The idea of intelligence is explored in the concepts of computers (using bits as their basic units of information), whales (in their songs and their disruptions by human activities), DNA, the human brain (the evolution of the brain stem, frontal lobes, neurons, cerebral hemispheres, and corpus callosum under the Triune Brain Model), and man-made structures for collective intelligence (cities, libraries, books, computers, and satellites). The episode ends with speculation on alien intelligence and the information conveyed on the Voyager Golden Record.
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00:30The surface of the Earth is far more beautiful and far more intricate than any lifeless world.
00:58Our planet is graced by life, and one quality that sets life apart is its complexity, slowly evolved through four billion years of natural selection.
01:08You can describe in detail how a rock is put together in a single paragraph, but to describe the basic structure of a tree or a blade of grass or even a one-celled animal, you'd need many volumes.
01:25It takes a great deal of information to make or even to characterize a living thing.
01:31The measuring rod, the unit of information, is something called the bit.
01:40It's an answer, either yes or no, to one unambiguously phrased question.
01:46So, to specify whether a light switch is on or off requires only a single bit.
01:51To specify something of greater complexity requires more bits.
01:55There's a popular game called 20 questions, which shows that a great deal can be specified in only 20 bits.
02:03For example, I have something in my hand.
02:07What is it?
02:08Is it alive?
02:10Yes.
02:10One bit.
02:11Is it an animal?
02:13Nope.
02:14Two bits.
02:15Is it big enough to see?
02:18Yep.
02:19Does it grow on the land?
02:20Yes.
02:21Is it a cultivated plant?
02:23Nope.
02:24Well, with only five bits, we've made some substantial progress to figuring out what it is.
02:29With 20 skillfully chosen questions, we could easily whittle all the cosmos down to a dandelion.
02:37In our explorations of the cosmos, the first step is to ask the right questions.
03:01Then, not with 20 questions, but with billions, we slowly distill from the complexity of the universe its underlying order.
03:12This game has a serious purpose.
03:15Its name is science.
03:19Out here in the great cosmic dark, there are countless stars and planets, some far older than our solar system.
03:28Although we cannot yet be certain, the same processes which led on Earth to the origin of life and intelligence should have been operating throughout the cosmos.
03:37There may be a million worlds in the Milky Way galaxy alone, which are at this moment inhabited by other intelligent beings.
03:46What a wonder, what a joy it would be to know something about non-human intelligence.
04:00And we can.
04:06Here is an exotic inhabited world, mostly covered with a liquid.
04:10We seek the dominant intelligence that lives beneath its fluid surface.
04:21This ocean of liquid water, kilometers deep, is teeming with strange forms of life.
04:45There are communities of transparent beings.
04:58There are societies of creatures which communicate by changing the patterns on their bodies.
05:03There are beings that give off their own light.
05:22There are hungry flowers that devour passers-by, gesticulating trees.
05:28All manner of creatures that seem to violate the boundaries between plants and animals.
05:35There are beings that flutter through the ocean like waltzing orchids.
05:59These are a few of the species that inhabit the water world called Earth.
06:22They are packed with information.
06:33They're packed with information.
06:35Every one of them is a rich behavioral repertoire to ensure its own survival.
06:37Every one of them is a rich behavioral repertoire to ensure its own survival.
06:40But the grandest creatures on the planet, the intelligent and graceful masters of the
06:54deep ocean, are the great whales.
06:57They are the largest animals ever to evolve on the planet Earth, larger by far than the
07:03dinosaurs.
07:04Their ancestors were meat-eating mammals who migrated 70 million years ago in slow steps
07:09from the land into the waters.
07:12Whales like these humpbacks are still mammals.
07:15We humans have much in common with them.
07:17Mothers suckle infants, there's a long childhood in which adults teach the young, and there's
07:22a great deal of play.
07:23These are mammalian characteristics, vital if an animal is to learn.
07:28But the sea is murky.
07:31The senses of sight and smell, which work well for mammals in the land, are not much use
07:36here.
07:36So the whales evolved an extraordinary ability to communicate by sound.
07:42For tens of millions of years, the whales had no natural enemies.
07:46And then, a new and alien and deadly creature suddenly appeared on the placid surface of the
07:53ocean.
08:07These, often noisy and occasionally deadly objects, first appeared in large numbers only a few centuries
08:15ago.
08:16They are artifacts manufactured by land creatures whose ancestors last lived in the oceans 350 million
08:24years ago.
08:25This particular one, however, is on a mission of understanding.
08:44It's called the Regina Maris, the Queen of the Sea, and one of its jobs is to record the sounds
08:55of whales.
08:56Some whale sounds are called songs, but we really don't know what their contents are.
09:07They range in frequency over a broad band of sounds down to frequencies well below the lowest sounds
09:15that the human ear can make out. A typical whale song lasts maybe 15 minutes, the longest perhaps half an hour.
09:24Occasionally, a group of whales will leave their winter waters in the middle of a song, and six months later,
09:31they'll return and pick the song up at precisely the spot that they left it off. Beat for beat, measure for measure, sound for sound.
09:42Whales are very good at remembering. Other times, they will come back after an absence of six months, and the piece will have changed.
09:53A different song will be on the whale hit parade. Very often, the members of the group will sing the same song together.
10:03By some mutual consensus, some collaborative songwriting, the piece changes slowly and often predictably.
10:13I'm not very good at singing the songs of whales, but here's a try.
10:18In January, a tiny fragment of a long whale song might sound like this.
10:27Whoop!
10:29Ah!
10:30In February, something like this.
10:34Whoop!
10:36Ah!
10:37Ah!
10:39And then in March, as maybe you'd predict.
10:43Whoop!
10:44Ah!
10:46Ah!
10:46Ah!
10:47One additional ah a month.
10:57The complex patterns in the songs of the whales are sometimes repeated precisely.
11:03If I imagine that the songs of the humpback whale are sung in a tonal language,
11:09then the number of bits of information in one song is about the same as the information content of the Iliad or the Odyssey.
11:17Is it just a romantic notion that the whales and their cousins, the dolphins, might have something akin to epic poetry?
11:36What might whales or dolphins have to talk or sing about?
12:05They have no manipulative organs.
12:09They can't make great engineering constructs as we can.
12:14But they're social creatures.
12:16They hunt and swim, fish, browse, frolic, mate, play, run from predators.
12:23There might be a great deal to talk about.
12:26The great danger for the whales is a newcomer.
12:45The whales are...
12:46...and upstarted animal only recently, through technology, become competent in the oceans.
12:51a creature called man for 99.99 percent of the history of whales there were no humans in the
13:01deep oceans during this period the whales evolved their extraordinary communication system some
13:08whales emit extremely loud sounds at a frequency of 20 hertz a hertz which is spelled h-e-r-t-z
13:14is a unit of sound frequency and it represents one sound wave entering my ear every second
13:20a frequency of 2,000 hertz sounds and looks like this 200 hertz like this
13:30and 20 hertz like this so although your television set may not transmit
13:36sounds with frequencies as low as 20 hertz the american biologist roger pain has calculated that
13:43there's a deep sound channel in the ocean at these frequencies through which two whales could
13:48communicate with each other essentially anywhere in the world one whale might be off the ross ice
13:55shelf in in antarctica and communicate with another whale in the aleutians in alaska for most of their
14:01history the whales seem to have established a global communications network what two whales might have
14:10to say to each other separated by 15 000 kilometers i haven't the foggiest idea but maybe it's a love song
14:18cast into the vastness of the deep
14:21now this calculation on the range of whale communications assumes that the oceans are quiet
14:32but in the 19th century sailing ships like this one began to be replaced by steam ships another
14:46invention of those strange land animals commercial and military vessels became more abundant
14:52noise pollution in the sea got much worse especially at a frequency of 20 hertz
14:59the crew of this vessel tried consciously to keep her quiet but when its engine is turned on it gets
15:09very loud at a frequency of 20 hertz whales communicating across the oceans must have experienced greater and
15:17greater difficulties the distance over which they could communicate must have steadily decreased
15:22two hundred years ago a typical distance that some whales could communicate across was perhaps
15:3010 000 kilometers today on a typical day the corresponding number is perhaps a few hundred kilometers
15:38we have cut off the whales from themselves creatures which were freely communicating
15:45for tens of millions of years have now effectively been silenced
15:49and we've done worse than that because there persists to this day a traffic in the dead bodies of whales
16:04there are humans who gratuitously hunt and slaughter whales and market the products for
16:09or dog food or lipstick many nations understand why whale murder is monstrous but the traffic continues chiefly by japan and norway and the soviet union
16:24we use the word monster to describe an animal somehow different from us somehow scary
16:30but who's the more monstrous the whales who ask only to be left alone to sing their rich and plaintive songs
16:38or the humans who set out to hunt them and destroy them and have brought many whale species close to the edge of extinction
16:47we're interested in communication with extraterrestrial intelligence
16:53wouldn't a good beginning be better communication with terrestrial intelligence
16:58with other human beings of different cultures and languages with the great apes with the dolphins
17:04but particularly with the whales
17:07but particularly with the whales
17:11to survive a whale must know how to do things
17:18To survive, a whale must know how to do things.
17:40This knowledge is stored in two principal ways,
17:43in the whale's genes and in their very large brains.
17:46We can think of their genes and brains as something like libraries inside their bodies.
17:51The information in the DNA, the genetic information,
17:54includes how to nurse, how to convert shrimp into blubber,
17:58how to hold your breath on a dive one kilometer below the surface.
18:02The information in the brains, the learned information,
18:05involves such things as who's your mother,
18:09or what the meaning is of that song we're hearing just now.
18:16The gene library of whales and people and almost everybody else on Earth is made of DNA.
18:22The only function of this complex molecule is to store and copy information.
18:33We see here the set of instructions in human DNA,
18:37written in a language billions of years older than any human tongue.
18:41Each colored cluster of atoms is a letter in the genetic alphabet,
18:45the language of life.
18:47And there are billions of letters, many billions of bits of information.
18:52If you came from somewhere very different,
18:54you wouldn't be able to specify a whale or a person in a game of 20 questions with only 20 bits.
19:00But a game called 10 billion questions might just work.
19:07Every organism on Earth contains as its inheritance and legacy a portable library.
19:14And the more bits of information you have, the more you can do.
19:18The simplest organism, a virus, needs only about 10,000 bits,
19:27equivalent to the amount of information on one page of an average book.
19:31These are all the instructions it needs to infect some other organism and to reproduce itself,
19:36which are the only things that viruses are any good at.
19:40A bacterium uses roughly a million bits of information, about a hundred printed pages.
19:45Bacteria have a lot more to do than viruses,
19:48because they're not thoroughgoing parasites.
19:50Bacteria have to make a living.
19:56What about a free-swimming, one-celled amoeba?
19:59These creatures are also microscopic.
20:02But in the realm of one-celled animals, they are giants,
20:06the whales of the microbial world.
20:10Each contains about 400 million bits in its DNA.
20:14The equivalent of about 80 volumes of 500 pages each.
20:18That's so much information it takes to make an amoeba.
20:21A creature like a small city, wandering through a drop of water.
20:30And what about a whale or a human being?
20:32Well, the answer seems to be that there's five billion bits.
20:38Five billion bits of information in our encyclopedia of life, in the nucleus of every one of our cells.
20:46So if written out in, say, ordinary English, those instructions, that information, would fill a thousand volumes.
20:56Think of it.
20:58In every one of the hundred trillion cells in your body, there's the contents of a complete library of instructions on how to make every part a view.
21:07Those cells are smart.
21:09If this were my gene library, it would contain everything my body knows how to do on its own without being taught.
21:18The ancient information is written in exhaustive, careful, redundant detail.
21:25How to laugh, how to sneeze, how to walk, how to recognize patterns, how to reproduce, how to digest an apple.
21:34If written out in the language of chemistry, what would the instructions for digesting the sugar in an apple look like?
21:42Well, let's see. Amino acid synthesis, polypeptide chains, transfer RNA, genetic code, enzyme expression, enzyme phosphorylation, we're getting warm.
21:55Hexos, monophosphate, shunt, citric acid cycle, here we are, anaerobic glycolysis.
22:02Now, eating an apple may seem like a very simple thing, but it's not.
22:09In fact, if I consciously had to remember and direct all the chemical steps required to get energy out of food, I'd probably starve to death.
22:20And yet, even a bacterium can do anaerobic glycolysis.
22:25That's why apples rot its lunchtime for the bacteria.
22:30They and we and all the creatures in between possess similar genetic instructions.
22:37Our separate gene libraries have many pages in common, which is, by the way, another reminder of the deep interconnection of all living things on our planet because of a common evolutionary heritage.
22:54Our present human technology can duplicate only a tiny fraction of the intricate biochemistry which our bodies seem to perform so effortlessly.
23:06But we're just beginning the study of biochemistry. Evolution has had billions of years of practice.
23:13The DNA knows.
23:18Now, what if what we had to do was so complicated that even several billion bits of information wasn't enough?
23:27What if, for example, the environment were changing so fast that the pre-coded genetic encyclopedia, which may have served us perfectly well in the past, is now not perfectly adequate?
23:41Why, then, even a gene library of a thousand volumes wouldn't be enough.
23:47That's why we have brains.
23:50Like our other organs, the brain has evolved, increasing over millions of years in complexity and information content.
24:03Its structure reflects all the stages through which it has passed.
24:07The brain has evolved from the inside out.
24:12Deep inside is the oldest part, the so-called brain stem.
24:17It conducts many of the basic biological functions, including the rhythms of life, like heartbeat and respiration.
24:25The higher functions of the brain have evolved in three successive stages, according to a provocative insight by the American biologist Paul McLean.
24:35You see, capping the brain stem is the so-called R complex, R for reptile.
24:42It's the seat of aggression, ritual, territoriality and social hierarchies.
24:49It evolved some hundreds of millions of years ago in our reptilian ancestors.
24:55So, deep inside our brain is something rather like the brain of a crocodile.
25:02Surrounding the R complex is the limbic system, or mammal brain.
25:08It evolved some tens of millions of years ago in ancestors who were mammals, alright, but not yet primates, like monkeys or apes.
25:18It's a major source of our moods and emotions, our concern and care for the young.
25:25And then finally, on the outside of the brain, living in a kind of uneasy truce with the more primitive brains beneath, is the cerebral cortex evolved millions of years ago in ancestors who were primates.
25:43This is the point of embarkation for all our cosmic journeys, the cerebral cortex, where matter is transformed into consciousness.
26:05Here, comprising more than two-thirds of the brain mass, is the realm both of intuition and of critical analysis.
26:14It's here that we have ideas and inspirations, here that we read and write, here that we do mathematics and music.
26:22The cortex regulates our conscious lives.
26:27It is the distinction of our species, the seat of our humanity.
26:32Art and science live here.
26:34Civilization is a product of the cerebral cortex.
26:41Behind the forehead are the frontal lobes of the cerebral cortex.
26:45They may be the places where we anticipate events, where we figure out the future.
26:50But if we can foresee an unpleasant future, we can take steps to avoid it.
26:55Down here, in the frontal lobes, may be the means of ensuring human survival, if we have the wisdom to pay attention.
27:06Inside the cerebral cortex is the microscopic structure of thought.
27:10The language of the brain is not the DNA language of the genes.
27:15What we know is encoded in cells called neurons, tiny switching elements,
27:20every connection representing one bit of information.
27:24How many neurons do each of us have?
27:26Maybe a hundred billion, comparable to the number of stars in the Milky Way galaxy.
27:31And there are something like a hundred trillion neural connections.
27:35This intricate and marvelous network of neurons has been called an enchanted loom,
27:46where millions of flashing shuttles weave a dissolving pattern.
27:52Even in sleep, the brain is pulsing and throbbing and flashing with the complex business of human life,
27:58dreaming, remembering, figuring things out.
28:01Our thoughts, our visions, our fantasies have a tangible, physical reality.
28:08What does a thought look like?
28:10Well, it's made of hundreds of electrochemical impulses.
28:14Over there, for example, is a spark of a memory.
28:18Maybe the smell of lilacs on a country road in childhood.
28:24And there goes a bit of an anxious all points bulletin.
28:29Perhaps, where did I leave my keys?
28:35The neurons store sounds, too, and snatches of music.
28:40Whole orchestras play inside our heads.
28:44The landscape of the human cerebral cortex is deeply furrowed.
28:54And there's a good reason for it.
28:56These convolutions greatly increase the surface area available for information storage
29:02in a skull of limited size.
29:05The world of thought is roughly divided into two hemispheres.
29:13Over there is the right hemisphere of the cerebral cortex.
29:16It's mainly responsible for pattern recognition, intuition, sensitivity, creative insights.
29:22And over here is the left hemisphere, presiding over rational, analytic, and critical thinking.
29:28These are the two sides, the dual strengths, the essential opposites that characterize human thinking.
29:44Before us are the means, both for generating ideas and for testing their validity.
29:51There's a continuous dialogue going on between the two hemispheres of the brain,
29:56which is channeled through this immense bundle of nerve fibers, which is called the corpus callosum.
30:03It's a bridge between creativity and analysis, both of which are necessary if we're to understand the world.
30:13The information content of the human brain, expressed in bits,
30:17is probably comparable to the number of connections between the neurons in the cortex.
30:21About a hundred trillion bits, ten to the fourteenth connections.
30:26If written out in English, it would fill some twenty million volumes,
30:30as many as in the world's largest libraries.
30:33The equivalent of twenty million volumes worth of information is inside the heads of every one of us.
30:39The brain is a very big place in a very small space.
30:44Most of the books in the brain are up here in the cerebral cortex.
30:51Down there, in the basement of the brain, are the functions that our remote ancestors mainly depended on for survival.
30:59Aggression, child-rearing, sex, the willingness to follow leaders blindly.
31:04Lots of things that we can still recognize in our lives today.
31:08Of the higher brain functions, some of them, like reading, writing, speaking,
31:14seem to be located in particular places in the cerebral cortex.
31:19On the other hand, each memory seems to be stored in many separate locales in the brain.
31:26Old memories are in lots of places.
31:29Here is one of my earliest memories.
31:47That's a good boy. Lunch is almost ready.
31:59you're...
32:15That was a long time ago.
32:18But its imprint has not faded in the library of this brain.
32:24But the brain does much more than just recollect.
32:36It intercompares, it synthesizes, it analyzes, it generates abstractions.
32:47The simplest thought, like the concept of the number one, has an elaborate logical underpinning.
32:52The brain has its own language for testing the structure and consistency of the world.
32:58But we never see the machinery of logical analysis, only the conclusions.
33:04There's so much more that we must figure out than the genes can know.
33:09That's why the brain library has 10,000 times more information in it than the gene library.
33:17Our passion for learning is the tool for our survival.
33:22And unlike the musty bindings of our gene library, in which hardly a word changes in a century,
33:34the brain library is made of loose-leaf books.
33:37We're constantly adding new pages and new volumes.
33:41Emotions and ritual behavior patterns are built very deeply into us.
33:56They're part of our humanity.
33:58But they're not characteristically human.
34:01Many other animals have feelings.
34:03What distinguishes our species is thought.
34:07The cerebral cortex is, in a way, a liberation.
34:12We need no longer be trapped in the genetically inherited behavior patterns of lizards and baboons,
34:21territoriality and aggression and dominance hierarchies.
34:25We are, each of us, largely responsible for what gets put into our brains,
34:31for what, as adults, we wind up caring for and knowing about.
34:37No longer at the mercy of the reptile brain, we can change ourselves.
34:44Think of the possibilities.
34:46Think of the possibilities.
35:16The city, like the brain, has evolved in successive stages.
35:23The vestiges of its past are still retained among the constructions of the present.
35:37A city like New York developed from a small center and slowly grew, leaving many of the old parts still functioning.
35:44Some of the major streets date to the 17th century, its commercial hub to the 18th century,
35:51the water and gas works to the 19th, the electrical and communication systems to the 20th century.
36:08The city has evolved much faster than the brain.
36:11Only 10,000 years ago, the human brain looked exactly as it does today, and we were just as smart.
36:17But there were no cities, only a few scattered encampments in the vast primordial forests.
36:24Today, it's just the opposite.
36:26Forests and grasslands often seem like scattered islands in a sea of cities.
36:30If 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.
36:41It might take you a while to figure out the details, but you would recognize by its complexity,
36:46unmistakable evidence for intelligent life.
36:50On closer scrutiny, you might even be able to recognize individual intelligent beings.
36:54The evolution of the city is due to their conscious activity.
37:05Millions of human beings working more or less together to preserve the city, to reconstruct it, and to change it.
37:12It might be more efficient if all civic systems were periodically replaced from top to bottom.
37:32But as in the brain, everything has to work during the renovation, so the city mostly adds new parts while the old parts continue, more or less, to function.
37:46For example, in the 17th century, you traveled between Brooklyn and Manhattan across the East River by ferry.
37:53In the 19th century, the technology became available to construct a suspension bridge across the river.
37:59It was built precisely at the site of the ferry terminal, because major thoroughfares were already converging there.
38:07Later, when it became possible to construct a tunnel under the river, that, too, was built in the same place and for the same reason.
38:15This use and restructuring of previous systems for new purposes is very much like the pattern of biological evolution.
38:23Or consider Third Avenue.
38:25In the 17th century, you made your way uptown on foot or on horseback.
38:32A little later, there were coaches, the horses prancing, the coachmen cracking their whips.
38:39And then these were replaced by horse-drawn trolleys clanging along fixed tracks on this avenue.
38:45Then electrical technology developed, and a great elevated railway line was constructed, called the Third Avenue L, which dominated this street until 1954, when it was utterly demolished.
39:01Anyway, the L was then replaced by buses and taxi cabs, which still are the main forms of public transportation on Third Avenue.
39:12Now, as gasoline becomes a rare commodity, the internal combustion engine will be replaced by something else.
39:19Maybe public transport on Third Avenue in the 21st century will be by, I don't know, pneumatic tubes or electric cars.
39:30Every step in the evolution of Third Avenue transport has been conservative, following a route first laid down in the 17th century.
39:41But the brain is still more conservative than the city.
39:46If this were the brain, we might have horse-drawn trolleys and the hill and buses, all operating simultaneously, redundantly, competitively.
39:58The vestiges of earlier history clearly in evidence.
40:00When our genes could not store all the information necessary for our survival, we slowly invented brains.
40:21But then the time came, maybe tens of thousands of years ago, when we needed to know more than could conveniently be stored in brains.
40:30So, we learned to stockpile enormous quantities of information outside our bodies.
40:40We are the only species on the planet, so far as we know, to have invented a communal memory.
40:47The warehouse of that memory is called the library.
40:53Libraries also have evolved.
40:55The Assyrian library of Asurbanipal had thousands of clay tablets.
41:00The celebrated library of Alexandria, in Egypt, consisted of almost a million papyrus scrolls.
41:07Great modern libraries, like the New York Public Library, contain some 10 million books.
41:12That's more than 10 to the 14th bits of information in words, more than 100 trillion bits.
41:23And if we count pictures, it's something like 10 to the 15th bits of information.
41:29Now, that's more than 10,000 times the total number of bits of information in our genes.
41:34If I were to read a book a week for my entire adult lifetime, and I lived an ordinary lifetime, when I was all done,
41:49I would have read maybe a few thousand books.
41:53No more.
41:54In this library, that's from about here, roughly, to about here.
42:11But that's only a tenth of a percent or so of the total number of books in the library.
42:16The trick is to know which books to read.
42:22But they're all here.
42:25What an astonishing thing a book is.
42:39It's a flat object made from a tree with flexible parts on which are imprinted lots of funny dark squiggles.
42:49But one glance at it, and you're inside the mind of another person.
42:56Maybe somebody dead for thousands of years.
43:00Across the millennia, an author is speaking clearly and silently inside your head, directly to you.
43:09Writing is perhaps the greatest of human inventions.
43:13Binding together people who never knew each other.
43:16Citizens of distant epochs.
43:18Books break the shackles of time.
43:23A book is proof that humans are capable of working magic.
43:28And this room is filled with magic.
43:33Some of the earliest authors wrote on bones and stones.
43:41Cuneiform writing is the remote ancestor of the modern Western alphabet.
43:45It was invented in the Near East about 5,000 years ago.
43:48It's purpose to keep records.
43:52Records of the purchase of grain, the sale of land, the triumphs of kings, the statutes of priests, the positions of the stars, the prayers to the gods.
44:04This cone was made around the year 2350 B.C.
44:114,300 years ago, there were people chipping and chiseling away the message on this cone.
44:17What is that message?
44:19It's a prayer.
44:20The inscription on this cylinder honors a king, Nebuchadnezzar, king of Babylon in the 6th century B.C.
44:32For thousands of years, writing was chiseled into stone, scratched onto wax or bark or leather, painted on bamboo or silk or paper, but always in editions of one copy.
44:48One copy at a time, always, except for inscriptions on monuments, for a tiny readership.
44:56But then, in China, between the 2nd and the 6th centuries, paper, ink, and printing with carved wooden blocks were all invented, more or less, together.
45:22Permitting many copies of a work to be made and distributed.
45:28This is Chinese magic from the 12th century.
45:35It took a thousand years for the idea to catch on in relatively remote and backward Europe.
45:41Just before the invention of movable type around the year 1450, there were no more than a few tens of thousands of books in all of Europe.
45:50Every one of them, handwritten.
45:53Fifty years later, there were 10 million printed books in Europe.
45:58Learning became available to anyone who could read.
46:03Suddenly, books were being printed all over the world.
46:07Magic was everywhere.
46:09It is 23 centuries since the founding of the Alexandrian Library.
46:16Since then, a hundred generations have lived and died.
46:20If information were passed on merely by word of mouth, how little we should know of our own past.
46:26How slow would be our progress.
46:28Everything would depend on what we had been told, on how accurate the account.
46:32Ancient learning might be revered, but in successive retellings, it would become muddled and then lost.
46:39Books permit us to voyage through time to tap the wisdom of our ancestors.
46:45A library connects us with the insights and knowledge of the greatest minds and the best teachers drawn from the whole planet and from all our history
46:56to instruct us without tiring and to inspire us to make our own contributions to the collective knowledge of the human species.
47:05There's a fair number of Gutenberg Bibles and first folios of Shakespeare in the world,
47:21but most of the books you see in front of you are limited editions with very few surviving copies.
47:27But there also exists in the world mass printings of paper-bound books that I think are still more wonderful.
47:38For the price of a modest meal, you get the history of Rome.
47:44Books are like seeds.
47:45They can lie dormant for centuries, but they may also produce flowers in the most unpromising soil.
47:52These books are the repositories of the knowledge of our species and of our long evolutionary journey from genes to brains to books.
48:05Libraries in ancient Egypt bore these words on their walls.
48:28Nourishment for the soul.
48:30And that's still a pretty fair assessment of what libraries provide.
48:53Even at night, the city, like the brain, is busy assimilating and distributing information.
48:59Information keeps it alive and provides the tools to adapt to changing conditions.
49:07The long human journey from genes to brains to books.
49:17Information itself evolves, nurtured by open communication and free inquiry.
49:23The units of biological evolution are genes.
49:30The units of cultural evolution are ideas.
49:33Ideas are transported all over the planet.
49:35They reproduce through communication.
49:37They are selected by analysis and debate.
49:41In the last few millennia, something extraordinary has been happening on the planet Earth.
49:46Rich information from distant lands and peoples has become routinely available.
49:51The number of bits to which we have access has grown dramatically.
50:02Computers can now store and process enormous amounts of information extremely rapidly.
50:08In our time, a revolution has begun.
50:10A revolution perhaps as significant as the evolution of DNA and nervous systems and the invention of writing.
50:19Direct communication among billions of human beings is now made possible by computers and satellites.
50:26The potential for a global intelligence is emerging, linking all the brains on Earth into a planetary consciousness.
50:33Elsewhere, there may be brains, even planetary brains, but there will be no brains quite like ours.
50:44Mutation and natural selection are basically random processes.
50:48If the Earth were started over again, intelligence might very well emerge, but anything closely resembling a human being would be unlikely.
50:56On another planet with a different sequence of random processes to make hereditary diversity and a different environment to select particular combinations of genes, the chance of finding beings very similar to us must be close to zero.
51:14But the chance of finding another form of intelligence isn't close to zero.
51:18Their brains may well have evolved from the inside out, as ours have.
51:22They may well have switching elements analogous to our neurons, but their neurons might be very different.
51:29Maybe they're superconductors, which work at very low temperatures, in which case their speed of thought might be 10 million times faster than ours.
51:38Or perhaps their neurons are not in direct physical contact with each other, but in radio communication, so a single intelligent being could be distributed among many different organisms.
51:53There may be planets on which intelligent beings have not 10 to the 11th neurons each, as we do, but 10 to the 20th, or 10 to the 30th.
52:04I wonder what they would know.
52:08If we could make contact, there would be much in their brains that would be of enormous interest to ours.
52:17And vice versa.
52:18I think extraterrestrial intelligence, even beings astonishingly more evolved than we, will be curious about us, about what we know, how we think, the course of our evolution, the prospects for our future.
52:31Within every human brain, patterns of electrochemical impulses are continuously forming and dissipating.
52:39They reflect our emotions, ideas, and memories.
52:42When recorded and amplified, these impulses sound like this.
52:47But would an extraterrestrial being, no matter how advanced, be able to read the mind that made these sounds?
52:57We ourselves are far from being able to do so.
53:00But in fact, we have sent the very impulses you are hearing, reflecting the emotions, ideas, and memories of one human being, on a voyage to the stars.
53:11In August and September 1977, two Voyager spacecraft were launched on an epic journey to the outer solar system and beyond.
53:30Their scientific mission was to explore the giant planets.
53:35First Jupiter and its satellites, and then Saturn and its system of moons.
53:39Space moon.
53:48Close encounters with these great worlds accelerate the Voyager spacecraft out of the solar system.
53:57As an incidental consequence of their trajectories, they will be carried inexorably into the realm of the stars, where they will wander forever.
54:05The ships will be slightly eroded within the solar system
54:11by micrometeorites, planetary ring systems, and radiation belts.
54:20But once past the planets, they will endure for a billion years
54:24in the cold vacuum of interstellar space.
54:29Perhaps in the distant future,
54:31beings of an alien civilization will intercept these ships.
54:34They will examine our spacecraft
54:36and understand much about our science and technology.
54:41But a machine alone can tell only so much about its makers.
54:45So each bears a golden phonograph record
54:48with not only the brainwaves of a woman from Earth,
54:52but also an anthology of the music and pictures and sounds of our planet,
54:57including greetings in 60 human languages
54:59and the salutations of the humpback whales.
55:03The record cover bears instructions on how to hear the sounds
55:07and see the pictures encoded on the disc,
55:09including some snapshots from the family album of a distant world.
55:21Take care.
55:29Take care.
55:30The Voyager record is a message in a bottle
55:47cast into the cosmic ocean.
55:50It contains some of our thoughts and our feelings,
55:54something of the information we store
55:55in genes and brains and books.
56:00The recipients, if any,
56:03will understand the pictures and sounds incompletely at best.
56:07But one thing would be clear about us.
56:10No one sends such a message on such a journey
56:12without a positive passion for the future.
56:16For all the possible vagaries of the message,
56:18they will be sure that we were a species endowed
56:21with hope and perseverance,
56:24at least a little intelligence,
56:26and a longing to make contact with the cosmos.
56:30Shhh.
56:31Shhh.
56:32Shhh.
56:33Shhh.
56:34Shhh.