#Cosmos #Science #Univers #Découverte #Doc #Odyssee #Planète #Exploration #Etoile #Nature #Astronomie
Catégorie
📺
TVTranscription
00:00The universe and everything that exists has existed or will exist one day.
00:07Follow me.
00:11A few decades ago, astronomer Carl Sagan led tens of millions of us
00:16to accompany him on an exciting adventure, the scientific exploration of our universe.
00:22It's time to get back on the road.
00:26The journey I'm taking you on will lead us from the infinitely small to the infinitely large.
00:31from the beginning of the universe to the distant future.
00:35We will explore galaxies, suns and worlds, gliding on the gravitational waves of spacetime.
00:41We will discover beings who live in fire and ice,
00:44but also planets that revolve around eternal stars.
00:48We will be dealing with atoms as heavy as stars and universes as small as atoms.
00:56The history of the universe is also our own.
00:59This is the odyssey of this hunter-gatherer people who managed to find the path to the stars.
01:07It's an adventure with multiple heroes.
01:20To make this journey, we need to use our imagination, but imagination alone is not enough.
01:26Nature's treasures are far more wonderful than anything we can imagine.
01:35If this adventure is possible, it is thanks to all those generations of researchers who knew how to obey a
01:41a set of simple principles.
01:43Verify all intuitions through experience and observation.
01:47Theorize the intuitions that are validated by these verifications and reject those that are not.
01:52Interpret the experimental results without preconceptions and take nothing for granted.
01:57If you accept these principles, the universe will open up to you.
02:03Come, I'll take you with me.
02:37Subtitling by Radio-Canada
02:58Subtitling by Radio-Canada
04:02Thanks to this vessel of the imagination, we escape the constraints of time and space.
04:06It can take us anywhere.
04:10If you're wondering where we are in space, look out of this bay window.
04:18As far as time is concerned, the past is beneath us.
04:24This is what the Earth looked like 250 million years ago.
04:32To take a look into the future, look up there.
04:36This is what our planet could look like in 250 million years.
04:41You need to be able to find your way back when you venture to the far reaches of the universe.
04:46Therefore, we need to know our cosmic address.
04:49This is the first line of this address.
05:14We are leaving Earth, the only home we have ever known.
05:18to guide us to the farthest reaches of the universe.
05:26Our closest neighbor is the Moon.
05:29Its surface contains neither an atmosphere nor an ocean.
05:33not even the slightest trace of life.
05:34Only the scars from asteroid impacts.
05:50Our star is the origin of all activity on our planet.
05:54From the wind to the waves, and through life itself.
05:57The Sun retains everything contained in our system
05:59under the influence of its gravitational field,
06:02starting with Mercury.
06:23Then comes Venus, covered by a veil of clouds.
06:27Greenhouse gases have made it a real form.
06:37Mars, a world whose surface is equal
06:40to that of the emerged lands of our planet.
06:55An asteroid belt encircles the Sun
06:58between the orbit of Mars and that of Jupiter.
07:13With its four giant moons and twelve smaller ones,
07:17Jupiter is a kind of solar system all by itself.
07:21Its mass is greater than that of all other planets.
07:23of the assembled system.
07:35Jupiter's Great Red Spot.
07:39A storm three times the size of our planet
07:41which has been blowing for centuries.
08:06The jewel of our solar system, Saturn.
08:10These rings are made up of a myriad of pieces of ice
08:14which gravitate around it like so many tiny moons.
08:32Subtitling by Radio-Canada
08:53Uranus and Neptune.
08:56The two most distant planets.
08:59Unknown during Antiquity,
09:00They were only discovered after the invention of the telescope.
09:06Beyond these planets,
09:08tens of thousands of frozen celestial bodies are found.
09:30Pluto is part of it.
09:46Of all the spacecraft launched by humans,
09:49Here is the one who went the furthest from us.
09:52The Voyager 1 probe.
09:55It carries a message for billions of years to come.
10:00A testament to what we were.
10:02from what we felt,
10:04and the music we created.
10:18We still have to explore the most remote regions.
10:21of this vast cosmic ocean
10:22and the worlds they contain.
10:37From here, the Sun looks like just another star.
10:40But it still exerts its gravitational force.
10:43on billions of frozen comets
10:44that wander to the far reaches of our solar system
10:47since the time of his training,
10:49almost 5 billion years ago.
10:51It forms the golden cloud.
10:54No one has ever seen this cloud.
10:55And that would be impossible anyway.
10:58Each of the elements that make it up
10:59is also distant from its nearest neighbor
11:01than the Earth of Saturn.
11:04This gigantic cloud of comets
11:06defines the boundaries of our solar system.
11:08This is the second line of our cosmic address.
11:18We are unable to detect the planets
11:20other solar systems
11:21that for the past few decades,
11:23but we already know that some exist
11:25a very large number.
11:26There are more of them than stars.
11:29These planets must be mostly
11:31very different from Earth
11:33and hostile to life as we know it.
11:35But what do we really know about life?
11:37We don't know of any so far.
11:39only one version,
11:41terrestrial life.
11:42Do you see anything?
11:43It's rather empty, isn't it?
11:46The human eye can only detect a tiny fraction
11:49light that travels through the universe.
11:51But science allows us to see
11:52that which our senses cannot perceive.
11:55Infrared rays are the rays made visible
11:58through night vision goggles.
12:00If we point an infrared camera
12:02over this darkness,
12:03We see a wandering planet,
12:05A world without the sun.
12:10Our galaxy contains billions of them
12:12drifting in perpetual night.
12:15They are orphans
12:16rejected by their original star
12:18at the time of training
12:19of their solar system.
12:23The wandering planets have a heart in molten form
12:25while their surface is frozen.
12:28Oceans of liquid water
12:29perhaps exist
12:30between these two extreme layers.
12:37Who knows?
12:38The creatures that swim there, perhaps.
12:46This is what it looks like
12:47The Milky Way in infrared.
12:49Each of these points is a star,
12:51including the less bright ones.
12:54How many stars?
12:56How many worlds?
12:58And how many ways are there to be alive?
13:01Are you looking for where we are?
13:04Look at this arm of the spiral.
13:06This is where we live
13:07approximately 30,000 light-years
13:09from the center of the galaxy.
13:11The Milky Way is the third line
13:13from our cosmic address.
13:16We are now
13:17100,000 light-years away
13:18of our planet.
13:20Light that travels faster
13:21that everything
13:22would take 100,000 years
13:23to come to us
13:24from Earth.
13:28This is the Andromeda spiral galaxy.
13:31the closest to ours.
13:33Our two giant galaxies
13:35and other smaller ones
13:36form what is called
13:37the local group.
13:46From here, you can't even see anymore
13:49the Milky Way.
13:50This is just one of thousands
13:51galaxies that constitute
13:53the Virgo Supercluster.
13:56At this scale,
13:58each of the light points
13:59that we can see
13:59is a galaxy.
14:02Each galaxy contains
14:04billions of suns
14:05and countless worlds.
14:07However, the supercluster
14:08of the Virgin as a whole
14:10forms only a tiny part
14:12of the universe.
14:15This is our universe,
14:17in the most comprehensive representation
14:19that we knew him,
14:20hundreds of billions of galaxies.
14:23This is the last line
14:25from our cosmic address,
14:26For now.
14:30Visible universe,
14:31What does that mean?
14:33Even aboard our spaceship
14:35of the imagination,
14:35there is a limit
14:37as far as we can see
14:38in space-time.
14:39This is our cosmic horizon.
14:42Beyond this horizon,
14:43extend from the regions
14:45of the universe
14:45who are really
14:46too far away.
14:47Despite the 13 billion
14:48800 million years
14:49elapsed since birth
14:51of the universe,
14:52the light of these regions
14:53didn't have time
14:53to reach us.
14:57Many astrophysicists
14:59think that the whole
15:00worlds,
15:01stars,
15:03galaxies
15:03and clumps of matter
15:05of our visible universe
15:06do not constitute
15:08that a tiny drop
15:09in an infinite ocean
15:11other universes.
15:15A multiverse.
15:18Universe after universe.
15:21Worlds
15:22endlessly.
15:29Do you feel small?
15:31On a universal scale,
15:33We are small.
15:35We may be
15:36tiny creatures
15:37on a grain of dust
15:38lost in the immensity
15:40of space.
15:40But we know how to see
15:41doing things on a grand scale.
15:43This idea that we have
15:45the universe is quite recent.
15:46A few centuries ago,
15:48our little world
15:49knew nothing of the cosmos
15:50which encompassed it.
15:52Telescopes did not exist.
15:54The universe was summed up
15:55from what we could see
15:56to the naked eye.
15:58In 1599,
16:00everyone knew
16:01than the sun,
16:02the planets
16:03and the stars
16:04were bright spots
16:05on a celestial vault
16:06which was spinning
16:07around the Earth
16:08and that we were
16:09in the center
16:10of a small universe
16:11which did not exist
16:12than for us.
16:16Across the entire planet,
16:17a single man
16:18believed in the idea
16:19of a universe
16:19infinitely larger.
16:21And where was he preparing?
16:23to spend New Year's Eve
16:24New Year 1600?
16:27In prison,
16:28naturally.
16:36There comes a time
16:37in our life
16:38to all
16:38where one becomes aware
16:40that one is not
16:40at the center of the universe
16:41but that one belongs,
16:43on the contrary,
16:44to something
16:44which is beyond our understanding.
16:46That's what's happening
16:47when we go out
16:47childhood
16:48And that's what happened.
16:50in the 16th century
16:50on the scale
16:51of an entire civilization.
16:55Imagine the world
16:55before the invention
16:56of the telescope.
16:58The cosmos was limited
16:59as far as we could see
17:00at a glance.
17:01It was obvious
17:02that the Earth
17:02was motionless
17:03and that all the stars
17:04from the sky,
17:05the sun,
17:05the moon,
17:06the stars,
17:06the planets
17:07were circling around us.
17:09That's when
17:09that a Polish astronomer
17:10named after Copernicus
17:11formulated a revolutionary theory.
17:14The Earth
17:15was not at the center
17:16of the world.
17:17This was just one of the planets
17:18which was spinning
17:19around the sun.
17:21Many of his contemporaries
17:22like Luther,
17:23the father of Protestantism,
17:25were horrified
17:26by this idea
17:26that they considered
17:27as an affront
17:28to the sacred text.
17:30But a man
17:30judged that Copernicus
17:31had not gone far enough.
17:34His name was
17:35Giordano Bruno
17:37and he was a rebel
17:38in the soul.
17:39He dreamed of breaking free.
17:40of this narrow universe.
17:42In Naples,
17:43during his youth
17:44of a Dominican monk,
17:45He was already apart.
17:47Freedom of thought
17:49was banned in Italy
17:50but Bruno wanted
17:50everything you need to know about the universe
17:52that his god had created.
17:53He read the forbidden books
17:55through the church,
17:56which led him
17:57to his downfall.
17:58In one of his books,
17:59an ancient Roman,
18:01dead for over 1500 years,
18:03he whispered the idea to him
18:04of a much larger universe,
18:06also infinite
18:07that the design
18:07that he had of his god.
18:14Lucretia asked
18:15to the reader
18:16to imagine
18:16to be on the limit
18:17of the universe
18:18and uncheck
18:19and uncheck
18:20an arrow
18:20outwards.
18:22If the arrow
18:22continues its course,
18:24then the universe
18:24extends beyond
18:25of what was considered
18:26like the limit.
18:27But if the arrow
18:28encounters an obstacle,
18:29a wall, for example.
18:31So it's this wall
18:31who now stands
18:32beyond
18:33of the supposed limit.
18:35If we uncheck now
18:36a new arrow
18:37from the top of this wall,
18:38the same alternative
18:39presents itself again.
18:41Or the
18:42file eternally
18:42across space,
18:43or she meets
18:45a new obstacle
18:45from which one can shoot
18:47a new arrow.
18:48In either case,
18:50The universe has no limits.
18:51It can only be infinite.
18:53Bruno found this
18:54Perfectly logical.
18:55The god he worshipped
18:56was infinite,
18:57he told himself.
18:58How could he
18:59to be otherwise
19:00of its creation?
19:16Therefore,
19:17he was going to know
19:18a life of wandering.
19:30When he turned 30,
19:31he had a dream
19:32which changed his destiny.
19:35In his dream,
19:36he was waking up
19:37in a limited world
19:38through a starry vault.
19:41It was the cosmos
19:42as it was represented
19:44at the time.
20:03He was seized by a panic,
20:04as if the floor of the world
20:06it was giving way beneath his feet.
20:08But he mustered his courage
20:09with both hands.
20:20Full of confidence,
20:21I took flight
20:22and I rose up
20:24towards infinity,
20:25leaving far behind me
20:27what my fellow human beings
20:28they could barely make it out.
20:29Where I was,
20:30there was no top,
20:31neither low,
20:32nor center,
20:33nor extremity.
20:35I saw that the sun
20:36was just a star
20:37among others
20:38and that each star
20:39was a sun
20:40who accompanied
20:40planets
20:41similar to ours.
20:43Becoming aware
20:44of this immensity
20:46touched me
20:46like a thunderbolt.
20:52Bruno preached
20:53the good word
20:54across Europe,
20:55shouting loudly
20:56that the universe
20:56was infinite.
20:57He thought
20:58than other faithful
20:59of God
21:00would not be lacking
21:00to share
21:01this vision
21:02more grandiose
21:02of creation.
21:04I was so naive.
21:08He was excommunicated
21:09by the Catholic Church
21:11in his native country,
21:12chased out of Switzerland
21:13by the Calvinists
21:14and Germany
21:16by the Lutherans.
21:18Guest
21:18at a conference
21:19in Oxford
21:20in England,
21:21Bruno hurried
21:21to go there.
21:25Finally,
21:25he thought,
21:26I have the opportunity
21:27to explain my point of view
21:28to an assembly
21:29of scholars.
21:34I came
21:35introduce yourself
21:36a new idea
21:36of the cosmos.
21:38Copernicus was right
21:39to assert
21:39that our world
21:40is not at the center
21:40of the universe.
21:42The Earth rotates
21:43around the Sun,
21:44it's just a planet
21:45among others.
21:47Copernicus gave birth
21:47dawn.
21:48I bring you
21:49the brightness of day.
21:51Blasphemy!
21:52The stars are
21:53other incandescent suns,
21:54made of the same material
21:56than the Earth.
21:57Each one has its own planets.
21:59There is water there,
22:00plants
22:01and animals
22:01as noble as ours.
22:03Are you crazy?
22:03Or just ignorant?
22:05Everyone knows
22:05that there is
22:06than one world.
22:07What everyone
22:08believe is false.
22:09Our infinite God
22:10created an infinite universe
22:12populated by an infinite number
22:13of worlds.
22:14Don't we read Aristotle?
22:16Where are you from?
22:17Or the Bible?
22:18Reject the inheritance
22:19from Antiquity,
22:19traditions,
22:20of faith
22:21and authority.
22:23Let's start from scratch.
22:24let us doubt that
22:25we took it for granted.
22:26Heretic!
22:27Blasphemer!
22:28Your God is too small.
22:30He's crazy!
22:32Blasphemer!
22:35A wiser man
22:36would have stopped there,
22:38But not Bruno.
22:41He was unable
22:42to keep it to himself
22:43his vision of an infinite universe
22:44And yet,
22:46he paid a very high price
22:47his audacity.
22:48It earned him
22:48to receive
22:49the cruellest
22:49and the most barbaric
22:50of all punishments.
22:57At the time
22:58where lived
22:58Giordano Bruno,
22:59it did not exist
23:00separation
23:01between the Church
23:01and the State
23:02and freedom of expression
23:03was not considered
23:04as a right
23:05inalienable
23:06of every individual.
23:07By expressing
23:08a point of view
23:08non-compliant
23:09to accepted beliefs
23:10we were exposing ourselves
23:11to serious trouble.
23:14Despite the danger,
23:15Bruno returned to Italy.
23:17Perhaps his native land
23:18He had ended up missing her.
23:20But he should have known
23:21that Rome
23:22was one of the places
23:23the most dangerous
23:24from all over Europe.
23:26The Catholic Church
23:27had created
23:27a jurisdiction
23:28not relevant
23:28that of his authority,
23:30the Inquisition.
23:32His goal was
23:32to pursue
23:33those who dared
23:34express
23:35opinions
23:35opposites
23:36to their dogmas.
23:41It was not necessary
23:42Bruno for a long time
23:43to fall
23:43in the claws
23:44of the police
23:45of thought.
23:52This vagabond
23:53who believed
23:54in a universe
23:54without end
23:55rots
23:56in a jail
23:56for eight years.
23:59Examination
24:00after questioning,
24:01He stubbornly refused
24:02to abjure
24:02his convictions.
24:04For what
24:04the Church
24:05was she giving herself
24:06so much evil
24:06To torture Bruno?
24:08What
24:09the Vatican
24:09Was he so afraid?
24:11If Bruno
24:12was right.
24:13the holy scriptures
24:14and the authority
24:15of the Church
24:15would be handed over
24:16in question.
24:19The Inquisition
24:20finally surrendered
24:21his verdict.
24:23You are being judged
24:25guilty
24:25of having questioned
24:26the Holy Trinity
24:27and Jesus Christ.
24:29Guilty
24:30of having believed
24:30that anger
24:31of God
24:31was not eternal
24:33and that we would be
24:34all forgiven
24:35in the afterlife.
24:36You are guilty
24:37to have affirmed
24:38existence
24:38other worlds.
24:41On your knees!
24:42All books
24:42that you wrote
24:43will be gathered
24:44in the square
24:45Saint Peter
24:46where they will be burned.
24:47My father,
24:49these eight years
24:50imprisonment
24:51left me
24:51a lot of time
24:52to reflect.
24:53SO,
24:54Do you recant?
24:55My love
24:56and my admiration
24:57towards my Creator
24:58inspire my vision
24:59of an infinite universe.
25:01You will be recovered
25:02to the governor of Rome
25:03who will inflict it on you
25:05the punishment
25:06reserved for those
25:07who do not repent
25:08not their sins.
25:10Take him away!
25:13Who knows
25:14if you are not afraid
25:15no more
25:15to pronounce
25:16my sentence
25:17that I
25:17to hear it.
25:18to hear it.
25:29Let's go!
26:03French subtitles?
26:27Ten years later, Galileo looked through a telescope for the first time and discovered that
26:34Bruno had been right.
26:36The Milky Way was made up of countless stars invisible to the naked eye, and some of the lights in the sky came from
26:42of different worlds from one another.
26:43Bruno was not a scientist. His vision of the universe was a mere supposition, unsupported by any evidence.
26:49by the slightest proof.
26:51Like many assumptions, it could have turned out to be false, but once launched, it served as a focal point.
26:56to others besides him, including those who wanted to refute it.
27:03Bruno had suspected the vast expanse that our universe covered, but not the immensity of time.
27:14How can we humans, who rarely live more than a century, conceive of the time that has passed?
27:19since the creation of our universe?
27:23The universe is 13 billion 800 million years old.
27:26To measure the scale of cosmic time, let us relate this duration to the 12 months of a single year.
27:45Our cosmic calendar begins on January 1st, with the birth of our universe.
27:50It contains a record of everything that has happened since then, up to the present day, that is, up to the
27:54December 31st at midnight.
27:57On this scale, each month symbolizes approximately one billion years, and each day is equivalent to almost 40 million years.
28:04'years.
28:06Let's go back as far as possible, to the very first moment of the universe.
28:12January 1st, the Big Bang.
28:27We cannot go back any further in time.
28:30For now.
28:34Our entire universe sprang from a point smaller than an atom.
28:38Space itself expanded in a massive explosion that caused the universe to expand.
28:43and gave birth to all the energy and matter that exists today.
28:49It may sound crazy, but the Big Bang theory is based on rigorous observations.
28:54which take into account the amount of helium present in the universe
28:58and the residual radiation from the radio waves generated by the explosion.
29:03As it expanded, the universe cooled and darkness reigned for 200 million years.
29:09Drawn together by gravity, pockets of gas heated up.
29:13until the first star appeared on January 10th.
29:21On January 13, these stars joined together to form the first small galaxies.
29:29By merging, they gave birth to larger galaxies, including our Milky Way.
29:36It was formed 11 billion years ago, on March 15th of our cosmic year.
29:45Among these hundreds of billions of suns, which one is ours?
29:49It does not yet exist; it will be born from the ashes of other stars.
29:56Do you see those lights that crackle like flashes?
29:59Each one is a supernova, the field of the sign of a giant star.
30:05Stars die and are born in molecular clouds like this one.
30:10They condense like drops of mist from gas and dust.
30:14At the center of stars, the temperature becomes so high that the nuclei of atoms fuse
30:19to form the oxygen in our atmosphere, the carbon in our muscles, or the iron in our blood.
30:26All these elements were forged in the heart of stars, long since vanished.
30:32And you, me, each one of us, we all come from the stars.
30:41These stellar materials are recycled and enriched again and again over several generations of stars.
30:52How much longer until the birth of our Sun?
30:55A very long time.
30:57It will not shine for another 6 billion years.
31:02Our Sun was born on August 31st on the cosmic calendar.
31:09That was 4.5 billion years ago.
31:13The Earth formed from a disk of gas and dust orbiting our
31:17young Sun.
31:18Repeated collisions of debris made it into an ever-larger ball.
31:30Do you see that asteroid?
31:32No, not this one, the other one next to it.
31:34We exist because the gravitational field of the first one deflected its course 2 cm to the left.
31:42What difference can 2 cm make on the scale of the Sun system?
31:47You'll find out soon.
31:50The Earth took quite a few hits during its first billion years.
31:57Fragments of debris in orbit collided and aggregated with each other until they formed our Moon.
32:04The Moon is a testament to this turbulent period.
32:08If you had been on Earth at that time, the Moon would have appeared 100 times brighter than
32:13'Today.
32:14Ten times closer, it was caught in a much more intimate gravitational embrace with our planet.
32:21When the Earth began to cool, the oceans appeared.
32:24The tidal range was then ten times greater.
32:28Over time, the friction of the tides on the ocean floor gradually pushed the Moon away.
32:39Life began on our little planet somewhere around here, on September 21st, 3 billion years ago.
32:45and a half years.
32:46We still don't know how life appeared.
32:49It could very well have come from another part of the Milky Way.
32:52The origin of life remains one of the great unsolved scientific enigmas.
33:00Life goes on.
33:02It assembles organic molecules to create increasingly complex beings.
33:09By November 9th, there are already organisms that breathe, move, feed, and interact with their environment.
33:18We owe a great deal to these valiant microbes.
33:22Ah, one more thing.
33:24They are the ones who invented sexuality.
33:30December 17th is a day to be remembered.
33:33It is at this time that larger plants and animals begin to proliferate in the oceans.
33:40The Tiktalik was one of the first animals to venture onto dry land.
33:46He must have felt like he'd discovered another planet.
33:51Forests, dinosaurs, birds, insects.
33:54All of this takes place during the last week of December.
34:00The first flower opens its petals on December 28th.
34:08As the trees in these forests die and decompose in the soil, their remains
34:14turn into coal.
34:16300 million years later, most of this coal fuels our energy needs and threatens our
34:24civilization.
34:30Do you remember that asteroid that veered to the right at the birth of our solar system?
34:36Well, he's back.
34:38On the cosmic calendar, it is December 30th at 6:24 AM.
34:52For over 100 million years, dinosaurs ruled the Earth.
34:56while our ancestors, two small mammals, burrowed into the ground.
35:01The asteroid changed all of that.
35:03If it had not deviated from its course, it would not have crashed to Earth.
35:07Dinosaurs might still be alive today, but we would never have existed.
35:12This perfectly illustrates the arbitrary and random nature of life.
35:19The universe is already 13.5 billion years old, but still no humans in sight.
35:26Within the vast expanse of time that our calendar represents,
35:29we only enter the scene at the very last hour of the last day of this cosmic year.
35:43It is 11:59:46 PM.
35:48The entirety of human history spans only 14 seconds.
35:51and all the people you've heard about lived there.
35:57Dynasties, battles, migrations, discoveries, wars, passions.
36:03Everything our history books talk about happened here.
36:07during the final seconds of our cosmic year.
36:10But if we want to explore such a fleeting moment in the history of the universe,
36:17We need to change our scale.
36:36We are newcomers to the universe.
36:39The history of men only begins at the end of the last day of our cosmic year.
36:44It is 9:45 pm on this evening of December 31st.
36:47Three and a half billion years ago,
36:49Our ancestors, yours and mine, left these traces.
36:55By standing on our own two feet, we take a different path.
36:58Once we are standing, our eyes are no longer fixed on the ground.
37:03We are now discovering the world with wonder.
37:10For most of human history,
37:12that is approximately 40,000 generations.
37:14We live as nomads within small tribes of hunter-gatherers.
37:20We manufacture tools,
37:23Let's tame fire and invent language.
37:26All of this during the last hour of the cosmic year.
37:37To discover the rest of our story,
37:40Let's change tanks again.
37:43It's the last minute of the last night of the year.
37:47It is 11:59 PM.
37:50We are still so young that we have to wait until the last 60 seconds
37:54so that we could start making our first drawings.
37:59That was barely 30,000 years ago.
38:09It was at this moment that we invented astronomy.
38:13In fact, we are all descendants of astronomers.
38:17Our survival depends on our interpretation of the stars.
38:19We need to be able to predict the arrival of winter.
38:22and the migration of herds.
38:24Then, 10,000 years ago,
38:27A revolution is shaking up our way of life.
38:30Our ancestors learned to shape their environment.
38:33They improve plants
38:34and domesticate animals
38:36cultivate the land
38:37and settle down.
38:40Nothing is the same anymore.
38:42For the first time in our history,
38:44We have too many possessions.
38:45to take everything with us.
38:47We need a way to count them.
38:51About 6,000 years ago,
38:52that is, 14 seconds before midnight,
38:53We invented writing.
38:56Very quickly, we notice much more
38:58than quantities of grain.
39:00Writing allows us to record our thoughts
39:02and to spread them through space and time.
39:05Thanks to inscriptions on clay tablets,
39:08We can aspire to immortality.
39:10The world is shaken by it.
39:14Moses was born 7 seconds ago.
39:17Buddha, 6 seconds ago.
39:20Jesus, 5 seconds ago.
39:23Muhammad, 3 seconds ago.
39:26It's only 2 seconds ago
39:28that European and Native American civilizations
39:30come into contact for better or for worse.
39:33It was only at the last second
39:35of our cosmic calendar
39:36that we begin to use science
39:38to understand the laws of nature.
39:41The advent of the scientific method is so radical
39:44that only 4 centuries separate the first use
39:47of a telescope by Galileo
39:49of the first manned expedition to the lunar surface.
39:53Thanks to science,
39:55we know where in space and time
39:58We are situated in the universe.
40:03Through us,
40:04The cosmos takes on its full meaning.
40:07A few decades ago,
40:09Carl Sagan imagined the first voyage
40:11across the universe.
40:13He was the most brilliant popularizer
40:15of the 20th century,
40:15but he remained first and foremost a scientist.
40:19Our current knowledge
40:21The planets owe him a great deal.
40:23He had anticipated the presence
40:25of methane lakes on Titan,
40:27Saturn's giant moon.
40:29He demonstrated that the Earth's atmosphere
40:32was initially
40:33very rich in greenhouse gases.
40:35He was the first to associate
40:37the seasons on Mars
40:38to these dust storms.
40:42Carl was a pioneer in research
40:44of extraterrestrial life and intelligence.
40:47He participated in all the exploration missions
40:50of the solar system in the first 40 years
40:52of the space age.
40:57But he did more than that.
41:02This has been the personal agenda
41:04by Carl Sagan for the year 1975.
41:10Who was I back then?
41:12Just a 17-year-old kid raised in the Bronx
41:15who dreamed of becoming a scientist.
41:17The most famous astronomer of the time
41:19found the time
41:20to invite me to Itaca in New York State
41:23so that I could spend a Saturday there in his company.
41:25I remember it like it was yesterday.
41:27It was snowing that day.
41:29He met me at the bus stop
41:30and gave me a tour of his laboratory
41:32at Cornell University.
41:34Carl took the book out of his desk
41:36and dedicated it to me for that.
41:41On the island, future astronomer,
41:44Carl.
41:46When he walked me back to the bus stop
41:48at the end of the day,
41:49The snow was falling even more heavily.
41:51He wrote down her phone number
41:53on a piece of paper
41:54and told me
41:55“If the bus is blocked,
41:57Call me,
41:58We'll put you up at our house for the night.
42:01I already knew that I wanted to be a scientist.
42:04but on that day,
42:05I am the kind of person
42:06that I wanted to become.
42:08By dedicating some of her time to me,
42:11He convinced me.
42:12as he has convinced so many others,
42:14to study, to teach
42:16and to dedicate myself to science.
42:19Scientific research
42:20is a collective approach
42:21that transcends generations.
42:23It's a torch
42:24that we pass on
42:25from teacher to disciple,
42:26an intellectual community
42:28which has its roots in Antiquity
42:29and extends all the way to the stars.
42:32So, follow me.
42:34Our journey has only just begun.
43:10Subtitling by Radio-Canada
43:24Subtitling by Radio-Canada
43:43Subtitling by Radio-Canada
43:46Subtitling by Radio-Canada
43:47...
Commentaires