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#CarlSagan covers a wide range of scientific subjects, including the origin of life and a #perspective of our place in the universe...
A 13-part #documentary #series that covers a wide range of #scientific #subjects, including the #origin of #life and a #perspective of our place in the universe narrated by famous American #Scientist – #Carl #Sagan.
A 13-part #documentary #series that covers a wide range of #scientific #subjects, including the #origin of #life and a #perspective of our place in the universe narrated by famous American #Scientist – #Carl #Sagan.
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LearningTranscript
00:00For more information, visit www.fema.gov
00:30The surface of the earth is far more beautiful
00:58and far more intricate than any lifeless world.
01:03Our planet is graced by life,
01:05and one quality that sets life apart is its complexity,
01:09slowly evolved through four billion years of natural selection.
01:15You can describe in detail how a rock is put together in a single paragraph,
01:21but to describe the basic structure of a tree
01:24or a blade of grass or even a one-celled animal,
01:27you'd need many volumes.
01:30It takes a great deal of information to make
01:32or even to characterize a living thing.
01:38The measuring rod, the unit of information,
01:41is something called the bit.
01:44It's an answer, either yes or no,
01:47to one unambiguously phrased question.
01:50So to specify whether a light switch is on or off
01:53requires only a single bit.
01:56To specify something of greater complexity requires more bits.
02:00There's a popular game called 20 questions,
02:03which shows that a great deal can be specified in only 20 bits.
02:07For example,
02:08I have something in my hand.
02:11What is it?
02:13Is it alive?
02:14Yes.
02:15One bit.
02:16Is it an animal?
02:17Nope.
02:18Two bits.
02:20Is it big enough to see?
02:22Yep.
02:23Does it grow on the land?
02:25Yes.
02:25Is it a cultivated plant?
02:27Nope.
02:28Well, with only five bits,
02:31we've made some substantial progress
02:32to figuring out what it is.
02:34With 20 skillfully chosen questions,
02:36we could easily whittle all the cosmos down
02:39to a dandelion.
02:41In our explorations of the cosmos,
03:03the first step is to ask the right questions.
03:07Then, not with 20 questions,
03:09but with billions,
03:11we slowly distill from the complexity of the universe
03:14its underlying order.
03:16This game has a serious purpose.
03:19Its name is science.
03:23Out here in the great cosmic dark,
03:27there are countless stars and planets,
03:30some far older than our solar system.
03:33Although we cannot yet be certain,
03:35the same processes which led on Earth
03:37to the origin of life and intelligence
03:38should have been operating throughout the cosmos.
03:42There may be a million worlds
03:44in the Milky Way galaxy alone,
03:46which are at this moment
03:47inhabited by other intelligent beings.
03:50What a wonder, what a joy it would be
04:01to know something about non-human intelligence.
04:04And we can.
04:11Here is an exotic inhabited world
04:13mostly covered with a liquid.
04:15We seek the dominant intelligence
04:23that lives beneath its fluid surface.
04:26This ocean of liquid water
04:45kilometers deep
04:46is teeming with strange forms of life.
04:49There are communities
04:55of transparent beings.
05:02There are societies of creatures
05:04which communicate by changing
05:06the patterns on their bodies.
05:07There are beings that give off
05:18their own light.
05:27There are hungry flowers
05:28that devour passers-by,
05:31gesticulating trees,
05:33all manner of creatures
05:35that seem to violate
05:37the boundaries between plants and animals.
05:39There are beings that flutter
06:00through the ocean
06:01like waltzing orchids.
06:03These are a few of the species
06:23that inhabit the water world
06:25called Earth.
06:26They're packed with information.
06:40Every one of them
06:40is a rich behavioral repertoire
06:42to ensure its own survival.
06:44But the grandest creatures
06:55on the planet,
06:56the intelligent and graceful masters
06:58of the deep ocean,
07:00are the great whales.
07:02They are the largest animals
07:03ever to evolve on the planet Earth,
07:05larger by far
07:07than the dinosaurs.
07:08Their ancestors
07:09were meat-eating mammals
07:10who migrated
07:1170 million years ago
07:13in slow steps
07:14from the land
07:15into the waters.
07:16Whales like these humpbacks
07:18are still mammals.
07:19We humans have much
07:20in common with them.
07:22Mothers suckle infants.
07:23There's a long childhood
07:24in which adults teach the young.
07:26And there's a great deal of play.
07:28These are mammalian characteristics,
07:30vital if an animal is to learn.
07:33But the sea is murky.
07:35The senses of sight and smell,
07:37which work well for mammals
07:38in the land,
07:39are not much use here.
07:40So the whales evolved
07:42an extraordinary ability
07:44to communicate by sound.
07:46For tens of millions of years,
07:48the whales had no natural enemies.
07:50And then,
07:51a new and alien
07:53and deadly creature
07:54suddenly appeared
07:55on the placid surface
07:57of the ocean.
07:57These often noisy
08:14and occasionally deadly objects
08:16first appeared in large numbers
08:18only a few centuries ago.
08:21They are artifacts
08:22manufactured by land creatures
08:24whose ancestors last lived
08:26in the oceans
08:27350 million years ago.
08:29This particular one, however,
08:45is on a mission
08:47of understanding.
08:48It's called
08:53the Regina Maris,
08:55the Queen of the Sea.
08:57And one of its jobs
08:58is to record
08:59the sounds
09:00of whales.
09:05Some whale sounds
09:06are called songs,
09:08but we really don't know
09:09what their contents are.
09:10They range in frequency
09:14over a broad band
09:16of sounds
09:16down to frequencies
09:18well below
09:18the lowest sounds
09:20that the human ear
09:20can make out.
09:22A typical whale song
09:23lasts maybe 15 minutes,
09:25the longest perhaps
09:26half an hour.
09:28Occasionally,
09:29a group of whales
09:30will leave their winter waters
09:32in the middle of a song.
09:34And six months later,
09:35they'll return
09:36and pick the song up
09:37at precisely the spot
09:39that they left it off.
09:41Beat for beat,
09:42measure for measure,
09:43sound for sound.
09:46Whales are very good
09:48at remembering.
09:51Other times,
09:52they will come back
09:53after an absence
09:54of six months
09:55and the piece
09:57will have changed.
09:57A different song
09:59will be on the whale
10:00hit parade.
10:03Very often,
10:04the members of the group
10:05will sing the same song
10:06together.
10:07By some mutual consensus,
10:10some collaborative
10:11songwriting,
10:13the piece changes
10:15slowly and often predictably.
10:17I'm not very good
10:18at singing the songs
10:20of whales,
10:20but here's a try.
10:23In January,
10:25a tiny fragment
10:27of a long whale song
10:28might sound like this.
10:31Whoop!
10:32In February,
10:36something like this.
10:38Whoop!
10:40Ah!
10:42Ah!
10:43And then in March,
10:44as maybe you'd predict,
10:47whoop!
10:48Ah!
10:50Ah!
10:51Ah!
10:52One additional
10:54Awe a month.
11:01The complex patterns
11:03in the songs
11:03of the whales
11:04are sometimes
11:05repeated precisely.
11:07If I imagine
11:08that the songs
11:09of the humpback whale
11:10are sung
11:10in a tonal language,
11:13then the number
11:13of bits of information
11:14in one song
11:15is about the same
11:17as the information
11:17content
11:18of the Iliad
11:19or the Odyssey.
11:33Is it just
11:34a romantic notion
11:35that the whales
11:35and their cousins
11:36the dolphins
11:37might have something
11:38akin to epic poetry?
11:41What might whales
12:07or dolphins
12:08have to talk
12:09or sing about?
12:11They have no
12:12manipulative organs.
12:13They can't make
12:14great engineering
12:15constructs
12:16as we can.
12:18But they're
12:19social creatures.
12:20They hunt
12:21and swim,
12:22fish,
12:23browse,
12:24frolic,
12:24mate,
12:25play,
12:26run from predators.
12:28There might be
12:28a great deal
12:29to talk about.
12:41The great danger
12:47for the whales
12:47is a newcomer,
12:50an upstart animal,
12:51only recently,
12:53through technology,
12:54become competent
12:55in the oceans.
12:57A creature
12:58called man.
13:01For 99.99%
13:03of the history
13:03of whales,
13:04there were no humans
13:05in the deep oceans.
13:06during this period,
13:08the whales
13:08evolved their
13:09extraordinary
13:10communication system.
13:12Some whales
13:13emit extremely loud
13:14sounds at a frequency
13:15of 20 hertz.
13:16A hertz,
13:17which is spelled
13:17H-E-R-T-Z,
13:19is a unit
13:19of sound frequency
13:20and it represents
13:21one sound wave
13:23entering my ear
13:24every second.
13:25A frequency
13:26of 2,000 hertz
13:27sounds and looks
13:28like this.
13:29200 hertz
13:34like this
13:34and 20 hertz
13:38like this,
13:38although your
13:39television set
13:40may not transmit
13:40sounds with frequencies
13:42as low as 20 hertz.
13:44The American biologist
13:46Roger Payne
13:47has calculated
13:47that there's
13:48a deep sound channel
13:49in the ocean
13:50at these frequencies
13:51through which
13:52two whales
13:52could communicate
13:53with each other
13:53essentially anywhere
13:55in the world.
13:56One whale might be
13:57off the Ross
13:59ice shelfed
14:00in Antarctica
14:01and communicate
14:02with another whale
14:03in the Aleutians
14:04in Alaska.
14:05For most of their
14:06history,
14:06the whales seem
14:07to have established
14:08a global
14:09communications network.
14:13What two whales
14:14might have to say
14:15to each other
14:16separated by 15,000
14:17kilometers,
14:18I haven't the
14:19foggiest idea.
14:20But maybe it's
14:21a love song
14:22cast into the
14:24vastness of the deep.
14:29Now, this calculation
14:32on the range
14:33of whale communications
14:34assumes that the
14:35oceans are quiet.
14:43But in the 19th century,
14:45sailing ships
14:46like this one
14:47began to be replaced
14:48by steamships,
14:50another invention
14:51of those strange
14:52land animals.
14:53Commercial and military
14:54vessels became
14:55more abundant.
14:59The noise pollution
15:00in the sea
15:00got much worse,
15:02especially at a
15:03frequency of 20 hertz.
15:08The crew of this
15:09vessel tried
15:10consciously to keep
15:11her quiet,
15:12but when its
15:12engine is turned on,
15:13it gets very loud
15:14at a frequency
15:15of 20 hertz.
15:17Whales communicating
15:19across the oceans
15:20must have experienced
15:21greater and greater
15:22difficulties.
15:22The distance
15:23over which they
15:24could communicate
15:25must have steadily
15:26decreased.
15:29200 years ago,
15:30a typical distance
15:32that some whales
15:32could communicate
15:33across was perhaps
15:3510,000 kilometers.
15:37Today, on a typical
15:38day, the corresponding
15:40number is perhaps
15:42a few hundred
15:42kilometers.
15:43We have cut off
15:44the whales from
15:45themselves.
15:47Creatures which were
15:48freely communicating
15:49for tens of millions
15:51of years have now
15:52effectively been
15:53silenced.
16:00And we've done
16:01worse than that,
16:02because there
16:03persists, to this
16:04day, a traffic
16:06in the dead bodies
16:07of whales.
16:09There are humans
16:10who gratuitously hunt
16:11and slaughter whales
16:12and market the
16:13products for dog food
16:15or lipstick.
16:16Many nations understand
16:19why whale murder
16:21is monstrous,
16:22but the traffic
16:23continues chiefly
16:24by Japan and Norway
16:27and the Soviet Union.
16:29We use the word
16:31monster to describe
16:31an animal somehow
16:33different from us,
16:34somehow scary.
16:36But who's the more
16:37monstrous?
16:38The whales who ask
16:39only to be left alone
16:41to sing their rich
16:42and plaintive songs,
16:43or the humans who set
16:45out to hunt them
16:46and destroy them
16:47and have brought
16:48many whale species
16:50close to the edge
16:51of extinction.
16:54We're interested
16:55in communication
16:56with extraterrestrial
16:57intelligence.
16:58Wouldn't a good
16:59beginning be better
17:00communication with
17:01terrestrial intelligence,
17:03with other human
17:04beings of different
17:05cultures and languages,
17:06with the great apes,
17:08with the dolphins,
17:09but particularly
17:10with the whales?
17:11To survive,
17:41a whale must know
17:43how to do things.
17:44This knowledge is stored
17:45in two principal ways,
17:47in the whale's genes
17:48and in their very large brains.
17:51We can think of their genes
17:52and brains as something
17:53like libraries
17:54inside their bodies.
17:56The information in the DNA,
17:58the genetic information,
17:59includes how to nurse,
18:01how to convert shrimp
18:02into blubber,
18:03how to hold your breath
18:04on a dive
18:05one kilometer
18:06below the surface.
18:07The information in the brains,
18:09the learned information,
18:11involves such things as
18:12who's your mother
18:13or what the meaning is
18:15of that song
18:15we're hearing just now.
18:20The gene library
18:21of whales
18:22and people
18:23and almost everybody
18:24else on Earth
18:25is made of DNA.
18:27The only function
18:28of this complex molecule
18:29is to store
18:30and copy information.
18:37We see here
18:38the set of instructions
18:39in human DNA,
18:41written in a language
18:43billions of years older
18:44than any human tongue.
18:46Each colored cluster
18:47of atoms
18:48is a letter
18:49in the genetic alphabet,
18:50the language of life.
18:51and there are
18:52billions of letters,
18:54many billions
18:55of bits of information.
18:57If you came
18:58from somewhere
18:58very different,
19:00you wouldn't be able
19:00to specify
19:01a whale or a person
19:03in a game
19:03of 20 questions
19:04with only 20 bits.
19:07But a game
19:07called 10 billion questions
19:09might just work.
19:12Every organism on Earth
19:13contains as its inheritance
19:15and legacy
19:16a portable library.
19:19And the more bits
19:19of information you have,
19:20the more you can do.
19:26The simplest organism,
19:28a virus,
19:29needs only about
19:3010,000 bits,
19:32equivalent to the amount
19:33of information
19:33on one page
19:34of an average book.
19:36These are all
19:36the instructions
19:37it needs
19:37to infect
19:38some other organism
19:39and to reproduce itself,
19:41which are the only things
19:42that viruses
19:42are any good at.
19:44A bacterium
19:45uses roughly
19:46a million bits
19:47of information,
19:48about 100 printed pages.
19:50Bacteria have a lot
19:51more to do
19:51than viruses
19:52because they're not
19:53thoroughgoing parasites.
19:54Bacteria
19:55have to make a living.
19:56What about a free-swimming
20:02one-celled amoeba?
20:04These creatures
20:05are also microscopic,
20:07but in the realm
20:08of one-celled animals,
20:09they are giants,
20:11the whales
20:12of the microbial world.
20:14Each contains
20:15about 400 million bits
20:17in its DNA,
20:19the equivalent
20:19of about 80 volumes
20:21of 500 pages each.
20:23That's so much information
20:24it takes
20:25to make an amoeba,
20:26a creature
20:27like a small city
20:28wandering
20:29through a drop of water.
20:34And what about a whale
20:36or a human being?
20:37Well, the answer
20:38seems to be
20:39that there's
20:40five billion bits,
20:43five billion bits
20:44of information
20:45in our encyclopedia
20:47of life,
20:47in the nucleus
20:48of every one
20:49of our cells.
20:50So, if written out
20:52in, say,
20:53ordinary English,
20:54those instructions,
20:56that information,
20:57would fill
20:58a thousand volumes.
21:01Think of it.
21:02In every one
21:04of the hundred trillion
21:06cells in your body,
21:07there's the contents
21:08of a complete library
21:09of instructions
21:10on how to make
21:10every part a view.
21:12Those cells are smart.
21:14If this were
21:15my gene library,
21:17it would contain
21:18everything my body
21:19knows how to do
21:20on its own
21:20without being taught.
21:22The ancient information
21:25is written
21:26in exhaustive,
21:27careful,
21:28redundant detail.
21:30How to laugh,
21:31how to sneeze,
21:32how to walk,
21:34how to recognize patterns,
21:36how to reproduce,
21:37how to digest
21:37an apple.
21:39If written out
21:40in the language
21:40of chemistry,
21:42what would
21:43the instructions
21:44for digesting
21:44the sugar
21:45in an apple
21:46look like?
21:47Well, let's see.
21:50Amino acid synthesis,
21:51polypeptide chains,
21:53transfer RNA,
21:54genetic code,
21:55enzyme expression,
21:57enzyme phosphorylation,
21:59we're getting warm,
22:00hexose, monophosphate,
22:01shunt, citric acid cycle,
22:04here we are,
22:05anaerobic glycolysis.
22:06Now, eating an apple
22:08may seem like
22:09a very simple thing,
22:11but it's not.
22:14In fact,
22:15if I consciously
22:16had to remember
22:17and direct
22:18all the chemical steps
22:20required to get energy
22:21out of food,
22:22I'd probably starve to death.
22:25And yet,
22:26even a bacterium
22:27can do anaerobic glycolysis.
22:30That's why apples
22:31rot its lunchtime
22:33for the bacteria.
22:35They and we
22:36and all the creatures
22:37in between
22:38possess similar
22:40genetic instructions.
22:42Our separate
22:43gene libraries
22:44have many pages
22:46in common,
22:47which is,
22:48by the way,
22:49another reminder
22:49of the deep interconnection
22:51of all living things
22:52on our planet
22:53because of a common
22:54evolutionary heritage.
22:55Our present human technology
23:01can duplicate
23:02only a tiny fraction
23:04of the intricate biochemistry
23:07which our bodies
23:08seem to perform
23:09so effortlessly.
23:11But we're just beginning
23:12the study of biochemistry.
23:14Evolution
23:14has had billions
23:16of years of practice.
23:17The DNA knows.
23:23Now,
23:23what if what we had
23:25to do
23:26was so complicated
23:27that even
23:28several billion
23:29bits of information
23:30wasn't enough?
23:32What if,
23:32for example,
23:33the environment
23:33were changing so fast
23:35that the pre-coded
23:37genetic encyclopedia,
23:39which may have served
23:40us perfectly well
23:41in the past,
23:42is now
23:42not perfectly
23:44adequate?
23:45why then
23:47even a gene library
23:49of a thousand volumes
23:51wouldn't be enough.
23:52That's why
23:53we have brains.
23:59Like our other organs,
24:00the brain has evolved,
24:02increasing
24:02over millions of years
24:03in complexity
24:05and information content.
24:07Its structure
24:08reflects all the stages
24:10through which it has passed.
24:12The brain
24:13has evolved
24:14from the inside
24:15out.
24:17Deep inside
24:18is the oldest part,
24:20the so-called brain stem.
24:21It conducts
24:22many of the basic
24:23biological functions,
24:24including
24:24the rhythms of life,
24:27like heartbeat
24:28and respiration.
24:30The higher functions
24:31of the brain
24:31have evolved
24:33in three successive stages,
24:35according to
24:36a provocative insight
24:37by the American
24:38biologist
24:38Paul McLean.
24:39You see,
24:40capping the brain stem
24:42is the so-called
24:43R-complex,
24:45R for reptile.
24:46It's the seat
24:47of aggression,
24:49ritual,
24:50territoriality,
24:51and social hierarchies.
24:53It evolved
24:55to some hundreds
24:56of millions
24:56of years ago
24:57in our reptilian
24:58ancestors.
25:00So,
25:01deep inside
25:02our brain
25:02is something
25:03rather like
25:04the brain
25:05of a crocodile.
25:07Surrounding
25:08the R-complex
25:09is the limbic system
25:11or mammal brain.
25:12It evolved
25:13some tens
25:14of millions
25:14of years ago
25:15in ancestors
25:16who were mammals,
25:18all right,
25:18but not yet primates
25:20like monkeys
25:21or apes.
25:22It's a major source
25:24of our moods
25:25and emotions,
25:26our concern
25:27and care
25:28for the young.
25:30And then,
25:30finally,
25:31on the outside
25:32of the brain,
25:34living in a kind
25:35of uneasy truce
25:37with the more
25:38primitive brains
25:39beneath,
25:39is the cerebral cortex
25:41evolved millions
25:43of years ago
25:44in ancestors
25:45who were primates.
25:59This is the point
26:01of embarkation
26:02for all our
26:03cosmic journeys,
26:05the cerebral cortex,
26:07where matter
26:07is transformed
26:09into consciousness.
26:10Here,
26:11comprising more than
26:12two-thirds
26:13of the brain mass,
26:15is the realm
26:15both of intuition
26:16and of critical analysis.
26:19It's here
26:19that we have ideas
26:20and inspirations,
26:22here that we read
26:23and write,
26:24here that we do
26:25mathematics
26:26and music.
26:28The cortex
26:28regulates
26:30our conscious lives.
26:31It is the distinction
26:34of our species,
26:35the seat
26:35of our humanity.
26:37Art and science
26:38live here.
26:39Civilization
26:40is a product
26:41of the cerebral cortex.
26:45Behind the forehead
26:47are the frontal lobes
26:48of the cerebral cortex.
26:50They may be the places
26:51where we anticipate events,
26:53where we figure out
26:54the future.
26:55But if we can foresee
26:56an unpleasant future,
26:58we can take steps
26:59to avoid it.
27:00Down here
27:01in the frontal lobes
27:02may be the means
27:03of ensuring
27:04human survival
27:04if we have the wisdom
27:06to pay attention.
27:11Inside the cerebral cortex
27:12is the microscopic
27:13structure of thought.
27:15The language of the brain
27:16is not the DNA language
27:18of the genes.
27:19What we know
27:20is encoded
27:21in cells called neurons,
27:23tiny switching elements,
27:24every connection
27:25representing one bit
27:27of information.
27:28How many neurons
27:29do each of us have?
27:30Maybe a hundred billion
27:32comparable to the number
27:33of stars
27:33in the Milky Way galaxy.
27:35And there are something
27:36like a hundred trillion
27:37neural connections.
27:42This intricate
27:43and marvelous
27:45network of neurons
27:46has been called
27:48an enchanted loom
27:50where millions
27:51of flashing shuttles
27:53weave a dissolving
27:55pattern.
27:56Even in sleep
27:57the brain is pulsing
27:59and throbbing
28:00and flashing
28:01with the complex business
28:02of human life,
28:03dreaming,
28:04remembering,
28:05figuring things out.
28:06Our thoughts,
28:08our visions,
28:09our fantasies
28:10have a tangible
28:11physical reality.
28:13What does a thought
28:14look like?
28:15Well, it's made
28:16of hundreds
28:16of electrochemical impulses.
28:18over there,
28:20for example,
28:21is a spark
28:22of a memory,
28:23maybe
28:24the smell
28:25of lilacs
28:26on a country road
28:27in childhood.
28:29And there
28:29goes a bit
28:31of an anxious
28:32all-points bulletin.
28:33Perhaps,
28:35where did I leave
28:35my keys?
28:36The neurons
28:40store sounds,
28:42too,
28:42and snatches
28:44of music.
28:45Whole orchestras
28:46play inside
28:48our heads.
28:54The landscape
28:55of the human
28:56cerebral cortex
28:57is deeply furrowed,
28:59and there's
28:59a good reason
29:00for it.
29:01These convolutions
29:02greatly increase
29:03the surface area
29:04available for information
29:06storage
29:06in a skull
29:07of limited size.
29:14The world of thought
29:15is roughly divided
29:16into two hemispheres.
29:18Over there
29:18is the right hemisphere
29:19of the cerebral cortex.
29:21It's mainly
29:21responsible for
29:22pattern recognition,
29:23intuition,
29:24sensitivity,
29:25creative insights.
29:27And over here
29:27is the left hemisphere,
29:29presiding over
29:30rational, analytic,
29:31and critical thinking.
29:36These are
29:40the two sides,
29:42the dual strengths,
29:45the essential opposites
29:46that characterize
29:47human thinking.
29:49Before us
29:50are the means,
29:51both for generating
29:53ideas
29:53and for testing
29:54their validity.
29:56There's a continuous
29:56dialogue going on
29:58between the two hemispheres
29:59of the brain
30:00channeled through
30:02this immense bundle
30:04of nerve fibers
30:05which is called
30:06the corpus callosum.
30:08It's a bridge
30:09between creativity
30:10and analysis,
30:12both of which
30:13are necessary
30:13if we're to
30:14understand the world.
30:17The information
30:19content of the human brain
30:20expressed in bits
30:22is probably comparable
30:23to the number
30:23of connections
30:24between the neurons
30:25in the cortex,
30:26about 100 trillion bits,
30:2810 to the 14th connections.
30:31If written out
30:32in English,
30:33it would fill
30:33some 20 million volumes,
30:35as many as in the world's
30:36largest libraries.
30:38The equivalent
30:38of 20 million volumes
30:40worth of information
30:41is inside the heads
30:42of every one of us.
30:44The brain
30:45is a very big place
30:46in a very small space.
30:51Most of the books
30:52in the brain
30:52are up here
30:53in the cerebral cortex.
30:55Down there,
30:57in the basement
30:57of the brain,
30:58are the functions
30:59that our remote ancestors
31:01mainly depended on
31:02for survival.
31:03Aggression,
31:04child-rearing,
31:05sex,
31:06the willingness
31:07to follow leaders blindly,
31:09lots of things
31:10that we can still recognize
31:11in our lives today.
31:13Of the higher brain functions,
31:15some of them,
31:16like reading,
31:17writing,
31:18speaking,
31:19seem to be located
31:20in particular places
31:22in the cerebral cortex.
31:24On the other hand,
31:25each memory
31:26seems to be stored
31:27in many separate
31:29locales
31:30in the brain.
31:31Old memories
31:32are in lots of places.
31:40Here's one of my
31:41earliest memories.
31:42that's a good boy.
31:53Lunch is almost ready.
31:55that was a long time ago.
32:20But its imprint
32:25has not faded
32:26in the library
32:27of this brain.
32:36But the brain
32:37does much more
32:38than just recollect.
32:40It intercompares,
32:41it synthesizes,
32:43it analyzes,
32:44it generates abstractions.
32:46The simplest thought,
32:53like the concept
32:54of the number one,
32:55has an elaborate
32:55logical underpinning.
32:57The brain
32:58has its own language
32:59for testing the structure
33:00and consistency
33:01of the world.
33:02But we never see
33:03the machinery
33:03of logical analysis,
33:05only the conclusions.
33:06There's so much more
33:10that we must figure out
33:11than the genes
33:12can know.
33:13That's why
33:14the brain library
33:16has 10,000 times
33:18more information
33:19in it
33:19than the gene library.
33:21Our passion
33:22for learning
33:23is the tool
33:24for our survival.
33:25And unlike
33:32the musty bindings
33:34of our gene library,
33:35in which hardly
33:36a word changes
33:37in a century,
33:38the brain library
33:39is made of
33:40loose-leaf books.
33:42We're constantly
33:43adding new pages
33:44and new volumes.
33:45Emotions
33:55and ritual
33:56behavior patterns
33:57are built
33:58very deeply
33:59into us.
34:00They're a part
34:01of our humanity.
34:03But they're not
34:03characteristically human.
34:06Many other animals
34:07have feelings.
34:08What distinguishes
34:09our species
34:09is thought.
34:12The cerebral cortex
34:13is, in a way,
34:15a liberation.
34:17We need no longer
34:18be trapped
34:19in the genetically
34:20inherited behavior
34:21patterns of lizards
34:23and baboons,
34:25territoriality
34:26and aggression
34:27and dominance
34:28hierarchies.
34:30We are,
34:31each of us,
34:32largely responsible
34:33for what gets
34:34put into our brains,
34:36for what,
34:36as adults,
34:37we wind up
34:38caring for
34:39and knowing about.
34:42No longer
34:43at the mercy
34:43of the reptile brain,
34:45we can change
34:47ourselves.
34:49Think of the
34:50possibilities.
34:50things.
34:53¶¶
35:22The city, like the brain, has evolved in successive stages.
35:28The vestiges of its past are still retained among the constructions of the present.
35:42A city like New York developed from a small center and slowly grew, leaving many of the old parts still functioning.
35:49Some of the major streets date to the 17th century.
35:53Its commercial hub to the 18th century.
35:55The water and gas works to the 19th.
35:58The electrical and communication systems to the 20th century.
36:01The city has evolved much faster than the brain.
36:16Only 10,000 years ago, the human brain looked exactly as it does today, and we were just as smart.
36:21But there were no cities, only a few scattered encampments in the vast primordial forests.
36:28Today, it's just the opposite.
36:31Forests and grasslands often seem like scattered islands in a sea of cities.
36:35If you were an observer from an alien world, you would have noticed that something very complicated has been happening here over the last few thousand years.
36:45It might take you a while to figure out the details, but you would recognize by its complexity, unmistakable evidence for intelligent life.
36:53On closer scrutiny, you might even be able to recognize individual intelligent beings.
36:59The evolution of the city is due to their conscious activity.
37:09Millions of human beings working more or less together to preserve the city, to reconstruct it, and to change it.
37:16It might be more efficient if all civic systems were periodically replaced from top to bottom.
37:37But as in the brain, everything has to work during the renovation.
37:41So the city mostly adds new parts, while the old parts continue, more or less, to function.
37:50For example, in the 17th century, you traveled between Brooklyn and Manhattan across the East River by ferry.
37:58In the 19th century, the technology became available to construct a suspension bridge across the river.
38:04It was built precisely at the site of the ferry terminal, because major thoroughfares were already converging there.
38:11Later, when it became possible to construct a tunnel under the river, that, too, was built in the same place, and for the same reason.
38:20This use and restructuring of previous systems for new purposes is very much like the pattern of biological evolution.
38:27Or consider Third Avenue.
38:30In the 17th century, you made your way uptown on foot or on horseback.
38:36A little later, there were coaches, the horses prancing, the coachmen cracking their whips.
38:43And then these were replaced by horse-drawn trolleys clanging along fixed tracks on this avenue.
38:50Then electrical technology developed, and a great elevated railway line was constructed, called the Third Avenue L, which dominated this street.
39:02Until 1954, when it was utterly demolished.
39:06Anyway, L was then replaced by buses and taxi cabs, which still are the main forms of public transportation on Third Avenue.
39:16Now, as gasoline becomes a rare commodity, the internal combustion engine will be replaced by something else.
39:24Maybe public transport on Third Avenue in the 21st century will be by, I don't know, pneumatic tubes or electric cars.
39:34Every step in the evolution of Third Avenue transport has been conservative, following a route first laid down in the 17th century.
39:46But the brain is still more conservative than the city.
39:50If this were the brain, we might have horse-drawn trolleys and the hill and buses, all operating simultaneously, redundantly, competitively.
40:02The vestiges of earlier history clearly in evidence.
40:05When our genes could not store all the information necessary for our survival, we slowly invented brains.
40:24But then, the time came, maybe tens of thousands of years ago, when we needed to know more than could conveniently be stored in brains.
40:34So, we learned to stockpile enormous quantities of information outside our bodies.
40:45We are the only species on the planet, so far as we know, to have invented a communal memory.
40:51The warehouse of that memory is called the library.
40:58Libraries also have evolved.
40:59The Assyrian library of Asurbanipal had thousands of clay tablets.
41:05The celebrated library of Alexandria, in Egypt, consisted of almost a million papyrus scrolls.
41:11Great modern libraries, like the New York Public Library, contain some 10 million books.
41:20That's more than 10 to the 14th bits of information in words.
41:25More than 100 trillion bits.
41:28And if we count pictures, it's something like 10 to the 15th bits of information.
41:34Now, that's more than 10,000 times the total number of bits of information in our genes.
41:39Something like 10 times the total amount of information in our brains.
41:44If I were to read a book a week for my entire adult lifetime, and I lived an ordinary lifetime, when I was all done, I would have read maybe a few thousand books.
41:58No more.
41:58In this library, that's from about here, roughly, to about here.
42:15But that's only a tenth of a percent or so of the total number of books in the library.
42:20The trick is to know which books to read.
42:27But they're all here.
42:29What an astonishing thing a book is.
42:42It's a flat object made from a tree with flexible parts on which are imprinted lots of funny, dark squiggles.
42:54But one glance at it, and you're inside the mind of another person.
43:00Maybe somebody dead for thousands of years.
43:04Across the millennia, an author is speaking clearly and silently inside your head, directly to you.
43:12Writing is perhaps the greatest of human inventions, binding together people who never knew each other, citizens of distant epochs.
43:24Books break the shackles of time.
43:27A book is proof that humans are capable of working magic.
43:32And this room is filled with magic.
43:35Some of the earliest authors wrote on bones and stones.
43:45Cuneiform writing is the remote ancestor of the modern Western alphabet.
43:49It was invented in the Near East about 5,000 years ago.
43:53Its purpose?
43:55To keep records.
43:57Records of the purchase of grain, the sale of land, the triumphs of kings, the statutes of priests,
44:04the positions of the stars, the prayers to the gods.
44:10This cone was made around the year 2350 B.C.
44:154,300 years ago, there were people chipping and chiseling away the message on this cone.
44:22What is that message?
44:23It's a prayer.
44:26The inscription on this cylinder honors a king.
44:32Nebuchadnezzar, king of Babylon in the 6th century B.C.
44:37For thousands of years, writing was chiseled into stone, scratched onto wax or bark or leather,
44:46painted on bamboo or silk or paper, but always in editions of one copy, one copy at a time.
44:54Always, except for inscriptions on monuments, for a tiny readership.
45:00But then, in China, between the 2nd and the 6th centuries, paper, ink, and printing with carved wooden blocks
45:24were all invented, more or less, together, permitting many copies of a work to be made and distributed.
45:32This is Chinese magic from the 12th century.
45:37It took a thousand years for the idea to catch on in relatively remote and backward Europe.
45:45Just before the invention of movable type around the year 1450,
45:52there were no more than a few tens of thousands of books in all of Europe,
45:55every one of them handwritten.
45:57Fifty years later, there were 10 million printed books in Europe.
46:03Learning became available to anyone who could read.
46:08Suddenly, books were being printed all over the world.
46:11Magic was everywhere.
46:13It is 23 centuries since the founding of the Alexandrian Library.
46:21Since then, a hundred generations have lived and died.
46:25If information were passed on merely by word of mouth,
46:28how little we should know of our own past.
46:30How slow would be our progress.
46:33Everything would depend on what we had been told, on how accurate the account.
46:37Ancient learning might be revered,
46:38but in successive retellings, it would become muddled and then lost.
46:44Books permit us to voyage through time to tap the wisdom of our ancestors.
46:51A library connects us with the insights and knowledge
46:55of the greatest minds and the best teachers
46:58drawn from the whole planet and from all our history
47:01to instruct us without tiring
47:03and to inspire us to make our own contributions
47:06to the collective knowledge of the human species.
47:13There's a fair number of Gutenberg Bibles
47:22and first folios of Shakespeare in the world,
47:25but most of the books you see in front of you
47:28are limited editions with very few surviving copies.
47:31But there also exists in the world mass printings of paper-bound books
47:38that I think are still more wonderful.
47:42For the price of a modest meal, you get the history of Rome.
47:48Books are like seeds.
47:50They can lie dormant for centuries,
47:51but they may also produce flowers in the most unpromising soil.
47:57These books are the repositories of the knowledge of our species
48:01and of our long evolutionary journey
48:05from genes to brains to books.
48:09Libraries in ancient Egypt bore these words on their walls.
48:31Nourishment for the soul.
48:36And that's still a pretty fair assessment of what libraries provide.
48:40Even at night, the city, like the brain,
49:01is busy assimilating and distributing information.
49:04Information keeps it alive
49:06and provides the tools to adapt to changing conditions.
49:12The long human journey from genes to brains to books.
49:22Information itself evolves,
49:24nurtured by open communication and free inquiry.
49:31The units of biological evolution are genes.
49:34The units of cultural evolution are ideas.
49:37Ideas are transported all over the planet.
49:40They reproduce through communication.
49:42They are selected by analysis and debate.
49:45In the last few millennia,
49:47something extraordinary has been happening on the planet Earth.
49:50Rich information from distant lands and peoples
49:53has become routinely available.
49:57The number of bits to which we have access
49:59has grown dramatically.
50:04Computers can now store and process enormous amounts of information
50:11extremely rapidly.
50:13In our time, a revolution has begun.
50:15A revolution perhaps as significant
50:17as the evolution of DNA and nervous systems
50:20and the invention of writing.
50:23Direct communication among billions of human beings
50:26is now made possible by computers and satellites.
50:29The potential for a global intelligence is emerging,
50:34linking all the brains on Earth
50:35into a planetary consciousness.
50:42Elsewhere, there may be brains,
50:44even planetary brains,
50:46but there will be no brains quite like ours.
50:49Mutation and natural selection
50:50are basically random processes.
50:52If the Earth were started over again,
50:55intelligence might very well emerge,
50:57but anything closely resembling a human being
50:59would be unlikely.
51:00On another planet with a different sequence
51:06of random processes to make hereditary diversity
51:08and a different environment
51:11to select particular combinations of genes,
51:14the chance of finding beings very similar to us
51:16must be close to zero.
51:19But the chance of finding another form of intelligence
51:21isn't close to zero.
51:23Their brains may well have evolved from the inside out,
51:26as ours have.
51:27They may well have switching elements
51:29analogous to our neurons,
51:31but their neurons might be very different.
51:33Maybe they're superconductors,
51:35which work at very low temperatures,
51:37in which case their speed of thought
51:40might be 10 million times faster than ours.
51:44Or perhaps their neurons are not in direct physical contact
51:49with each other,
51:50but in radio communication,
51:51so a single intelligent being
51:54could be distributed
51:55among many different organisms.
51:58There may be planets
51:59on which intelligent beings have
52:01not 10 to the 11th neurons each,
52:04as we do,
52:05but 10 to the 20th,
52:07or 10 to the 30th.
52:10I wonder what they would know.
52:13If we could make contact,
52:15there would be much in their brains
52:17that would be of enormous interest
52:19to ours.
52:20And vice versa.
52:23I think extraterrestrial intelligence,
52:25even beings astonishingly more evolved than we,
52:28will be curious about us,
52:30about what we know,
52:31how we think,
52:32the course of our evolution,
52:34the prospects for our future.
52:37Within every human brain,
52:38patterns of electrochemical impulses
52:40are continuously forming and dissipating.
52:43They reflect our emotions,
52:45ideas, and memories.
52:46When recorded and amplified,
52:49these impulses sound like this.
52:55But would an extraterrestrial being,
52:56no matter how advanced,
52:58be able to read the mind
52:59that made these sounds?
53:01We ourselves are far from being able to do so.
53:05But in fact,
53:06we have sent the very impulses you are hearing,
53:09reflecting the emotions, ideas,
53:10and memories of one human being
53:12on a voyage to the stars.
53:24In August and September 1977,
53:27two Voyager spacecraft were launched
53:30on an epic journey
53:31to the outer solar system
53:33and beyond.
53:35Their scientific mission
53:36was to explore the giant planets.
53:39First Jupiter and its satellites,
53:42and then Saturn and its system of moons.
53:44Close encounters with these great worlds
53:55accelerate the Voyager spacecraft
53:57out of the solar system.
54:01As an incidental consequence
54:03of their trajectories,
54:05they will be carried inexorably
54:06into the realm of the stars,
54:08where they will wander forever.
54:10The ships will be slightly eroded
54:14within the solar system
54:15by micrometeorites,
54:17planetary ring systems,
54:19and radiation belts.
54:24But once past the planets,
54:26they will endure for a billion years
54:29in the cold vacuum
54:30of interstellar space.
54:34Perhaps in the distant future,
54:36beings of an alien civilization
54:37will intercept these ships.
54:39They will examine our spacecraft
54:41and understand much
54:42about our science and technology.
54:45But a machine alone
54:47can tell only so much
54:48about its makers.
54:50So each bears a golden phonograph record
54:53with not only the brainwaves
54:55of a woman from Earth,
54:56but also an anthology
54:57of the music and pictures
54:59and sounds of our planet,
55:01including greetings
55:02in 60 human languages
55:04and the salutations
55:05of the humpback whales.
55:07The record cover
55:09bears instructions
55:10on how to hear the sounds
55:11and see the pictures
55:12encoded on the disc,
55:14including some snapshots
55:16from the family album
55:17of a distant world.
55:19of a human being.
55:26I will be here.
55:28I will be here.
55:31I will be here.
55:36The Voyager record is a message in a bottle
55:51cast into the cosmic ocean.
55:54It contains some of our thoughts and our feelings,
55:58something of the information we store
56:00in genes and brains and books.
56:03The recipients, if any, will understand the pictures
56:09and sounds incompletely at best.
56:11But one thing would be clear about us.
56:14No one sends such a message on such a journey
56:17without a positive passion for the future.
56:20For all the possible vagaries of the message,
56:23they will be sure that we were a species endowed
56:26with hope and perseverance,
56:29at least a little intelligence,
56:30and a longing to make contact with the cosmos.
56:35Shh!
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