Get to your point.
I've been talking with our friends
Mr. Wren and Mr. Hooke.
That scoundrel Hooke's no friend of mine.
Yes, I understand, sir.
But the thing is, we've been debating
the puzzling question of planetary motion.
We all agree that some
force of attraction from
the sun governs the
motions of the planets.
We suspect there must be
a mathematical law...
...to describe how this force
changes with distance.
And knowing of your skill--
Yes, yes, the attraction of gravity
weakens with the square of the distance.
That's why the planets move in ellipses.
But, sir, how can you know this?
Why, I have calculated it
some five years ago.
I beg you, show it to me.
The calculation is here somewhere.
Well, no matter. I shall redo it
and be sure to send it on to you.
This is stupendous. Why have
we not had word of it before?
TYSON: Newton remembered all too well
what Hooke had done to him...
...the last time he put forth an idea.
Just when Halley
may have begun to wonder...
...if Newton was bluffing,
as Hooke had done earlier...
...a messenger arrived
with an envelope from Newton.
Here are the opening pages
of modern science...
...with its all-embracing
vision of nature...
...universal laws of motion, gravity...
...not just for the Earth
but for the cosmos.
Halley raced back to Cambridge.
Mr. Newton,
I beseech you to work all of this
into a book as soon as possible.
I can assure you
the Royal Society will publish it.
TYSON".
But there was one little problem.
We are in agreement that Mr. Newton
has produced a masterpiece.
However, I'm afraid
the Royal Society has...
Well, regrettably,
sales for the History of Fish...
...have not lived up
to our financial expectations.
TYSON".
It's an impressive book.
Extremely comprehensive, really.
It's filled with lavish illustrations
of, well, fish.
The disappointing sales
led to a bigger problem.
The Royal Society pretty
much blew its total
annual budget on the
History of Fish.
In fact, they were so strapped for cash...
...they had to pay poor Halley's salary
with copies of their worst-selling book.
With no money to print
Newton's Principia...
...the scientific revolution
hung in the balance.
Without Halley's heroic efforts...
...the reclusive Newton's masterwork
might never have seen the light of day.
But Halley was a man on a mission...
...absolutely determined to bring
Newton's genius to the world.
That pre-scientific world,
the world ruled by fear...
...was poised at the edge of a revolution.
Everything depended
on whether or not Edmond Halley...
...could get Newton's book
out to the wider world.
Halley resolved not only
to edit Newton's book...
...but to publish it at his own expense.
Newton completed the first two volumes...
...laying the mathematical framework
for the physics of motion.
The third volume would settle once and
for all who won the coffeehouse wager.
Newton applied his principles to explain
all the known motions of the Earth...
...the moon and the planets.
Unfortunately, there was this problem.
Now Halley also took on the role
of Newton's psychotherapist.
Isaac, I'm afraid that Mr. Hooke...
...requires an acknowledgment
in the preface of your third volume.
But I have done so,
thanking him, Mr. Wren and yourself...
...for prodding me to think again
on astronomical matters.
Mr. Hooke has been going
about London...
...saying that you got
the law of gravity from him.
Why, that litigious little...
Never. I would sooner burn the third volume
than deface it with such a lie.
To hell with Hooke.
He will be long forgotten when
your ideas are still being celebrated.
More copies of that dreadful book?
Wherever shall we put them all?
We talked about this, Mary, dear.
This is my salary from the Society.
They have nothing else
with which to pay me.
If only Mr. Hooke and Mr. Newton
were more like you.
TYSON". Halley and Wren decided
to confront Hooke about his false claims.
That law is mine, I tell you.
I proved it first.
Then fetch your
proof here at once.
Let us see it. Surely we have
waited on it long enough.
You'll simply have
to take my word for it.
Empty claims may persuade elsewhere,
but not here.
Put up or shut up, Mr. Hooke.
Blasted Newton.
I'll make him pay.
TYSON".
If it wasn't for Edmond Halley...
...Newton's great book would've never
been conceived, nor written, nor printed.
Okay, but so what?
What difference does that make to us?
What's the big deal?
When Isaac Newton was born in this house
in 1642, the world was very different.
Everyone looked at the
perfection of the
clockwork motions of the
planets in the sky...
...and could only understand it
as the work of a master clockmaker.
How else to explain it?
There was only one way such a thing
could come about in their imagination.
Only one answer for them: God.
For reasons beyond our understanding,
God just created the solar system that way.
But this explanation is
the closing of a door.
It doesn't lead to other questions.
Along came Newton, a God-loving man
who's also a genius.
He could write the laws of nature
in perfect mathematical sentences.
Formulas that applied universally
to apples, moons, planets and so much more.
With one foot still in the Middle Ages...
...Isaac Newton imagined
the whole solar system.
Newton's laws of gravity
and motion revealed
how the sun held distant
worlds captive.
His laws swept away the need
for a master clockmaker...
...to explain the precision
and beauty of the solar system.
Gravity is the clockmaker.
Matter obeyed commandments
we could discover...
...laws the Bible hadn't mentioned.
Newton's answer to why
the solar system is the way it is...
...opened the way
to an infinite number of questions.
Principia also happened to include
the invention of calculus...
...and the first sound theoretical basis
for an end to our imprisonment on Earth:
space travel.
Newton envisioned
the firing of a cannonball...
...with increasingly
greater explosive thrust.
He reasoned that with enough velocity...
...the bounds of gravity could be broken...
...and the cannonball could escape
to orbit the Earth.
This changed everything.
[MAN SPEAKS INDISTINCTLY OVER RADIO]
TYSON: Newton's Principia Mathematica
set us free in another way.
By finding the natural laws governing
the comings and goings of comets...
...he decoupled the
motions of the heavens...
...from their ancient connections
to our fears.
If Halley hadn't been standing
next to Newton for all those years...
...perhaps the world would remember him...
...for his own host of
accomplishments and discoveries.
But the only thing that comes to mind
for most people is the comet.
The irony is that discovering a comet...
...is actually one of the few things
that Halley never did.
Mountain of ice to starboard.
Come about.
Come about!
MAN:
Aye, aye, Captain Halley!
TYSON:
After the publication of the Principia...
...Halley was commanded by his king
to lead three ocean voyages...
...scientific expeditions to solve
navigational problems for the British navy.
Halley used this opportunity to make the
first map of the Earth's magnetic field.
[THUNDER RUMBLING]
TYSON:
And he was also a businessman.
Halley perfected the diving bell...
...and used his invention to start
a flourishing commercial salvage operation.
Hmm. Our Dr. Halley's gone
and done it this time.
I reckon he's been down there
at least three hours.
TYSON: Not one to risk the lives of others,
Halley personally tested his own invention.
I make it exactly four hours
since our descent.
Not at all bad for 10 fathoms.
TYSON".
He invented the weather map.
And the symbols he devised for indicating
prevailing winds are still in use today.
Halley laid the groundwork
for the science of population statistics.
How?
He compared the birth, marriage, death and
population densities of London and Paris.
He actually had to pace off
the entire perimeter of Paris on foot...
...to learn its true dimensions.
He came to the conclusion
that since roughly half of all adults...
...fail to reproduce children,
who themselves survive to reproduce...
...every married
couple must have four
children in order to
maintain the population.
And it was Edmond Halley who gave us
the actual scale of the solar system.
He figured out a clever way
to find the distance from Earth to the sun.
It involved precisely
measuring the time it took
for the planet Venus to
cross the sun's disc.
Twenty-seven years after Halley's death...
...Captain James Cook
made his first voyage to Tahiti...
...for the express purpose of testing
Halley's method...
...during a transit of
Venus across the sun.
Using a special filter
to protect his vision...
...from being destroyed
by looking directly at the sun...
...Cook and his men made it possible
for us to know...
...that the sun is 93
million miles from Earth.
And Halley was the first
to realize that the
so-called fixed stars
were not fixed at all.
How'd he do it?
He pored over the observations...
...made by the ancient Greek astronomers
of the brightest stars.
And he compared
their observations...
...with the ones he himself made
of the same stars 1800 years later.
Why hadn't anyone
noticed this before?
Halley figured out that it would
only become apparent...
...if you waited long enough
between observations.
It's hard to perceive the motions
of things that are far away.
And the stars are so
very far away that you
would need to track them
for many centuries...
...before you could detect
that they moved at all.
TYSON: Halley discovered the first clue
to a magnificent reality:
All the stars are in motion,
streaming past each other...
...rising and falling
like merry-go-round horses...
...in their Newtonian dance
around the center of our galaxy.
And, oh, yes, there was that thing
about the comet.
What were those strange
and beautiful celestial visitors...
...that appeared without warning
from time to time?
Halley set out to solve this mystery
as a detective would...
...by gathering
all credible eyewitness testimony.
The earliest precise observations
of a comet that Halley could find...
...were made in Constantinople
by Nicephorus Gregoras...
...a Byzantine astronomer and monk,
in June 1337.
Halley hunted down every
astronomical observation of a comet...
...recorded in Europe
between 1472 and 1698.
And remember, there was no such thing
as a search engine or a computer.
All Halley had were his books and his mind.
Now here comes the hard part:
Halley had to take the observations
made for each comet...
...and find the shape
of its actual path through space.
No one else but Newton
had yet attempted...
...to apply his new set of laws
to an astronomical question.
In an arduous tour de force
of mathematical brilliance...
...Halley discovered that comets were bound
to the sun in long elliptical orbits.
And he was the first to know
that the comets seen in 1531
...1607, and 1682...
...were one and the same.
A single comet that
returned every 76 years.
In a stunning example
of true pattern recognition...
...he predicted it would be seen again
more than 5O years in the future.
For millennia,
comets had been props for mystics...
...who considered them to be
merely omens of human events.
Halley shattered their monopoly,
beating them at their own game.
A game that no scientist
had ever played before:
prophecy .
And he did not hedge his bet.
Like Babe Ruth predicting where his next
home run would land in the stands...
...Halley stated flatly that the comet
would return at the end of 1758...
...from a particular part of the sky,
following a specific path.
There is hardly a prophecy
attempted by the mystics...
...that ever even strives
for comparable precision.
That's Halley's Comet.
Out here at the edge of the solar system,
it doesn't look like much.
Just a big hunk of ice and rock in space.
That's because beyond the orbit of Neptune,
nearly 5 billion kilometers from the sun...
...comets lead very quiet lives.
As it reaches the far end of its orbit...
...it'll slow down
till the sun allows it to go no farther.
Then it'll begin its long fall
back to the inner solar system.
Halley's Comet is in free fall
around the sun.
Everything in our solar system...
...the Earth, the moon,
the other planets, comets, asteroids...
...all of them are falling around the sun.
Gravity pulls the planets towards the sun,
but because of their orbital momentum...
...they keep moving around the sun,
never falling into it.
Robert Hooke had died years before, having
ruined his health with some bad habits:
daily doses of wormwood, opium, mercury.
A few months later,
Newton was elected to
replace him as president
of the Royal Society.
It is said that a portrait of Hooke
once hung on these walls.
Halley lived on to accomplish
many more astonishing feats.
He worked right up to his death at age 85.
His final act was to call
for a glass of wine.
He downed it with pleasure
and breathed his last breath.
[GLASS SHATTERS]
TYSON: Some believe that it
was on a night like this...
...that Isaac Newton finally took
his revenge against Robert Hooke.
Heh.
TYSON".
But Halley's prophecy was not forgotten.
Fifty years later, as the time
of the predicted return approached...
...the world's astronomers vied to be
the first to catch sight of his comet.
They weren't disappointed.
It's been welcomed back
every 76 years since.
When Halley's Comet
returns to our skies,
sunlight will warm up the
ice on its surface...
...once again setting loose
the dust and gases trapped within.
Halley's Comet most recently
visited our neighborhood back in 1986.
And if you're seeing this in 2061,
then you'll know it's back.
May you feel the wonder of all those
who came before you...
...and none of the fear.
Newton's laws made it possible
for Edmond Halley...
...to see some 50 years into the future
and predict the behavior of a single comet.
Scientists have been using
these laws ever since...
...opening the way to the moon,
and even beyond our solar system.
The baby in the basket
is learning to walk...
...and to know the cosmos.
Which brings me to one last prophecy.
Using nothing more
than Newton's laws of gravitation...
...we astronomers can confidently predict
that several billion years from now...
...our home galaxy, the Milky Way...
...will merge with our neighboring
galaxy Andromeda.
Because the distances between the stars
are so great compared to their sizes...
...few if any stars
in either galaxy will actually collide.
Any life on the worlds
of that far-off future should be safe...
...but they would be treated to an amazing,
billion-year-long light show...
...a dance of a half a trillion stars...
...to music first heard
on one little world...
...by a man who had but one true friend.
TYSON:
We were born into a mystery...
...one that has haunted us since
at least as long as we've been human.
We awakened on this tiny world
beneath a blanket of stars...
...like an abandoned baby
left on a doorstep...
...without a note to explain
where we came from, who we are...
...how our universe came to be...
...and with no idea
how to end our cosmic isolation.
We've had to figure it
all out for ourselves.
Best thing we had going for us
was our intelligence...
...especially our gift for
pattern recognition...
...sharpened over eons of evolution.
The ones who were good
at spotting prey and predator...
...telling poisonous plants
from the nourishing ones...
...had a better chance
to live and reproduce.
They survived and passed on those genes
for pattern recognition...
...with its obvious advantages.
Cultures all over the planet
looked up at the same stars...
...and found different pictures there.
We used this gift
for recognizing patterns in nature...
...to read the calendar in the sky.
The messages written in the stars
told our forefathers and mothers...
...when to camp and when to move on...
...when the migratory herds and when
the rains and the cold would come...
...and when they would cease for a time.
When they observed the connection
between the motions of the stars...
...and the seasonal cycles
of life on Earth...
...they concluded, naturally,
that what happens up there...
...must be directed at us down here.
It makes sense, right?
If the sky was a calendar and somebody
stuck a Post-it note on top of it...
...what else could it be but a message?
And so when the heavenly order
was suddenly violated...
...by the apparition of a comet in the sky,
they took it personally.
Can we really blame them?
Back then, they had no other logical
explanation for what was happening.
This was long before
anyone had yet to imagine Earth...
...as a spinning planet with a tilted axis,
revolving around the sun.
Every ancient human culture
made the same mistake:
The comet must be a message
sent by the gods, or one particular god.
And almost invariably our ancestors
concluded the news was not good.
It didn't matter if you were an ancient
Aztec, Anglo-Saxon, Babylonian, Hindu.
Comets were portents of doom.
The only difference among them was the
precise nature of the coming disaster.
"Disaster," as in the
Greek word for "bad star."
To the Masai of East Africa,
a comet meant famine.
To the Zulu in the south, it meant war.
To the Eghap people of the west,
it meant disease.
To the Djaga of Zaire,
specifically smallpox.
To their neighbors, the Lube,
a comet foretold the death of a leader.
The ancient Chinese
were remarkably systematic.
Starting in roughly 1400 BC...
...they began recording and cataloging
the apparitions of comets.
A three-tailed comet
meant calamity for the state.
A four-tailed comet
signified an epidemic was coming.
The human talent for pattern recognition
is a two-edged sword.
We're especially good at finding patterns
even when they aren't really there...
...something known as
"false pattern recognition."
We hunger for significance...
...for signs that our personal existence
is of special meaning to the universe.
To that end, we're all too eager
to deceive ourselves and others...
...to discern a sacred image
in a grilled cheese sandwich...
...or find a divine warning in a comet.
Today we know exactly
where comets come from...
...and what they're made of.
TYSON".
Our Ship of the Imagination...
...fueled by equal parts
of science and wonder...
...can take us anywhere in space and time.
It can travel faster than light...
...and render visible those things
that cannot be seen.
It's carrying us to a mysterious realm
that lies one light-year from the sun.
What is this swarm of worlds?
Was it organized by alien beings?
No, just gravity.
These are the snows of yesteryear.
Drifting mountains of ice and rock.
The preserved remnants
of the birth of the solar system.
It's called the Oort
cloud, after Jan Oort...
...the Dutch astronomer who
foretold its existence back in 1950.
He was trying to solve a paradox.
There's so many ways for comets to die.
Because they cross the orbits of planets,
comets frequently collide with them.
Comets are largely made of ice,
so every time they come near the sun...
...they lose a part of themselves
through evaporation.
And after several thousand trips,
their ice is all gone...
...and what remains of the comet
is now an asteroid.
Comets can be gravitationally
ejected from the solar system...
...and exiled into space.
And yet somehow the comets keep coming.
Oort and other astronomers wondered,
"Where do all the comets come from?"
Oort calculated the rate
at which new comets appear...
...and concluded that there must
be a vast spherical swarm of them...
...a few light-years across,
surrounding the sun.
Oort's logic still holds up...
...even after all the discoveries
we've made about comets...
...and the solar system
in the many decades since.
And yet the Oort cloud is a sight
that no one has ever seen.
Nor could we. It's dark out here.
And each comet is about as far
from its closest neighbor...
...as the Earth is from Saturn.
But science gives us
special powers of our own.
It gave Jan Oort the gift of prophecy.
Oort was also the first
to correctly estimate...
...the distance between the sun
and the center of our galaxy.
That's a big deal, finding out
where we are in the Milky Way.
Our star is about
30,000 light-years from the center.
Oort was also the first guy
to use a radio telescope...
...to map the galaxy's spiral structure.
And he discovered that the center of our
galaxy was a place of titanic explosions...
...the first indication
that there might have
been a supermassive black
hole lurking there.
Does the fact that most of us know
the names of mass murderers...
...but have never heard of Jan Oort,
say anything about us?
The Oort cloud is so enormous...
...that it takes one of its comets
about a million years...
...to complete a single
trip around the sun.
Out here at the far edge
of the solar system...
...even a little tug from
the gravity of a passing star...
...can liberate some of these comets from
their gravitational bondage to the sun.
Some comets are flung out of the solar
system to wander interstellar space.
But for others there's a different fate.
This one is plunging towards the sun,
gaining speed in an unbroken free fall...
...that lasts hundreds
of thousands of years.
When Neptune's gravity gives it another
tug, there's a small change in course.
Mighty Jupiter, the most massive object
in our solar system other than the sun...
...attracts the comet
with its powerful gravitational pull...
...bending its path.
When our comet reaches
the inner solar system...
...heat from the sun bakes it.
A beautiful transformation begins.
The barren, sooty iceberg
now sports a glowing halo...
...and a tail.
These layers tell the story
of how the comet was made...
...some 4 billion years ago.
During the 40,000
generations of humanity...
...there must have been roughly
100,000 apparitions of a bright comet.
For all that time, the best we could do
was look up in helpless wonder...
...prisoners of Earth with nowhere to turn
for an explanation...
...beyond our guilt and our fears.
But then a friendship began
between two men...
...that led to a permanent revolution
in human thought.
Isaac Newton and Edmond Halley
could not know it...
...but their collaboration
would ultimately set us free...
...from our long confinement
on this tiny world.
TYSON: The comet of 1664
sent shivers of dread throughout Europe.
And the terror seemed justified...
...when the plague and the Great
Fire of London followed soon after.
WOMAN:
There, with long bloody hair...
...a blazing star threatens the world...
...with famine, plague and war.
To princes, it spells death.
To kingdoms, many crosses.
To all estates, inevitable losses.
To herdsmen, rot.
To plowmen, hapless seasons.
To sailors, it brings storms.
To cities, civil treasons.
TYSON".
But for one child...
...the comet was not the
least bit frightening.
For him, it was a thing of wonder.
Like all of us,
Edmond Halley was born curious.
Hell's bells.
TYSON: He was lucky to have a father who
encouraged and nurtured his curiosity...
...buying him the best
scientific instruments,
and even funding
his expedition...
...to make the first accurate star map
of the Southern Hemisphere.
Halley dropped out of Oxford when he was 20
and sailed to St. Helena...
...an island below the equator,
off the west coast of Africa.
Hell's bells.
TYSON: Problem was, nobody told Halley
that the weather on St. Helena...
...was generally lousy.
It took him 12 frustrating months...
...to observe enough southern stars
to make a complete map.
The gods and heroes of ancient Greece...
...were now joined by the mythic figures
of a new world and age:
a toucan, a compass, a bird of paradise.
When Halley came home
with the other half of the sky...
...his map created a sensation.
Now merchants and explorers
could navigate by the stars...
...visible anywhere on Earth.
At the time,
the Royal Society of London...
...was the world's clearinghouse
of scientific discovery.
Its motto, "Nullius in verba,"
sums up the heart of the scientific method.
It's Latin for "see for yourself."
In other words, question authority.
Halley's star maps caught the attention
of the Society's curator of experiments.
I'd show him to you if I
could, but no portrait
of Robert Hooke exists
from his time...
...only the verbal descriptions
of his contemporaries.
They called him "lean, bent, ugly."
He was possibly the most
inventive person who ever lived.
And despite his appearance, he was the most
sought-after party guest in all of London.
Why? Hooke's insatiable curiosity
encompassed absolutely everything.
Hooke discovered a little cosmos...
...and we still call it
by the name he gave it: the cell.
Hooke discovered the
cell by looking at a
piece of cork with one
of his own inventions:
the compound microscope.
He anticipated aspects of Darwin's
theory of evolution by almost 200 years.
Hooke also improved the telescope.
The drawings he made of the
astronomical bodies he observed...
...attest to his uncanny precision.
After the Great Fire
destroyed central London in 1666...
...Hooke partnered with the architect
Christopher Wren...
...to redesign and rebuild the city.
Hooke was the foremost
experimentalist of his age.
Using coiled springs,
he derived the law of elasticity...
...known today as Hooke's law.
He perfected the air pump,
the height of technology in its time...
...and used it to experiment
on respiration and sound.
And he experimented with cannabis.
He reported to a meeting
of the Royal Society...
...that a sea captain friend of his, quote,
"had so often experimented with it...
...that there is no cause of fear,
though possibly there may be of laughter."
But coffee was the drug of choice
for England in the 17th century.
Coffeehouses sprang up
all over London.
[INAUDIBLE DIALOGUE]
This is where people came to get news...
...to launch new ventures,
and to debate ideas.
The coffeehouse was an oasis of equality
in a class-obsessed society.
Here a poor man needn't give up his seat
to a rich man, nor submit to his opinion.
It was a kind of laboratory of democracy.
In this highly caffeinated atmosphere...
...Halley and Hooke met Christopher Wren
to discuss a deep mystery:
Why do the planets move as they do?
The astronomer Johannes Kepler
had demonstrated some 80 years before...
...that the orbits of the planets
around the sun...
...were not perfect circles,
but actually ellipses...
...and that the closer a planet
was to the sun, the faster it moved.
Why? Could some invisible
force from the sun
be responsible for
this change in motion?
If so, how did it work?
Could there be a simple
mathematical law to describe it?
Maybe something like
Hooke's law of elasticity?
Perhaps.
But try as he might,
Christopher Wren couldn't figure it out.
Damned if I haven't tried. It's beyond me.
I'll wager a book worth 40 shillings
to the man who can solve it.
HOOKE: That book is mine, Mr. Wren.
I've already done the calculation.
TYSON".
Halley was delighted.
Show us, Mr. Hooke.
TYSON". But months passed,
and Hooke failed to deliver.
He couldn't do the math.
None of them could.
Finally Halley had enough
of Hooke's excuses.
Halley knew there must be someone,
somewhere, up to the challenge.
What about that mathematician
at Cambridge?
He was a clever fellow.
He had solved central questions
about the nature of light years before...
...when he was still only 22.
And he invented the reflecting telescope.
Odd bird.
Dropped out of sight a while back.
Some squabble over Hooke
and his discovery about light.
Went completely to pieces over it, has
been hiding out in Cambridge ever since.
Halley wondered if this strange and, by all
accounts, exceedingly difficult man...
...might succeed where Hooke
and others had failed.
What he couldn't know, what no one
could possibly imagine at the time...
...were the countless ways the world
would be forever changed by this meeting...
...on an August day in 1684.
TYSON: Isaac Newton was born in England
on Christmas Day in 1642.
[PANTING]
TYSON: Before he even opened his eyes,
his father was already dead.
His mother left him when he was only 3
and did not return until he was 11 .
[CHILDREN CHATTERING]
TYSON: When she did,
it was with a new family and husband...
...a stepfather who Isaac Newton despised.
Newton's refuge
from his miserable family life...
...was his passion
to understand how things worked...
...especially nature itself.
In 1661 the talented young Isaac entered
Trinity College at Cambridge University...
...where he was a consistently
lousy student...
...one without friends or a loving family
to provide any warmth or encouragement.
Newton mostly kept to himself,
sequestered in his room...
...studying ancient Greek philosophers,
geometry and languages...
...and pondering deep questions on the
nature of matter, space, time and motion.
This budding scientist
was also a passionate mystic.
Newton believed that a secret knowledge
called alchemy...
...known only to a small group
of ancient philosophers...
...was waiting to be rediscovered.
He hoped to learn how to change
ordinary metals into silver and gold...
...and maybe even cook up the elixir
of life, the key to immortality.
He was also obsessed with finding
hidden messages in the words of the Bible.
He combed through translations
in several different languages...
...hoping to decipher
coded instructions from God.
He made elaborate calculations in an effort
to discover the date of the Second Coming.
His lifelong research in alchemy
and biblical chronology never led anywhere.
When Halley found Newton that fateful day,
he was living as a virtual recluse.
Newton had gone into hiding
13 years earlier...
...after Robert Hooke had publicly
accused Newton...
...of stealing his groundbreaking work
on light and color.
In fact, it was Isaac Newton who solved
the mystery of the spectrum of light...
...not Robert Hooke.
The wound was painful and deep...
...and Newton resolved to never
expose himself...
...to that kind of public humiliation
ever again.
Sir, I don't suppose you recall
our meeting a few years ago?
Yes, Mr. Halley.
I'm sorry to bother you.
Never mind the formalities.
Get to your point.
I've been talking with our friends
Mr. Wren and Mr. Hooke.
That scoundrel Hooke's no friend of mine.
Yes, I understand, sir.
But the thing is, we've been debating
the puzzling question of planetary motion.
We all agree that some
force of attraction from
the sun governs the
motions of the planets.
We suspect there must be
a mathematical law...
...to describe how this force
changes with distance.
And knowing of your skill--
Yes, yes, the attraction of gravity
weakens with the square of the distance.
That's why the planets move in ellipses.
But, sir, how can you know this?
Why, I have calculated it
some five years ago.
I beg you, show it to me.
The calculation is here somewhere.
Well, no matter. I shall redo it
and be sure to send it on to you.
This is stupendous. Why have
we not had word of it before?
TYSON: Newton remembered all too well
what Hooke had done to him...
...the last time he put forth an idea.
Just when Halley
may have begun to wonder...
...if Newton was bluffing,
as Hooke had done earlier...
...a messenger arrived
with an envelope from Newton.
Here are the opening pages
of modern science...
...with its all-embracing
vision of nature...
...universal laws of motion, gravity...
...not just for the Earth
but for the cosmos.
Halley raced back to Cambridge.
Mr. Newton,
I beseech you to work all of this
into a book as soon as possible.
I can assure you
the Royal Society will publish it.
TYSON".
But there was one little problem.
We are in agreement that Mr. Newton
has produced a masterpiece.
However, I'm afraid
the Royal Society has...
Well, regrettably,
sales for the History of Fish...
...have not lived up
to our financial expectations.
TYSON".
It's an impressive book.
Extremely comprehensive, really.
It's filled with lavish illustrations
of, well, fish.
The disappointing sales
led to a bigger problem.
The Royal Society pretty
much blew its total
annual budget on the
History of Fish.
In fact, they were so strapped for cash...
...they had to pay poor Halley's salary
with copies of their worst-selling book.
With no money to print
Newton's Principia...
...the scientific revolution
hung in the balance.
Without Halley's heroic efforts...
...the reclusive Newton's masterwork
might never have seen the light of day.
But Halley was a man on a mission...
...absolutely determined to bring
Newton's genius to the world.
That pre-scientific world,
the world ruled by fear...
...was poised at the edge of a revolution.
Everything depended
on whether or not Edmond Halley...
...could get Newton's book
out to the wider world.
Halley resolved not only
to edit Newton's book...
...but to publish it at his own expense.
Newton completed the first two volumes...
...laying the mathematical framework
for the physics of motion.
The third volume would settle once and
for all who won the coffeehouse wager.
Newton applied his principles to explain
all the known motions of the Earth...
...the moon and the planets.
Unfortunately, there was this problem.
Now Halley also took on the role
of Newton's psychotherapist.
Isaac, I'm afraid that Mr. Hooke...
...requires an acknowledgment
in the preface of your third volume.
But I have done so,
thanking him, Mr. Wren and yourself...
...for prodding me to think again
on astronomical matters.
Mr. Hooke has been going
about London...
...saying that you got
the law of gravity from him.
Why, that litigious little...
Never. I would sooner burn the third volume
than deface it with such a lie.
To hell with Hooke.
He will be long forgotten when
your ideas are still being celebrated.
More copies of that dreadful book?
Wherever shall we put them all?
We talked about this, Mary, dear.
This is my salary from the Society.
They have nothing else
with which to pay me.
If only Mr. Hooke and Mr. Newton
were more like you.
TYSON". Halley and Wren decided
to confront Hooke about his false claims.
That law is mine, I tell you.
I proved it first.
Then fetch your
proof here at once.
Let us see it. Surely we have
waited on it long enough.
You'll simply have
to take my word for it.
Empty claims may persuade elsewhere,
but not here.
Put up or shut up, Mr. Hooke.
Blasted Newton.
I'll make him pay.
TYSON".
If it wasn't for Edmond Halley...
...Newton's great book would've never
been conceived, nor written, nor printed.
Okay, but so what?
What difference does that make to us?
What's the big deal?
When Isaac Newton was born in this house
in 1642, the world was very different.
Everyone looked at the
perfection of the
clockwork motions of the
planets in the sky...
...and could only understand it
as the work of a master clockmaker.
How else to explain it?
There was only one way such a thing
could come about in their imagination.
Only one answer for them: God.
For reasons beyond our understanding,
God just created the solar system that way.
But this explanation is
the closing of a door.
It doesn't lead to other questions.
Along came Newton, a God-loving man
who's also a genius.
He could write the laws of nature
in perfect mathematical sentences.
Formulas that applied universally
to apples, moons, planets and so much more.
With one foot still in the Middle Ages...
...Isaac Newton imagined
the whole solar system.
Newton's laws of gravity
and motion revealed
how the sun held distant
worlds captive.
His laws swept away the need
for a master clockmaker...
...to explain the precision
and beauty of the solar system.
Gravity is the clockmaker.
Matter obeyed commandments
we could discover...
...laws the Bible hadn't mentioned.
Newton's answer to why
the solar system is the way it is...
...opened the way
to an infinite number of questions.
Principia also happened to include
the invention of calculus...
...and the first sound theoretical basis
for an end to our imprisonment on Earth:
space travel.
Newton envisioned
the firing of a cannonball...
...with increasingly
greater explosive thrust.
He reasoned that with enough velocity...
...the bounds of gravity could be broken...
...and the cannonball could escape
to orbit the Earth.
This changed everything.
[MAN SPEAKS INDISTINCTLY OVER RADIO]
TYSON: Newton's Principia Mathematica
set us free in another way.
By finding the natural laws governing
the comings and goings of comets...
...he decoupled the
motions of the heavens...
...from their ancient connections
to our fears.
If Halley hadn't been standing
next to Newton for all those years...
...perhaps the world would remember him...
...for his own host of
accomplishments and discoveries.
But the only thing that comes to mind
for most people is the comet.
The irony is that discovering a comet...
...is actually one of the few things
that Halley never did.
Mountain of ice to starboard.
Come about.
Come about!
MAN:
Aye, aye, Captain Halley!
TYSON:
After the publication of the Principia...
...Halley was commanded by his king
to lead three ocean voyages...
...scientific expeditions to solve
navigational problems for the British navy.
Halley used this opportunity to make the
first map of the Earth's magnetic field.
[THUNDER RUMBLING]
TYSON:
And he was also a businessman.
Halley perfected the diving bell...
...and used his invention to start
a flourishing commercial salvage operation.
Hmm. Our Dr. Halley's gone
and done it this time.
I reckon he's been down there
at least three hours.
TYSON: Not one to risk the lives of others,
Halley personally tested his own invention.
I make it exactly four hours
since our descent.
Not at all bad for 10 fathoms.
TYSON".
He invented the weather map.
And the symbols he devised for indicating
prevailing winds are still in use today.
Halley laid the groundwork
for the science of population statistics.
How?
He compared the birth, marriage, death and
population densities of London and Paris.
He actually had to pace off
the entire perimeter of Paris on foot...
...to learn its true dimensions.
He came to the conclusion
that since roughly half of all adults...
...fail to reproduce children,
who themselves survive to reproduce...
...every married
couple must have four
children in order to
maintain the population.
And it was Edmond Halley who gave us
the actual scale of the solar system.
He figured out a clever way
to find the distance from Earth to the sun.
It involved precisely
measuring the time it took
for the planet Venus to
cross the sun's disc.
Twenty-seven years after Halley's death...
...Captain James Cook
made his first voyage to Tahiti...
...for the express purpose of testing
Halley's method...
...during a transit of
Venus across the sun.
Using a special filter
to protect his vision...
...from being destroyed
by looking directly at the sun...
...Cook and his men made it possible
for us to know...
...that the sun is 93
million miles from Earth.
And Halley was the first
to realize that the
so-called fixed stars
were not fixed at all.
How'd he do it?
He pored over the observations...
...made by the ancient Greek astronomers
of the brightest stars.
And he compared
their observations...
...with the ones he himself made
of the same stars 1800 years later.
Why hadn't anyone
noticed this before?
Halley figured out that it would
only become apparent...
...if you waited long enough
between observations.
It's hard to perceive the motions
of things that are far away.
And the stars are so
very far away that you
would need to track them
for many centuries...
...before you could detect
that they moved at all.
TYSON: Halley discovered the first clue
to a magnificent reality:
All the stars are in motion,
streaming past each other...
...rising and falling
like merry-go-round horses...
...in their Newtonian dance
around the center of our galaxy.
And, oh, yes, there was that thing
about the comet.
What were those strange
and beautiful celestial visitors...
...that appeared without warning
from time to time?
Halley set out to solve this mystery
as a detective would...
...by gathering
all credible eyewitness testimony.
The earliest precise observations
of a comet that Halley could find...
...were made in Constantinople
by Nicephorus Gregoras...
...a Byzantine astronomer and monk,
in June 1337.
Halley hunted down every
astronomical observation of a comet...
...recorded in Europe
between 1472 and 1698.
And remember, there was no such thing
as a search engine or a computer.
All Halley had were his books and his mind.
Now here comes the hard part:
Halley had to take the observations
made for each comet...
...and find the shape
of its actual path through space.
No one else but Newton
had yet attempted...
...to apply his new set of laws
to an astronomical question.
In an arduous tour de force
of mathematical brilliance...
...Halley discovered that comets were bound
to the sun in long elliptical orbits.
And he was the first to know
that the comets seen in 1531
...1607, and 1682...
...were one and the same.
A single comet that
returned every 76 years.
In a stunning example
of true pattern recognition...
...he predicted it would be seen again
more than 5O years in the future.
For millennia,
comets had been props for mystics...
...who considered them to be
merely omens of human events.
Halley shattered their monopoly,
beating them at their own game.
A game that no scientist
had ever played before:
prophecy .
And he did not hedge his bet.
Like Babe Ruth predicting where his next
home run would land in the stands...
...Halley stated flatly that the comet
would return at the end of 1758...
...from a particular part of the sky,
following a specific path.
There is hardly a prophecy
attempted by the mystics...
...that ever even strives
for comparable precision.
That's Halley's Comet.
Out here at the edge of the solar system,
it doesn't look like much.
Just a big hunk of ice and rock in space.
That's because beyond the orbit of Neptune,
nearly 5 billion kilometers from the sun...
...comets lead very quiet lives.
As it reaches the far end of its orbit...
...it'll slow down
till the sun allows it to go no farther.
Then it'll begin its long fall
back to the inner solar system.
Halley's Comet is in free fall
around the sun.
Everything in our solar system...
...the Earth, the moon,
the other planets, comets, asteroids...
...all of them are falling around the sun.
Gravity pulls the planets towards the sun,
but because of their orbital momentum...
...they keep moving around the sun,
never falling into it.
Robert Hooke had died years before, having
ruined his health with some bad habits:
daily doses of wormwood, opium, mercury.
A few months later,
Newton was elected to
replace him as president
of the Royal Society.
It is said that a portrait of Hooke
once hung on these walls.
Halley lived on to accomplish
many more astonishing feats.
He worked right up to his death at age 85.
His final act was to call
for a glass of wine.
He downed it with pleasure
and breathed his last breath.
[GLASS SHATTERS]
TYSON: Some believe that it
was on a night like this...
...that Isaac Newton finally took
his revenge against Robert Hooke.
Heh.
TYSON".
But Halley's prophecy was not forgotten.
Fifty years later, as the time
of the predicted return approached...
...the world's astronomers vied to be
the first to catch sight of his comet.
They weren't disappointed.
It's been welcomed back
every 76 years since.
When Halley's Comet
returns to our skies,
sunlight will warm up the
ice on its surface...
...once again setting loose
the dust and gases trapped within.
Halley's Comet most recently
visited our neighborhood back in 1986.
And if you're seeing this in 2061,
then you'll know it's back.
May you feel the wonder of all those
who came before you...
...and none of the fear.
Newton's laws made it possible
for Edmond Halley...
...to see some 50 years into the future
and predict the behavior of a single comet.
Scientists have been using
these laws ever since...
...opening the way to the moon,
and even beyond our solar system.
The baby in the basket
is learning to walk...
...and to know the cosmos.
Which brings me to one last prophecy.
Using nothing more
than Newton's laws of gravitation...
...we astronomers can confidently predict
that several billion years from now...
...our home galaxy, the Milky Way...
...will merge with our neighboring
galaxy Andromeda.
Because the distances between the stars
are so great compared to their sizes...
...few if any stars
in either galaxy will actually collide.
Any life on the worlds
of that far-off future should be safe...
...but they would be treated to an amazing,
billion-year-long light show...
...a dance of a half a trillion stars...
...to music first heard
on one little world...
...by a man who had but one true friend.