1 00:00:03,500 --> 00:00:07,133 TYSON: Can we know the universe? 2 00:00:08,133 --> 00:00:11,233 Are our brains capable of comprehending the cosmos in 3 00:00:11,367 --> 00:00:13,900 all of its complexity and splendor? 4 00:00:14,967 --> 00:00:17,500 We don't yet know the answer to that question because our 5 00:00:17,633 --> 00:00:20,166 brain remains almost as much of a mystery 6 00:00:20,300 --> 00:00:22,300 as the universe itself. 7 00:00:23,500 --> 00:00:26,200 We think that the number of processing units in your brain 8 00:00:26,333 --> 00:00:29,867 is roughly equal to all the stars in 1,000 galaxies. 9 00:00:31,133 --> 00:00:33,633 At least 100 trillion. 10 00:00:33,934 --> 00:00:36,367 And it's possible that the real number of processing units 11 00:00:36,500 --> 00:00:38,734 is ten times larger. 12 00:00:39,033 --> 00:00:41,066 We're inside a brain. 13 00:00:41,200 --> 00:00:44,400 It's in the grip of a Category 5 hurricane of chemical and 14 00:00:44,533 --> 00:00:46,133 electrical forces. 15 00:00:46,934 --> 00:00:49,266 The storm came without warning, 16 00:00:49,500 --> 00:00:52,533 spreading chaos and heartache far beyond its path... 17 00:00:53,600 --> 00:00:56,734 But it also provided the first clues to the nature of this 18 00:00:56,867 --> 00:00:58,567 little cosmos. 19 00:01:05,000 --> 00:01:09,900 (theme music plays) 20 00:01:29,433 --> 00:01:35,200 ♪ ♪ 21 00:01:55,900 --> 00:02:01,233 ♪ ♪ 22 00:02:06,433 --> 00:02:10,633 TYSON: We are traveling 2,500 years back in time to the island 23 00:02:10,767 --> 00:02:12,800 of Kos in the Aegean Sea. 24 00:02:14,300 --> 00:02:16,533 This is the story of a giant leap in the 25 00:02:16,667 --> 00:02:18,133 history of thought. 26 00:02:18,767 --> 00:02:21,166 It was here that one of the most powerful spells 27 00:02:21,300 --> 00:02:25,200 ever to cloud the mind was first broken. 28 00:02:27,600 --> 00:02:29,500 Imagine you are the loving parents of a 29 00:02:29,633 --> 00:02:31,767 precious only child. 30 00:02:31,900 --> 00:02:34,467 The boy is given to moments of brilliance, 31 00:02:34,600 --> 00:02:36,567 which charm and impress your friends. 32 00:02:37,800 --> 00:02:39,500 But there's something wrong... 33 00:02:42,100 --> 00:02:44,767 A storm is brewing inside his head... 34 00:02:47,333 --> 00:02:48,767 GOVERNESS: Peleus! Peleus! 35 00:03:01,066 --> 00:03:06,033 ♪ ♪ 36 00:03:18,467 --> 00:03:21,333 TYSON: This was medicine 2,500 years ago in Greece. 37 00:03:22,166 --> 00:03:25,166 The idea that the ritual appeasement of one of the gods 38 00:03:25,300 --> 00:03:27,867 could bring about the cure for an epileptic seizure was 39 00:03:28,000 --> 00:03:29,867 magical thinking. 40 00:03:30,400 --> 00:03:33,734 When the Greeks and people of other cultures performed their rituals, 41 00:03:33,867 --> 00:03:35,700 some of the afflicted recovered, 42 00:03:36,133 --> 00:03:37,834 due to the finite course of the illness, 43 00:03:37,967 --> 00:03:40,166 or to their own immune systems. 44 00:03:40,500 --> 00:03:42,233 But to the patients and their loved ones, 45 00:03:42,367 --> 00:03:45,300 it meant that the gods had been appeased. 46 00:03:46,000 --> 00:03:47,700 And when the patient died? 47 00:03:48,066 --> 00:03:50,033 That just meant the gods were so angry, 48 00:03:50,166 --> 00:03:52,100 nothing could be done. 49 00:03:52,500 --> 00:03:57,600 This way of thinking was a by-product of that great human strength, and weakness, 50 00:03:57,734 --> 00:04:00,000 called pattern recognition. 51 00:04:03,367 --> 00:04:06,834 In this case, false pattern recognition. 52 00:04:06,967 --> 00:04:09,500 The belief that epilepsy was caused by the anger of the 53 00:04:09,633 --> 00:04:13,266 gods was the confusion of correlation with causation, 54 00:04:14,233 --> 00:04:15,934 and the wishful thinking that prevails when 55 00:04:16,066 --> 00:04:18,734 people feel powerless. 56 00:04:19,233 --> 00:04:21,233 That's not to say that the ancient Greeks didn't have 57 00:04:21,367 --> 00:04:23,734 remedies, plants and minerals, they used as medicines. 58 00:04:24,934 --> 00:04:27,433 But for a disease as mysterious as epilepsy, 59 00:04:28,367 --> 00:04:30,367 they could only light their incense and pray. 60 00:04:31,734 --> 00:04:34,200 They didn't even know it had anything to do with the brain. 61 00:04:35,900 --> 00:04:38,500 And then came Hippocrates. 62 00:04:39,900 --> 00:04:42,567 Hippocrates rejected the notion that angry gods were 63 00:04:42,700 --> 00:04:44,734 the cause of disease and injury. 64 00:04:45,133 --> 00:04:48,800 He wrote: "The physician must investigate the entire patient, 65 00:04:48,934 --> 00:04:51,400 his diet and his environment... 66 00:04:52,133 --> 00:04:54,233 The best physician is the one who is able 67 00:04:54,367 --> 00:04:56,233 to prevent illness. 68 00:04:56,367 --> 00:04:59,166 Nothing happens without a natural cause." 69 00:05:00,767 --> 00:05:03,266 For this alone, he could be called the Father of Medicine. 70 00:05:04,133 --> 00:05:07,500 He is credited with codifying an ethos for doctors. 71 00:05:08,800 --> 00:05:12,800 The oath ascribed to him in the 3rd century BCE is still 72 00:05:12,934 --> 00:05:16,400 taken today by those who would practice medicine. 73 00:05:18,300 --> 00:05:20,400 And it was Hippocrates who was among the first 74 00:05:20,533 --> 00:05:23,700 to declare the brain to be the seat of consciousness. 75 00:05:24,934 --> 00:05:26,367 It's hard to believe, 76 00:05:26,500 --> 00:05:29,066 but this was once a revolutionary concept. 77 00:05:29,200 --> 00:05:31,367 The prevailing wisdom being that we actually 78 00:05:31,500 --> 00:05:33,900 thought with our hearts. 79 00:05:34,033 --> 00:05:36,734 And it may have been here where he made one of 80 00:05:36,867 --> 00:05:39,633 the great prophecies in the history of science. 81 00:05:41,800 --> 00:05:45,066 Hippocrates understood that he and his contemporaries 82 00:05:45,200 --> 00:05:47,734 called epilepsy "the sacred disease" 83 00:05:48,667 --> 00:05:51,700 because they didn't understand its physical cause. 84 00:05:51,834 --> 00:05:57,033 He wrote, "When we do, we will no longer think it divine." 85 00:05:59,367 --> 00:06:01,233 That little boy wasn't cursed. 86 00:06:01,367 --> 00:06:04,567 There was a physical malfunction inside his brain. 87 00:06:04,934 --> 00:06:07,900 As long as we searched for it in the whim of the gods, 88 00:06:08,033 --> 00:06:11,700 we had no hope of helping him, or ourselves. 89 00:06:12,533 --> 00:06:14,934 Yet thousands of years passed, 90 00:06:15,066 --> 00:06:17,233 and the brain remained a mystery. 91 00:06:19,400 --> 00:06:22,033 Between 420 BCE and the 19th century, 92 00:06:22,867 --> 00:06:25,967 our understanding of the cosmos grew by leaps and bounds. 93 00:06:26,900 --> 00:06:29,033 We discovered the speed of light, 94 00:06:29,166 --> 00:06:30,467 the laws of gravity, 95 00:06:30,600 --> 00:06:33,967 and we learned that our Sun is part of a greater galaxy 96 00:06:34,100 --> 00:06:38,934 of stars and yet, 2,300 years after Hippocrates, 97 00:06:39,066 --> 00:06:41,633 we still knew virtually nothing about the part of 98 00:06:41,767 --> 00:06:44,900 ourselves that made it possible to make these discoveries: 99 00:06:45,700 --> 00:06:47,266 our brains. 100 00:06:47,400 --> 00:06:50,734 It could be said that we actually knew less. 101 00:06:50,867 --> 00:06:52,867 The study of the brain had become stuck in a 102 00:06:53,000 --> 00:06:56,266 pseudoscientific dead-end called "phrenology," 103 00:06:56,400 --> 00:06:59,934 which held that from the shape of a person's skull, 104 00:07:00,066 --> 00:07:01,800 you could deduce their intelligence and 105 00:07:01,934 --> 00:07:04,567 trustworthiness. 106 00:07:04,834 --> 00:07:07,266 A frenzy of head-measuring ensued. 107 00:07:07,400 --> 00:07:09,800 A gift for languages resided above the cheekbone, 108 00:07:10,767 --> 00:07:13,200 and marital fidelity located behind the ears. 109 00:07:14,667 --> 00:07:15,967 And not surprisingly, 110 00:07:16,100 --> 00:07:18,200 European phrenologists discovered that their 111 00:07:18,333 --> 00:07:20,834 particular heads represented the universal 112 00:07:20,967 --> 00:07:22,967 standard of cerebral excellence. 113 00:07:24,500 --> 00:07:26,600 The first real insight regarding the connection 114 00:07:26,734 --> 00:07:31,266 between the mind and the brain was made in France in 1861. 115 00:07:31,767 --> 00:07:35,066 And here again, epilepsy played a critical role... 116 00:07:44,467 --> 00:07:47,500 The Bicêtre psychiatric hospital was state-of-the-art 117 00:07:47,633 --> 00:07:49,266 in Paris back then. 118 00:07:49,400 --> 00:07:51,567 In the previous century, it had been the first to 119 00:07:51,700 --> 00:07:54,633 introduce humane practices in the treatment of the insane 120 00:07:54,767 --> 00:07:56,800 and the mentally disabled. 121 00:07:58,166 --> 00:08:01,333 And among the doctors there, surgeon Paul Broca was 122 00:08:01,467 --> 00:08:03,600 especially admired for his enlightened treatment 123 00:08:03,734 --> 00:08:05,300 of his patients. 124 00:08:12,734 --> 00:08:14,200 TAN: Tan... 125 00:08:18,567 --> 00:08:21,300 TYSON: The patient's name was Louis Leborgne. 126 00:08:23,000 --> 00:08:24,300 TAN: Tan... 127 00:08:24,633 --> 00:08:26,734 TYSON: But everyone called him "Tan" after the 128 00:08:26,867 --> 00:08:29,967 only syllable that he had uttered since he was 30. 129 00:08:30,233 --> 00:08:32,133 He was now 51. 130 00:08:32,667 --> 00:08:35,600 Tan had been having epileptic seizures since childhood, 131 00:08:35,734 --> 00:08:37,767 but he was committed to Bicêtre because he had lost 132 00:08:37,900 --> 00:08:42,433 all powers of speech except for being able to say "tan." 133 00:08:43,667 --> 00:08:45,867 Now, poor Tan lay dying. 134 00:08:46,667 --> 00:08:48,367 His right side had become paralyzed, 135 00:08:48,500 --> 00:08:50,734 and gangrene had set in. 136 00:08:50,867 --> 00:08:52,700 Prior to Tan's medical crisis, 137 00:08:52,834 --> 00:08:55,734 Broca had been speculating that specific regions 138 00:08:55,867 --> 00:08:58,033 of the brain might be responsible for 139 00:08:58,166 --> 00:09:00,033 the powers of speech and memory. 140 00:09:02,133 --> 00:09:04,533 Broca wanted to know everything he possibly could 141 00:09:04,667 --> 00:09:07,000 about the dying patient in expectation of what a 142 00:09:07,133 --> 00:09:08,867 post-mortem might reveal. 143 00:09:10,700 --> 00:09:14,533 We do not know if Tan's epilepsy caused the damage to his brain, 144 00:09:14,667 --> 00:09:17,100 or whether an unreported childhood injury 145 00:09:17,233 --> 00:09:19,400 caused his epilepsy and later loss of speech. 146 00:09:25,100 --> 00:09:26,367 TAN: Tan... 147 00:09:45,734 --> 00:09:47,367 TYSON: But because of Tan's fate, 148 00:09:47,500 --> 00:09:49,633 Paul Broca was able to connect, 149 00:09:49,767 --> 00:09:53,433 for the very first time, a part of the human brain, 150 00:09:53,567 --> 00:09:55,300 in this case the region that was damaged, 151 00:09:55,433 --> 00:09:58,867 and its specialized function: the ability to use language. 152 00:09:59,767 --> 00:10:00,967 His reward... 153 00:10:01,100 --> 00:10:03,867 that part of our brain has been known ever since 154 00:10:04,000 --> 00:10:05,934 as "Broca's area." 155 00:10:08,967 --> 00:10:12,100 Paul Broca's own brain ended up in a jar 156 00:10:12,233 --> 00:10:14,967 like this one in a back storage room of the 157 00:10:15,100 --> 00:10:17,734 anthropological museum he directed, 158 00:10:18,133 --> 00:10:21,834 with shelf upon shelf of the brains of mass murderers and 159 00:10:21,967 --> 00:10:24,433 other master criminals, as well as congenital 160 00:10:24,567 --> 00:10:27,800 abnormalities that seemed to fascinate the public of the 161 00:10:27,934 --> 00:10:29,600 19th century. 162 00:10:29,734 --> 00:10:32,100 Broca was a humanist. 163 00:10:32,233 --> 00:10:34,500 He concluded that there were deep connections in brain 164 00:10:34,633 --> 00:10:38,100 physiology between non-human primates and us. 165 00:10:39,467 --> 00:10:42,266 He founded a society of freethinkers in his youth, 166 00:10:42,400 --> 00:10:44,433 and believed passionately in the importance 167 00:10:44,567 --> 00:10:46,166 of unobstructed inquiry. 168 00:10:46,967 --> 00:10:49,667 He lived his life in pursuit of that aim. 169 00:10:50,200 --> 00:10:54,000 But he, too, was partly blinded by the prejudices that 170 00:10:54,133 --> 00:10:56,433 permeated his society. 171 00:10:57,266 --> 00:11:00,500 He thought men mentally superior to women, 172 00:11:00,633 --> 00:11:03,600 and whites superior to everyone else. 173 00:11:04,100 --> 00:11:08,066 His falling short of humanist ideals shows that even someone 174 00:11:08,200 --> 00:11:10,600 as committed to the free pursuit of knowledge 175 00:11:10,734 --> 00:11:14,333 as Broca could still be deceived by endemic bigotry. 176 00:11:16,200 --> 00:11:18,967 Society corrupts the best of us. 177 00:11:19,100 --> 00:11:20,467 It's a little unfair, 178 00:11:20,600 --> 00:11:22,867 I think, to criticize a person for not sharing 179 00:11:23,000 --> 00:11:24,934 the enlightenment of a later age, 180 00:11:25,066 --> 00:11:29,233 but it is also profoundly saddening that such prejudices 181 00:11:29,367 --> 00:11:31,467 were so pervasive. 182 00:11:33,133 --> 00:11:37,100 The question raises nagging uncertainties about which of 183 00:11:37,233 --> 00:11:41,000 the assumptions of our own age will be considered 184 00:11:41,133 --> 00:11:44,000 unforgivable by the next... 185 00:11:46,800 --> 00:11:49,200 Broca established for the first time that there were 186 00:11:49,333 --> 00:11:52,400 physical correlations between anatomy and function, 187 00:11:53,233 --> 00:11:56,400 but what of the crackling energy of consciousness? 188 00:11:56,533 --> 00:11:59,367 What of the stuff that dreams are made of? 189 00:12:00,734 --> 00:12:02,667 Can't put them in a jar... 190 00:12:17,667 --> 00:12:20,667 ♪ ♪ 191 00:12:26,767 --> 00:12:29,266 TYSON: When the ancient Egyptians looked up at night, 192 00:12:29,400 --> 00:12:31,200 they saw the underbody of Nut, 193 00:12:32,100 --> 00:12:33,834 Goddess of the Milky Way. 194 00:12:34,233 --> 00:12:36,367 When they closed their eyes and began to dream, 195 00:12:36,934 --> 00:12:39,266 they believed they were transiting to the afterlife. 196 00:12:39,900 --> 00:12:42,633 And so, dreaming was ritualized into a form of 197 00:12:42,767 --> 00:12:45,900 worship, a means to learn what their future held, 198 00:12:46,600 --> 00:12:49,800 or to send a message to the gods, as they slumbered. 199 00:12:50,433 --> 00:12:52,066 The faithful would make a pilgrimage to 200 00:12:52,200 --> 00:12:54,066 a temple to dream. 201 00:13:01,433 --> 00:13:03,433 To prepare themselves, they would withdraw to a 202 00:13:03,567 --> 00:13:05,333 place of isolation, 203 00:13:05,467 --> 00:13:08,567 and fast to cleanse their mind and body. 204 00:13:14,467 --> 00:13:17,967 A prayer might be written to a particular god... 205 00:13:18,500 --> 00:13:22,467 and burned. 206 00:13:28,467 --> 00:13:31,100 It was hoped that its smoke would convey the contents to 207 00:13:31,233 --> 00:13:33,633 the underworld. 208 00:13:39,800 --> 00:13:43,200 If we could only materialize and decipher the dreaming that 209 00:13:43,333 --> 00:13:46,300 went on at the Temple of Dendera so long ago. 210 00:13:47,767 --> 00:13:50,300 And what of your dream just last night? 211 00:13:50,433 --> 00:13:53,400 The ancient Egyptians were mystified by the boundary that 212 00:13:53,533 --> 00:13:56,000 separates our waking and sleeping life. 213 00:13:56,900 --> 00:13:59,767 They believed that we were actually transported to 214 00:13:59,900 --> 00:14:02,867 another physical realm, and that dreams had 215 00:14:03,000 --> 00:14:04,967 a material reality. 216 00:14:05,367 --> 00:14:07,567 How else to explain the stunning detail of a 217 00:14:07,700 --> 00:14:09,834 particularly vivid dream? 218 00:14:10,800 --> 00:14:13,767 More than 1,000 years after the last dreamers awakened at 219 00:14:13,900 --> 00:14:17,700 Dendera, there was a scientist who believed that conscious 220 00:14:17,834 --> 00:14:20,834 and unconscious thoughts do have a material reality, 221 00:14:21,367 --> 00:14:23,700 that dreams were actually physical phenomena 222 00:14:23,834 --> 00:14:26,667 that could be recorded. 223 00:14:28,700 --> 00:14:31,433 And he found a way to do it. 224 00:14:31,734 --> 00:14:36,066 In a place of broken minds and shattered dreams... 225 00:14:45,100 --> 00:14:48,033 This is the Manicomio di Collegno, 226 00:14:48,166 --> 00:14:50,000 in Turin, Italy. 227 00:14:50,367 --> 00:14:53,233 Built as a monastery in the 17th century, 228 00:14:53,600 --> 00:14:56,600 it had become a psychiatric hospital by 1850. 229 00:14:56,734 --> 00:15:00,934 It was abandoned decades ago, but it still reverberates with 230 00:15:01,066 --> 00:15:04,033 centuries of human suffering and loneliness. 231 00:15:05,734 --> 00:15:08,367 It was here that Angelo Mosso came to perform 232 00:15:08,500 --> 00:15:10,867 experiments on dreams and thoughts. 233 00:15:12,133 --> 00:15:14,567 Mosso was a child of the working class who 234 00:15:14,700 --> 00:15:17,266 boot-strapped himself into becoming a scientist. 235 00:15:17,767 --> 00:15:19,467 His primary research had been in 236 00:15:19,600 --> 00:15:21,967 pharmacology and physiology. 237 00:15:22,100 --> 00:15:24,934 And it was all focused on making life better 238 00:15:25,066 --> 00:15:26,900 for the working poor. 239 00:15:27,700 --> 00:15:31,200 He viewed science as a means to improve labor conditions. 240 00:15:33,300 --> 00:15:36,834 In a time when people were literally worked to death, 241 00:15:36,967 --> 00:15:39,333 without recourse or legal protection, 242 00:15:39,467 --> 00:15:42,333 Mosso designed and built an ergograph, 243 00:15:42,467 --> 00:15:45,166 or "fatigue recorder," so that he could demonstrate 244 00:15:45,300 --> 00:15:48,266 experimentally what the relentless stress of hard 245 00:15:48,400 --> 00:15:50,867 labor did to the human body and mind. 246 00:15:52,033 --> 00:15:55,834 To Mosso, exhaustion was both a physical and emotional state, 247 00:15:57,100 --> 00:15:59,667 not a sign of human weakness or a character flaw. 248 00:16:00,633 --> 00:16:02,700 And it was your body's way of telling you to stop 249 00:16:02,834 --> 00:16:05,066 what you were doing to avoid injury. 250 00:16:05,600 --> 00:16:09,700 Mosso reasoned that fatigue had an evolutionary advantage, 251 00:16:09,834 --> 00:16:11,133 much like fear. 252 00:16:11,533 --> 00:16:14,066 (screams) 253 00:16:20,467 --> 00:16:22,633 (goats bleeting) 254 00:16:29,066 --> 00:16:32,567 To demonstrate this, Mosso began thinking about designing 255 00:16:32,700 --> 00:16:35,967 an apparatus that could record the body's blood flow. 256 00:16:59,200 --> 00:17:01,333 The table that Mosso's assistant floated on was 257 00:17:01,467 --> 00:17:04,633 exquisitely balanced, and was all attached to a rotating 258 00:17:04,767 --> 00:17:08,166 drum with a stylus that recorded the blood flow. 259 00:17:24,066 --> 00:17:26,867 It was the beginning of medical imaging, 260 00:17:27,333 --> 00:17:30,300 a tool that had never existed before. 261 00:17:33,900 --> 00:17:36,333 But if the actions of the heart could be recorded, 262 00:17:36,467 --> 00:17:38,600 what about the brain? 263 00:17:38,734 --> 00:17:41,934 How could you transcribe the brain's delicate murmurings 264 00:17:42,066 --> 00:17:45,200 when they were housed in a protective skull? 265 00:17:45,667 --> 00:17:48,734 There was no way to do that without harming a patient... 266 00:17:48,867 --> 00:17:50,333 Or was there? 267 00:17:54,133 --> 00:17:56,533 When he was not even two years old, 268 00:17:56,667 --> 00:17:59,266 Giovanni Thron fell from a great height. 269 00:17:59,767 --> 00:18:02,734 His skull had been so badly shattered it was necessary to 270 00:18:02,867 --> 00:18:05,500 remove some of the pieces. 271 00:18:05,934 --> 00:18:08,467 As a result of the blow, he began to have frequent 272 00:18:08,600 --> 00:18:11,200 and violent epileptic seizures. 273 00:18:11,934 --> 00:18:13,900 Fearing that they might be contagious, 274 00:18:14,033 --> 00:18:16,367 his parents abandoned him at the mental hospital 275 00:18:16,500 --> 00:18:18,934 in Turin by the time he was five. 276 00:18:19,667 --> 00:18:22,967 And there he languished for six years. 277 00:18:23,934 --> 00:18:27,166 The catastrophic injury that had ruined Giovanni's life had 278 00:18:27,300 --> 00:18:29,767 left a doorway to his brain. 279 00:18:30,133 --> 00:18:33,467 Mosso designed and built the machine so sensitive it could 280 00:18:33,600 --> 00:18:36,266 register the blood coursing through his brain. 281 00:18:36,600 --> 00:18:39,467 But Giovanni was so agitated during his waking hours, 282 00:18:39,600 --> 00:18:42,400 Mosso could only study him while he slept. 283 00:18:43,066 --> 00:18:45,667 Mosso needed Giovanni to be perfectly still in 284 00:18:45,800 --> 00:18:48,300 order to record the faint signature of his thoughts. 285 00:18:50,633 --> 00:18:54,200 GHOST: When I saw Giovanni in February, 1877, 286 00:18:54,333 --> 00:18:57,066 he had a large opening in the skull covered with skin. 287 00:18:58,533 --> 00:19:00,767 The terrible fall had forever arrested 288 00:19:00,900 --> 00:19:03,000 his intellectual development. 289 00:19:03,533 --> 00:19:05,367 It was a saddening circumstance, 290 00:19:05,500 --> 00:19:09,000 that in the midst of the ruin of his mind, one single, 291 00:19:09,133 --> 00:19:13,800 higher idea had remained, a remnant of his earlier 292 00:19:14,233 --> 00:19:18,166 intellectual life, a motto which he constantly repeated: 293 00:19:20,667 --> 00:19:24,900 'I want to go to school.' It was one of the most 294 00:19:25,033 --> 00:19:29,734 interesting sights to observe in the stillness of night, 295 00:19:29,867 --> 00:19:32,200 what was going on in his brain, 296 00:19:32,333 --> 00:19:34,467 when there was no external cause to disturb this 297 00:19:34,600 --> 00:19:37,500 mysterious life of sleep. 298 00:19:37,633 --> 00:19:40,900 The brain-pulse remained for 10 or 20 minutes quite regular 299 00:19:41,033 --> 00:19:42,367 and very weak... 300 00:19:42,500 --> 00:19:47,033 and then began suddenly, without any apparent cause to 301 00:19:47,166 --> 00:19:50,433 swell and beat more vigorously. 302 00:19:51,667 --> 00:19:53,734 The dreams, perhaps, 303 00:19:53,867 --> 00:19:56,800 come to cheer the repose of the unhappy boy? 304 00:19:57,233 --> 00:19:59,934 That the face of his mother and the recollections of his 305 00:20:00,066 --> 00:20:03,367 early childhood glow bright in his memory? 306 00:20:04,066 --> 00:20:06,500 Lighting up the darkness of his intelligence, 307 00:20:06,633 --> 00:20:10,200 and make his brain pulsate with excitement? 308 00:20:10,333 --> 00:20:13,100 Or was it an unconscious agitation of matter, 309 00:20:13,233 --> 00:20:18,066 like the ebb and flow of an unknown and solitary sea? 310 00:20:30,033 --> 00:20:33,934 TYSON: On that snowy night, Angelo Mosso gave the brain 311 00:20:34,066 --> 00:20:37,166 its first pen to write with. 312 00:20:37,500 --> 00:20:39,533 He had invented neuroimaging, 313 00:20:39,667 --> 00:20:41,300 and showed that even in sleep, 314 00:20:41,433 --> 00:20:43,900 the brain is pulsing, throbbing, 315 00:20:44,033 --> 00:20:46,867 flashing with the complex business of life... 316 00:20:47,266 --> 00:20:50,867 dreaming, remembering, figuring things out. 317 00:20:52,300 --> 00:20:55,266 Our thoughts, visions, fantasies and our dreams, 318 00:20:55,400 --> 00:20:58,100 do have a material reality. 319 00:20:59,433 --> 00:21:02,000 Three months after the night of dreams, 320 00:21:02,133 --> 00:21:05,767 Giovanni died of anemia. 321 00:21:07,400 --> 00:21:10,233 He was not yet 12. 322 00:21:20,600 --> 00:21:23,000 Angelo Mosso's breakthrough in pioneering the field of 323 00:21:23,133 --> 00:21:26,300 neuroscience inspired another man to take Mosso's 324 00:21:26,433 --> 00:21:29,000 work one giant step further. 325 00:21:29,900 --> 00:21:33,600 He wanted to demonstrate that psychic powers are real. 326 00:21:34,500 --> 00:21:37,700 It all happened because of a freak accident... 327 00:21:39,567 --> 00:21:42,166 (gunshots) 328 00:21:42,934 --> 00:21:46,467 Hans Berger dreamed of becoming an astronomer, 329 00:21:46,600 --> 00:21:49,767 but it was too hard, and so in 1892, 330 00:21:50,567 --> 00:21:52,934 he enlisted in the German army. 331 00:22:06,934 --> 00:22:09,734 Berger was shaken by his brush with death, 332 00:22:09,867 --> 00:22:11,900 but something happened that night that shocked 333 00:22:12,033 --> 00:22:14,000 him even more... 334 00:22:17,600 --> 00:22:19,867 A telegram had arrived from his father, 335 00:22:20,000 --> 00:22:22,033 a cold and distant man who had never sent him 336 00:22:22,166 --> 00:22:24,400 a telegram before. 337 00:22:24,533 --> 00:22:27,500 Berger's older sister had become panic-stricken with the 338 00:22:27,633 --> 00:22:30,033 certainty that something terrible had happened 339 00:22:30,166 --> 00:22:32,233 to her little brother. 340 00:22:32,367 --> 00:22:34,567 Was it possible, Berger wondered, 341 00:22:34,700 --> 00:22:38,000 that in the moment that he realized he was going to die, 342 00:22:38,133 --> 00:22:40,967 his brain had somehow telepathically delivered a 343 00:22:41,100 --> 00:22:44,500 message to the person he was closest to, his sister? 344 00:22:46,433 --> 00:22:48,667 Berger became a physician and a professor at 345 00:22:48,800 --> 00:22:50,967 the University of Jena. 346 00:22:51,367 --> 00:22:54,200 By day, he worked with his students and colleagues, 347 00:22:54,333 --> 00:22:56,800 who found him to be awkwardly formal, 348 00:22:56,934 --> 00:22:58,900 and scientifically unadventurous. 349 00:22:59,567 --> 00:23:02,333 But by night, he went to a secret laboratory where he 350 00:23:02,467 --> 00:23:04,567 conducted experiments on the brain's activity. 351 00:23:10,834 --> 00:23:14,100 Berger believed that this was his best chance of proving 352 00:23:14,233 --> 00:23:17,333 that psychic energy was real. 353 00:23:18,533 --> 00:23:20,767 He feared that if anyone were to discover his real 354 00:23:20,900 --> 00:23:24,467 scientific objective, he'd be laughed out of the profession. 355 00:23:33,867 --> 00:23:36,900 He kept his secret for 20 years. 356 00:23:41,233 --> 00:23:43,567 Berger's electroencephalograph made it 357 00:23:43,700 --> 00:23:46,600 possible to interpret the signals that the brain sends, 358 00:23:46,734 --> 00:23:49,767 and to diagnose many neurological diseases, 359 00:23:49,900 --> 00:23:52,066 including epilepsy. 360 00:23:52,600 --> 00:23:54,967 He never did find any evidence for psychic energy, 361 00:23:55,100 --> 00:23:57,567 or telepathic communication. 362 00:23:57,700 --> 00:24:00,033 Berger sunk into a deep depression, 363 00:24:00,166 --> 00:24:03,500 and hanged himself in his secret laboratory in 1941. 364 00:24:06,500 --> 00:24:10,533 The EEG is still in use today, although we now have far more 365 00:24:10,667 --> 00:24:13,900 accurate ways of seeing and recording what the brain does, 366 00:24:14,266 --> 00:24:17,066 and we even have the ability to decrypt the electrochemical 367 00:24:17,200 --> 00:24:19,600 language of thought. 368 00:24:19,867 --> 00:24:23,333 Exactly 100 years after Angelo Mosso first recorded 369 00:24:23,467 --> 00:24:25,800 the electrical whispers of Giovanni's dreams, 370 00:24:27,100 --> 00:24:30,033 the brain waves of a woman newly fallen in love, 371 00:24:30,166 --> 00:24:33,266 were included in the Voyager Interstellar Message, 372 00:24:33,400 --> 00:24:35,800 destined to sail the Milky Way 373 00:24:35,934 --> 00:24:38,734 for a billion years or more. 374 00:24:39,667 --> 00:24:42,567 From horse-drawn carriage to interstellar craft, 375 00:24:42,700 --> 00:24:44,533 in just a 100 years. 376 00:24:44,667 --> 00:24:47,633 From telegrams to sending our thoughts hand-delivered to one 377 00:24:47,767 --> 00:24:49,400 another at the speed of light, 378 00:24:49,533 --> 00:24:52,934 and our deepest feelings to a billion years from now. 379 00:24:53,700 --> 00:24:56,100 How did we make that leap? 380 00:24:56,233 --> 00:24:57,867 And why us? 381 00:24:58,000 --> 00:25:01,700 Of all the billions of species that have ever lived on Earth, 382 00:25:01,834 --> 00:25:04,000 why us and no other? 383 00:25:18,767 --> 00:25:24,567 ♪ ♪ 384 00:25:38,800 --> 00:25:41,800 TYSON: Primates who descended from the African savannah have 385 00:25:41,934 --> 00:25:45,133 sent their robot emissaries to explore the red deserts of 386 00:25:45,266 --> 00:25:48,233 Mars, and ring that world with satellites. 387 00:25:51,266 --> 00:25:54,100 We've only been at this since the mid-20th century, 388 00:25:54,233 --> 00:25:57,066 not even a lifetime, yet look at how far beyond 389 00:25:57,200 --> 00:25:59,266 our little world our robots have ventured. 390 00:26:00,734 --> 00:26:02,667 One of our craft, Voyager 1, 391 00:26:02,800 --> 00:26:04,867 has broken free of the Sun, 392 00:26:05,000 --> 00:26:08,300 and now sails the deep ocean of interstellar space. 393 00:26:10,266 --> 00:26:12,033 And every one of those odysseys of 394 00:26:12,166 --> 00:26:14,500 discovery began here. 395 00:26:16,533 --> 00:26:18,700 It's easy to see why the seat of all these mythic 396 00:26:18,834 --> 00:26:21,000 achievements would itself seem beyond our 397 00:26:21,133 --> 00:26:23,266 ability to understand. 398 00:26:23,834 --> 00:26:26,066 It's hard to believe that our minds are made of 399 00:26:26,200 --> 00:26:29,767 the same matter as our stomachs and our feet. 400 00:26:31,200 --> 00:26:34,467 Consciousness seems supernatural. 401 00:26:34,867 --> 00:26:37,033 Identity, awe... 402 00:26:37,166 --> 00:26:40,767 Skepticism, imagination, love. 403 00:26:41,834 --> 00:26:44,133 How do you assemble transcendence from the 404 00:26:44,266 --> 00:26:46,667 periodic table of the elements? 405 00:26:53,433 --> 00:26:55,400 We are at the bottom of the sea, 406 00:26:55,533 --> 00:26:57,667 off the coast of Chile and Peru. 407 00:26:57,800 --> 00:27:01,400 This is perhaps the largest living organism on Earth. 408 00:27:01,734 --> 00:27:05,567 It's a community of microbes that is the size of a country... 409 00:27:05,867 --> 00:27:07,567 Greece. 410 00:27:07,700 --> 00:27:11,000 But there's something even more amazing about it than its immensity. 411 00:27:12,633 --> 00:27:17,467 The ancient ancestors of these colonies represent an early step in 412 00:27:17,600 --> 00:27:20,133 the development of brains. 413 00:27:20,266 --> 00:27:23,667 When the microbes living at the center of this vast mat get hungry, 414 00:27:24,200 --> 00:27:26,400 they dispatch electrochemical messages to 415 00:27:26,533 --> 00:27:28,266 their fellow citizens at the outer-edge. 416 00:27:30,633 --> 00:27:33,834 These communiqués travel through passages called ion channels. 417 00:27:35,767 --> 00:27:38,934 A message goes out on amber waves of potassium from 418 00:27:39,066 --> 00:27:41,266 "Sparta to Athens" saying, 419 00:27:41,400 --> 00:27:44,500 "Hey, guys, stop hogging all the food!" 420 00:27:44,633 --> 00:27:46,934 And the residents of the mat's outer edge respond 421 00:27:47,066 --> 00:27:49,533 by reducing their intake of nutrients. 422 00:27:50,934 --> 00:27:53,600 It's possible that their ancient ancestors evolved 423 00:27:53,734 --> 00:27:56,767 cells called neurons that specialized in 424 00:27:56,900 --> 00:27:58,633 this kind of messaging. 425 00:28:00,367 --> 00:28:02,967 Neurons are the basic unit of nervous systems in almost 426 00:28:03,100 --> 00:28:06,567 every life form in the animal kingdom, including us. 427 00:28:07,633 --> 00:28:11,066 And they vary very little in nature, if at all, 428 00:28:11,200 --> 00:28:12,734 from species to species, 429 00:28:12,867 --> 00:28:15,166 but vary dramatically in number. 430 00:28:15,300 --> 00:28:17,867 In fact, we now think that epilepsy, 431 00:28:18,000 --> 00:28:20,333 that so-called "sacred disease," 432 00:28:20,467 --> 00:28:24,266 is a misfiring in the brain of our own ion channels. 433 00:28:26,934 --> 00:28:30,233 Think of it: A microbial mat and Isaac Newton, 434 00:28:30,367 --> 00:28:33,000 separated by hundreds of millions of years of evolution, 435 00:28:33,800 --> 00:28:36,500 but sharing the same basic currency of thought. 436 00:28:38,033 --> 00:28:40,700 The messaging system pioneered by the microbes 437 00:28:40,834 --> 00:28:42,500 some four billion years ago, 438 00:28:42,633 --> 00:28:44,767 is still inside us. 439 00:28:45,066 --> 00:28:48,467 No one looking at a microbial mat three billion years ago 440 00:28:48,600 --> 00:28:51,600 could have predicted that the one-celled organisms 441 00:28:51,734 --> 00:28:54,600 of life on Earth would evolve into you. 442 00:28:56,433 --> 00:28:59,133 That's what happens when living things and environments 443 00:28:59,266 --> 00:29:01,800 interact over the eons. 444 00:29:01,934 --> 00:29:04,667 New forms and ways of being alive and aware 445 00:29:04,800 --> 00:29:07,066 come into existence. 446 00:29:07,433 --> 00:29:10,467 When the whole becomes greater than the sum of its parts, 447 00:29:10,600 --> 00:29:13,000 it's called emergence. 448 00:29:19,867 --> 00:29:21,900 See the thing that looks like a shred of a ruffle 449 00:29:22,033 --> 00:29:24,500 from a gaudy dress? 450 00:29:24,767 --> 00:29:26,700 You might think it's kind of silly. 451 00:29:26,834 --> 00:29:29,066 But, you would be so wrong. 452 00:29:29,767 --> 00:29:32,934 Long, long ago, some 600 million years ago, 453 00:29:33,066 --> 00:29:35,834 life first evolved something new to planet Earth, 454 00:29:36,200 --> 00:29:38,734 a command center that could perceive and react 455 00:29:38,867 --> 00:29:41,066 to its environment... 456 00:29:41,200 --> 00:29:42,633 a brain. 457 00:29:42,767 --> 00:29:45,867 Now, life inched closer to the stars. 458 00:29:46,133 --> 00:29:48,767 We think it first happened inside a flatworm... 459 00:29:48,900 --> 00:29:52,166 this little guy's ancestor, the first animal hunter. 460 00:29:54,200 --> 00:29:56,467 A brain was just what a hunter would need to 461 00:29:56,600 --> 00:29:59,567 seek out and plan a strategy for attack. 462 00:30:00,000 --> 00:30:02,700 Binocular vision allowed the flatworm to perceive the 463 00:30:02,834 --> 00:30:06,667 dimension of depth more sharply and objects with greater clarity, 464 00:30:07,867 --> 00:30:10,400 all the better to triangulate on prey. 465 00:30:11,100 --> 00:30:15,000 The flatworm brain had a pair of dense nerve clusters called "ganglia." 466 00:30:16,500 --> 00:30:18,133 Cords extended from them, 467 00:30:18,266 --> 00:30:20,433 carrying instructions and sensations to the rest of its 468 00:30:20,567 --> 00:30:23,834 body via some 8,000 neurons. 469 00:30:24,500 --> 00:30:27,166 Not many compared with the life forms that would come later, 470 00:30:27,300 --> 00:30:29,233 but a momentous beginning. 471 00:30:29,367 --> 00:30:31,600 Flatworms have something called auricles on the sides 472 00:30:31,734 --> 00:30:34,066 of their heads where their ears should be, 473 00:30:34,200 --> 00:30:36,066 but they're actually noses. 474 00:30:36,934 --> 00:30:39,600 We may not look much alike, but we have a lot in common. 475 00:30:41,233 --> 00:30:43,567 We share the same chemicals that control our nervous systems, 476 00:30:44,367 --> 00:30:46,633 called "neurotransmitters." 477 00:30:46,767 --> 00:30:49,400 We get addicted to the same drugs. 478 00:30:49,533 --> 00:30:51,967 Flatworms can learn. 479 00:30:52,100 --> 00:30:54,100 They process information about their environment 480 00:30:54,233 --> 00:30:56,100 and act accordingly. 481 00:30:56,233 --> 00:30:58,834 We think they're nature's first animals to have a front, 482 00:30:58,967 --> 00:31:00,533 a back and a head, 483 00:31:00,667 --> 00:31:03,033 a blueprint that remains state of the art, 484 00:31:03,166 --> 00:31:05,500 600 million years later. 485 00:31:06,500 --> 00:31:09,934 And they were the true pioneers in the deepest sense 486 00:31:10,066 --> 00:31:11,333 of that word. 487 00:31:11,467 --> 00:31:13,200 Unlike any life form before them, 488 00:31:13,333 --> 00:31:15,934 they developed the habit of venturing into the unknown 489 00:31:16,066 --> 00:31:18,800 territory in search of what they craved. 490 00:31:20,233 --> 00:31:22,900 Okay, flatworms are cool, but there's a big difference 491 00:31:23,033 --> 00:31:25,467 between a flatworm brain and ours. 492 00:31:27,066 --> 00:31:29,333 How did we get from there to here? 493 00:31:29,467 --> 00:31:31,633 We don't yet know. 494 00:31:31,767 --> 00:31:34,567 That's mainly because brains tend to be squishy. 495 00:31:34,700 --> 00:31:37,633 They don't leave distinct imprints in the fossil record. 496 00:31:37,767 --> 00:31:40,266 But the brain preserves its evolutionary past... 497 00:31:41,834 --> 00:31:43,300 Why? 498 00:31:43,433 --> 00:31:47,233 Because our brains are a little like New York City... 499 00:31:48,100 --> 00:31:51,600 (honking and sirens) 500 00:32:02,133 --> 00:32:06,166 (honking and sirens) 501 00:32:11,467 --> 00:32:15,166 TYSON: Most of the world's great cities have grown haphazardly, 502 00:32:15,300 --> 00:32:16,333 little by little, 503 00:32:16,467 --> 00:32:18,700 in response to the needs of the moment; 504 00:32:18,834 --> 00:32:20,734 very rarely is a city planned for 505 00:32:20,867 --> 00:32:22,633 the remote future. 506 00:32:23,333 --> 00:32:24,467 In New York City, 507 00:32:24,600 --> 00:32:26,200 many of the streets date all the way back 508 00:32:26,333 --> 00:32:28,333 to the 17th century... 509 00:32:28,467 --> 00:32:30,433 the stock exchange to the 18th... 510 00:32:31,667 --> 00:32:33,600 the waterworks and the electrical power system 511 00:32:33,734 --> 00:32:36,133 to the 19th century. 512 00:32:36,266 --> 00:32:38,800 And the communications bandwidth to the 20th. 513 00:32:46,533 --> 00:32:50,567 A city is like a brain: it develops from a small center 514 00:32:51,900 --> 00:32:54,133 and slowly grows and changes, 515 00:32:54,767 --> 00:32:57,333 leaving many old parts still functioning. 516 00:32:58,834 --> 00:33:01,767 New York can't afford to suspend its water supply, 517 00:33:01,900 --> 00:33:03,400 or its transportation system, 518 00:33:03,533 --> 00:33:05,667 while they're being replaced by something more efficient. 519 00:33:06,867 --> 00:33:09,467 Changes have to happen piecemeal. 520 00:33:11,600 --> 00:33:13,834 And that's how it is for the brain. 521 00:33:15,433 --> 00:33:18,133 There is no way for evolution to rip out the ancient 522 00:33:18,266 --> 00:33:21,400 interior of the brain because of its imperfections and 523 00:33:21,533 --> 00:33:24,734 replace it with something of more modern manufacture. 524 00:33:25,834 --> 00:33:29,433 The brain and the city both must function continuously 525 00:33:29,567 --> 00:33:31,700 during the renovation. 526 00:33:32,033 --> 00:33:34,600 That's why our limbic system is surrounded by 527 00:33:34,734 --> 00:33:36,100 the cerebral cortex. 528 00:33:36,233 --> 00:33:39,633 The old part is in charge of too many vital mechanisms for 529 00:33:39,767 --> 00:33:42,200 it to be replaced altogether. 530 00:33:42,333 --> 00:33:44,533 So, it's sometimes counterproductive. 531 00:33:44,667 --> 00:33:47,300 But that's a necessary consequence of evolution. 532 00:33:48,533 --> 00:33:51,967 The city is a gift of the cerebral cortex. 533 00:33:56,300 --> 00:33:59,000 But the brain's language is not encoded in the DNA of 534 00:33:59,133 --> 00:34:03,834 genes because the vocabulary of life is too small. 535 00:34:03,967 --> 00:34:06,834 Our brains need a language with 10,000 times 536 00:34:06,967 --> 00:34:08,800 as many words. 537 00:34:08,934 --> 00:34:11,200 The information content of the human brain expressed 538 00:34:11,333 --> 00:34:15,367 in bits is probably comparable to the total number of connections 539 00:34:15,500 --> 00:34:16,967 among the neurons... 540 00:34:17,100 --> 00:34:20,567 about a thousand trillion bits. 541 00:34:23,433 --> 00:34:26,467 If all the contents of your brain were transcribed into 542 00:34:26,600 --> 00:34:30,667 written language, it would amount to vastly more books 543 00:34:30,800 --> 00:34:34,033 than are contained in the largest libraries on earth. 544 00:34:34,166 --> 00:34:37,433 The equivalent of more than four billion books 545 00:34:37,567 --> 00:34:39,867 are inside your head. 546 00:34:40,000 --> 00:34:44,967 The brain is a very big place in a very small space. 547 00:34:49,233 --> 00:34:51,967 It's written in those neurons pioneered by 548 00:34:52,100 --> 00:34:54,834 the undersea microbial mats. 549 00:34:55,400 --> 00:34:58,700 These are tiny electrochemical switching elements, 550 00:34:58,834 --> 00:35:01,867 typically a few hundredths of a millimeter across. 551 00:35:02,400 --> 00:35:05,266 Each of us has 86 billion neurons, 552 00:35:05,400 --> 00:35:08,500 comparable to the number of stars in the Milky Way galaxy. 553 00:35:09,300 --> 00:35:12,433 The neurons and their parts, axons, dendrites, 554 00:35:12,567 --> 00:35:15,500 synapses and the cell bodies themselves make up 555 00:35:15,633 --> 00:35:17,800 a network in the brain. 556 00:35:18,166 --> 00:35:20,200 Many neurons have thousands of connections 557 00:35:20,333 --> 00:35:22,133 with their neighbors. 558 00:35:22,266 --> 00:35:26,967 Dendrites, those pathways sent out by neurons to connect with other neurons, 559 00:35:27,100 --> 00:35:29,767 extend these nerve cells to synapses until 560 00:35:29,900 --> 00:35:32,900 they create a full-blown network of consciousness. 561 00:35:52,100 --> 00:35:56,300 The neurochemistry of the brain is astonishingly busy, 562 00:35:56,700 --> 00:35:59,333 the circuitry of a machine more wonderful than any 563 00:35:59,467 --> 00:36:01,734 devised by humans. 564 00:36:01,867 --> 00:36:04,934 Your brain functions are due to those 100 trillion 565 00:36:05,066 --> 00:36:08,100 neural connections that make you, you. 566 00:36:08,867 --> 00:36:11,533 Your deepest feelings of love and awe... 567 00:36:11,667 --> 00:36:14,433 those moments when we glimpse the grandeur of nature, 568 00:36:14,567 --> 00:36:17,400 and all the elegant architecture of consciousness... 569 00:36:17,867 --> 00:36:21,367 are made possible by those connections. 570 00:36:21,800 --> 00:36:24,433 This is the essence of emergence: 571 00:36:24,567 --> 00:36:27,233 tiny units of matter operating collectively 572 00:36:27,367 --> 00:36:28,734 to become something much more 573 00:36:28,867 --> 00:36:30,500 than themselves, 574 00:36:30,633 --> 00:36:33,100 to enable the cosmos to know itself. 575 00:36:34,734 --> 00:36:38,133 But there's a vision of emergence that takes it even higher. 576 00:36:38,266 --> 00:36:40,600 Can we know the universe? 577 00:36:41,300 --> 00:36:44,367 And will it ever come to know us? 578 00:37:03,967 --> 00:37:06,900 TYSON: Can we know the universe? 579 00:37:07,200 --> 00:37:10,200 All those galaxies, solar systems, numberless worlds, 580 00:37:10,767 --> 00:37:14,033 moons, comets, beings, and their dreams... 581 00:37:14,900 --> 00:37:18,367 everything that ever was, is, or will be? 582 00:37:25,867 --> 00:37:29,066 Can we know the universe? 583 00:37:29,567 --> 00:37:33,000 I'm not sure we can even know a grain of salt. 584 00:37:33,133 --> 00:37:36,066 Consider one microgram of table salt, 585 00:37:36,200 --> 00:37:38,900 a speck just barely large enough for someone with keen 586 00:37:39,033 --> 00:37:41,900 eyesight to see without a microscope. 587 00:37:42,433 --> 00:37:45,834 In that grain of salt there are about 10 to the power 16 588 00:37:45,967 --> 00:37:47,900 sodium and chlorine atoms. 589 00:37:48,734 --> 00:37:49,934 What does that mean? 590 00:37:50,066 --> 00:37:54,000 It means that there are 10 million billion atoms in this 591 00:37:54,133 --> 00:37:56,700 and every other single grain of salt. 592 00:37:57,300 --> 00:37:59,667 To know the grain of salt deeply, 593 00:37:59,800 --> 00:38:02,000 requires us to know at least the three-dimensional 594 00:38:02,133 --> 00:38:04,066 positions of each of these atoms. 595 00:38:04,200 --> 00:38:06,266 In fact, there's much more to be known... 596 00:38:07,033 --> 00:38:10,333 for example, the nature of the forces between the atoms. 597 00:38:10,934 --> 00:38:12,667 But okay, let's try to keep it simple, 598 00:38:12,800 --> 00:38:14,567 we'll leave that aside. 599 00:38:14,700 --> 00:38:18,433 Is the number of all the positions more or less than 600 00:38:18,567 --> 00:38:21,033 the number of things which the brain can know? 601 00:38:21,967 --> 00:38:24,500 How much can the brain know? 602 00:38:24,834 --> 00:38:27,233 If you do the calculation, with all the neurons and their 603 00:38:27,367 --> 00:38:29,633 dendrites, axons, synapses... 604 00:38:29,767 --> 00:38:32,333 we can know 100 trillion things. 605 00:38:33,633 --> 00:38:37,066 But this is only 1% of the number of atoms in 606 00:38:37,200 --> 00:38:38,967 our grain of salt. 607 00:38:39,100 --> 00:38:41,967 So in this sense, the universe is unmanageable, 608 00:38:42,633 --> 00:38:45,500 astonishingly immune to any human attempt 609 00:38:45,633 --> 00:38:47,233 at full knowledge. 610 00:38:47,367 --> 00:38:50,533 We cannot, at this level, fully know a grain of salt, 611 00:38:50,667 --> 00:38:52,600 much less the universe. 612 00:38:52,734 --> 00:38:54,433 But let's look a little more deeply at our 613 00:38:54,567 --> 00:38:56,734 microgram of salt. 614 00:38:57,266 --> 00:38:59,300 Salt happens to be a crystal in which, 615 00:38:59,433 --> 00:39:02,233 except for defects in the structure of its lattice, 616 00:39:02,367 --> 00:39:04,967 the position of every sodium and chlorine 617 00:39:05,100 --> 00:39:06,834 atom is predetermined. 618 00:39:06,967 --> 00:39:09,900 If we shrink ourselves into this crystalline world, 619 00:39:10,033 --> 00:39:14,033 we would see rank upon rank of atoms in an ordered array, 620 00:39:14,166 --> 00:39:16,533 a regularly alternating structure... 621 00:39:16,667 --> 00:39:19,266 sodium, chlorine, sodium, chlorine... 622 00:39:20,266 --> 00:39:23,100 specifying the sheet of atoms we are flying through, 623 00:39:23,233 --> 00:39:25,767 and all the sheets above us and below us. 624 00:39:27,300 --> 00:39:30,734 An absolutely pure grain of salt could have the position 625 00:39:30,867 --> 00:39:33,166 of every atom specified by something like 626 00:39:33,300 --> 00:39:35,467 ten bits of information. 627 00:39:35,600 --> 00:39:38,133 This wouldn't strain our brain's carrying capacity. 628 00:39:38,266 --> 00:39:41,233 We'd still have plenty of room for other stuff. 629 00:39:41,367 --> 00:39:44,767 Now, imagine a universe with natural laws that govern its 630 00:39:44,900 --> 00:39:48,533 behavior to the same degree of regularity that's true 631 00:39:48,667 --> 00:39:50,700 for a grain of salt. 632 00:39:50,834 --> 00:39:53,367 That universe would be knowable. 633 00:39:53,500 --> 00:39:55,900 Even if it had many complicated laws, 634 00:39:56,033 --> 00:39:59,266 we'd still have a shot at knowing that cosmos. 635 00:40:12,333 --> 00:40:14,734 It wouldn't matter if the reality of that universe 636 00:40:14,867 --> 00:40:17,166 exceeded the information-carrying capacity 637 00:40:17,300 --> 00:40:19,233 of one of our brains. 638 00:40:19,367 --> 00:40:21,900 We'd just go outside our bodies and build a computer to 639 00:40:22,033 --> 00:40:24,600 store the surplus information. 640 00:40:25,066 --> 00:40:27,166 And we'd still, in some sense, 641 00:40:27,300 --> 00:40:29,433 know the universe. 642 00:40:29,834 --> 00:40:32,934 Now, imagine a universe with no such laws, 643 00:40:33,533 --> 00:40:36,266 one that behaves in a completely unpredictable fashion. 644 00:40:36,967 --> 00:40:40,333 That universe would contain something like 10 to the 80th 645 00:40:40,467 --> 00:40:42,734 elementary particles. 646 00:40:43,100 --> 00:40:46,367 The inhabitants would find everyday experience a muddled 647 00:40:46,500 --> 00:40:50,633 jumble of events with no predictability, no regularity. 648 00:40:52,367 --> 00:40:54,934 And if they ever came to exist, 649 00:40:55,066 --> 00:40:57,400 they would be in grave peril. 650 00:41:03,533 --> 00:41:07,467 Lucky for us, we live in a universe with important parts 651 00:41:07,600 --> 00:41:09,500 that are knowable. 652 00:41:09,633 --> 00:41:11,934 The universe belongs to those who, 653 00:41:12,066 --> 00:41:15,000 at least to some degree, have figured it out. 654 00:41:16,000 --> 00:41:19,233 It's an astonishing fact that there are laws of nature, 655 00:41:19,367 --> 00:41:20,900 rules that summarize... 656 00:41:21,033 --> 00:41:23,700 not just qualitatively but quantitatively, 657 00:41:23,834 --> 00:41:26,567 how the cosmos works. 658 00:41:26,700 --> 00:41:30,600 But what about the cosmos inside each of us... 659 00:41:30,734 --> 00:41:34,033 That unknown and solitary sea? 660 00:41:34,633 --> 00:41:36,967 There are something like 100 trillion... 661 00:41:37,100 --> 00:41:40,900 that is, one-hundred thousand billion connections 662 00:41:41,367 --> 00:41:43,433 in your cerebral cortex. 663 00:41:43,567 --> 00:41:46,967 That's 100 times as many connections inside you as all 664 00:41:47,100 --> 00:41:49,900 the galaxies of the visible universe. 665 00:41:50,667 --> 00:41:52,934 We're just at the beginning of a great 666 00:41:53,066 --> 00:41:55,233 journey of exploration. 667 00:41:55,367 --> 00:41:58,900 Just as biologists succeeded in mapping the human genome, 668 00:41:59,333 --> 00:42:02,266 neuroscientists are attempting to map something 669 00:42:02,400 --> 00:42:06,133 far more complex and unique to each and every one of us. 670 00:42:07,133 --> 00:42:09,800 It's called our connectome. 671 00:42:14,333 --> 00:42:17,767 If we could truly know another person's connectome, 672 00:42:17,900 --> 00:42:21,467 the singular wiring diagram of all their memories, 673 00:42:21,600 --> 00:42:24,066 thoughts, fears, dreams... 674 00:42:25,600 --> 00:42:27,667 How would we treat each other? 675 00:42:27,800 --> 00:42:30,433 Could we heal the brain of its countless torments, 676 00:42:31,300 --> 00:42:34,266 and free all the Giovanni's of the world? 677 00:42:35,333 --> 00:42:39,600 Could we send one of our connectomes on a future interstellar probe, 678 00:42:40,133 --> 00:42:41,834 or ever hope to receive one from the 679 00:42:41,967 --> 00:42:45,100 being of another world? 680 00:42:57,734 --> 00:43:01,800 Would that be the ultimate realization of emergence... 681 00:43:02,500 --> 00:43:07,700 a cosmos interconnected by thoughts and dreams? 682 00:43:10,700 --> 00:43:12,133 Captioned by Cotter Captioning Services.