YouTube

Got a YouTube account?

New: enable viewer-created translations and captions on your YouTube channel!

English subtitles

← After billions of years of monotony, the universe is waking up

Get Embed Code
24 Languages

Showing Revision 8 created 11/08/2019 by Brian Greene.

  1. I'm thrilled to be talking to you
    by this high-tech method.
  2. Of all humans who have ever lived,
  3. the overwhelming majority
    would have found what we are doing here
  4. incomprehensible, unbelievable.
  5. Because, for thousands of centuries,

  6. in the dark time
    before the scientific revolution
  7. and the Enlightenment,
  8. people had low expectations.
  9. For their lives,
    for their descendants' lives.
  10. Typically, they expected
  11. nothing significantly new
    or better to be achieved, ever.
  12. This pessimism
    famously appears in the Bible,
  13. in one of the few biblical passages
    with a named author.
  14. He's called Qohelet,
    he's an enigmatic chap.
  15. He wrote, "What has been is what will be,
  16. and what has been done
    is what will be done;
  17. there is nothing new under the sun.
  18. Is there something of which it is said,
    'Look, this is new.'
  19. No, that thing was already done
    in the ages that came before us."
  20. Qohelet was describing a world
    without novelty.

  21. By novelty I mean something new
    in Qohelet's sense,
  22. not merely something that's changed,
  23. but a significant change
    with lasting effects,
  24. where people really would say,
  25. "Look, this is new,"
  26. and, preferably, "good."
  27. So, purely random changes aren't novelty.
  28. OK, Heraclitus did say
    a man can't step in the same river twice,
  29. because it's not the same river,
    he's not the same man.
  30. But if the river is changing randomly,
  31. it really is the same river.
  32. In contrast,

  33. if an idea in a mind
    spreads to other minds,
  34. and changes lives for generations,
  35. that is novelty.
  36. Human life without novelty
  37. is life without creativity,
    without progress.
  38. It's a static society, a zero-sum game.
  39. That was the living hell
    in which Qohelet lived.
  40. Like everyone, until a few centuries ago.
  41. It was hell, because for humans,
  42. suffering is intimately
    related to staticity.
  43. Because staticity isn't just frustrating.
  44. All sources of suffering --
  45. famine, pandemics, incoming asteroids,
  46. and things like war and slavery,
  47. hurt people only until we have created
    the knowledge to prevent them.
  48. There's a story in Somerset Maugham's
    novel "Of Human Bondage"

  49. about an ancient sage
  50. who summarizes the entire
    history of mankind as,
  51. "He was born,
  52. he suffered and he died."
  53. And it goes on:
  54. "Life was insignificant
    and death without consequence."
  55. And indeed, the overwhelming majority
    of humans who have ever lived
  56. had lives of suffering and grueling labor,
  57. before dying young and in agony.
  58. And yes, in most generations
  59. nothing had any novel consequence
    for subsequent generations.
  60. Nevertheless, when ancient people
    tried to explain their condition,

  61. they typically did so
    in grandiose cosmic terms.
  62. Which was the right thing to do,
    as it turns out.
  63. Even though their actual
    explanations, their myths,
  64. were largely false.
  65. Some tried to explain
  66. the grimness and monotony of their world
  67. in terms of an endless cosmic war
    between good and evil,
  68. in which humans were the battleground.
  69. Which neatly explained why their own
    experience was full of suffering,
  70. and why progress never happened.
  71. But it wasn't true.
  72. Amazingly enough,

  73. all their conflict and suffering
  74. were just due to the way
    they processed ideas.
  75. Being satisfied with dogma,
    and just-so stories,
  76. rather than criticizing them
  77. and trying to guess better explanations
    of the world and of their own condition.
  78. Twentieth-century physics
    did create better explanations,
  79. but still in terms of a cosmic war.
  80. This time, the combatants
    were order and chaos, or entropy.
  81. That story does allow
    for hope for the future.
  82. But in another way,
  83. it's even bleaker than the ancient myths,
  84. because the villain, entropy,
  85. is preordained to have the final victory,
  86. when the inexorable laws of thermodynamics
    shut down all novelty
  87. with the so-called
    heat death of the universe.
  88. Currently, there's a story
    of a local battle in that war,

  89. between sustainability, which is order,
  90. and wastefulness, which is chaos --
  91. that's the contemporary take
    on good and evil,
  92. often with the added twist
    that humans are the evil,
  93. so we shouldn't even try to win.
  94. And recently,
  95. there have been tales
    of another cosmic war,
  96. between gravity,
    which collapses the universe,
  97. and dark energy, which finally shreds it.
  98. So this time,
  99. whichever of those cosmic forces wins,
  100. we lose.
  101. All those pessimistic accounts
    of the human condition

  102. contain some truth,
  103. but as prophecies,
  104. they're all misleading,
    and all for the same reason.
  105. None of them portrays humans
    as what we really are.
  106. As Jacob Bronowski said,
  107. "Man is not a figure in the landscape --
  108. he is the shaper of the landscape."
  109. In other words,
  110. humans are not playthings
    of cosmic forces,
  111. we are users of cosmic forces.
  112. I'll say more about that in a moment,
  113. but first, what sorts
    of thing create novelty?
  114. Well, the beginning
    of the universe surely did.
  115. The big bang, nearly 14 billion years ago,

  116. created space, time and energy,
  117. everything physical.
  118. And then, immediately,
  119. what I call the first era of novelty,
  120. with the first atom, the first star,
  121. the first black hole,
  122. the first galaxy.
  123. But then, at some point,
  124. novelty vanished from the universe.
  125. Perhaps from as early
    as 12 or 13 billion years ago,
  126. right up to the present day,
  127. there's never been any new kind
    of astronomical object.
  128. There's only been what I call
    the great monotony.
  129. So, Qohelet was accidentally
    even more right
  130. about the universe beyond the Sun
  131. than he was about under the Sun.
  132. So long as the great monotony lasts,
  133. what has been out there
  134. really is what will be.
  135. And there is nothing out there
  136. of which it can truly be said,
    "Look, this is new."
  137. Nevertheless,

  138. at some point during the great monotony,
  139. there was an event --
    inconsequential at the time,
  140. and even billions of years later,
  141. it had affected nothing
    beyond its home planet --
  142. yet eventually, it could cause
    cosmically momentous novelty.
  143. That event was the origin of life:
  144. creating the first genetic knowledge,
  145. coding for biological adaptations,
  146. coding for novelty.
  147. On Earth, it utterly
    transformed the surface.
  148. Genes in the DNA
    of single-celled organisms
  149. put oxygen in the air,
  150. extracted CO2,
  151. put chalk and iron ore into the ground,
  152. hardly a cubic inch of the surface
    to some depth has remained unaffected
  153. by those genes.
  154. The Earth became,
    if not a novel place on the cosmic scale,
  155. certainly a weird one.
  156. Just as an example, beyond Earth,

  157. only a few hundred different
    chemical substances have been detected.
  158. Presumably, there are some more
    in lifeless locations,
  159. but on Earth,
  160. evolution created billions
    of different chemicals.
  161. And then the first plants, animals,
  162. and then, in some ancestor
    species of ours,
  163. explanatory knowledge.
  164. For the first time in the universe,
    for all we know.
  165. Explanatory knowledge
    is the defining adaptation of our species.

  166. It differs from
    the nonexplanatory knowledge
  167. in DNA, for instance,
  168. by being universal.
  169. That is to say,
    whatever can be understood,
  170. can be understood
    through explanatory knowledge.
  171. And more, any physical process
  172. can be controlled by such knowledge,
  173. limited only by the laws of physics.
  174. And so, explanatory knowledge, too,
  175. has begun to transform
    the Earth's surface.
  176. And soon, the Earth will become
    the only known object in the universe
  177. that turns aside incoming asteroids
    instead of attracting them.
  178. Qohelet was understandably misled

  179. by the painful slowness
    of progress in his day.
  180. Novelty in human life
    was still too rare, too gradual,
  181. to be noticed in one generation.
  182. And in the biosphere,
  183. the evolution of novel species
    was even slower.
  184. But both things were happening.
  185. Now, why is there a great monotony
    in the universe at large,

  186. and what makes our planet buck that trend?
  187. Well, the universe at large
    is relatively simple.
  188. Stars are so simple
  189. that we can predict their behavior
    billions of years into the future,
  190. and retrodict how they formed
    billions of years ago.
  191. So why is the universe simple?
  192. Basically, it's because big,
    massive, powerful things
  193. strongly affect lesser things,
    and not vice versa.
  194. I call that the hierarchy rule.
  195. For example, when a comet hits the Sun,
  196. the Sun carries on just as before,
  197. but the comet is vaporized.
  198. For the same reason,
  199. big things are not much affected
    by small parts of themselves,
  200. i.e., by details.
  201. Which means that their overall behavior
  202. is simple.
  203. And since nothing very new
    can happen to things
  204. that remain simple,
  205. the hierarchy rule,
    by causing large-scale simplicity,
  206. has caused the great monotony.
  207. But, the saving grace is
  208. the hierarchy rule is not a law of nature.
  209. It just happens to have held
    so far in the universe,
  210. except here.
  211. In our biosphere,
    molecule-sized objects, genes,

  212. control vastly disproportionate resources.
  213. The first genes for photosynthesis,
  214. by causing their own proliferation,
  215. and then transforming
    the surface of the planet,
  216. have violated or reversed
    the hierarchy rule
  217. by the mind-blowing factor
    of 10 to the power 40.
  218. Explanatory knowledge
    is potentially far more powerful
  219. because of universality,
  220. and more rapidly created.
  221. When human knowledge
    has achieved a factor 10 to the 40,
  222. it will pretty much control
    the entire galaxy,
  223. and will be looking beyond.
  224. So humans,

  225. and any other explanation creators
    who may exist out there,
  226. are the ultimate agents
    of novelty for the universe.
  227. We are the reason and the means
  228. by which novelty and creativity,
    knowledge, progress,
  229. can have objective,
    large-scale physical effects.
  230. From the human perspective,
  231. the only alternative
    to that living hell of static societies
  232. is continual creation of new ideas,
  233. behaviors, new kinds of objects.
  234. This robot will soon be obsolete,
  235. because of new explanatory
    knowledge, progress.
  236. But from the cosmic perspective,

  237. explanatory knowledge
    is the nemesis of the hierarchy rule.
  238. It's the destroyer of the great monotony.
  239. So it's the creator
    of the next cosmological era,
  240. the Anthropocene.
  241. If one can speak of a cosmic war,
  242. it's not the one portrayed
    in those pessimistic stories.
  243. It's a war between monotony and novelty,
  244. between stasis and creativity.
  245. And in this war,
  246. our side is not destined to lose.
  247. If we choose to apply our unique
    capacity to create explanatory knowledge,
  248. we could win.
  249. Thanks.

  250. (Applause)