1 00:00:48,728 --> 00:00:51,458 SAGAN: The surface of the Earth is far more beautiful... 2 00:00:51,664 --> 00:00:55,395 ...and far more intricate than any lifeless world. 3 00:00:55,601 --> 00:00:57,796 Our planet is graced by life. 4 00:00:58,003 --> 00:01:01,734 And one quality that sets life apart is its complexity... 5 00:01:01,941 --> 00:01:06,537 ...slowly evolved through 4 billion years of natural selection. 6 00:01:08,981 --> 00:01:10,778 You can describe in detail... 7 00:01:10,983 --> 00:01:14,282 ...how a rock is put together in a single paragraph. 8 00:01:14,487 --> 00:01:17,149 But to describe the basic structure of a tree... 9 00:01:17,590 --> 00:01:20,184 ...or a blade of grass or even a one-celled animal... 10 00:01:20,393 --> 00:01:22,554 ...you'd need many volumes. 11 00:01:22,762 --> 00:01:25,162 It takes a great deal of information to make... 12 00:01:25,364 --> 00:01:28,959 ...or even to characterize a living thing. 13 00:01:31,604 --> 00:01:34,129 The measuring rod, the unit of information... 14 00:01:34,340 --> 00:01:37,104 ...is something called the bit. 15 00:01:37,309 --> 00:01:39,504 It's an answer, either yes or no... 16 00:01:39,712 --> 00:01:42,943 ...to one unambiguously phrased question. 17 00:01:43,149 --> 00:01:46,380 So to specify whether a light switch is on or off... 18 00:01:46,585 --> 00:01:48,450 ...requires only a single bit. 19 00:01:48,654 --> 00:01:52,784 To specify something of greater complexity requires more bits. 20 00:01:52,992 --> 00:01:56,086 There's a popular game called 20 Questions... 21 00:01:56,295 --> 00:02:00,231 ...which shows that a great deal can be specified in only 20 bits. 22 00:02:00,433 --> 00:02:02,025 For example... 23 00:02:02,234 --> 00:02:04,225 ...I have something in my hand. 24 00:02:04,437 --> 00:02:05,836 What is it? 25 00:02:06,038 --> 00:02:07,528 Is it alive? Yes. 26 00:02:07,740 --> 00:02:09,037 One bit. 27 00:02:09,241 --> 00:02:11,266 Is it an animal? Nope. 28 00:02:11,477 --> 00:02:12,967 Two bits. 29 00:02:13,212 --> 00:02:15,772 Is it big enough to see? Yep. 30 00:02:16,248 --> 00:02:18,375 Does it grow on the land? Yes. 31 00:02:18,584 --> 00:02:20,984 Is it a cultivated plant? Nope. 32 00:02:21,454 --> 00:02:23,388 Well, with only five bits... 33 00:02:23,589 --> 00:02:26,456 ...we've made substantial progress to figuring out what it is. 34 00:02:26,659 --> 00:02:29,093 With 20 skillfully chosen questions... 35 00:02:29,295 --> 00:02:32,753 ...we could easily whittle all the cosmos down... 36 00:02:33,466 --> 00:02:35,058 ...to a dandelion. 37 00:02:36,035 --> 00:02:38,560 (BLOWS DANDELION) 38 00:02:53,686 --> 00:02:56,211 In our explorations of the cosmos... 39 00:02:56,422 --> 00:02:59,516 ...the first step is to ask the right questions. 40 00:02:59,725 --> 00:03:03,422 Then, not with 20 questions, but with billions... 41 00:03:03,629 --> 00:03:07,087 ...we slowly distill from the complexity of the universe... 42 00:03:07,299 --> 00:03:09,233 ...its underlying order. 43 00:03:09,435 --> 00:03:11,960 This game has a serious purpose. 44 00:03:12,171 --> 00:03:15,140 Its name is science. 45 00:03:16,709 --> 00:03:19,576 Out here in the great cosmic dark... 46 00:03:19,778 --> 00:03:22,303 ...there are countless stars and planets... 47 00:03:22,515 --> 00:03:25,712 ...some far older than our solar system. 48 00:03:25,918 --> 00:03:29,547 Though we cannot be certain, the same processes which led on Earth... 49 00:03:29,755 --> 00:03:31,655 ...to the origin of life and intelligence... 50 00:03:31,857 --> 00:03:34,690 ...should've been operating throughout the cosmos. 51 00:03:34,894 --> 00:03:38,796 There may be a million worlds in the Milky Way galaxy alone... 52 00:03:38,998 --> 00:03:40,397 ...which are at this moment... 53 00:03:40,599 --> 00:03:44,330 ...inhabited by other intelligent beings. 54 00:03:51,777 --> 00:03:54,302 What a wonder, what a joy it would be... 55 00:03:54,513 --> 00:03:57,380 ...to know something about non-human intelligence. 56 00:03:57,583 --> 00:03:59,107 And we can. 57 00:04:03,989 --> 00:04:06,457 Here is an exotic inhabited world... 58 00:04:06,659 --> 00:04:08,854 ...mostly covered with a liquid. 59 00:04:13,832 --> 00:04:16,096 We seek the dominant intelligence... 60 00:04:16,302 --> 00:04:19,635 ...that lives beneath its fluid surface. 61 00:04:35,788 --> 00:04:39,224 This ocean of liquid water kilometers deep... 62 00:04:39,425 --> 00:04:42,986 ...is teeming with strange forms of life. 63 00:04:47,533 --> 00:04:51,162 There are communities of transparent beings. 64 00:04:55,608 --> 00:04:58,133 There are societies of creatures which communicate... 65 00:04:58,344 --> 00:05:01,177 ...by changing the patterns on their bodies. 66 00:05:09,188 --> 00:05:12,589 There are beings that give off their own light. 67 00:05:20,032 --> 00:05:23,866 There are hungry flowers that devour passersby... 68 00:05:24,069 --> 00:05:26,094 ...gesticulating trees. 69 00:05:26,472 --> 00:05:29,669 All manner of creatures that seem to violate... 70 00:05:29,875 --> 00:05:33,174 ...the boundaries between plants and animals. 71 00:05:51,730 --> 00:05:54,528 There are beings that flutter through the ocean like... 72 00:05:54,867 --> 00:05:56,960 ...waltzing orchids. 73 00:06:14,153 --> 00:06:16,018 These are a few of the species... 74 00:06:16,221 --> 00:06:19,088 ...that inhabit the water world called Earth. 75 00:06:30,869 --> 00:06:32,302 They're packed with information. 76 00:06:32,838 --> 00:06:35,432 Each one has a rich behavioral repertoire... 77 00:06:35,641 --> 00:06:37,734 ...to ensure its own survival. 78 00:06:46,685 --> 00:06:48,915 But the grandest creatures on the planet... 79 00:06:49,321 --> 00:06:53,052 ...the intelligent and graceful masters of the deep ocean... 80 00:06:53,258 --> 00:06:55,055 ...are the great whales. 81 00:06:55,260 --> 00:06:58,127 They are the largest animals ever to evolve on Earth... 82 00:06:58,330 --> 00:07:01,128 ...larger, by far, than the dinosaurs. 83 00:07:01,333 --> 00:07:04,564 Their ancestors were meat-eating mammals who migrated... 84 00:07:04,770 --> 00:07:09,207 ...70 million years ago in slow steps from the land into the waters. 85 00:07:09,441 --> 00:07:12,069 Whales, like these humpbacks, are still mammals. 86 00:07:12,311 --> 00:07:14,336 We humans have much in common with them. 87 00:07:14,546 --> 00:07:16,207 Mothers suckle infants... 88 00:07:16,415 --> 00:07:19,077 ...there's a long childhood when adults teach the young... 89 00:07:19,284 --> 00:07:22,879 ...and there's a lot of play. These are mammalian characteristics. 90 00:07:23,088 --> 00:07:25,818 Vital if an animal is to learn. 91 00:07:26,024 --> 00:07:27,821 But the sea is murky. 92 00:07:28,026 --> 00:07:29,960 The senses of sight and smell... 93 00:07:30,162 --> 00:07:31,925 ...which work well for mammals on the land... 94 00:07:32,131 --> 00:07:33,689 ...are not much use here. 95 00:07:33,899 --> 00:07:36,663 So the whales evolved an extraordinary ability... 96 00:07:36,869 --> 00:07:39,360 ...to communicate by sound. 97 00:07:39,571 --> 00:07:43,371 For tens of millions of years, the whales had no natural enemies. 98 00:07:43,575 --> 00:07:47,136 And then, a new and alien and deadly creature... 99 00:07:47,379 --> 00:07:51,247 ...suddenly appeared on the placid surface of the ocean. 100 00:07:52,651 --> 00:07:54,676 (WHALES SINGING) 101 00:08:04,963 --> 00:08:09,332 These often noisy and occasionally deadly objects... 102 00:08:09,535 --> 00:08:13,528 ...first appeared in large numbers only a few centuries ago. 103 00:08:13,739 --> 00:08:15,331 They are artifacts... 104 00:08:15,541 --> 00:08:17,532 ...manufactured by land creatures... 105 00:08:17,743 --> 00:08:20,143 ...whose ancestors last lived in the oceans... 106 00:08:20,345 --> 00:08:22,836 ...350 million years ago. 107 00:08:32,558 --> 00:08:34,856 (BELL RINGS) 108 00:08:36,929 --> 00:08:38,624 This particular one, however... 109 00:08:38,831 --> 00:08:41,925 ...is on a mission of understanding. 110 00:08:44,903 --> 00:08:47,872 It's called the Regina Maris... 111 00:08:48,440 --> 00:08:49,907 ...the "Queen of the Sea." 112 00:08:50,108 --> 00:08:54,442 And one of its jobs is to record the sounds of the whales. 113 00:08:57,749 --> 00:09:00,741 Some whale sounds are called songs... 114 00:09:00,953 --> 00:09:03,888 ...but we really don't know what their contents are. 115 00:09:04,089 --> 00:09:06,387 They range in frequency... 116 00:09:06,592 --> 00:09:09,254 ...over a broadband of sounds... 117 00:09:09,461 --> 00:09:11,827 ...down to frequencies well below... 118 00:09:12,197 --> 00:09:14,757 ...the lowest sounds the human ear can make out. 119 00:09:14,967 --> 00:09:17,765 A typical whale song lasts maybe 15 minutes. 120 00:09:17,970 --> 00:09:21,064 The longest, perhaps half an hour. 121 00:09:21,273 --> 00:09:25,300 Occasionally, a group of whales will leave their winter waters... 122 00:09:25,544 --> 00:09:27,409 ...in the middle of a song... 123 00:09:27,613 --> 00:09:30,707 ...and six months later they'll return and pick the song up... 124 00:09:30,916 --> 00:09:33,350 ...at precisely the spot that they left it off. 125 00:09:33,552 --> 00:09:34,610 Beat for beat. 126 00:09:34,853 --> 00:09:36,150 Measure for measure. 127 00:09:36,355 --> 00:09:37,879 Sound for sound. 128 00:09:39,558 --> 00:09:43,517 Whales are very good at remembering. 129 00:09:44,162 --> 00:09:46,960 Other times they will come back after... 130 00:09:47,165 --> 00:09:50,134 ...an absence of six months, and the piece will have changed. 131 00:09:50,335 --> 00:09:55,034 A different song will be on the whale hit parade. 132 00:09:56,341 --> 00:10:00,744 Very often the members of the group will sing the same song together. 133 00:10:00,946 --> 00:10:05,883 By some mutual consensus, some collaborative songwriting... 134 00:10:06,184 --> 00:10:10,280 ...the piece changes slowly and often predictably. 135 00:10:10,489 --> 00:10:13,981 I'm not very good at singing the songs of whales... 136 00:10:14,192 --> 00:10:16,057 ...but here's a try. 137 00:10:16,261 --> 00:10:17,819 In January... 138 00:10:18,030 --> 00:10:22,160 ...a tiny fragment of a long whale song... 139 00:10:22,367 --> 00:10:24,028 ...might sound like this. 140 00:10:24,236 --> 00:10:27,103 Whoop. Ahh. 141 00:10:28,106 --> 00:10:31,098 In February, something like this. 142 00:10:31,310 --> 00:10:36,213 Whoop. Ahh. Ahh. 143 00:10:36,682 --> 00:10:39,913 And then in March, as maybe you'd predict... 144 00:10:40,118 --> 00:10:45,021 Whoop. Ahh. Ahh. Ahh. 145 00:10:46,091 --> 00:10:49,652 One additional "ahh" a month. 146 00:10:49,861 --> 00:10:53,228 (WHALES SINGING) 147 00:10:54,700 --> 00:10:57,396 The complex patterns in the songs of the whales... 148 00:10:57,602 --> 00:11:00,127 ...are sometimes repeated precisely. 149 00:11:00,339 --> 00:11:03,775 If I imagine that the songs of the humpback whale are sung... 150 00:11:03,976 --> 00:11:05,773 ...in a tonal language... 151 00:11:05,978 --> 00:11:08,640 ...then the number of bits of information in one song... 152 00:11:08,847 --> 00:11:11,179 ...is the same as the information content... 153 00:11:11,383 --> 00:11:14,375 ...of the Iliad or the Odyssey. 154 00:11:19,324 --> 00:11:21,383 (SPLASHING) 155 00:11:26,031 --> 00:11:27,692 Is it just a romantic notion... 156 00:11:27,899 --> 00:11:30,367 ...that the whales and their cousins, the dolphins... 157 00:11:30,569 --> 00:11:34,562 ...might have something akin to epic poetry? 158 00:11:59,264 --> 00:12:03,860 What might whales or dolphins have to talk or sing about? 159 00:12:04,069 --> 00:12:06,094 They have no manipulative organs. 160 00:12:06,304 --> 00:12:10,434 They can't make great engineering constructs as we can. 161 00:12:11,510 --> 00:12:13,205 But they're social creatures. 162 00:12:13,412 --> 00:12:15,880 They hunt and swim, fish... 163 00:12:16,081 --> 00:12:18,208 ...browse, frolic, mate, play... 164 00:12:19,151 --> 00:12:20,812 ...run from predators. 165 00:12:21,019 --> 00:12:22,919 There might be a lot to talk about. 166 00:12:38,570 --> 00:12:42,529 The great danger for the whales is a newcomer... 167 00:12:42,741 --> 00:12:46,575 ...an upstart animal only recently through technology... 168 00:12:46,778 --> 00:12:49,372 ...become competent in the oceans: 169 00:12:50,749 --> 00:12:52,876 A creature called man. 170 00:12:54,152 --> 00:12:56,882 For 99.99% of the history of whales... 171 00:12:57,089 --> 00:12:59,387 ...there were no humans in the deep oceans. 172 00:12:59,991 --> 00:13:02,016 During this period, the whales evolved... 173 00:13:02,227 --> 00:13:04,525 ...their extraordinary communications system. 174 00:13:04,729 --> 00:13:08,859 Some whales emit extremely loud sounds at a frequency of 20 hertz. 175 00:13:09,067 --> 00:13:13,265 A hertz, which is spelled H-E-R-T-Z, is a unit of sound frequency... 176 00:13:13,472 --> 00:13:18,068 ...and it represents one sound wave entering my ear every second. 177 00:13:18,276 --> 00:13:20,870 A frequency of 2000 hertz sounds... 178 00:13:21,079 --> 00:13:22,808 ...and looks like this. 179 00:13:23,014 --> 00:13:25,505 (HIGH PITCHED TONE) 180 00:13:26,084 --> 00:13:28,211 200 hertz, like this. 181 00:13:28,420 --> 00:13:29,648 (MEDIUM PITCHED TONE) 182 00:13:29,855 --> 00:13:31,413 And 20 hertz, like this. 183 00:13:31,623 --> 00:13:33,454 Although your TV set may not transmit... 184 00:13:33,658 --> 00:13:36,650 ...sounds with frequencies as low as 20 hertz. 185 00:13:37,696 --> 00:13:40,256 The American biologist Roger Payne has calculated... 186 00:13:40,465 --> 00:13:44,265 ...that there's a deep sound channel in the ocean at these frequencies... 187 00:13:44,469 --> 00:13:47,131 ...through which two whales could communicate... 188 00:13:47,339 --> 00:13:48,931 ...anywhere in the world. 189 00:13:49,141 --> 00:13:53,976 One whale might be off the Ross Ice Shelf then in Antarctica... 190 00:13:54,179 --> 00:13:57,842 ...and communicate with another whale in the Aleutians in Alaska. 191 00:13:58,183 --> 00:14:00,981 For most of their history, whales seem to have established... 192 00:14:01,186 --> 00:14:04,314 ...a global communications network. 193 00:14:06,057 --> 00:14:08,719 What two whales might have to say to each other... 194 00:14:08,927 --> 00:14:13,261 ...separated by 15,000 kilometers, I haven't the foggiest idea. 195 00:14:13,465 --> 00:14:15,865 But maybe it's a love song... 196 00:14:16,067 --> 00:14:19,730 ...cast into the vastness of the deep. 197 00:14:23,842 --> 00:14:27,005 Now, this calculation on the range of whale communications... 198 00:14:27,212 --> 00:14:30,238 ...assumes that the oceans are quiet. 199 00:14:34,152 --> 00:14:35,016 (WOOD CREAKS) 200 00:14:35,220 --> 00:14:36,653 (BELL RINGS) 201 00:14:36,855 --> 00:14:39,824 But in the 19th century, sailing ships like this one... 202 00:14:40,158 --> 00:14:42,718 ...began to be replaced by steamships... 203 00:14:42,928 --> 00:14:46,193 ...another invention of those strange land animals. 204 00:14:46,398 --> 00:14:50,164 Commercial and military vessels became more abundant. 205 00:14:52,003 --> 00:14:54,164 The noise pollution in the sea got much worse... 206 00:14:54,773 --> 00:14:57,867 ...especially at a frequency of 20 hertz. 207 00:14:58,777 --> 00:15:00,972 (ENGINE HUMS) 208 00:15:01,580 --> 00:15:04,606 The crew of this vessel try consciously to keep her quiet. 209 00:15:04,816 --> 00:15:05,942 But when its engine is on... 210 00:15:06,151 --> 00:15:08,711 ...it gets very loud at a frequency of 20 hertz. 211 00:15:10,422 --> 00:15:12,617 Whales communicating across the oceans... 212 00:15:12,824 --> 00:15:15,759 ...must've experienced greater and greater difficulties. 213 00:15:15,961 --> 00:15:18,088 The distance over which they could communicate... 214 00:15:18,296 --> 00:15:20,764 ...must have steadily decreased. 215 00:15:21,933 --> 00:15:23,628 Two hundred years ago... 216 00:15:23,835 --> 00:15:26,770 ...a typical distance that some whales could communicate across... 217 00:15:26,972 --> 00:15:29,941 ...was perhaps 10,000 kilometers. 218 00:15:30,141 --> 00:15:32,439 Today, on a typical day... 219 00:15:32,644 --> 00:15:36,273 ...the corresponding number is perhaps a few 100 kilometers. 220 00:15:36,481 --> 00:15:39,678 We have cut off the whales from themselves. 221 00:15:39,884 --> 00:15:42,478 Creatures which were freely communicating... 222 00:15:42,687 --> 00:15:44,484 ...for tens of millions of years... 223 00:15:44,689 --> 00:15:47,715 ...have now effectively been silenced. 224 00:15:53,531 --> 00:15:55,465 And we've done worse than that... 225 00:15:55,667 --> 00:15:58,067 ...because there persists till this day... 226 00:15:58,270 --> 00:16:01,865 ...a traffic in the dead bodies of whales. 227 00:16:02,073 --> 00:16:05,167 There are humans who gratuitously hunt and slaughter whales... 228 00:16:05,377 --> 00:16:10,314 ...and market the products for dog food or lipstick. 229 00:16:11,216 --> 00:16:15,516 Many nations understand why whale murder is monstrous... 230 00:16:15,720 --> 00:16:18,211 ...but the traffic continues chiefly... 231 00:16:18,423 --> 00:16:21,984 ...by Japan and Norway and the Soviet Union. 232 00:16:22,894 --> 00:16:25,089 We use "monster" to describe an animal... 233 00:16:25,330 --> 00:16:28,493 ...somehow different from us, somehow scary. 234 00:16:29,301 --> 00:16:31,269 But who's the more monstrous... 235 00:16:31,469 --> 00:16:33,562 ...the whales, who ask to be left alone... 236 00:16:33,772 --> 00:16:36,434 ...to sing their rich and plaintive songs... 237 00:16:36,708 --> 00:16:40,667 ...or the humans, who set out to hunt them and destroy them... 238 00:16:40,879 --> 00:16:44,975 ...and have brought many whale species close to the edge of extinction? 239 00:16:47,385 --> 00:16:50,912 We're interested in communication with extraterrestrial intelligence. 240 00:16:51,122 --> 00:16:53,022 Wouldn't a good beginning be... 241 00:16:53,224 --> 00:16:56,022 ...better communication with terrestrial intelligence... 242 00:16:56,227 --> 00:16:59,594 ...with other human beings of different cultures and languages... 243 00:16:59,798 --> 00:17:01,993 ...with the great apes, with the dolphins... 244 00:17:02,200 --> 00:17:04,691 ...but particularly with the whales? 245 00:17:33,698 --> 00:17:37,293 To survive, a whale must know how to do things. 246 00:17:37,502 --> 00:17:39,936 This knowledge is stored in two principal ways... 247 00:17:40,138 --> 00:17:43,733 ...in the whale's genes and in their very large brains. 248 00:17:43,942 --> 00:17:45,807 We can think of their genes and brains... 249 00:17:46,010 --> 00:17:48,911 ...as something like libraries inside their bodies. 250 00:17:49,114 --> 00:17:51,878 The information in the DNA, the genetic information... 251 00:17:52,083 --> 00:17:53,880 ...includes how to nurse... 252 00:17:54,085 --> 00:17:56,246 ...how to convert shrimp into blubber... 253 00:17:56,454 --> 00:18:00,390 ...how to hold your breath on a dive one kilometer below the surface. 254 00:18:00,592 --> 00:18:03,425 The information in the brains, the learned information... 255 00:18:03,628 --> 00:18:05,186 ...involves such things as... 256 00:18:05,397 --> 00:18:06,455 ...who's your mother... 257 00:18:06,664 --> 00:18:10,122 ...or what the meaning is of that song we're hearing just now. 258 00:18:13,304 --> 00:18:16,296 The gene library of whales and people... 259 00:18:16,508 --> 00:18:17,998 ...and everybody else on Earth... 260 00:18:18,209 --> 00:18:19,801 ...is made of DNA. 261 00:18:20,011 --> 00:18:22,104 The only function of this complex molecule... 262 00:18:22,313 --> 00:18:26,147 ...is to store and copy information. 263 00:18:30,155 --> 00:18:34,114 We see here the set of instructions in human DNA... 264 00:18:34,325 --> 00:18:38,989 ...written in a language billions of years older than any human tongue. 265 00:18:39,197 --> 00:18:41,131 Each colored cluster of atoms... 266 00:18:41,332 --> 00:18:44,768 ...is a letter in the genetic alphabet: The language of life. 267 00:18:44,969 --> 00:18:46,436 There are billions of letters... 268 00:18:46,638 --> 00:18:49,903 ...many billions of bits of information. 269 00:18:50,408 --> 00:18:52,535 If you came from somewhere very different... 270 00:18:52,744 --> 00:18:55,804 ...you wouldn't be able to specify a whale or a person... 271 00:18:56,014 --> 00:18:59,450 ...in a game of 20 Questions with only 20 bits. 272 00:18:59,651 --> 00:19:03,052 But a game called 10 Billion Questions... 273 00:19:03,254 --> 00:19:04,949 ...might just work. 274 00:19:05,156 --> 00:19:06,487 Every organism on Earth... 275 00:19:06,691 --> 00:19:09,455 ...contains as its inheritance and legacy... 276 00:19:09,661 --> 00:19:11,526 ...a portable library. 277 00:19:11,729 --> 00:19:16,098 And the more bits of information you have, the more you can do. 278 00:19:19,737 --> 00:19:21,932 The simplest organism, a virus... 279 00:19:22,140 --> 00:19:24,370 ...needs only about 10,000 bits. 280 00:19:24,576 --> 00:19:28,637 Equal to the amount of information on one page of an average book. 281 00:19:28,847 --> 00:19:30,576 These are all the instructions it needs... 282 00:19:30,782 --> 00:19:33,615 ...to infect some other organism and to reproduce itself... 283 00:19:33,818 --> 00:19:37,219 ...which are the only things that viruses are any good at. 284 00:19:37,422 --> 00:19:40,949 A bacterium uses roughly a million bits of information... 285 00:19:41,159 --> 00:19:42,922 ...about 100 printed pages. 286 00:19:43,127 --> 00:19:45,391 Bacteria have a lot more to do than viruses. 287 00:19:45,597 --> 00:19:50,125 They're not thoroughgoing parasites. Bacteria have to make a living. 288 00:19:53,872 --> 00:19:57,000 What about a free-swimming one-celled amoeba? 289 00:19:57,208 --> 00:19:59,472 These creatures are also microscopic... 290 00:19:59,944 --> 00:20:02,105 ...but in the realm of one-celled animals... 291 00:20:02,313 --> 00:20:03,746 ...they are giants. 292 00:20:03,948 --> 00:20:06,974 The whales of the microbial world. 293 00:20:07,185 --> 00:20:11,713 Each contains about 400 million bits in its DNA... 294 00:20:11,923 --> 00:20:15,984 ...the equivalent of about 80 volumes of 500 pages each. 295 00:20:16,194 --> 00:20:18,822 That's how much information it takes to make an amoeba... 296 00:20:19,030 --> 00:20:23,967 ...a creature like a small city wandering through a drop of water. 297 00:20:27,739 --> 00:20:29,900 And what about a whale or a human being? 298 00:20:30,108 --> 00:20:31,973 Well, the answer seems to be... 299 00:20:32,176 --> 00:20:36,044 ...that there's 5 billion bits. 300 00:20:36,247 --> 00:20:40,274 Five billion bits of information in our encyclopedia of life... 301 00:20:40,485 --> 00:20:43,352 ...in the nucleus of every one of our cells. 302 00:20:43,555 --> 00:20:47,116 So if written out in, say, ordinary English... 303 00:20:47,325 --> 00:20:49,953 ...those instructions, that information... 304 00:20:50,161 --> 00:20:54,029 ...would fill 1000 volumes. 305 00:20:54,232 --> 00:20:55,324 Think of it. 306 00:20:55,533 --> 00:20:59,765 In every one of the 100 trillion cells in your body... 307 00:20:59,971 --> 00:21:02,940 ...there's the contents of a complete library of instructions... 308 00:21:03,141 --> 00:21:07,134 ...on how to make every part of you. Those cells are smart. 309 00:21:07,345 --> 00:21:09,836 If this were my gene library... 310 00:21:10,048 --> 00:21:12,949 ...it would contain everything my body knows how to do... 311 00:21:13,151 --> 00:21:14,880 ...without being taught. 312 00:21:15,086 --> 00:21:17,884 The ancient information... 313 00:21:18,089 --> 00:21:22,924 ...is written in exhaustive, careful, redundant detail. 314 00:21:23,127 --> 00:21:26,790 How to laugh, how to sneeze, how to walk... 315 00:21:26,998 --> 00:21:29,398 ...how to recognize patterns, how to reproduce... 316 00:21:29,601 --> 00:21:31,660 ...how to digest an apple. 317 00:21:32,170 --> 00:21:34,832 If written out in the language of chemistry... 318 00:21:35,039 --> 00:21:36,597 ...what would the instructions... 319 00:21:36,808 --> 00:21:39,538 ...for digesting the sugar in an apple look like? 320 00:21:39,744 --> 00:21:41,769 Well, let's see. 321 00:21:42,847 --> 00:21:45,475 Amino acid synthesis, polypeptide chains... 322 00:21:45,683 --> 00:21:50,017 ...transfer RNA, genetic code, enzyme expression... 323 00:21:50,221 --> 00:21:52,781 ...enzyme phosphorylation. We're getting warm. 324 00:21:52,991 --> 00:21:56,859 Hexose monophosphate shunt, citric acid cycle... 325 00:21:57,061 --> 00:21:59,621 Here we are. Anaerobic glycolysis. 326 00:21:59,831 --> 00:22:01,458 Now, eating an apple... 327 00:22:01,666 --> 00:22:04,226 ...may seem like a very simple thing... 328 00:22:04,969 --> 00:22:06,698 ...but it's not. 329 00:22:06,904 --> 00:22:10,806 In fact, if I consciously had to remember and direct... 330 00:22:11,009 --> 00:22:15,343 ...all the chemical steps required to get energy out of food... 331 00:22:15,546 --> 00:22:17,707 ...I’d probably starve to death. 332 00:22:17,915 --> 00:22:22,682 And yet, even a bacterium can do anaerobic glycolysis. 333 00:22:22,887 --> 00:22:27,824 That's why apples rot. It's lunchtime for the bacteria. 334 00:22:28,026 --> 00:22:31,553 They and we and all the creatures in between... 335 00:22:31,763 --> 00:22:35,062 ...possess similar genetic instructions. 336 00:22:35,266 --> 00:22:37,757 Our separate gene libraries... 337 00:22:37,969 --> 00:22:40,699 ...have many pages in common... 338 00:22:40,905 --> 00:22:43,999 ...which is another reminder of the deep interconnection... 339 00:22:44,208 --> 00:22:46,904 ...of all living things on our planet because of... 340 00:22:47,111 --> 00:22:49,136 ...a common evolutionary heritage. 341 00:22:51,983 --> 00:22:54,508 Our present human technology... 342 00:22:54,719 --> 00:22:59,622 ...can duplicate only a tiny fraction of the intricate biochemistry... 343 00:22:59,824 --> 00:23:04,056 ...which our bodies seem to perform so effortlessly. 344 00:23:04,262 --> 00:23:06,822 But we're just beginning the study of biochemistry. 345 00:23:07,031 --> 00:23:11,195 Evolution has had billions of years of practice. 346 00:23:12,170 --> 00:23:14,604 The DNA knows. 347 00:23:15,807 --> 00:23:20,403 Now, what if what we had to do was so complicated... 348 00:23:20,611 --> 00:23:24,638 ...that even several billion bits of information wasn't enough? 349 00:23:24,849 --> 00:23:28,341 What if, for example, the environment were changing so fast... 350 00:23:28,553 --> 00:23:32,011 ...that the pre-coded genetic encyclopedia... 351 00:23:32,223 --> 00:23:35,681 ...which may have served us perfectly well in the past is now... 352 00:23:35,893 --> 00:23:38,987 ...not perfectly adequate? 353 00:23:39,197 --> 00:23:40,755 Why, then... 354 00:23:40,965 --> 00:23:45,231 ...even a gene library of 1000 volumes wouldn't be enough. 355 00:23:45,436 --> 00:23:48,633 That's why we have brains. 356 00:23:52,110 --> 00:23:54,374 Like our other organs, the brain has evolved... 357 00:23:54,579 --> 00:23:57,047 ...increasing over millions of years... 358 00:23:57,248 --> 00:24:00,240 ...in complexity and information content. 359 00:24:00,451 --> 00:24:04,888 Its structure reflects all the stages through which it has passed. 360 00:24:05,323 --> 00:24:10,022 The brain has evolved from the inside out. 361 00:24:10,228 --> 00:24:13,857 Deep inside is the oldest part, the so-called brain stem. 362 00:24:14,465 --> 00:24:17,093 It conducts many of the basic biological functions... 363 00:24:17,301 --> 00:24:19,735 ...including the rhythms of life... 364 00:24:19,937 --> 00:24:22,770 ...like heartbeat and respiration. 365 00:24:22,974 --> 00:24:25,943 The higher functions of the brain have evolved... 366 00:24:26,144 --> 00:24:29,705 ...in three successive stages according to a provocative insight... 367 00:24:29,914 --> 00:24:32,747 ...by the American biologist Paul MacLean. 368 00:24:32,950 --> 00:24:37,284 You see, capping the brain stem is the so-called R-complex... 369 00:24:37,488 --> 00:24:39,251 "R" for reptile. 370 00:24:39,457 --> 00:24:41,186 It's the seat of... 371 00:24:41,425 --> 00:24:44,622 ...aggression, ritual, territoriality... 372 00:24:44,829 --> 00:24:46,694 ...and social hierarchies. 373 00:24:46,898 --> 00:24:50,061 It evolved some hundreds of millions of years ago... 374 00:24:50,268 --> 00:24:52,566 ...in our reptilian ancestors. 375 00:24:52,770 --> 00:24:57,537 So, deep inside our brains is something rather like... 376 00:24:57,742 --> 00:25:00,040 ...the brain of a crocodile. 377 00:25:00,244 --> 00:25:03,907 Surrounding the R-complex is the limbic system... 378 00:25:04,115 --> 00:25:05,343 ...or mammal brain. 379 00:25:05,550 --> 00:25:07,848 It evolved some tens of millions of years ago... 380 00:25:08,286 --> 00:25:10,777 ...in ancestors who were mammals all right... 381 00:25:10,988 --> 00:25:15,425 ...but not yet primates like monkeys or apes. 382 00:25:15,626 --> 00:25:19,187 It's a major source of our moods and emotions... 383 00:25:19,397 --> 00:25:22,696 ...our concern and care for the young. 384 00:25:22,900 --> 00:25:26,734 And then, finally, on the outside of the brain... 385 00:25:27,338 --> 00:25:30,398 ...living in a kind of uneasy truce with... 386 00:25:30,608 --> 00:25:34,305 ...the more primitive brains beneath, is the cerebral cortex... 387 00:25:34,512 --> 00:25:36,912 ...evolved millions of years ago... 388 00:25:37,114 --> 00:25:39,605 ...in ancestors who were primates. 389 00:25:52,930 --> 00:25:55,398 This is the point of embarkation... 390 00:25:55,600 --> 00:25:57,693 ...for all our cosmic journeys. 391 00:25:57,902 --> 00:25:59,597 The cerebral cortex... 392 00:25:59,804 --> 00:26:03,001 ...where matter is transformed into consciousness. 393 00:26:03,207 --> 00:26:07,507 Here, comprising more than two-thirds of the brain mass... 394 00:26:07,712 --> 00:26:11,512 ...is the realm both of intuition and of critical analysis. 395 00:26:11,716 --> 00:26:14,913 It's here that we have ideas and inspirations. 396 00:26:15,119 --> 00:26:16,882 Here that we read and write. 397 00:26:17,088 --> 00:26:20,421 Here that we do mathematics and music. 398 00:26:20,625 --> 00:26:24,322 The cortex regulates our conscious lives. 399 00:26:24,528 --> 00:26:27,463 It is the distinction of our species... 400 00:26:27,665 --> 00:26:29,656 ...the seat of our humanity. 401 00:26:29,867 --> 00:26:32,131 Art and science live here. 402 00:26:32,336 --> 00:26:36,238 Civilization is a product of the cerebral cortex. 403 00:26:38,843 --> 00:26:39,969 Behind the forehead... 404 00:26:40,177 --> 00:26:43,112 ...are the frontal lobes of the cerebral cortex. 405 00:26:43,314 --> 00:26:45,874 They may be where we anticipate events... 406 00:26:46,083 --> 00:26:48,313 ...where we figure out the future. 407 00:26:48,519 --> 00:26:50,749 But if we can foresee an unpleasant future... 408 00:26:50,955 --> 00:26:52,889 ...we can take steps to avoid it. 409 00:26:53,090 --> 00:26:55,115 Down here in the frontal lobes... 410 00:26:55,326 --> 00:26:57,886 ...may be the means of ensuring human survival... 411 00:26:58,095 --> 00:27:00,825 ...if we have the wisdom to pay attention. 412 00:27:03,768 --> 00:27:08,205 Inside the cerebral cortex is the microscopic structure of thought. 413 00:27:08,406 --> 00:27:12,001 The language of the brain is not the DNA language of the genes. 414 00:27:12,209 --> 00:27:15,736 What we know is encoded in cells called neurons... 415 00:27:15,947 --> 00:27:17,278 ...tiny switching elements... 416 00:27:17,481 --> 00:27:21,281 ...every connection representing one bit of information. 417 00:27:21,485 --> 00:27:24,682 How many neurons do each of us have? Maybe 100 billion. 418 00:27:24,889 --> 00:27:28,188 Comparable to the number of stars in the Milky Way galaxy. 419 00:27:28,392 --> 00:27:32,920 And there are something like 100 trillion neural connections. 420 00:27:34,999 --> 00:27:39,333 This intricate and marvelous network of neurons... 421 00:27:39,537 --> 00:27:43,303 ...has been called an enchanted loom... 422 00:27:43,507 --> 00:27:46,305 ...where millions of flashing shuttles... 423 00:27:46,510 --> 00:27:49,206 ...weave a dissolving pattern. 424 00:27:49,413 --> 00:27:52,974 Even in sleep, the brain is pulsing and throbbing and flashing... 425 00:27:53,184 --> 00:27:56,085 ...with the complex business of human life: 426 00:27:56,287 --> 00:27:59,313 Dreaming, remembering, figuring things out. 427 00:27:59,523 --> 00:28:02,651 Our thoughts, our visions, our fantasies... 428 00:28:02,860 --> 00:28:05,852 ...have a tangible, physical reality. 429 00:28:06,063 --> 00:28:07,860 What does a thought look like? 430 00:28:08,065 --> 00:28:12,001 Well, it's made of hundreds of electrochemical impulses. 431 00:28:12,803 --> 00:28:14,464 Over there, for example, is... 432 00:28:14,672 --> 00:28:16,071 ...a spark of a memory. 433 00:28:16,273 --> 00:28:17,535 Maybe... 434 00:28:17,742 --> 00:28:21,701 ...the smell of lilacs on a country road in childhood. 435 00:28:21,912 --> 00:28:26,246 And there goes a bit of an anxious all points bulletin. 436 00:28:26,450 --> 00:28:29,942 Perhaps, "Where did I leave my keys? " 437 00:28:32,656 --> 00:28:35,784 The neurons store sounds too... 438 00:28:35,993 --> 00:28:37,790 ...and snatches of music. 439 00:28:37,995 --> 00:28:42,329 Whole orchestras play inside our heads. 440 00:28:47,738 --> 00:28:52,004 The landscape of the human cerebral cortex is deeply furrowed. 441 00:28:52,209 --> 00:28:53,642 There's a good reason for it. 442 00:28:53,844 --> 00:28:55,334 These convolutions... 443 00:28:55,546 --> 00:28:59,539 ...greatly increase the surface area available for information storage... 444 00:28:59,750 --> 00:29:03,049 ...in a skull of limited size. 445 00:29:07,391 --> 00:29:10,554 The world of thought is divided into two hemispheres. 446 00:29:10,761 --> 00:29:13,491 Over there is the right hemisphere of the cerebral cortex. 447 00:29:13,697 --> 00:29:16,359 It's mainly responsible for pattern recognition... 448 00:29:16,567 --> 00:29:19,661 ...intuition, sensitivity, creative insights. 449 00:29:19,870 --> 00:29:22,065 And over here is the left hemisphere... 450 00:29:22,273 --> 00:29:26,437 ...presiding over rational, analytic and critical thinking. 451 00:29:32,016 --> 00:29:35,110 These are the two sides... 452 00:29:35,319 --> 00:29:39,346 ...the dual strengths, the essential opposites... 453 00:29:39,557 --> 00:29:41,525 ...that characterize human thinking. 454 00:29:41,725 --> 00:29:44,285 Before us are the means... 455 00:29:44,495 --> 00:29:48,556 ...both for generating ideas and for testing their validity. 456 00:29:48,766 --> 00:29:53,066 There's a continuous dialogue between the two hemispheres of the brain... 457 00:29:53,270 --> 00:29:57,639 ...channeled through this immense bundle of nerve fibers... 458 00:29:57,842 --> 00:30:00,606 ...which is called the corpus callosum. 459 00:30:00,811 --> 00:30:05,145 It's a bridge between creativity and analysis... 460 00:30:05,349 --> 00:30:09,410 ...both of which are necessary if we are to understand the world. 461 00:30:10,955 --> 00:30:14,857 The information content of the human brain expressed in bits... 462 00:30:15,059 --> 00:30:17,425 ...is comparable to the number of connections between... 463 00:30:17,628 --> 00:30:19,095 ...the neurons in the cortex... 464 00:30:19,296 --> 00:30:21,196 ...about 100 trillion bits... 465 00:30:21,398 --> 00:30:24,196 ...10 to the 14th connections. 466 00:30:24,401 --> 00:30:27,859 If written out in English, it would fill 20 million volumes... 467 00:30:28,072 --> 00:30:30,540 ...as many as in the world's largest libraries. 468 00:30:30,741 --> 00:30:34,302 The equivalent of 20 million volumes worth of information... 469 00:30:34,512 --> 00:30:36,878 ...is inside the heads of every one of us. 470 00:30:37,081 --> 00:30:41,814 The brain is a very big place in a very small space. 471 00:30:43,888 --> 00:30:48,348 Most of the books in the brain are up here in the cerebral cortex. 472 00:30:48,559 --> 00:30:51,460 Down there, in the basement of the brain... 473 00:30:51,662 --> 00:30:53,687 ...are the functions that our ancestors... 474 00:30:53,898 --> 00:30:55,889 ...mainly depended on for survival: 475 00:30:56,100 --> 00:30:59,092 Aggression, child rearing, sex... 476 00:30:59,303 --> 00:31:01,794 ...the willingness to follow leaders blindly. 477 00:31:02,006 --> 00:31:05,407 Lots of things that we can still recognize in our lives today. 478 00:31:05,609 --> 00:31:07,702 Of the higher brain functions... 479 00:31:07,912 --> 00:31:09,539 ...some of them, like... 480 00:31:09,747 --> 00:31:11,772 ...reading, writing, speaking... 481 00:31:11,982 --> 00:31:16,885 ...seem to be located in particular places in the cerebral cortex. 482 00:31:17,087 --> 00:31:19,282 On the other hand, each memory... 483 00:31:19,490 --> 00:31:23,893 ...seems to be stored in many separate locales in the brain. 484 00:31:24,094 --> 00:31:26,790 Old memories are in lots of places. 485 00:31:33,671 --> 00:31:35,502 Here is one of my earliest memories. 486 00:31:42,379 --> 00:31:44,643 (POURS LIQUID) 487 00:31:44,848 --> 00:31:46,110 MOTHER: That's a good boy. 488 00:31:46,317 --> 00:31:48,649 Lunch is almost ready. 489 00:31:52,690 --> 00:31:53,816 (CLICKS ON RADIO) 490 00:31:54,024 --> 00:31:57,391 (MUSIC PLAYS) 491 00:32:11,942 --> 00:32:14,137 That was a long time ago. 492 00:32:16,146 --> 00:32:18,842 But its imprint has not faded... 493 00:32:19,049 --> 00:32:22,018 ...in the library of this brain. 494 00:32:29,560 --> 00:32:32,893 But the brain does much more than just recollect. 495 00:32:33,097 --> 00:32:34,325 It inter-compares. 496 00:32:34,531 --> 00:32:36,931 It synthesizes. It analyzes. 497 00:32:37,134 --> 00:32:39,602 It generates abstractions. 498 00:32:44,742 --> 00:32:47,472 The simplest thought, like the concept of the number one... 499 00:32:47,678 --> 00:32:49,976 ...has an elaborate, logical underpinning. 500 00:32:50,180 --> 00:32:51,841 The brain has its own language... 501 00:32:52,049 --> 00:32:54,916 ...for testing the world's structure and consistency. 502 00:32:55,119 --> 00:32:57,679 But we never see the machinery of logical analysis... 503 00:32:57,888 --> 00:32:59,719 ...only the conclusions. 504 00:33:01,625 --> 00:33:04,355 There is so much more that we must figure out... 505 00:33:04,561 --> 00:33:06,222 ...than the genes can know. 506 00:33:06,430 --> 00:33:08,864 That's why the brain library... 507 00:33:09,066 --> 00:33:12,502 ...has 10,000 times more information in it... 508 00:33:12,703 --> 00:33:14,136 ...than the gene library. 509 00:33:14,338 --> 00:33:19,037 Our passion for learning is the tool for our survival. 510 00:33:24,315 --> 00:33:28,251 And unlike the musty bindings of our gene library... 511 00:33:28,452 --> 00:33:30,886 ...in which hardly a word changes in a century... 512 00:33:31,088 --> 00:33:34,751 ...the brain library is made of loose-leaf books. 513 00:33:34,958 --> 00:33:38,917 We're constantly adding new pages and new volumes. 514 00:33:47,004 --> 00:33:50,667 Emotions and ritual behavior patterns... 515 00:33:50,874 --> 00:33:52,671 ...are built very deeply into us. 516 00:33:52,876 --> 00:33:55,777 They're part of our humanity. 517 00:33:55,979 --> 00:33:58,539 But they're not characteristically human. 518 00:33:58,749 --> 00:34:00,740 Many other animals have feelings. 519 00:34:00,951 --> 00:34:04,580 What distinguishes our species is thought. 520 00:34:04,788 --> 00:34:09,657 The cerebral cortex is, in a way, a liberation. 521 00:34:09,860 --> 00:34:11,987 We need no longer be trapped... 522 00:34:12,196 --> 00:34:15,222 ...in the genetically inherited behavior patterns... 523 00:34:15,432 --> 00:34:17,764 ...of lizards and baboons: 524 00:34:17,968 --> 00:34:20,596 Territoriality and aggression... 525 00:34:20,804 --> 00:34:23,204 ...and dominance hierarchies. 526 00:34:23,407 --> 00:34:24,874 We are, each of us... 527 00:34:25,075 --> 00:34:28,602 ...largely responsible for what gets put into our brains... 528 00:34:28,812 --> 00:34:33,010 ...for what, as adults, we wind up caring for... 529 00:34:33,217 --> 00:34:34,809 ...and knowing about. 530 00:34:35,018 --> 00:34:38,044 No longer at the mercy of the reptile brain... 531 00:34:38,255 --> 00:34:41,656 ...we can change ourselves. 532 00:34:41,859 --> 00:34:44,123 Think of the possibilities. 533 00:35:15,759 --> 00:35:17,750 The city, like the brain... 534 00:35:17,961 --> 00:35:20,429 ...has evolved in successive stages. 535 00:35:20,631 --> 00:35:23,429 The vestiges of its past are still retained... 536 00:35:23,634 --> 00:35:26,933 ...among the constructions of the present. 537 00:35:35,245 --> 00:35:38,078 A city like New York developed from a small center... 538 00:35:38,282 --> 00:35:42,218 ...and slowly grew leaving many of the old parts still functioning. 539 00:35:42,419 --> 00:35:45,388 Some of the major streets date to the 17th century. 540 00:35:45,589 --> 00:35:48,217 Its commercial hub, to the 18th century. 541 00:35:48,425 --> 00:35:50,791 The water and gas works, to the 19th. 542 00:35:50,994 --> 00:35:55,294 The electrical and communications systems, to the 20th century. 543 00:36:05,642 --> 00:36:08,634 The city has evolved much faster than the brain. 544 00:36:08,846 --> 00:36:10,711 Only 10,000 years ago... 545 00:36:10,914 --> 00:36:13,144 ...the human brain looked exactly as it does today... 546 00:36:13,350 --> 00:36:14,817 ...and we were just as smart. 547 00:36:15,018 --> 00:36:16,417 But there were no cities... 548 00:36:16,620 --> 00:36:21,421 ...only a few scattered encampments in the vast primordial forests. 549 00:36:21,625 --> 00:36:23,422 Today, it's just the opposite. 550 00:36:23,627 --> 00:36:28,564 Forests and grasslands often seem like scattered islands in a sea of cities. 551 00:36:30,200 --> 00:36:32,327 If you were an observer from an alien world... 552 00:36:32,536 --> 00:36:34,697 ...you would've noticed that something complicated... 553 00:36:34,905 --> 00:36:37,897 ...has been happening over the last few thousand years. 554 00:36:38,108 --> 00:36:40,975 It might take you a while to figure out the details... 555 00:36:41,178 --> 00:36:43,578 ...but you would recognize by its complexity... 556 00:36:43,780 --> 00:36:46,578 ...unmistakable evidence for intelligent life. 557 00:36:47,584 --> 00:36:49,643 On closer scrutiny, you might recognize... 558 00:36:49,853 --> 00:36:51,582 ...individual, intelligent beings. 559 00:36:57,728 --> 00:37:01,425 The evolution of the city is due to their conscious activity. 560 00:37:02,032 --> 00:37:05,490 Millions of human beings working, more or less, together... 561 00:37:05,702 --> 00:37:08,466 ...to preserve the city, to reconstruct it... 562 00:37:08,672 --> 00:37:10,162 ...and to change it. 563 00:37:23,754 --> 00:37:26,723 It might be more efficient if all civic systems... 564 00:37:26,924 --> 00:37:29,688 ...were periodically replaced from top to bottom. 565 00:37:29,893 --> 00:37:31,588 But, as in the brain... 566 00:37:31,795 --> 00:37:34,628 ...everything has to work during the renovation. 567 00:37:34,831 --> 00:37:36,731 So the city mostly adds new parts... 568 00:37:36,934 --> 00:37:40,665 ...while the old parts continue, more or less, to function. 569 00:37:43,874 --> 00:37:46,035 For example, in the 17th century... 570 00:37:46,243 --> 00:37:48,404 ...you traveled between Brooklyn and Manhattan... 571 00:37:48,612 --> 00:37:50,842 ...across the East River by ferry. 572 00:37:51,048 --> 00:37:54,575 In the 19th century, the technology became available to construct... 573 00:37:54,785 --> 00:37:56,582 ...a suspension bridge across the river. 574 00:37:56,787 --> 00:37:59,813 It was built precisely at the site of the ferry terminal... 575 00:38:00,023 --> 00:38:03,720 ...because major thoroughfares were already converging there. 576 00:38:04,962 --> 00:38:08,090 When it was possible to construct a tunnel under the river... 577 00:38:08,298 --> 00:38:12,598 ...that, too, was built in the same place and for the same reason. 578 00:38:12,803 --> 00:38:16,569 This use and restructuring of previous systems for new purposes... 579 00:38:16,773 --> 00:38:20,174 ...is very much like the pattern of biological evolution. 580 00:38:20,377 --> 00:38:22,811 Or consider Third Avenue. 581 00:38:23,013 --> 00:38:24,503 In the 17th century... 582 00:38:24,715 --> 00:38:28,583 ...you made your way uptown on foot or on horseback. 583 00:38:29,086 --> 00:38:31,816 A little later, there were coaches... 584 00:38:32,022 --> 00:38:35,423 ...the horses prancing, the coachmen cracking their whips. 585 00:38:36,026 --> 00:38:39,689 And then these were replaced by horse-drawn trolleys... 586 00:38:39,896 --> 00:38:43,263 ...clanging along fixed tracks on this avenue. 587 00:38:43,467 --> 00:38:45,958 Then electrical technology developed... 588 00:38:46,169 --> 00:38:49,798 ...and a great elevated railway line was constructed... 589 00:38:50,774 --> 00:38:54,574 ...called the Third Avenue El, which dominated the street... 590 00:38:54,778 --> 00:38:59,147 ...until 1954, when it was utterly demolished. 591 00:38:59,349 --> 00:39:04,286 Anyway, the El was then replaced by buses and taxicabs... 592 00:39:04,554 --> 00:39:06,784 ...which still are the main forms... 593 00:39:06,990 --> 00:39:09,220 ...of public transportation on Third Avenue. 594 00:39:10,027 --> 00:39:13,121 Now as gasoline becomes a rare commodity... 595 00:39:13,330 --> 00:39:16,857 ...the combustion engine will be replaced by something else. 596 00:39:17,067 --> 00:39:22,004 Maybe public transport on Third Avenue in the 21st century... 597 00:39:22,539 --> 00:39:27,272 ...will be by, I don't know, pneumatic tubes or electric cars. 598 00:39:28,078 --> 00:39:32,344 Every step in the evolution of Third Avenue transport... 599 00:39:32,549 --> 00:39:34,744 ...has been conservative... 600 00:39:34,951 --> 00:39:37,112 ...following a route first laid down... 601 00:39:37,320 --> 00:39:39,083 ...in the 17th century. 602 00:39:39,289 --> 00:39:43,385 But the brain is still more conservative than the city. 603 00:39:43,627 --> 00:39:47,427 If this were the brain, we might have horse-drawn trolleys... 604 00:39:47,631 --> 00:39:49,326 ...and the El and buses... 605 00:39:49,533 --> 00:39:52,024 ...all operating simultaneously... 606 00:39:52,235 --> 00:39:54,760 ...redundantly, competitively. 607 00:39:54,971 --> 00:39:57,838 The vestiges of earlier history clearly in evidence. 608 00:40:08,919 --> 00:40:11,353 When our genes could not store... 609 00:40:11,555 --> 00:40:14,285 ...all the information necessary for our survival... 610 00:40:14,491 --> 00:40:17,654 ...we slowly invented brains. 611 00:40:18,395 --> 00:40:23,025 But then the time came, maybe tens of thousands of years ago... 612 00:40:23,300 --> 00:40:25,427 ...when we needed to know more than... 613 00:40:25,635 --> 00:40:28,035 ...could conveniently be stored in brains. 614 00:40:31,808 --> 00:40:36,040 So we learned to stockpile enormous quantities of information... 615 00:40:36,246 --> 00:40:37,736 ...outside our bodies. 616 00:40:37,948 --> 00:40:40,917 We are the only species on Earth, so far as we know... 617 00:40:41,118 --> 00:40:44,144 ...to have invented a communal memory. 618 00:40:44,354 --> 00:40:47,949 The warehouse of that memory is called the library. 619 00:40:50,660 --> 00:40:52,491 Libraries also have evolved. 620 00:40:52,696 --> 00:40:54,891 The Assyrian library of Ashurbanipal... 621 00:40:55,098 --> 00:40:57,430 ...had thousands of clay tablets. 622 00:40:57,634 --> 00:41:00,535 The celebrated Library of Alexandria in Egypt... 623 00:41:00,737 --> 00:41:03,865 ...consisted of almost a million papyrus scrolls. 624 00:41:04,074 --> 00:41:07,373 Great modern libraries, like the New York Public Library... 625 00:41:07,577 --> 00:41:10,569 ...contain some 10 million books. 626 00:41:13,617 --> 00:41:18,054 That's more than 10 to the 14th bits of information in words. 627 00:41:18,255 --> 00:41:22,282 More than 100 trillion bits, and if we count pictures... 628 00:41:22,492 --> 00:41:26,519 ...it's something like 10 to the 15th bits of information. 629 00:41:26,730 --> 00:41:28,891 Now, that's more than 10,000 times... 630 00:41:29,099 --> 00:41:32,159 ...the total number of bits of information in our genes. 631 00:41:32,369 --> 00:41:33,927 Something like 10 times... 632 00:41:34,137 --> 00:41:37,538 ...the total amount of information in our brains. 633 00:41:37,741 --> 00:41:40,403 If I were to read a book a week... 634 00:41:40,610 --> 00:41:43,306 ...for my entire adult lifetime... 635 00:41:43,513 --> 00:41:45,481 ...and I lived an ordinary lifetime... 636 00:41:45,682 --> 00:41:46,910 ...when I was all done... 637 00:41:47,117 --> 00:41:50,609 ...I would've read maybe a few thousand books. 638 00:41:50,821 --> 00:41:52,083 No more. 639 00:41:52,289 --> 00:41:56,953 In this library, that's from about here... 640 00:42:02,265 --> 00:42:03,698 ...roughly... 641 00:42:05,402 --> 00:42:07,893 ...to about here. 642 00:42:08,104 --> 00:42:11,164 But that's only a 10th of a percent or so... 643 00:42:11,374 --> 00:42:14,070 ...of the total number of books in the library. 644 00:42:14,277 --> 00:42:18,407 The trick is to know which books to read. 645 00:42:20,283 --> 00:42:22,843 But they're all here. 646 00:42:32,162 --> 00:42:36,189 What an astonishing thing a book is. 647 00:42:36,399 --> 00:42:39,891 It's a flat object made from a tree... 648 00:42:40,103 --> 00:42:44,540 ...with flexible parts on which are imprinted... 649 00:42:44,741 --> 00:42:47,676 ...lots of funny dark squiggles. 650 00:42:47,878 --> 00:42:50,108 But one glance at it... 651 00:42:50,313 --> 00:42:53,146 ...and you're inside the mind of another person. 652 00:42:53,350 --> 00:42:57,081 Maybe somebody dead for thousands of years. 653 00:42:57,287 --> 00:42:59,255 Across the millennia... 654 00:42:59,456 --> 00:43:02,983 ...an author is speaking clearly and silently... 655 00:43:03,193 --> 00:43:06,094 ...inside your head, directly to you. 656 00:43:06,296 --> 00:43:10,289 Writing is perhaps the greatest of human inventions. 657 00:43:10,500 --> 00:43:13,435 Binding together people who never knew each other. 658 00:43:13,637 --> 00:43:16,401 Citizens of distant epochs. 659 00:43:16,606 --> 00:43:19,973 Books break the shackles of time. 660 00:43:20,176 --> 00:43:25,113 A book is proof that humans are capable of working magic. 661 00:43:25,382 --> 00:43:28,715 And this room is filled with magic. 662 00:43:30,921 --> 00:43:33,981 Some of the earliest authors wrote on... 663 00:43:34,624 --> 00:43:37,650 ...bones and stones. 664 00:43:37,861 --> 00:43:42,161 Cuneiform writing is the remote ancestor of the Western alphabet. 665 00:43:42,365 --> 00:43:46,267 It was invented in the Near East about 5000 years ago. 666 00:43:46,469 --> 00:43:48,096 Its purpose? 667 00:43:48,305 --> 00:43:49,397 To keep records. 668 00:43:49,606 --> 00:43:53,303 Records of the purchase of grain, the sale of land... 669 00:43:53,510 --> 00:43:57,310 ...the triumphs of kings, the statutes of priests... 670 00:43:57,514 --> 00:43:59,675 ...the positions of the stars... 671 00:43:59,883 --> 00:44:02,681 ...the prayers to the gods. 672 00:44:02,886 --> 00:44:05,650 This cone was made... 673 00:44:05,855 --> 00:44:08,346 ...around the year 2350 B.C. 674 00:44:08,558 --> 00:44:12,688 4300 years ago, there were people chipping and chiseling away... 675 00:44:12,896 --> 00:44:14,454 ...the message on this cone. 676 00:44:14,664 --> 00:44:16,461 What is that message? 677 00:44:16,666 --> 00:44:18,463 It's a prayer. 678 00:44:18,668 --> 00:44:22,126 The inscription on this cylinder... 679 00:44:23,139 --> 00:44:25,403 ...honors a king. 680 00:44:25,942 --> 00:44:30,276 Nebuchadnezzar, king of Babylon, in the 6th century B.C. 681 00:44:30,480 --> 00:44:34,143 For thousands of years, writing was chiseled into stone... 682 00:44:34,351 --> 00:44:38,378 ...scratched onto wax or bark or leather... 683 00:44:38,588 --> 00:44:42,490 ...painted on bamboo or silk or paper... 684 00:44:42,692 --> 00:44:45,889 ...but always in editions of one copy. 685 00:44:46,096 --> 00:44:47,927 One copy at a time... 686 00:44:48,131 --> 00:44:51,726 ...always, except for inscriptions on monuments... 687 00:44:51,935 --> 00:44:53,994 ...for a tiny readership. 688 00:45:07,083 --> 00:45:10,382 But then in China... 689 00:45:10,587 --> 00:45:13,317 ...between the 2nd and the 6th centuries... 690 00:45:13,523 --> 00:45:17,482 ...paper, ink and printing with carved wooden blocks... 691 00:45:17,694 --> 00:45:20,288 ...were all invented, more or less, together... 692 00:45:20,497 --> 00:45:25,434 ...permitting many copies of a work to be made and distributed. 693 00:45:25,702 --> 00:45:28,899 This is Chinese magic... 694 00:45:29,105 --> 00:45:31,130 ...from the 12th century. 695 00:45:32,642 --> 00:45:35,076 It took 1000 years for the idea to catch on... 696 00:45:35,278 --> 00:45:38,406 ...in relatively remote and backward Europe. 697 00:45:38,615 --> 00:45:42,483 Just before the invention of movable type... 698 00:45:42,752 --> 00:45:45,016 ...around the year 1450... 699 00:45:45,221 --> 00:45:48,019 ...there were only a few tens of thousands of books in Europe. 700 00:45:48,224 --> 00:45:50,784 Every one of them handwritten. 701 00:45:50,994 --> 00:45:55,829 Fifty years later, there were 10 million printed books in Europe. 702 00:45:56,032 --> 00:46:00,298 Learning became available to anyone who could read. 703 00:46:00,503 --> 00:46:03,734 Suddenly, books were being printed all over the world. 704 00:46:03,940 --> 00:46:06,966 Magic was everywhere. 705 00:46:08,778 --> 00:46:10,541 It is 23 centuries... 706 00:46:10,747 --> 00:46:13,147 ...since the founding of the Alexandrian library. 707 00:46:13,683 --> 00:46:17,517 Since then, 100 generations have lived and died. 708 00:46:17,720 --> 00:46:20,553 If information were passed on merely by word of mouth... 709 00:46:20,757 --> 00:46:22,816 ...how little we should know of our own past... 710 00:46:23,026 --> 00:46:25,392 ...how slow would be our progress. 711 00:46:25,595 --> 00:46:27,825 Everything would depend on what we'd been told... 712 00:46:28,031 --> 00:46:29,623 ...on how accurate the account. 713 00:46:29,833 --> 00:46:31,630 Ancient learning might be revered... 714 00:46:31,835 --> 00:46:34,929 ...but in successive retellings, it would become muddled... 715 00:46:35,138 --> 00:46:36,537 ...and then lost. 716 00:46:36,739 --> 00:46:39,674 Books permit us to voyage through time... 717 00:46:39,876 --> 00:46:42,868 ...to tap the wisdom of our ancestors. 718 00:46:44,581 --> 00:46:47,948 A library connects us with the insights and knowledge... 719 00:46:48,151 --> 00:46:50,881 ...of the greatest minds and the best teachers... 720 00:46:51,087 --> 00:46:54,113 ...drawn from the whole planet and from all our history... 721 00:46:54,324 --> 00:46:56,554 ...to instruct us without tiring... 722 00:46:56,759 --> 00:46:59,592 ...and to inspire us to make our own contributions... 723 00:46:59,796 --> 00:47:03,459 ...to the collective knowledge of the human species. 724 00:47:11,541 --> 00:47:15,341 There's a fair number of Gutenberg Bibles... 725 00:47:15,545 --> 00:47:18,412 ...and first folios of Shakespeare in the world... 726 00:47:18,615 --> 00:47:20,947 ...but most of the books you see here... 727 00:47:21,151 --> 00:47:25,520 ...are limited editions with very few surviving copies. 728 00:47:25,722 --> 00:47:27,713 But there also exists in the world... 729 00:47:27,924 --> 00:47:31,291 ...mass printings of paperbound books... 730 00:47:31,494 --> 00:47:35,089 ...that I think are still more wonderful. 731 00:47:35,298 --> 00:47:37,698 For the price of a modest meal... 732 00:47:37,901 --> 00:47:40,631 ...you get the history of Rome. 733 00:47:41,271 --> 00:47:45,207 Books are like seeds: They can lie dormant for centuries... 734 00:47:45,408 --> 00:47:50,072 ...but they may also produce flowers in the most unpromising soil. 735 00:47:50,280 --> 00:47:55,217 These books are the repositories of the knowledge of our species... 736 00:47:55,485 --> 00:47:58,648 ...and of our long evolutionary journey... 737 00:47:58,855 --> 00:48:02,518 ...from genes to brains to books. 738 00:48:20,877 --> 00:48:22,469 Libraries in ancient Egypt... 739 00:48:22,679 --> 00:48:24,647 ...bore these words on their walls: 740 00:48:25,415 --> 00:48:28,748 "Nourishment for the soul." 741 00:48:29,118 --> 00:48:33,680 And that's still a pretty fair assessment of what libraries provide. 742 00:48:50,707 --> 00:48:53,870 Even at night, the city, like the brain... 743 00:48:54,077 --> 00:48:56,841 ...is busy assimilating and distributing information. 744 00:48:57,046 --> 00:48:58,809 Information keeps it alive... 745 00:48:59,015 --> 00:49:03,213 ...and provides the tools to adapt to changing conditions. 746 00:49:05,288 --> 00:49:06,550 The long human journey... 747 00:49:06,756 --> 00:49:11,022 ...from genes to brains to books continues. 748 00:49:15,131 --> 00:49:16,928 Information itself evolves... 749 00:49:17,133 --> 00:49:21,433 ...nurtured by open communication and free inquiry. 750 00:49:24,641 --> 00:49:26,836 The units of biological evolution are genes. 751 00:49:27,243 --> 00:49:29,939 The units of cultural evolution are ideas. 752 00:49:30,146 --> 00:49:32,444 Ideas are transported all over the planet. 753 00:49:32,715 --> 00:49:34,342 They reproduce through communication. 754 00:49:34,684 --> 00:49:37,915 They are selected by analysis and debate. 755 00:49:38,121 --> 00:49:42,217 In the last few millennia, something extraordinary has happened on Earth. 756 00:49:42,959 --> 00:49:46,292 Rich information from distant lands and peoples... 757 00:49:46,496 --> 00:49:48,987 ...has become routinely available. 758 00:49:50,433 --> 00:49:52,594 The number of bits to which we have access... 759 00:49:52,802 --> 00:49:54,895 ...has grown dramatically. 760 00:49:59,776 --> 00:50:02,210 Computers can now store and process... 761 00:50:02,412 --> 00:50:05,438 ...enormous amounts of information extremely rapidly. 762 00:50:05,648 --> 00:50:08,412 In our time, a revolution has begun. 763 00:50:08,618 --> 00:50:10,518 A revolution perhaps as significant... 764 00:50:10,720 --> 00:50:13,382 ...as the evolution of DNA and nervous systems... 765 00:50:13,589 --> 00:50:15,079 ...and the invention of writing. 766 00:50:16,225 --> 00:50:19,592 Direct communication among billions of human beings... 767 00:50:19,796 --> 00:50:22,993 ...is now made possible by computers and satellites. 768 00:50:23,666 --> 00:50:26,601 The potential for a global intelligence is emerging. 769 00:50:26,803 --> 00:50:31,001 Linking all the brains on Earth into a planetary consciousness. 770 00:50:34,811 --> 00:50:36,870 Elsewhere, there may be brains... 771 00:50:37,080 --> 00:50:38,877 ...even planetary brains... 772 00:50:39,082 --> 00:50:41,516 ...but there will be no brains quite like ours. 773 00:50:41,718 --> 00:50:45,552 Mutation and natural selection are basically random processes. 774 00:50:45,755 --> 00:50:47,620 If the Earth were started over again... 775 00:50:47,824 --> 00:50:49,758 ...intelligence might very well emerge... 776 00:50:49,959 --> 00:50:54,328 ...but anything closely resembling a human being would be unlikely. 777 00:50:55,698 --> 00:51:00,067 On another planet with a different sequence of random processes... 778 00:51:00,269 --> 00:51:01,964 ...to make heredity diversity... 779 00:51:02,171 --> 00:51:04,366 ...and a different environment... 780 00:51:04,574 --> 00:51:06,906 ...to select particular combinations of genes... 781 00:51:07,110 --> 00:51:09,840 ...the chance of finding beings very similar to us... 782 00:51:10,046 --> 00:51:11,513 ...must be close to zero. 783 00:51:12,081 --> 00:51:14,140 But the chance of finding another form of intelligence... 784 00:51:14,350 --> 00:51:15,442 ...isn't close to zero. 785 00:51:15,651 --> 00:51:19,781 Their brains may well have evolved from the inside out as ours have. 786 00:51:19,989 --> 00:51:23,789 They may well have switching elements analogous to our neurons... 787 00:51:23,993 --> 00:51:26,188 ...but their neurons might be different. 788 00:51:26,396 --> 00:51:30,059 Maybe they're superconductors which work at very low temperatures... 789 00:51:30,266 --> 00:51:33,064 ...in which case, their speed of thought... 790 00:51:33,269 --> 00:51:36,170 ...might be 10 million times faster than ours. 791 00:51:36,906 --> 00:51:39,807 Or perhaps their neurons are not in... 792 00:51:40,009 --> 00:51:42,876 ...direct physical contact with each other... 793 00:51:43,079 --> 00:51:45,411 ...but in radio communication. 794 00:51:45,615 --> 00:51:47,378 So a single intelligent being... 795 00:51:47,583 --> 00:51:50,950 ...could be distributed among many different organisms. 796 00:51:51,154 --> 00:51:54,146 There may be planets in which intelligent beings have... 797 00:51:54,357 --> 00:51:58,521 ...not 10 to the 11th neurons each, as we do... 798 00:51:58,728 --> 00:52:01,993 ...but 10 to the 20th or 10 to the 30th. 799 00:52:02,698 --> 00:52:06,031 I wonder what they would know. 800 00:52:06,235 --> 00:52:07,862 If we could make contact... 801 00:52:08,070 --> 00:52:09,162 ...there would be... 802 00:52:09,372 --> 00:52:13,570 ...much in their brains that would be of enormous interest to ours. 803 00:52:14,310 --> 00:52:15,800 And vice versa. 804 00:52:16,012 --> 00:52:17,912 I think extraterrestrial intelligence... 805 00:52:18,114 --> 00:52:20,912 ...even beings astonishingly more evolved than we... 806 00:52:21,117 --> 00:52:24,609 ...will be curious about us, about what we know, how we think... 807 00:52:24,821 --> 00:52:28,917 ...the course of our evolution, the prospects for our future. 808 00:52:29,992 --> 00:52:33,291 Within every human brain, patterns of electrochemical impulses... 809 00:52:33,496 --> 00:52:36,260 ...are continuously forming and dissipating. 810 00:52:36,466 --> 00:52:39,663 They reflect our emotions, ideas and memories. 811 00:52:39,869 --> 00:52:42,030 When recorded and amplified... 812 00:52:42,238 --> 00:52:45,002 ...these impulses sound like this. 813 00:52:45,208 --> 00:52:47,733 (RUMBLING) 814 00:52:47,944 --> 00:52:50,742 But would an extraterrestrial being, no matter how advanced... 815 00:52:50,947 --> 00:52:53,973 ...be able to read the mind that made these sounds? 816 00:52:54,183 --> 00:52:57,209 We ourselves are far from being able to do so. 817 00:52:57,954 --> 00:53:01,412 But in fact, we have sent the very impulses you are hearing... 818 00:53:01,624 --> 00:53:05,617 ...reflecting the emotions, ideas and memories of one human being... 819 00:53:05,828 --> 00:53:09,491 ...on a voyage to the stars. 820 00:53:16,772 --> 00:53:19,900 In August and September 1977... 821 00:53:20,109 --> 00:53:22,942 ...two Voyager spacecraft were launched... 822 00:53:23,145 --> 00:53:27,605 ...on an epic journey to the outer solar system and beyond. 823 00:53:28,150 --> 00:53:32,177 Their scientific mission was to explore the giant planets... 824 00:53:32,522 --> 00:53:34,353 ...first Jupiter and its satellites... 825 00:53:34,557 --> 00:53:37,651 ...and then Saturn and its system of moons. 826 00:53:45,701 --> 00:53:48,261 Close encounters with these great worlds... 827 00:53:48,471 --> 00:53:52,498 ...accelerate the Voyager spacecraft out of the solar system. 828 00:53:54,777 --> 00:53:57,541 As an incidental consequence of their trajectories... 829 00:53:57,747 --> 00:54:01,239 ...they will be carried inexorably into the realm of the stars... 830 00:54:01,450 --> 00:54:03,680 ...where they will wander forever. 831 00:54:05,588 --> 00:54:08,580 The ships will be slightly eroded within the solar system... 832 00:54:08,791 --> 00:54:11,624 ...by micrometeorites, planetary rings systems... 833 00:54:11,827 --> 00:54:13,886 ...and radiation belts. 834 00:54:17,833 --> 00:54:19,300 But once past the planets... 835 00:54:19,502 --> 00:54:22,130 ...they will endure for a billion years... 836 00:54:22,338 --> 00:54:25,739 ...in the cold vacuum of interstellar space. 837 00:54:26,776 --> 00:54:28,471 Perhaps in the distant future... 838 00:54:28,678 --> 00:54:32,307 ...beings of an alien civilization will intercept these ships. 839 00:54:32,515 --> 00:54:34,107 They'll examine our spacecraft... 840 00:54:34,317 --> 00:54:37,684 ...and understand much about our science and technology. 841 00:54:38,821 --> 00:54:42,848 But a machine alone can tell only so much about its makers. 842 00:54:43,059 --> 00:54:45,857 So each bears a golden phonograph record... 843 00:54:46,062 --> 00:54:48,997 ...with not only the brain waves of a woman from Earth... 844 00:54:49,198 --> 00:54:53,794 ...but also an anthology of music, pictures and sounds of our planet... 845 00:54:54,003 --> 00:54:57,200 ...including greetings in 60 human languages... 846 00:54:57,406 --> 00:55:00,671 ...and the salutations of the humpback whales. 847 00:55:00,876 --> 00:55:04,141 The record cover bears instructions on how to hear the sounds... 848 00:55:04,347 --> 00:55:06,542 ...and see the pictures encoded on the disk. 849 00:55:06,749 --> 00:55:10,685 Including some snapshots from the family album... 850 00:55:10,886 --> 00:55:12,979 ...of a distant world. 851 00:55:41,817 --> 00:55:44,650 The Voyager record is a message in a bottle... 852 00:55:44,854 --> 00:55:47,482 ...cast into the cosmic ocean. 853 00:55:47,690 --> 00:55:50,659 It contains some of our thoughts and our feelings... 854 00:55:50,860 --> 00:55:52,987 ...something of the information we store... 855 00:55:53,195 --> 00:55:56,631 ...in genes and brains and books. 856 00:55:58,067 --> 00:56:00,126 The recipients, if any... 857 00:56:00,336 --> 00:56:04,272 ...will understand the pictures and sounds incompletely at best. 858 00:56:04,473 --> 00:56:06,737 But one thing would be clear about us: 859 00:56:06,942 --> 00:56:09,740 No one sends such a message on such a journey... 860 00:56:09,945 --> 00:56:13,108 ...without a positive passion for the future. 861 00:56:13,315 --> 00:56:15,783 For all the possible vagaries of the message... 862 00:56:15,985 --> 00:56:19,148 ...they will be sure that we were a species endowed... 863 00:56:19,355 --> 00:56:23,724 ...with hope and perseverance, at least a little intelligence... 864 00:56:23,926 --> 00:56:28,192 ...and a longing to make contact with the cosmos.