1 00:00:04,352 --> 00:00:08,008 TYSON: Can we know the universe? 2 00:00:09,009 --> 00:00:12,099 Are our brains capable of comprehending the cosmos in 3 00:00:12,273 --> 00:00:14,753 all of its complexity and splendor? 4 00:00:15,798 --> 00:00:18,366 We don't yet know the answer to that question because our 5 00:00:18,540 --> 00:00:20,933 brain remains almost as much of a mystery 6 00:00:21,108 --> 00:00:23,197 as the universe itself. 7 00:00:24,415 --> 00:00:27,070 We think that the number of processing units in your brain 8 00:00:27,244 --> 00:00:30,769 is roughly equal to all the stars in 1,000 galaxies. 9 00:00:31,988 --> 00:00:34,556 At least 100 trillion. 10 00:00:34,817 --> 00:00:37,211 And it's possible that the real number of processing units 11 00:00:37,385 --> 00:00:39,648 is ten times larger. 12 00:00:39,952 --> 00:00:41,954 We're inside a brain. 13 00:00:42,129 --> 00:00:45,262 It's in the grip of a Category 5 hurricane of chemical and 14 00:00:45,436 --> 00:00:47,047 electrical forces. 15 00:00:47,830 --> 00:00:50,224 The storm came without warning, 16 00:00:50,441 --> 00:00:53,401 spreading chaos and heartache far beyond its path... 17 00:00:54,489 --> 00:00:57,492 But it also provided the first clues to the nature of this 18 00:00:57,666 --> 00:00:59,407 little cosmos. 19 00:01:05,848 --> 00:01:10,766 [theme music plays] 20 00:01:30,307 --> 00:01:36,096 ♪ ♪ 21 00:01:56,725 --> 00:02:02,078 ♪ ♪ 22 00:02:07,257 --> 00:02:11,435 TYSON: We are traveling 2,500 years back in time to the island 23 00:02:11,609 --> 00:02:13,655 of Kos in the Aegean Sea. 24 00:02:15,222 --> 00:02:17,354 This is the story of a giant leap in the 25 00:02:17,528 --> 00:02:19,051 history of thought. 26 00:02:19,661 --> 00:02:22,011 It was here that one of the most powerful spells 27 00:02:22,185 --> 00:02:26,058 ever to cloud the mind was first broken. 28 00:02:28,452 --> 00:02:30,324 Imagine you are the loving parents of a 29 00:02:30,498 --> 00:02:32,587 precious only child. 30 00:02:32,761 --> 00:02:35,285 The boy is given to moments of brilliance, 31 00:02:35,459 --> 00:02:37,418 which charm and impress your friends. 32 00:02:38,680 --> 00:02:40,377 But there's something wrong... 33 00:02:42,945 --> 00:02:45,643 A storm is brewing inside his head... 34 00:02:48,211 --> 00:02:49,647 GOVERNESS: Peleus! Peleus! 35 00:03:01,877 --> 00:03:06,882 ♪ ♪ 36 00:03:19,329 --> 00:03:22,202 TYSON: This was medicine 2,500 years ago in Greece. 37 00:03:23,028 --> 00:03:25,988 The idea that the ritual appeasement of one of the gods 38 00:03:26,162 --> 00:03:28,643 could bring about the cure for an epileptic seizure was 39 00:03:28,817 --> 00:03:30,819 magical thinking. 40 00:03:31,341 --> 00:03:34,562 When the Greeks and people of other cultures performed their rituals, 41 00:03:34,736 --> 00:03:36,607 some of the afflicted recovered, 42 00:03:36,999 --> 00:03:38,653 due to the finite course of the illness, 43 00:03:38,827 --> 00:03:41,090 or to their own immune systems. 44 00:03:41,395 --> 00:03:43,092 But to the patients and their loved ones, 45 00:03:43,266 --> 00:03:46,182 it meant that the gods had been appeased. 46 00:03:46,835 --> 00:03:48,619 And when the patient died? 47 00:03:48,967 --> 00:03:50,882 That just meant the gods were so angry, 48 00:03:51,056 --> 00:03:53,145 nothing could be done. 49 00:03:53,537 --> 00:03:58,368 This way of thinking was a by-product of that great human strength, and weakness, 50 00:03:58,542 --> 00:04:00,805 called pattern recognition. 51 00:04:04,200 --> 00:04:07,682 In this case, false pattern recognition. 52 00:04:07,856 --> 00:04:10,337 The belief that epilepsy was caused by the anger of the 53 00:04:10,511 --> 00:04:14,079 gods was the confusion of correlation with causation, 54 00:04:15,037 --> 00:04:16,691 and the wishful thinking that prevails when 55 00:04:16,865 --> 00:04:19,607 people feel powerless. 56 00:04:20,042 --> 00:04:22,044 That's not to say that the ancient Greeks didn't have 57 00:04:22,218 --> 00:04:24,612 remedies, plants and minerals, they used as medicines. 58 00:04:25,830 --> 00:04:28,311 But for a disease as mysterious as epilepsy, 59 00:04:29,225 --> 00:04:31,227 they could only light their incense and pray. 60 00:04:32,576 --> 00:04:35,057 They didn't even know it had anything to do with the brain. 61 00:04:36,754 --> 00:04:39,366 And then came Hippocrates. 62 00:04:40,802 --> 00:04:43,413 Hippocrates rejected the notion that angry gods were 63 00:04:43,587 --> 00:04:45,676 the cause of disease and injury. 64 00:04:46,068 --> 00:04:49,637 He wrote: "The physician must investigate the entire patient, 65 00:04:49,811 --> 00:04:52,204 his diet and his environment... 66 00:04:52,944 --> 00:04:54,990 The best physician is the one who is able 67 00:04:55,164 --> 00:04:57,035 to prevent illness. 68 00:04:57,209 --> 00:04:59,995 Nothing happens without a natural cause." 69 00:05:01,605 --> 00:05:04,129 For this alone, he could be called the Father of Medicine. 70 00:05:05,000 --> 00:05:08,351 He is credited with codifying an ethos for doctors. 71 00:05:09,657 --> 00:05:13,617 The oath ascribed to him in the 3rd century BCE is still 72 00:05:13,791 --> 00:05:17,229 taken today by those who would practice medicine. 73 00:05:19,144 --> 00:05:21,233 And it was Hippocrates who was among the first 74 00:05:21,408 --> 00:05:24,541 to declare the brain to be the seat of consciousness. 75 00:05:25,760 --> 00:05:27,196 It's hard to believe, 76 00:05:27,370 --> 00:05:29,894 but this was once a revolutionary concept. 77 00:05:30,068 --> 00:05:32,157 The prevailing wisdom being that we actually 78 00:05:32,332 --> 00:05:34,769 thought with our hearts. 79 00:05:34,943 --> 00:05:37,598 And it may have been here where he made one of 80 00:05:37,772 --> 00:05:40,470 the great prophecies in the history of science. 81 00:05:42,646 --> 00:05:45,910 Hippocrates understood that he and his contemporaries 82 00:05:46,084 --> 00:05:48,565 called epilepsy "“the sacred disease"” 83 00:05:49,566 --> 00:05:52,482 because they didn't understand its physical cause. 84 00:05:52,656 --> 00:05:57,835 He wrote, "When we do, we will no longer think it divine." 85 00:06:00,185 --> 00:06:01,970 That little boy wasn't cursed. 86 00:06:02,144 --> 00:06:05,452 There was a physical malfunction inside his brain. 87 00:06:05,800 --> 00:06:08,672 As long as we searched for it in the whim of the gods, 88 00:06:08,846 --> 00:06:12,546 we had no hope of helping him, or ourselves. 89 00:06:13,373 --> 00:06:15,723 Yet thousands of years passed, 90 00:06:15,897 --> 00:06:18,073 and the brain remained a mystery. 91 00:06:20,249 --> 00:06:22,904 Between 420 BCE and the 19th century, 92 00:06:23,687 --> 00:06:26,777 our understanding of the cosmos grew by leaps and bounds. 93 00:06:27,735 --> 00:06:29,824 We discovered the speed of light, 94 00:06:29,998 --> 00:06:31,695 the laws of gravity, 95 00:06:31,869 --> 00:06:34,829 and we learned that our Sun is part of a greater galaxy 96 00:06:35,003 --> 00:06:39,790 of stars and yet, 2,300 years after Hippocrates, 97 00:06:39,964 --> 00:06:42,489 we still knew virtually nothing about the part of 98 00:06:42,663 --> 00:06:45,753 ourselves that made it possible to make these discoveries: 99 00:06:46,536 --> 00:06:48,103 our brains. 100 00:06:48,277 --> 00:06:51,585 It could be said that we actually knew less. 101 00:06:51,759 --> 00:06:53,674 The study of the brain had become stuck in a 102 00:06:53,848 --> 00:06:57,025 pseudoscientific dead-end called "“phrenology,"” 103 00:06:57,199 --> 00:07:00,681 which held that from the shape of a person's skull, 104 00:07:00,855 --> 00:07:02,509 you could deduce their intelligence and 105 00:07:02,683 --> 00:07:05,425 trustworthiness. 106 00:07:05,686 --> 00:07:08,036 A frenzy of head-measuring ensued. 107 00:07:08,210 --> 00:07:10,647 A gift for languages resided above the cheekbone, 108 00:07:11,561 --> 00:07:13,998 and marital fidelity located behind the ears. 109 00:07:15,478 --> 00:07:16,914 And not surprisingly, 110 00:07:17,088 --> 00:07:19,003 European phrenologists discovered that their 111 00:07:19,177 --> 00:07:21,615 particular heads represented the universal 112 00:07:21,789 --> 00:07:23,747 standard of cerebral excellence. 113 00:07:25,357 --> 00:07:27,403 The first real insight regarding the connection 114 00:07:27,577 --> 00:07:32,147 between the mind and the brain was made in France in 1861. 115 00:07:32,626 --> 00:07:35,890 And here again, epilepsy played a critical role... 116 00:07:45,334 --> 00:07:48,293 The Bicêtre psychiatric hospital was state-of-the-art 117 00:07:48,468 --> 00:07:50,078 in Paris back then. 118 00:07:50,252 --> 00:07:52,341 In the previous century, it had been the first to 119 00:07:52,515 --> 00:07:55,387 introduce humane practices in the treatment of the insane 120 00:07:55,562 --> 00:07:57,607 and the mentally disabled. 121 00:07:59,000 --> 00:08:02,090 And among the doctors there, surgeon Paul Broca was 122 00:08:02,264 --> 00:08:04,353 especially admired for his enlightened treatment 123 00:08:04,527 --> 00:08:06,094 of his patients. 124 00:08:13,536 --> 00:08:15,016 TAN: Tan... 125 00:08:19,411 --> 00:08:22,110 TYSON: The patient's name was Louis Leborgne. 126 00:08:23,807 --> 00:08:25,156 TAN: Tan... 127 00:08:25,461 --> 00:08:27,550 TYSON: But everyone called him "Tan" after the 128 00:08:27,724 --> 00:08:30,814 only syllable that he had uttered since he was 30. 129 00:08:31,075 --> 00:08:32,990 He was now 51. 130 00:08:33,469 --> 00:08:36,428 Tan had been having epileptic seizures since childhood, 131 00:08:36,603 --> 00:08:38,605 but he was committed to Bicêtre because he had lost 132 00:08:38,779 --> 00:08:43,261 all powers of speech except for being able to say "“tan."” 133 00:08:44,480 --> 00:08:46,743 Now, poor Tan lay dying. 134 00:08:47,483 --> 00:08:49,180 His right side had become paralyzed, 135 00:08:49,354 --> 00:08:51,574 and gangrene had set in. 136 00:08:51,748 --> 00:08:53,489 Prior to Tan's medical crisis, 137 00:08:53,663 --> 00:08:56,492 Broca had been speculating that specific regions 138 00:08:56,666 --> 00:08:58,799 of the brain might be responsible for 139 00:08:58,973 --> 00:09:00,801 the powers of speech and memory. 140 00:09:02,977 --> 00:09:05,327 Broca wanted to know everything he possibly could 141 00:09:05,501 --> 00:09:07,764 about the dying patient in expectation of what a 142 00:09:07,938 --> 00:09:09,679 post-mortem might reveal. 143 00:09:11,551 --> 00:09:15,337 We do not know if Tan's epilepsy caused the damage to his brain, 144 00:09:15,511 --> 00:09:17,905 or whether an unreported childhood injury 145 00:09:18,079 --> 00:09:20,211 caused his epilepsy and later loss of speech. 146 00:09:25,913 --> 00:09:27,175 TAN: Tan... 147 00:09:46,586 --> 00:09:48,196 TYSON: But because of Tan's fate, 148 00:09:48,370 --> 00:09:50,459 Paul Broca was able to connect, 149 00:09:50,633 --> 00:09:54,245 for the very first time, a part of the human brain, 150 00:09:54,419 --> 00:09:56,160 in this case the region that was damaged, 151 00:09:56,334 --> 00:09:59,686 and its specialized function: the ability to use language. 152 00:10:00,600 --> 00:10:02,123 His reward... 153 00:10:02,297 --> 00:10:04,691 that part of our brain has been known ever since 154 00:10:04,865 --> 00:10:06,780 as "Broca's area." 155 00:10:09,870 --> 00:10:12,960 Paul Broca's own brain ended up in a jar 156 00:10:13,134 --> 00:10:15,832 like this one in a back storage room of the 157 00:10:16,006 --> 00:10:18,661 anthropological museum he directed, 158 00:10:19,053 --> 00:10:22,709 with shelf upon shelf of the brains of mass murderers and 159 00:10:22,883 --> 00:10:25,276 other master criminals, as well as congenital 160 00:10:25,450 --> 00:10:28,628 abnormalities that seemed to fascinate the public of the 161 00:10:28,802 --> 00:10:30,412 19th century. 162 00:10:30,586 --> 00:10:32,980 Broca was a humanist. 163 00:10:33,154 --> 00:10:35,373 He concluded that there were deep connections in brain 164 00:10:35,547 --> 00:10:38,986 physiology between non-human primates and us. 165 00:10:40,378 --> 00:10:43,077 He founded a society of freethinkers in his youth, 166 00:10:43,251 --> 00:10:45,296 and believed passionately in the importance 167 00:10:45,470 --> 00:10:47,081 of unobstructed inquiry. 168 00:10:47,908 --> 00:10:50,606 He lived his life in pursuit of that aim. 169 00:10:51,128 --> 00:10:54,784 But he, too, was partly blinded by the prejudices that 170 00:10:54,958 --> 00:10:57,308 permeated his society. 171 00:10:58,135 --> 00:11:01,312 He thought men mentally superior to women, 172 00:11:01,486 --> 00:11:04,489 and whites superior to everyone else. 173 00:11:04,968 --> 00:11:08,929 His falling short of humanist ideals shows that even someone 174 00:11:09,103 --> 00:11:11,453 as committed to the free pursuit of knowledge 175 00:11:11,627 --> 00:11:15,196 as Broca could still be deceived by endemic bigotry. 176 00:11:17,067 --> 00:11:19,766 Society corrupts the best of us. 177 00:11:19,940 --> 00:11:21,419 It's a little unfair, 178 00:11:21,593 --> 00:11:23,726 I think, to criticize a person for not sharing 179 00:11:23,900 --> 00:11:25,815 the enlightenment of a later age, 180 00:11:25,989 --> 00:11:30,080 but it is also profoundly saddening that such prejudices 181 00:11:30,254 --> 00:11:32,300 were so pervasive. 182 00:11:34,041 --> 00:11:38,001 The question raises nagging uncertainties about which of 183 00:11:38,175 --> 00:11:41,788 the assumptions of our own age will be considered 184 00:11:41,962 --> 00:11:44,878 unforgivable by the next... 185 00:11:47,707 --> 00:11:50,100 Broca established for the first time that there were 186 00:11:50,274 --> 00:11:53,234 physical correlations between anatomy and function, 187 00:11:54,104 --> 00:11:57,194 but what of the crackling energy of consciousness? 188 00:11:57,368 --> 00:12:00,197 What of the stuff that dreams are made of? 189 00:12:01,590 --> 00:12:03,505 Can't put them in a jar... 190 00:12:18,476 --> 00:12:21,523 ♪ ♪ 191 00:12:27,485 --> 00:12:29,923 TYSON: When the ancient Egyptians looked up at night, 192 00:12:30,097 --> 00:12:31,881 they saw the underbody of Nut, 193 00:12:32,795 --> 00:12:34,579 Goddess of the Milky Way. 194 00:12:34,971 --> 00:12:37,104 When they closed their eyes and began to dream, 195 00:12:37,669 --> 00:12:40,020 they believed they were transiting to the afterlife. 196 00:12:40,629 --> 00:12:43,327 And so, dreaming was ritualized into a form of 197 00:12:43,501 --> 00:12:46,678 worship, a means to learn what their future held, 198 00:12:47,375 --> 00:12:50,508 or to send a message to the gods, as they slumbered. 199 00:12:51,205 --> 00:12:52,684 The faithful would make a pilgrimage to 200 00:12:52,859 --> 00:12:54,730 a temple to dream. 201 00:13:02,129 --> 00:13:04,044 To prepare themselves, they would withdraw to a 202 00:13:04,218 --> 00:13:06,002 place of isolation, 203 00:13:06,176 --> 00:13:09,223 and fast to cleanse their mind and body. 204 00:13:15,185 --> 00:13:18,667 A prayer might be written to a particular god... 205 00:13:19,189 --> 00:13:23,150 and burned. 206 00:13:29,199 --> 00:13:31,723 It was hoped that its smoke would convey the contents to 207 00:13:31,898 --> 00:13:34,335 the underworld. 208 00:13:40,558 --> 00:13:43,910 If we could only materialize and decipher the dreaming that 209 00:13:44,084 --> 00:13:47,000 went on at the Temple of Dendera so long ago. 210 00:13:48,436 --> 00:13:51,004 And what of your dream just last night? 211 00:13:51,178 --> 00:13:54,050 The ancient Egyptians were mystified by the boundary that 212 00:13:54,224 --> 00:13:56,661 separates our waking and sleeping life. 213 00:13:57,575 --> 00:14:00,404 They believed that we were actually transported to 214 00:14:00,578 --> 00:14:03,494 another physical realm, and that dreams had 215 00:14:03,668 --> 00:14:05,670 a material reality. 216 00:14:06,062 --> 00:14:08,195 How else to explain the stunning detail of a 217 00:14:08,369 --> 00:14:10,501 particularly vivid dream? 218 00:14:11,502 --> 00:14:14,462 More than 1,000 years after the last dreamers awakened at 219 00:14:14,636 --> 00:14:18,379 Dendera, there was a scientist who believed that conscious 220 00:14:18,553 --> 00:14:21,556 and unconscious thoughts do have a material reality, 221 00:14:22,078 --> 00:14:24,341 that dreams were actually physical phenomena 222 00:14:24,515 --> 00:14:27,344 that could be recorded. 223 00:14:29,390 --> 00:14:32,175 And he found a way to do it. 224 00:14:32,480 --> 00:14:36,788 In a place of broken minds and shattered dreams... 225 00:14:45,841 --> 00:14:48,670 This is the Manicomio di Collegno, 226 00:14:48,844 --> 00:14:50,759 in Turin, Italy. 227 00:14:51,107 --> 00:14:53,936 Built as a monastery in the 17th century, 228 00:14:54,284 --> 00:14:57,244 it had become a psychiatric hospital by 1850. 229 00:14:57,418 --> 00:15:01,552 It was abandoned decades ago, but it still reverberates with 230 00:15:01,726 --> 00:15:04,686 centuries of human suffering and loneliness. 231 00:15:06,383 --> 00:15:09,038 It was here that Angelo Mosso came to perform 232 00:15:09,212 --> 00:15:11,475 experiments on dreams and thoughts. 233 00:15:12,824 --> 00:15:15,218 Mosso was a child of the working class who 234 00:15:15,392 --> 00:15:17,960 boot-strapped himself into becoming a scientist. 235 00:15:18,439 --> 00:15:20,093 His primary research had been in 236 00:15:20,267 --> 00:15:22,617 pharmacology and physiology. 237 00:15:22,791 --> 00:15:25,576 And it was all focused on making life better 238 00:15:25,750 --> 00:15:27,622 for the working poor. 239 00:15:28,405 --> 00:15:31,887 He viewed science as a means to improve labor conditions. 240 00:15:34,020 --> 00:15:37,501 In a time when people were literally worked to death, 241 00:15:37,675 --> 00:15:40,026 without recourse or legal protection, 242 00:15:40,200 --> 00:15:43,029 Mosso designed and built an ergograph, 243 00:15:43,203 --> 00:15:45,857 or "“fatigue recorder,"” so that he could demonstrate 244 00:15:46,032 --> 00:15:48,904 experimentally what the relentless stress of hard 245 00:15:49,078 --> 00:15:51,602 labor did to the human body and mind. 246 00:15:52,734 --> 00:15:56,477 To Mosso, exhaustion was both a physical and emotional state, 247 00:15:57,739 --> 00:16:00,350 not a sign of human weakness or a character flaw. 248 00:16:01,308 --> 00:16:03,310 And it was your body's way of telling you to stop 249 00:16:03,484 --> 00:16:05,747 what you were doing to avoid injury. 250 00:16:06,269 --> 00:16:10,317 Mosso reasoned that fatigue had an evolutionary advantage, 251 00:16:10,491 --> 00:16:11,796 much like fear. 252 00:16:12,188 --> 00:16:14,712 [screams] 253 00:16:21,110 --> 00:16:23,286 [goats bleeting] 254 00:16:29,771 --> 00:16:33,253 To demonstrate this, Mosso began thinking about designing 255 00:16:33,427 --> 00:16:36,647 an apparatus that could record the body's blood flow. 256 00:16:59,844 --> 00:17:01,977 The table that Mosso's assistant floated on was 257 00:17:02,151 --> 00:17:05,285 exquisitely balanced, and was all attached to a rotating 258 00:17:05,459 --> 00:17:08,810 drum with a stylus that recorded the blood flow. 259 00:17:24,739 --> 00:17:27,568 It was the beginning of medical imaging, 260 00:17:28,003 --> 00:17:30,962 a tool that had never existed before. 261 00:17:34,618 --> 00:17:36,968 But if the actions of the heart could be recorded, 262 00:17:37,143 --> 00:17:39,275 what about the brain? 263 00:17:39,449 --> 00:17:42,583 How could you transcribe the brain's delicate murmurings 264 00:17:42,757 --> 00:17:45,934 when they were housed in a protective skull? 265 00:17:46,369 --> 00:17:49,372 There was no way to do that without harming a patient... 266 00:17:49,546 --> 00:17:51,026 Or was there? 267 00:17:54,769 --> 00:17:57,163 When he was not even two years old, 268 00:17:57,337 --> 00:17:59,948 Giovanni Thron fell from a great height. 269 00:18:00,383 --> 00:18:03,343 His skull had been so badly shattered it was necessary to 270 00:18:03,517 --> 00:18:06,215 remove some of the pieces. 271 00:18:06,563 --> 00:18:09,044 As a result of the blow, he began to have frequent 272 00:18:09,218 --> 00:18:11,829 and violent epileptic seizures. 273 00:18:12,526 --> 00:18:14,571 Fearing that they might be contagious, 274 00:18:14,745 --> 00:18:17,008 his parents abandoned him at the mental hospital 275 00:18:17,183 --> 00:18:19,620 in Turin by the time he was five. 276 00:18:20,360 --> 00:18:23,624 And there he languished for six years. 277 00:18:24,625 --> 00:18:27,802 The catastrophic injury that had ruined Giovanni's life had 278 00:18:27,976 --> 00:18:30,500 left a doorway to his brain. 279 00:18:30,848 --> 00:18:34,113 Mosso designed and built the machine so sensitive it could 280 00:18:34,287 --> 00:18:36,985 register the blood coursing through his brain. 281 00:18:37,290 --> 00:18:40,119 But Giovanni was so agitated during his waking hours, 282 00:18:40,293 --> 00:18:43,078 Mosso could only study him while he slept. 283 00:18:43,731 --> 00:18:46,342 Mosso needed Giovanni to be perfectly still in 284 00:18:46,516 --> 00:18:48,997 order to record the faint signature of his thoughts. 285 00:18:51,347 --> 00:18:54,742 GHOST: When I saw Giovanni in February, 1877, 286 00:18:54,916 --> 00:18:57,701 he had a large opening in the skull covered with skin. 287 00:18:59,181 --> 00:19:01,357 The terrible fall had forever arrested 288 00:19:01,531 --> 00:19:03,620 his intellectual development. 289 00:19:04,186 --> 00:19:05,970 It was a saddening circumstance, 290 00:19:06,145 --> 00:19:09,626 that in the midst of the ruin of his mind, one single, 291 00:19:09,800 --> 00:19:14,501 higher idea had remained, a remnant of his earlier 292 00:19:14,936 --> 00:19:18,809 intellectual life, a motto which he constantly repeated: 293 00:19:21,334 --> 00:19:25,555 'I want to go to school.' It was one of the most 294 00:19:25,729 --> 00:19:30,343 interesting sights to observe in the stillness of night, 295 00:19:30,517 --> 00:19:32,780 what was going on in his brain, 296 00:19:32,954 --> 00:19:35,086 when there was no external cause to disturb this 297 00:19:35,261 --> 00:19:38,133 mysterious life of sleep. 298 00:19:38,307 --> 00:19:41,528 The brain-pulse remained for 10 or 20 minutes quite regular 299 00:19:41,702 --> 00:19:43,312 and very weak... 300 00:19:43,486 --> 00:19:47,621 and then began suddenly, without any apparent cause to 301 00:19:47,795 --> 00:19:51,102 swell and beat more vigorously. 302 00:19:52,278 --> 00:19:54,410 The dreams, perhaps, 303 00:19:54,584 --> 00:19:57,544 come to cheer the repose of the unhappy boy? 304 00:19:57,979 --> 00:20:00,590 That the face of his mother and the recollections of his 305 00:20:00,764 --> 00:20:04,072 early childhood glow bright in his memory? 306 00:20:04,812 --> 00:20:07,162 Lighting up the darkness of his intelligence, 307 00:20:07,336 --> 00:20:10,861 and make his brain pulsate with excitement? 308 00:20:11,035 --> 00:20:13,777 Or was it an unconscious agitation of matter, 309 00:20:13,951 --> 00:20:18,782 like the ebb and flow of an unknown and solitary sea? 310 00:20:30,794 --> 00:20:34,624 TYSON: On that snowy night, Angelo Mosso gave the brain 311 00:20:34,798 --> 00:20:37,932 its first pen to write with. 312 00:20:38,193 --> 00:20:40,195 He had invented neuroimaging, 313 00:20:40,369 --> 00:20:42,023 and showed that even in sleep, 314 00:20:42,197 --> 00:20:44,634 the brain is pulsing, throbbing, 315 00:20:44,808 --> 00:20:47,637 flashing with the complex business of life... 316 00:20:48,029 --> 00:20:51,598 dreaming, remembering, figuring things out. 317 00:20:52,990 --> 00:20:55,906 Our thoughts, visions, fantasies and our dreams, 318 00:20:56,080 --> 00:20:58,779 do have a material reality. 319 00:21:00,128 --> 00:21:02,652 Three months after the night of dreams, 320 00:21:02,826 --> 00:21:06,439 Giovanni died of anemia. 321 00:21:08,092 --> 00:21:10,921 He was not yet 12. 322 00:21:21,323 --> 00:21:23,717 Angelo Mosso's breakthrough in pioneering the field of 323 00:21:23,891 --> 00:21:26,981 neuroscience inspired another man to take Mosso's 324 00:21:27,155 --> 00:21:29,723 work one giant step further. 325 00:21:30,637 --> 00:21:34,336 He wanted to demonstrate that psychic powers are real. 326 00:21:35,250 --> 00:21:38,384 It all happened because of a freak accident... 327 00:21:40,255 --> 00:21:42,910 [gunshots] 328 00:21:43,693 --> 00:21:47,175 Hans Berger dreamed of becoming an astronomer, 329 00:21:47,349 --> 00:21:50,526 but it was too hard, and so in 1892, 330 00:21:51,310 --> 00:21:53,573 he enlisted in the German army. 331 00:22:07,630 --> 00:22:10,416 Berger was shaken by his brush with death, 332 00:22:10,590 --> 00:22:12,548 but something happened that night that shocked 333 00:22:12,722 --> 00:22:14,681 him even more... 334 00:22:18,293 --> 00:22:20,556 A telegram had arrived from his father, 335 00:22:20,730 --> 00:22:22,689 a cold and distant man who had never sent him 336 00:22:22,863 --> 00:22:25,082 a telegram before. 337 00:22:25,256 --> 00:22:28,172 Berger's older sister had become panic-stricken with the 338 00:22:28,347 --> 00:22:30,697 certainty that something terrible had happened 339 00:22:30,871 --> 00:22:32,916 to her little brother. 340 00:22:33,090 --> 00:22:35,266 Was it possible, Berger wondered, 341 00:22:35,441 --> 00:22:38,661 that in the moment that he realized he was going to die, 342 00:22:38,835 --> 00:22:41,664 his brain had somehow telepathically delivered a 343 00:22:41,838 --> 00:22:45,233 message to the person he was closest to, his sister? 344 00:22:47,148 --> 00:22:49,324 Berger became a physician and a professor at 345 00:22:49,498 --> 00:22:51,761 the University of Jena. 346 00:22:52,022 --> 00:22:54,808 By day, he worked with his students and colleagues, 347 00:22:54,982 --> 00:22:57,463 who found him to be awkwardly formal, 348 00:22:57,637 --> 00:22:59,595 and scientifically unadventurous. 349 00:23:00,248 --> 00:23:02,990 But by night, he went to a secret laboratory where he 350 00:23:03,164 --> 00:23:05,253 conducted experiments on the brain's activity. 351 00:23:11,520 --> 00:23:14,741 Berger believed that this was his best chance of proving 352 00:23:14,915 --> 00:23:18,005 that psychic energy was real. 353 00:23:19,223 --> 00:23:21,443 He feared that if anyone were to discover his real 354 00:23:21,617 --> 00:23:25,142 scientific objective, he'd be laughed out of the profession. 355 00:23:34,543 --> 00:23:37,590 He kept his secret for 20 years. 356 00:23:41,942 --> 00:23:44,248 Berger's electroencephalograph made it 357 00:23:44,423 --> 00:23:47,295 possible to interpret the signals that the brain sends, 358 00:23:47,469 --> 00:23:50,429 and to diagnose many neurological diseases, 359 00:23:50,603 --> 00:23:52,735 including epilepsy. 360 00:23:53,257 --> 00:23:55,564 He never did find any evidence for psychic energy, 361 00:23:55,738 --> 00:23:58,219 or telepathic communication. 362 00:23:58,393 --> 00:24:00,700 Berger sunk into a deep depression, 363 00:24:00,874 --> 00:24:04,181 and hanged himself in his secret laboratory in 1941. 364 00:24:07,228 --> 00:24:11,188 The EEG is still in use today, although we now have far more 365 00:24:11,362 --> 00:24:14,627 accurate ways of seeing and recording what the brain does, 366 00:24:14,931 --> 00:24:17,717 and we even have the ability to decrypt the electrochemical 367 00:24:17,891 --> 00:24:20,328 language of thought. 368 00:24:20,589 --> 00:24:23,984 Exactly 100 years after Angelo Mosso first recorded 369 00:24:24,158 --> 00:24:26,508 the electrical whispers of Giovanni's dreams, 370 00:24:27,770 --> 00:24:30,730 the brain waves of a woman newly fallen in love, 371 00:24:30,904 --> 00:24:33,907 were included in the Voyager Interstellar Message, 372 00:24:34,081 --> 00:24:36,431 destined to sail the Milky Way 373 00:24:36,605 --> 00:24:39,434 for a billion years or more. 374 00:24:40,391 --> 00:24:43,220 From horse-drawn carriage to interstellar craft, 375 00:24:43,394 --> 00:24:45,222 in just a 100 years. 376 00:24:45,396 --> 00:24:48,269 From telegrams to sending our thoughts hand-delivered to one 377 00:24:48,443 --> 00:24:50,097 another at the speed of light, 378 00:24:50,271 --> 00:24:53,535 and our deepest feelings to a billion years from now. 379 00:24:54,362 --> 00:24:56,712 How did we make that leap? 380 00:24:56,886 --> 00:24:58,845 And why us? 381 00:24:59,019 --> 00:25:02,283 Of all the billions of species that have ever lived on Earth, 382 00:25:02,457 --> 00:25:04,633 why us and no other? 383 00:25:19,300 --> 00:25:25,132 ♪ ♪ 384 00:25:39,450 --> 00:25:42,366 TYSON: Primates who descended from the African savannah have 385 00:25:42,541 --> 00:25:45,674 sent their robot emissaries to explore the red deserts of 386 00:25:45,848 --> 00:25:48,808 Mars, and ring that world with satellites. 387 00:25:51,854 --> 00:25:54,640 We've only been at this since the mid-20th century, 388 00:25:54,814 --> 00:25:57,599 not even a lifetime, yet look at how far beyond 389 00:25:57,773 --> 00:25:59,775 our little world our robots have ventured. 390 00:26:01,298 --> 00:26:03,170 One of our craft, Voyager 1, 391 00:26:03,344 --> 00:26:05,346 has broken free of the Sun, 392 00:26:05,520 --> 00:26:08,828 and now sails the deep ocean of interstellar space. 393 00:26:10,873 --> 00:26:12,483 And every one of those odysseys of 394 00:26:12,658 --> 00:26:15,051 discovery began here. 395 00:26:17,140 --> 00:26:19,186 It's easy to see why the seat of all these mythic 396 00:26:19,360 --> 00:26:21,492 achievements would itself seem beyond our 397 00:26:21,667 --> 00:26:23,843 ability to understand. 398 00:26:24,408 --> 00:26:26,628 It's hard to believe that our minds are made of 399 00:26:26,802 --> 00:26:30,327 the same matter as our stomachs and our feet. 400 00:26:31,807 --> 00:26:35,028 Consciousness seems supernatural. 401 00:26:35,419 --> 00:26:37,508 Identity, awe... 402 00:26:37,683 --> 00:26:41,338 Skepticism, imagination, love. 403 00:26:42,426 --> 00:26:44,690 How do you assemble transcendence from the 404 00:26:44,864 --> 00:26:47,257 periodic table of the elements? 405 00:26:53,960 --> 00:26:55,875 We are at the bottom of the sea, 406 00:26:56,049 --> 00:26:58,225 off the coast of Chile and Peru. 407 00:26:58,399 --> 00:27:02,011 This is perhaps the largest living organism on Earth. 408 00:27:02,272 --> 00:27:06,102 It's a community of microbes that is the size of a country... 409 00:27:06,363 --> 00:27:08,539 Greece. 410 00:27:08,714 --> 00:27:11,542 But there's something even more amazing about it than its immensity. 411 00:27:13,240 --> 00:27:17,984 The ancient ancestors of these colonies represent an early step in 412 00:27:18,158 --> 00:27:20,682 the development of brains. 413 00:27:20,856 --> 00:27:24,251 When the microbes living at the center of this vast mat get hungry, 414 00:27:24,773 --> 00:27:26,949 they dispatch electrochemical messages to 415 00:27:27,123 --> 00:27:28,821 their fellow citizens at the outer-edge. 416 00:27:31,258 --> 00:27:34,391 These communiqués travel through passages called ion channels. 417 00:27:36,393 --> 00:27:39,483 A message goes out on amber waves of potassium from 418 00:27:39,658 --> 00:27:41,790 "“Sparta to Athens"” saying, 419 00:27:41,964 --> 00:27:45,098 "“Hey, guys, stop hogging all the food!"” 420 00:27:45,272 --> 00:27:47,491 And the residents of the mat's outer edge respond 421 00:27:47,666 --> 00:27:50,103 by reducing their intake of nutrients. 422 00:27:51,539 --> 00:27:54,107 It's possible that their ancient ancestors evolved 423 00:27:54,281 --> 00:27:57,284 cells called neurons that specialized in 424 00:27:57,458 --> 00:27:59,155 this kind of messaging. 425 00:28:00,940 --> 00:28:03,464 Neurons are the basic unit of nervous systems in almost 426 00:28:03,638 --> 00:28:07,120 every life form in the animal kingdom, including us. 427 00:28:08,164 --> 00:28:11,559 And they vary very little in nature, if at all, 428 00:28:11,733 --> 00:28:13,256 from species to species, 429 00:28:13,430 --> 00:28:15,650 but vary dramatically in number. 430 00:28:15,824 --> 00:28:18,392 In fact, we now think that epilepsy, 431 00:28:18,566 --> 00:28:20,829 that so-called "“sacred disease,"” 432 00:28:21,003 --> 00:28:24,790 is a misfiring in the brain of our own ion channels. 433 00:28:27,488 --> 00:28:30,796 Think of it: A microbial mat and Isaac Newton, 434 00:28:30,970 --> 00:28:33,537 separated by hundreds of millions of years of evolution, 435 00:28:34,364 --> 00:28:37,019 but sharing the same basic currency of thought. 436 00:28:38,629 --> 00:28:41,241 The messaging system pioneered by the microbes 437 00:28:41,415 --> 00:28:43,025 some four billion years ago, 438 00:28:43,199 --> 00:28:45,375 is still inside us. 439 00:28:45,680 --> 00:28:49,031 No one looking at a microbial mat three billion years ago 440 00:28:49,205 --> 00:28:52,078 could have predicted that the one-celled organisms 441 00:28:52,252 --> 00:28:55,124 of life on Earth would evolve into you. 442 00:28:56,996 --> 00:28:59,607 That's what happens when living things and environments 443 00:28:59,781 --> 00:29:02,305 interact over the eons. 444 00:29:02,479 --> 00:29:05,178 New forms and ways of being alive and aware 445 00:29:05,352 --> 00:29:07,658 come into existence. 446 00:29:08,007 --> 00:29:10,966 When the whole becomes greater than the sum of its parts, 447 00:29:11,140 --> 00:29:13,534 it's called emergence. 448 00:29:20,410 --> 00:29:22,369 See the thing that looks like a shred of a ruffle 449 00:29:22,543 --> 00:29:25,067 from a gaudy dress? 450 00:29:25,328 --> 00:29:27,200 You might think it's kind of silly. 451 00:29:27,374 --> 00:29:29,593 But, you would be so wrong. 452 00:29:30,333 --> 00:29:33,467 Long, long ago, some 600 million years ago, 453 00:29:33,641 --> 00:29:36,426 life first evolved something new to planet Earth, 454 00:29:36,731 --> 00:29:39,212 a command center that could perceive and react 455 00:29:39,386 --> 00:29:41,562 to its environment... 456 00:29:41,736 --> 00:29:43,172 a brain. 457 00:29:43,346 --> 00:29:46,480 Now, life inched closer to the stars. 458 00:29:46,741 --> 00:29:49,352 We think it first happened inside a flatworm... 459 00:29:49,526 --> 00:29:52,747 this little guy's ancestor, the first animal hunter. 460 00:29:54,793 --> 00:29:57,056 A brain was just what a hunter would need to 461 00:29:57,230 --> 00:30:00,189 seek out and plan a strategy for attack. 462 00:30:00,581 --> 00:30:03,279 Binocular vision allowed the flatworm to perceive the 463 00:30:03,453 --> 00:30:07,240 dimension of depth more sharply and objects with greater clarity, 464 00:30:08,415 --> 00:30:11,070 all the better to triangulate on prey. 465 00:30:11,766 --> 00:30:15,596 The flatworm brain had a pair of dense nerve clusters called "ganglia." 466 00:30:17,076 --> 00:30:18,773 Cords extended from them, 467 00:30:18,947 --> 00:30:20,993 carrying instructions and sensations to the rest of its 468 00:30:21,167 --> 00:30:24,474 body via some 8,000 neurons. 469 00:30:25,127 --> 00:30:27,738 Not many compared with the life forms that would come later, 470 00:30:27,913 --> 00:30:29,784 but a momentous beginning. 471 00:30:29,958 --> 00:30:32,178 Flatworms have something called auricles on the sides 472 00:30:32,352 --> 00:30:34,615 of their heads where their ears should be, 473 00:30:34,789 --> 00:30:36,704 but they're actually noses. 474 00:30:37,574 --> 00:30:40,273 We may not look much alike, but we have a lot in common. 475 00:30:41,927 --> 00:30:44,233 We share the same chemicals that control our nervous systems, 476 00:30:45,017 --> 00:30:47,236 called "“neurotransmitters."” 477 00:30:47,410 --> 00:30:49,978 We get addicted to the same drugs. 478 00:30:50,152 --> 00:30:52,459 Flatworms can learn. 479 00:30:52,633 --> 00:30:54,591 They process information about their environment 480 00:30:54,765 --> 00:30:56,637 and act accordingly. 481 00:30:56,811 --> 00:30:59,379 We think they're nature's first animals to have a front, 482 00:30:59,553 --> 00:31:01,120 a back and a head, 483 00:31:01,294 --> 00:31:03,600 a blueprint that remains state of the art, 484 00:31:03,774 --> 00:31:06,125 600 million years later. 485 00:31:07,126 --> 00:31:10,433 And they were the true pioneers in the deepest sense 486 00:31:10,607 --> 00:31:11,913 of that word. 487 00:31:12,087 --> 00:31:13,784 Unlike any life form before them, 488 00:31:13,959 --> 00:31:16,483 they developed the habit of venturing into the unknown 489 00:31:16,657 --> 00:31:19,399 territory in search of what they craved. 490 00:31:20,835 --> 00:31:23,490 Okay, flatworms are cool, but there's a big difference 491 00:31:23,664 --> 00:31:26,058 between a flatworm brain and ours. 492 00:31:27,668 --> 00:31:29,888 How did we get from there to here? 493 00:31:30,062 --> 00:31:32,194 We don't yet know. 494 00:31:32,368 --> 00:31:35,197 That's mainly because brains tend to be squishy. 495 00:31:35,371 --> 00:31:38,200 They don't leave distinct imprints in the fossil record. 496 00:31:38,374 --> 00:31:40,899 But the brain preserves its evolutionary past... 497 00:31:42,422 --> 00:31:43,989 Why? 498 00:31:44,163 --> 00:31:47,818 Because our brains are a little like New York City... 499 00:31:48,689 --> 00:31:52,127 [honking and sirens] 500 00:32:02,529 --> 00:32:06,620 [honking and sirens] 501 00:32:11,930 --> 00:32:15,585 TYSON: Most of the world's great cities have grown haphazardly, 502 00:32:15,759 --> 00:32:17,065 little by little, 503 00:32:17,239 --> 00:32:19,111 in response to the needs of the moment; 504 00:32:19,285 --> 00:32:21,156 very rarely is a city planned for 505 00:32:21,330 --> 00:32:23,028 the remote future. 506 00:32:23,767 --> 00:32:25,204 In New York City, 507 00:32:25,378 --> 00:32:26,640 many of the streets date all the way back 508 00:32:26,814 --> 00:32:28,772 to the 17th century... 509 00:32:28,947 --> 00:32:30,905 the stock exchange to the 18th... 510 00:32:32,167 --> 00:32:34,039 the waterworks and the electrical power system 511 00:32:34,213 --> 00:32:36,563 to the 19th century. 512 00:32:36,737 --> 00:32:39,261 And the communications bandwidth to the 20th. 513 00:32:47,052 --> 00:32:51,012 A city is like a brain: it develops from a small center 514 00:32:52,318 --> 00:32:54,581 and slowly grows and changes, 515 00:32:55,234 --> 00:32:57,758 leaving many old parts still functioning. 516 00:32:59,281 --> 00:33:02,154 New York can't afford to suspend its water supply, 517 00:33:02,328 --> 00:33:03,851 or its transportation system, 518 00:33:04,025 --> 00:33:06,071 while they're being replaced by something more efficient. 519 00:33:07,333 --> 00:33:09,900 Changes have to happen piecemeal. 520 00:33:12,077 --> 00:33:14,253 And that's how it is for the brain. 521 00:33:15,906 --> 00:33:18,605 There is no way for evolution to rip out the ancient 522 00:33:18,779 --> 00:33:21,782 interior of the brain because of its imperfections and 523 00:33:21,956 --> 00:33:25,264 replace it with something of more modern manufacture. 524 00:33:25,612 --> 00:33:29,094 The brain and the city both must function continuously 525 00:33:29,268 --> 00:33:31,487 during the renovation. 526 00:33:31,792 --> 00:33:34,273 That's why our limbic system is surrounded by 527 00:33:34,447 --> 00:33:36,101 the cerebral cortex. 528 00:33:36,275 --> 00:33:39,365 The old part is in charge of too many vital mechanisms for 529 00:33:39,539 --> 00:33:41,932 it to be replaced altogether. 530 00:33:42,107 --> 00:33:44,283 So, it's sometimes counterproductive. 531 00:33:44,457 --> 00:33:47,068 But that's a necessary consequence of evolution. 532 00:33:48,330 --> 00:33:51,681 The city is a gift of the cerebral cortex. 533 00:33:56,034 --> 00:33:58,688 But the brain's language is not encoded in the DNA of 534 00:33:58,862 --> 00:34:03,519 genes because the vocabulary of life is too small. 535 00:34:03,693 --> 00:34:06,522 Our brains need a language with 10,000 times 536 00:34:06,696 --> 00:34:08,481 as many words. 537 00:34:08,655 --> 00:34:10,961 The information content of the human brain expressed 538 00:34:11,136 --> 00:34:15,053 in bits is probably comparable to the total number of connections 539 00:34:15,227 --> 00:34:16,663 among the neurons... 540 00:34:16,837 --> 00:34:20,275 about a thousand trillion bits. 541 00:34:23,191 --> 00:34:26,194 If all the contents of your brain were transcribed into 542 00:34:26,368 --> 00:34:30,416 written language, it would amount to vastly more books 543 00:34:30,590 --> 00:34:33,767 than are contained in the largest libraries on earth. 544 00:34:33,941 --> 00:34:37,118 The equivalent of more than four billion books 545 00:34:37,292 --> 00:34:39,599 are inside your head. 546 00:34:39,773 --> 00:34:44,734 The brain is a very big place in a very small space. 547 00:34:48,999 --> 00:34:51,654 It's written in those neurons pioneered by 548 00:34:51,828 --> 00:34:54,570 the undersea microbial mats. 549 00:34:55,136 --> 00:34:58,400 These are tiny electrochemical switching elements, 550 00:34:58,574 --> 00:35:01,621 typically a few hundredths of a millimeter across. 551 00:35:02,143 --> 00:35:04,972 Each of us has 86 billion neurons, 552 00:35:05,146 --> 00:35:08,236 comparable to the number of stars in the Milky Way galaxy. 553 00:35:09,019 --> 00:35:12,153 The neurons and their parts, axons, dendrites, 554 00:35:12,327 --> 00:35:15,156 synapses and the cell bodies themselves make up 555 00:35:15,330 --> 00:35:17,550 a network in the brain. 556 00:35:17,898 --> 00:35:19,856 Many neurons have thousands of connections 557 00:35:20,030 --> 00:35:22,381 with their neighbors. 558 00:35:22,555 --> 00:35:26,689 Dendrites, those pathways sent out by neurons to connect with other neurons, 559 00:35:26,863 --> 00:35:29,518 extend these nerve cells to synapses until 560 00:35:29,692 --> 00:35:32,652 they create a full-blown network of consciousness. 561 00:35:51,845 --> 00:35:56,066 The neurochemistry of the brain is astonishingly busy, 562 00:35:56,415 --> 00:35:58,982 the circuitry of a machine more wonderful than any 563 00:35:59,157 --> 00:36:01,420 devised by humans. 564 00:36:01,594 --> 00:36:04,597 Your brain functions are due to those 100 trillion 565 00:36:04,771 --> 00:36:07,861 neural connections that make you, you. 566 00:36:08,601 --> 00:36:11,256 Your deepest feelings of love and awe... 567 00:36:11,430 --> 00:36:14,128 those moments when we glimpse the grandeur of nature, 568 00:36:14,302 --> 00:36:17,175 and all the elegant architecture of consciousness... 569 00:36:17,610 --> 00:36:21,091 are made possible by those connections. 570 00:36:21,527 --> 00:36:24,138 This is the essence of emergence: 571 00:36:24,312 --> 00:36:26,923 tiny units of matter operating collectively 572 00:36:27,097 --> 00:36:28,403 to become something much more 573 00:36:28,577 --> 00:36:30,231 than themselves, 574 00:36:30,405 --> 00:36:32,842 to enable the cosmos to know itself. 575 00:36:34,496 --> 00:36:37,847 But there's a vision of emergence that takes it even higher. 576 00:36:38,021 --> 00:36:40,372 Can we know the universe? 577 00:36:41,068 --> 00:36:44,114 And will it ever come to know us? 578 00:37:03,569 --> 00:37:06,572 TYSON: Can we know the universe? 579 00:37:06,833 --> 00:37:09,836 All those galaxies, solar systems, numberless worlds, 580 00:37:10,402 --> 00:37:13,666 moons, comets, beings, and their dreams... 581 00:37:14,536 --> 00:37:17,974 everything that ever was, is, or will be? 582 00:37:25,460 --> 00:37:28,724 Can we know the universe? 583 00:37:29,203 --> 00:37:32,598 I'm not sure we can even know a grain of salt. 584 00:37:32,772 --> 00:37:35,688 Consider one microgram of table salt, 585 00:37:35,862 --> 00:37:38,517 a speck just barely large enough for someone with keen 586 00:37:38,691 --> 00:37:41,563 eyesight to see without a microscope. 587 00:37:42,085 --> 00:37:45,437 In that grain of salt there are about 10 to the power 16 588 00:37:45,611 --> 00:37:47,482 sodium and chlorine atoms. 589 00:37:48,353 --> 00:37:49,963 What does that mean? 590 00:37:50,137 --> 00:37:53,532 It means that there are 10 million billion atoms in this 591 00:37:53,706 --> 00:37:56,274 and every other single grain of salt. 592 00:37:56,883 --> 00:37:59,233 To know the grain of salt deeply, 593 00:37:59,407 --> 00:38:01,540 requires us to know at least the three-dimensional 594 00:38:01,714 --> 00:38:03,629 positions of each of these atoms. 595 00:38:03,803 --> 00:38:05,892 In fact, there's much more to be known... 596 00:38:06,675 --> 00:38:09,983 for example, the nature of the forces between the atoms. 597 00:38:10,549 --> 00:38:12,202 But okay, let's try to keep it simple, 598 00:38:12,377 --> 00:38:14,161 we'll leave that aside. 599 00:38:14,335 --> 00:38:18,034 Is the number of all the positions more or less than 600 00:38:18,208 --> 00:38:20,602 the number of things which the brain can know? 601 00:38:21,560 --> 00:38:24,171 How much can the brain know? 602 00:38:24,432 --> 00:38:26,826 If you do the calculation, with all the neurons and their 603 00:38:27,000 --> 00:38:29,219 dendrites, axons, synapses... 604 00:38:29,394 --> 00:38:31,961 we can know 100 trillion things. 605 00:38:33,267 --> 00:38:36,662 But this is only 1% of the number of atoms in 606 00:38:36,836 --> 00:38:38,577 our grain of salt. 607 00:38:38,751 --> 00:38:41,580 So in this sense, the universe is unmanageable, 608 00:38:42,276 --> 00:38:45,061 astonishingly immune to any human attempt 609 00:38:45,235 --> 00:38:46,933 at full knowledge. 610 00:38:47,107 --> 00:38:50,110 We cannot, at this level, fully know a grain of salt, 611 00:38:50,284 --> 00:38:52,155 much less the universe. 612 00:38:52,330 --> 00:38:53,983 But let's look a little more deeply at our 613 00:38:54,157 --> 00:38:56,334 microgram of salt. 614 00:38:56,856 --> 00:38:59,249 Salt happens to be a crystal in which, 615 00:38:59,424 --> 00:39:02,165 except for defects in the structure of its lattice, 616 00:39:02,340 --> 00:39:04,907 the position of every sodium and chlorine 617 00:39:05,081 --> 00:39:06,822 atom is predetermined. 618 00:39:06,996 --> 00:39:09,869 If we shrink ourselves into this crystalline world, 619 00:39:10,043 --> 00:39:13,960 we would see rank upon rank of atoms in an ordered array, 620 00:39:14,134 --> 00:39:16,484 a regularly alternating structure... 621 00:39:16,658 --> 00:39:19,269 sodium, chlorine, sodium, chlorine... 622 00:39:20,270 --> 00:39:23,056 specifying the sheet of atoms we are flying through, 623 00:39:23,230 --> 00:39:25,754 and all the sheets above us and below us. 624 00:39:27,321 --> 00:39:30,672 An absolutely pure grain of salt could have the position 625 00:39:30,846 --> 00:39:33,153 of every atom specified by something like 626 00:39:33,327 --> 00:39:35,460 ten bits of information. 627 00:39:35,634 --> 00:39:38,114 This wouldn't strain our brain's carrying capacity. 628 00:39:38,288 --> 00:39:41,204 We'd still have plenty of room for other stuff. 629 00:39:41,379 --> 00:39:44,773 Now, imagine a universe with natural laws that govern its 630 00:39:44,947 --> 00:39:48,473 behavior to the same degree of regularity that's true 631 00:39:48,647 --> 00:39:50,649 for a grain of salt. 632 00:39:50,823 --> 00:39:53,347 That universe would be knowable. 633 00:39:53,521 --> 00:39:55,828 Even if it had many complicated laws, 634 00:39:56,002 --> 00:39:59,309 we'd still have a shot at knowing that cosmos. 635 00:40:12,366 --> 00:40:14,760 It wouldn't matter if the reality of that universe 636 00:40:14,934 --> 00:40:17,153 exceeded the information-carrying capacity 637 00:40:17,327 --> 00:40:19,242 of one of our brains. 638 00:40:19,417 --> 00:40:21,897 We'd just go outside our bodies and build a computer to 639 00:40:22,071 --> 00:40:24,683 store the surplus information. 640 00:40:25,118 --> 00:40:27,163 And we'd still, in some sense, 641 00:40:27,337 --> 00:40:29,557 know the universe. 642 00:40:29,905 --> 00:40:33,039 Now, imagine a universe with no such laws, 643 00:40:33,605 --> 00:40:36,390 one that behaves in a completely unpredictable fashion. 644 00:40:37,086 --> 00:40:40,350 That universe would contain something like 10 to the 80th 645 00:40:40,525 --> 00:40:42,831 elementary particles. 646 00:40:43,179 --> 00:40:46,400 The inhabitants would find everyday experience a muddled 647 00:40:46,574 --> 00:40:50,665 jumble of events with no predictability, no regularity. 648 00:40:52,406 --> 00:40:54,887 And if they ever came to exist, 649 00:40:55,061 --> 00:40:57,411 they would be in grave peril. 650 00:41:03,591 --> 00:41:07,377 Lucky for us, we live in a universe with important parts 651 00:41:07,552 --> 00:41:09,510 that are knowable. 652 00:41:09,684 --> 00:41:11,904 The universe belongs to those who, 653 00:41:12,078 --> 00:41:15,081 at least to some degree, have figured it out. 654 00:41:16,082 --> 00:41:19,259 It's an astonishing fact that there are laws of nature, 655 00:41:19,433 --> 00:41:20,913 rules that summarize... 656 00:41:21,087 --> 00:41:23,698 not just qualitatively but quantitatively, 657 00:41:23,872 --> 00:41:26,614 how the cosmos works. 658 00:41:26,788 --> 00:41:30,575 But what about the cosmos inside each of us... 659 00:41:30,749 --> 00:41:34,100 That unknown and solitary sea? 660 00:41:34,709 --> 00:41:36,972 There are something like 100 trillion... 661 00:41:37,146 --> 00:41:40,976 that is, one-hundred thousand billion connections 662 00:41:41,455 --> 00:41:43,457 in your cerebral cortex. 663 00:41:43,631 --> 00:41:46,982 That's 100 times as many connections inside you as all 664 00:41:47,156 --> 00:41:49,942 the galaxies of the visible universe. 665 00:41:51,073 --> 00:41:53,249 We're just at the beginning of a great 666 00:41:53,423 --> 00:41:55,556 journey of exploration. 667 00:41:55,730 --> 00:41:59,299 Just as biologists succeeded in mapping the human genome, 668 00:41:59,691 --> 00:42:02,607 neuroscientists are attempting to map something 669 00:42:02,781 --> 00:42:06,436 far more complex and unique to each and every one of us. 670 00:42:07,481 --> 00:42:10,136 It's called our connectome. 671 00:42:14,662 --> 00:42:18,100 If we could truly know another person's connectome, 672 00:42:18,274 --> 00:42:21,800 the singular wiring diagram of all their memories, 673 00:42:21,974 --> 00:42:24,454 thoughts, fears, dreams... 674 00:42:25,978 --> 00:42:28,023 How would we treat each other? 675 00:42:28,197 --> 00:42:30,809 Could we heal the brain of its countless torments, 676 00:42:31,679 --> 00:42:34,639 and free all the Giovanni's of the world? 677 00:42:35,727 --> 00:42:39,992 Could we send one of our connectomes on a future interstellar probe, 678 00:42:40,514 --> 00:42:42,168 or ever hope to receive one from the 679 00:42:42,342 --> 00:42:45,475 being of another world? 680 00:42:58,097 --> 00:43:02,188 Would that be the ultimate realization of emergence... 681 00:43:02,884 --> 00:43:08,020 a cosmos interconnected by thoughts and dreams? 682 00:43:11,066 --> 00:43:12,502 Captioned by Cotter Captioning Services.