1 00:00:02,288 --> 00:00:03,621 600 years ago, 2 00:00:05,198 --> 00:00:09,234 men from Europe set out in wooden ships 3 00:00:09,235 --> 00:00:12,235 and ushered in the Age of Discovery. 4 00:00:14,310 --> 00:00:18,369 Ruthless, driven men like Christopher Columbus, 5 00:00:18,370 --> 00:00:20,310 the conquistadors, 6 00:00:20,311 --> 00:00:23,792 and those who followed in their bloody wake. 7 00:00:23,793 --> 00:00:27,960 They conquered a new world and connected the planet. 8 00:00:29,533 --> 00:00:33,709 You may think it's the story of greed on a global scale. 9 00:00:33,710 --> 00:00:36,436 You may think you know what happened, 10 00:00:36,437 --> 00:00:38,854 but there's a deeper history. 11 00:00:41,301 --> 00:00:45,986 The voyages of Columbus and the Age of Discovery 12 00:00:45,987 --> 00:00:48,737 have roots in the depths of time, 13 00:00:49,931 --> 00:00:53,848 in a land bridge that populated two continents, 14 00:00:55,877 --> 00:00:59,158 in tectonic plates that tore North and South America 15 00:00:59,159 --> 00:01:03,326 from Afro-Eurasia and created two huge world zones, 16 00:01:06,281 --> 00:01:10,448 and in precious metals forged in the heat of a dying star. 17 00:01:14,226 --> 00:01:18,999 Links in the chain of events of deep time history. 18 00:01:19,000 --> 00:01:20,749 I'm Jonathan Markley. 19 00:01:20,750 --> 00:01:22,639 When I was trained as an historian, 20 00:01:22,640 --> 00:01:24,146 we were taught to think of history 21 00:01:24,147 --> 00:01:26,615 as just the story of humankind, 22 00:01:26,616 --> 00:01:28,292 but if you think about it, 23 00:01:28,293 --> 00:01:31,165 there's much more to the story. 24 00:01:31,166 --> 00:01:34,550 We should trace our history into deep time, 25 00:01:34,551 --> 00:01:37,788 to the formation of our planet, our solar system, 26 00:01:37,789 --> 00:01:39,872 even the universe itself. 27 00:01:41,971 --> 00:01:44,438 In this series, we're taking a new look 28 00:01:44,439 --> 00:01:47,467 at important eras in human history 29 00:01:47,468 --> 00:01:50,051 by flashing back at key moments 30 00:01:51,486 --> 00:01:54,629 to show how events from deep in time, 31 00:01:54,630 --> 00:01:58,237 exploding stars, the clash of continents, 32 00:01:58,238 --> 00:02:02,155 secretly shaped the stories we thought we knew. 33 00:02:03,050 --> 00:02:05,269 By revealing the surprising links 34 00:02:05,270 --> 00:02:08,823 between human history and the deep past, 35 00:02:08,824 --> 00:02:12,824 we'll show how our civilization and innovations, 36 00:02:14,497 --> 00:02:17,215 our voyages and battles 37 00:02:19,261 --> 00:02:23,357 are driven not only by the decisions we make 38 00:02:23,358 --> 00:02:25,358 but by physics, geology, 39 00:02:26,480 --> 00:02:28,063 biology, chemistry, 40 00:02:29,685 --> 00:02:33,199 by forces that can be too small to see 41 00:02:33,200 --> 00:02:35,509 or so far back in time 42 00:02:35,510 --> 00:02:38,853 that the only way to understand their influence 43 00:02:38,854 --> 00:02:40,854 is to think in a whole new way. 44 00:02:47,896 --> 00:02:49,902 We live in a connected world, 45 00:02:49,903 --> 00:02:52,175 exchanging information at the speed of light 46 00:02:52,176 --> 00:02:54,434 across oceans and continents. 47 00:02:54,435 --> 00:02:56,044 Everybody knows that. 48 00:02:56,045 --> 00:02:59,352 What you might not realize is that long before humanity, 49 00:02:59,353 --> 00:03:02,144 the whole world was literally connected. 50 00:03:11,486 --> 00:03:13,819 The Earth never stays still. 51 00:03:16,255 --> 00:03:18,406 More than a dozen tectonic plates 52 00:03:18,407 --> 00:03:21,407 keep the surface in constant motion. 53 00:03:25,915 --> 00:03:27,748 1.1 billion years ago, 54 00:03:29,615 --> 00:03:32,097 all the Earth's surface is connected 55 00:03:32,098 --> 00:03:34,598 in the supercontinent Rodinia. 56 00:03:35,579 --> 00:03:38,448 Over the next 10 million centuries, 57 00:03:38,449 --> 00:03:40,647 the planet's jigsaw pieces move apart 58 00:03:40,648 --> 00:03:43,648 and reform into new supercontinents. 59 00:03:45,246 --> 00:03:46,579 First, Pannotia. 60 00:03:49,782 --> 00:03:53,699 After that breaks up, a supercontinent Pangaea, 61 00:03:59,194 --> 00:04:01,885 whose destruction will give birth 62 00:04:01,886 --> 00:04:03,886 to the Age of Discovery. 63 00:04:06,116 --> 00:04:09,033 Because some 200 million years ago, 64 00:04:09,947 --> 00:04:13,614 plate tectonics begin to tear Pangaea apart. 65 00:04:15,347 --> 00:04:18,203 Over tens of millions of years, 66 00:04:18,204 --> 00:04:21,537 Europe breaks away from northern Africa. 67 00:04:22,656 --> 00:04:24,965 The eastern half of Africa is torn away 68 00:04:24,966 --> 00:04:27,134 to form South America. 69 00:04:27,135 --> 00:04:29,655 In another quarter billion years, 70 00:04:29,656 --> 00:04:31,717 these continental jigsaw pieces 71 00:04:31,718 --> 00:04:35,051 will once again form a single land mass, 72 00:04:36,670 --> 00:04:39,067 but for now, the world is segregated 73 00:04:39,068 --> 00:04:42,401 into two major and very different zones. 74 00:04:45,866 --> 00:04:48,533 In one world zone, Afro-Eurasia, 75 00:04:50,193 --> 00:04:54,360 the linked continents of Africa, Europe, and Asia. 76 00:04:56,720 --> 00:04:59,970 57% of the land mass of the world, 77 00:05:02,236 --> 00:05:03,653 with more people, 78 00:05:06,977 --> 00:05:08,060 more animals, 79 00:05:13,716 --> 00:05:17,383 and more plants than anywhere else on Earth. 80 00:05:19,657 --> 00:05:23,824 This is the zone where civilization first appears. 81 00:05:26,150 --> 00:05:29,733 In the other zone, North and South America, 82 00:05:30,667 --> 00:05:33,167 home to younger civilizations. 83 00:05:34,358 --> 00:05:36,700 In the late 15th century, 84 00:05:36,701 --> 00:05:39,066 at the time of Christopher Columbus, 85 00:05:39,067 --> 00:05:40,720 these two massive world zones exist 86 00:05:40,721 --> 00:05:43,888 in complete isolation from each other. 87 00:05:45,640 --> 00:05:49,260 People living with no idea that each other even existed. 88 00:05:49,261 --> 00:05:50,919 You might as well have been living on different planets 89 00:05:50,920 --> 00:05:52,087 at that stage. 90 00:05:54,800 --> 00:05:58,053 So, deep time forces have set the stage 91 00:05:58,054 --> 00:06:00,471 for the voyages of discovery. 92 00:06:02,169 --> 00:06:04,252 Two isolated world zones, 93 00:06:05,426 --> 00:06:07,509 separated by vast oceans, 94 00:06:09,640 --> 00:06:12,640 one of which is about to be crossed. 95 00:06:16,169 --> 00:06:17,563 The launchpad for this crossing is 96 00:06:17,564 --> 00:06:21,147 the Port of Palos, Spain, August 3rd, 1492. 97 00:06:27,818 --> 00:06:30,827 An Italian mariner named Christopher Columbus 98 00:06:30,828 --> 00:06:32,578 is about to set sail. 99 00:06:35,257 --> 00:06:38,757 His plan, find a new trade route to China. 100 00:06:41,381 --> 00:06:43,613 Columbus has no idea 101 00:06:43,614 --> 00:06:46,287 that because of Earth's geology and geography, 102 00:06:46,288 --> 00:06:49,787 his plan is going to utterly fail 103 00:06:49,788 --> 00:06:52,377 or how that epic failure 104 00:06:52,378 --> 00:06:55,791 will make his voyage one of the most influential expeditions 105 00:06:55,792 --> 00:06:58,125 in the history of humankind. 106 00:07:00,459 --> 00:07:04,760 What's driving Columbus' journey into the unknown? 107 00:07:04,761 --> 00:07:09,707 What does he hope to get once he arrives in China? 108 00:07:09,708 --> 00:07:12,541 Believe it or not, an insecticide. 109 00:07:19,012 --> 00:07:22,289 You heard right, an insecticide. 110 00:07:22,290 --> 00:07:25,032 It all starts about 150 million years ago 111 00:07:25,033 --> 00:07:27,325 with the evolution of this plant, 112 00:07:27,326 --> 00:07:29,845 known as Piper nigrum. 113 00:07:29,846 --> 00:07:31,926 It first grew in the mountains of India, 114 00:07:31,927 --> 00:07:34,274 where there are a lot of pests, 115 00:07:34,275 --> 00:07:38,124 and to survive, a plant needs to defend itself. 116 00:07:38,125 --> 00:07:42,566 So, Piper nigrum evolved a special molecule to do just that, 117 00:07:42,567 --> 00:07:44,438 a combination of the common elements 118 00:07:44,439 --> 00:07:47,689 carbon, hydrogen, oxygen, and nitrogen. 119 00:07:48,890 --> 00:07:51,557 The molecule is called piperine. 120 00:07:52,945 --> 00:07:56,403 It's lethal to bugs, but it doesn't kill us. 121 00:07:56,404 --> 00:07:57,561 We're too big. 122 00:07:57,562 --> 00:08:00,398 It just gives us a bit of a spicy kick. 123 00:08:00,399 --> 00:08:02,026 You eat it all the time. 124 00:08:02,027 --> 00:08:04,514 It's better known as black pepper, 125 00:08:04,515 --> 00:08:05,515 and in 1492, 126 00:08:07,361 --> 00:08:11,384 wealthy Europeans can't get enough of the stuff. 127 00:08:11,385 --> 00:08:15,552 Black pepper was the most valuable product out there. 128 00:08:16,861 --> 00:08:20,886 But because of the forces of deep time, 129 00:08:20,887 --> 00:08:25,054 black pepper isn't easy for the European elite to get. 130 00:08:28,462 --> 00:08:32,596 Stand outside on a moonlit night and look up. 131 00:08:32,597 --> 00:08:34,775 What could the moon possibly have to do 132 00:08:34,776 --> 00:08:36,776 with where pepper grows? 133 00:08:37,669 --> 00:08:41,486 To find out, we need to turn back the clock 134 00:08:41,487 --> 00:08:43,654 to when there was no moon. 135 00:08:46,107 --> 00:08:50,190 4.5 billion years ago, there's no moon in the sky 136 00:08:51,478 --> 00:08:54,061 and the Earth is still forming. 137 00:08:56,098 --> 00:08:58,784 Then... We think that an object, 139 00:08:58,785 --> 00:09:02,513 perhaps an asteroid roughly the size of Mars, 140 00:09:02,514 --> 00:09:04,188 plowed into the Earth. 141 00:09:11,452 --> 00:09:14,049 The material that got splattered off Earth 142 00:09:14,050 --> 00:09:15,891 and the impacting object 143 00:09:15,892 --> 00:09:20,352 initially formed a ring or a disc around Earth, 144 00:09:20,353 --> 00:09:23,551 from which the moon coalesced in less than a century. 145 00:09:26,163 --> 00:09:29,272 The impact that led to the formation of the moon 146 00:09:29,273 --> 00:09:31,892 is also probably the event that caused 147 00:09:31,893 --> 00:09:33,812 Earth's axis to be tilted, 148 00:09:33,813 --> 00:09:36,230 in our case, by 23.5 degrees. 149 00:09:38,223 --> 00:09:40,723 This tilt is key. 150 00:09:42,265 --> 00:09:44,639 It means that the midsection of the planet 151 00:09:44,640 --> 00:09:49,632 gets much more sustained light and heat from the sun. 152 00:09:49,633 --> 00:09:53,361 The tilt of Earth's axis, this 23.5 degree tilt, 153 00:09:53,362 --> 00:09:56,529 is why we have tropical zones on Earth 154 00:09:58,740 --> 00:10:01,942 and then the temperate regions. 155 00:10:05,732 --> 00:10:09,443 After a cosmic collision creates the tropics, 156 00:10:09,444 --> 00:10:12,434 plants evolve to survive there, 157 00:10:12,435 --> 00:10:16,143 and only there in the case of spices like black pepper, 158 00:10:16,144 --> 00:10:18,575 which generally needs to be planted in soil 159 00:10:18,576 --> 00:10:23,493 with a temperature between 75 and 85 degrees Fahrenheit. 160 00:10:23,494 --> 00:10:25,377 So, if you're not living in southeast Asia 161 00:10:25,378 --> 00:10:26,778 and you really want pepper, 162 00:10:26,779 --> 00:10:28,318 you can't just produce it yourself. 163 00:10:28,319 --> 00:10:31,402 You have to buy it in from that area. 164 00:10:33,182 --> 00:10:34,581 Because deep time 165 00:10:34,582 --> 00:10:38,169 has created an uneven distribution of resources, 166 00:10:38,170 --> 00:10:40,848 Humans have to create networks of exchange 167 00:10:40,849 --> 00:10:44,599 to bridge the distance to get what they want. 168 00:10:46,726 --> 00:10:50,893 Before Columbus, how did Europeans get their black pepper? 169 00:10:52,898 --> 00:10:56,343 Let's zoom out for a bigger picture view of the world 170 00:10:56,344 --> 00:10:59,427 as it existed when Columbus was born. 171 00:11:00,431 --> 00:11:04,329 Here's India, at the southeastern end of Eurasia, 172 00:11:04,330 --> 00:11:07,997 the source of black pepper and other spices. 173 00:11:09,473 --> 00:11:11,658 Indian merchants trade these spices 174 00:11:11,659 --> 00:11:14,992 with merchants from this country, China, 175 00:11:16,559 --> 00:11:18,966 a huge land with a temperate climate, 176 00:11:18,967 --> 00:11:22,384 rich soil, and immense natural resources. 177 00:11:24,482 --> 00:11:25,952 For most of human history, 178 00:11:25,953 --> 00:11:28,591 the great Chinese dynasties were the most powerful, 179 00:11:28,592 --> 00:11:31,654 wealthiest states on the planet. 180 00:11:31,655 --> 00:11:33,614 In the early 15th century, 181 00:11:33,615 --> 00:11:36,904 China is rich enough to send huge trading fleets 182 00:11:36,905 --> 00:11:40,072 across the Indian Ocean to East Africa 183 00:11:41,089 --> 00:11:45,389 under the command of the famous admiral Zheng He. 184 00:11:48,676 --> 00:11:52,889 Even when political pressure ends those voyages, 185 00:11:52,890 --> 00:11:55,152 the Chinese continue the centuries-long tradition 186 00:11:55,153 --> 00:11:59,482 of the trade routes, later called Silk Roads. 187 00:11:59,483 --> 00:12:03,346 Merchants carry precious goods, including spices, 188 00:12:03,347 --> 00:12:05,014 across land and sea. 189 00:12:06,973 --> 00:12:08,806 The spices are passed on to merchants 190 00:12:08,807 --> 00:12:11,032 in the Islamic countries 191 00:12:11,033 --> 00:12:14,651 that stretch from northern India to the Middle East, 192 00:12:14,652 --> 00:12:17,019 Turkey, and North Africa. 193 00:12:17,020 --> 00:12:19,959 Finally, merchants from the Italian city-states, 194 00:12:19,960 --> 00:12:21,588 like Venice or Genoa, 195 00:12:21,589 --> 00:12:24,506 acquire the spices from Turkish or Middle Eastern ports 196 00:12:24,507 --> 00:12:28,340 and bring them to customers in Western Europe. 197 00:12:30,000 --> 00:12:31,996 So, that's how spices like black pepper 198 00:12:31,997 --> 00:12:33,830 get to medieval Europe 199 00:12:35,096 --> 00:12:39,263 and why Europeans have to pay through the nose to get them. 200 00:12:41,765 --> 00:12:44,895 Europe doesn't just import spices and luxury goods. 201 00:12:44,896 --> 00:12:46,626 It's imported most of its mathematics 202 00:12:46,627 --> 00:12:48,885 and technology from the East. 203 00:12:48,886 --> 00:12:52,259 1,000 years after the fall of the Roman Empire, 204 00:12:52,260 --> 00:12:56,075 Europe is a ragged collection of competing nation-states. 205 00:12:56,076 --> 00:12:58,472 Put 'em all together, and their population and wealth 206 00:12:58,473 --> 00:13:00,723 can't match China or India. 207 00:13:02,725 --> 00:13:05,304 So, it's a real crisis when the Silk Road 208 00:13:05,305 --> 00:13:09,218 is suddenly shut down and the flow of spices stops 209 00:13:09,219 --> 00:13:12,552 because of the Turkish Sultan Mehmet II. 210 00:13:14,490 --> 00:13:18,169 The sultan has a stranglehold on trade 211 00:13:18,170 --> 00:13:21,544 because of geology and geography. 212 00:13:21,545 --> 00:13:23,821 The prehistoric collision of continents 213 00:13:23,822 --> 00:13:26,882 has created two arms of the Southern Ocean, 214 00:13:26,883 --> 00:13:30,151 the Persian Gulf and the Red Sea, 215 00:13:30,152 --> 00:13:33,658 that jut into the Middle East center, 216 00:13:33,659 --> 00:13:38,054 while the Mediterranean washes its northern shores, 217 00:13:38,055 --> 00:13:41,696 and the Black Sea stretches along Turkey's coast. 218 00:13:41,697 --> 00:13:44,197 So, Turkey is perfectly positioned 219 00:13:44,198 --> 00:13:48,090 to strike at the heart of East/West commerce. 220 00:13:50,070 --> 00:13:51,564 By assaulting Constantinople 221 00:13:51,565 --> 00:13:54,331 and other Christian ports and cities in the region, 222 00:13:54,332 --> 00:13:57,332 the sultan shuts the Silk Road down. 223 00:14:00,728 --> 00:14:02,770 Evidence of what happened still exists 224 00:14:02,771 --> 00:14:05,604 in a certain building in Istanbul. 225 00:14:07,760 --> 00:14:11,927 It has a Greek name, Hagia Sophia, or Holy Wisdom. 226 00:14:15,339 --> 00:14:17,803 Today, it's a museum. 227 00:14:17,804 --> 00:14:20,616 It was originally built as a church, 228 00:14:20,617 --> 00:14:24,453 the most famous Christian shrine of the Byzantine Empire, 229 00:14:24,454 --> 00:14:27,787 when Istanbul was called Constantinople. 230 00:14:28,775 --> 00:14:31,252 But along with the Christian iconography, 231 00:14:31,253 --> 00:14:34,003 there are quotes from the Qur'an. 232 00:14:37,182 --> 00:14:41,349 That's because the church was transformed into a mosque 233 00:14:42,588 --> 00:14:45,588 when the sultan captured it in 1453. 234 00:14:48,603 --> 00:14:50,541 This causes a shock wave across Western Europe, 235 00:14:50,542 --> 00:14:53,255 because Constantinople is essentially the gateway 236 00:14:53,256 --> 00:14:55,093 between Europe and the Orient. 237 00:14:55,094 --> 00:14:57,331 It's the place where spices 238 00:14:57,332 --> 00:15:01,499 and other exotic luxuries from the Orient enter Europe. 239 00:15:02,616 --> 00:15:04,575 But one country in Europe 240 00:15:04,576 --> 00:15:08,407 has already been planning to get around the Silk Road, 241 00:15:08,408 --> 00:15:10,945 a country that was considered insignificant, 242 00:15:10,946 --> 00:15:13,196 even by European standards. 243 00:15:15,025 --> 00:15:17,647 Yet, in the early 1400s, 244 00:15:17,648 --> 00:15:21,731 ground zero for the Age of Discovery is Portugal. 245 00:15:23,232 --> 00:15:25,104 Instead of depending on the Silk Road, 246 00:15:25,105 --> 00:15:29,112 Prince Henry, later called the Navigator, 247 00:15:29,113 --> 00:15:32,543 wants to find a direct sea route to India. 248 00:15:32,544 --> 00:15:34,794 Portugal is a poor country, 249 00:15:35,936 --> 00:15:40,103 but if it takes over the spice trade, it'll be rich. 250 00:15:41,642 --> 00:15:43,234 Let's be frank about this. 251 00:15:43,235 --> 00:15:45,264 The early explorers did not go 252 00:15:45,265 --> 00:15:47,695 into the unknown for their health. 253 00:15:47,696 --> 00:15:50,827 No, they did it for financial gain. 254 00:15:50,828 --> 00:15:52,261 Prince Henry's plan 255 00:15:52,262 --> 00:15:55,676 is to do what no one has ever done: 256 00:15:55,677 --> 00:15:58,561 sail around the southern tip of Africa 257 00:15:58,562 --> 00:16:00,729 and into the Indian Ocean. 258 00:16:02,310 --> 00:16:04,250 But there's a geological reason 259 00:16:04,251 --> 00:16:07,668 that sailing around Africa won't be easy. 260 00:16:09,622 --> 00:16:11,950 Africa's Atlantic coastline has very few 261 00:16:11,951 --> 00:16:14,118 natural harbors or inlets. 262 00:16:15,557 --> 00:16:18,880 So when the Portuguese sail south, 263 00:16:18,881 --> 00:16:23,290 there aren't a lot of safe places to anchor. 264 00:16:23,291 --> 00:16:24,319 There are many, many areas 265 00:16:24,320 --> 00:16:26,783 where it's almost impossible to land 266 00:16:29,547 --> 00:16:31,286 and where prevailing currents and wind patterns 267 00:16:31,287 --> 00:16:34,716 make it very dangerous to try to get in and come out again, 268 00:16:34,717 --> 00:16:36,428 so we imagine these expeditions slowly working 269 00:16:36,429 --> 00:16:37,962 further and further down, 270 00:16:37,963 --> 00:16:39,660 then coming back to Portugal, 271 00:16:39,661 --> 00:16:42,862 accumulating more and more information. 272 00:16:42,863 --> 00:16:45,069 Over the decades, Prince Henry's ships 273 00:16:45,070 --> 00:16:47,903 do find a handful of safe harbors. 274 00:16:48,990 --> 00:16:53,157 They start trading in everything from ivory to slaves. 275 00:16:57,348 --> 00:16:59,098 But the decades pass. 276 00:17:00,248 --> 00:17:02,996 Henry the Navigator dies, 277 00:17:02,997 --> 00:17:07,164 and his successors still haven't made it around Africa. 278 00:17:10,819 --> 00:17:14,945 So far, the geographical barriers imposed by deep time 279 00:17:14,946 --> 00:17:16,613 have been too great. 280 00:17:18,376 --> 00:17:19,543 Then, in 1484, 281 00:17:22,312 --> 00:17:24,798 Christopher Columbus comes to the Portuguese 282 00:17:24,799 --> 00:17:26,132 with a new plan. 283 00:17:28,495 --> 00:17:30,015 Never mind Africa. 284 00:17:30,016 --> 00:17:34,099 Save time and money by sailing over the Atlantic. 285 00:17:35,667 --> 00:17:37,082 They assumed that if you cross this ocean 286 00:17:37,083 --> 00:17:39,406 that we see off our western shores here, 287 00:17:39,407 --> 00:17:43,382 that eventually we'll simply come to East Asia. 288 00:17:43,383 --> 00:17:45,095 Columbus is sure 289 00:17:45,096 --> 00:17:47,652 that if he sails far enough west, 290 00:17:47,653 --> 00:17:50,172 he'll end up in the Far East, 291 00:17:50,173 --> 00:17:53,673 because he's sure that the Earth is round. 292 00:17:55,825 --> 00:17:57,662 But, contrary to myth, 293 00:17:57,663 --> 00:18:00,672 Columbus isn't trying to prove that it's round. 294 00:18:00,673 --> 00:18:04,591 Most educated Europeans know the Earth is a sphere. 295 00:18:04,592 --> 00:18:07,052 The ancient Greek philosopher Aristotle 296 00:18:07,053 --> 00:18:08,862 had calculated the roundness of the Earth 297 00:18:08,863 --> 00:18:10,530 2,000 years earlier. 298 00:18:15,023 --> 00:18:17,855 But Columbus and other Europeans have no insight 299 00:18:17,856 --> 00:18:19,773 into a deeper question: 300 00:18:21,916 --> 00:18:24,499 why exactly is the Earth round? 301 00:18:26,676 --> 00:18:29,685 What's the scientific reason that planets like ours 302 00:18:29,686 --> 00:18:33,186 are spherical instead of some other shape? 303 00:18:34,341 --> 00:18:37,258 It's a question that we can answer, 304 00:18:39,101 --> 00:18:43,268 and there's a clue in some recent astronomical photos. 305 00:18:44,495 --> 00:18:47,448 Look at these two objects. 306 00:18:47,449 --> 00:18:51,449 One is a comet visited by a space probe in 2014. 307 00:18:52,629 --> 00:18:54,212 The other is Pluto. 308 00:18:56,246 --> 00:18:59,746 Why does the comet have an irregular shape 309 00:19:00,674 --> 00:19:03,591 while Pluto is a sphere like Earth? 310 00:19:06,134 --> 00:19:09,965 Well, the answer is gravity is attractive, 311 00:19:09,966 --> 00:19:13,549 or, as we tell our students, gravity sucks. 312 00:19:15,113 --> 00:19:17,665 In other words, objects in space 313 00:19:17,666 --> 00:19:21,583 form when gravity pulls cosmic debris together. 314 00:19:23,616 --> 00:19:25,593 The force of gravity always pulls 315 00:19:25,594 --> 00:19:28,261 towards the center of an object. 316 00:19:30,093 --> 00:19:33,343 As you add mass, gravity gets stronger. 317 00:19:35,833 --> 00:19:38,492 You see, gravity sucks evenly, 318 00:19:38,493 --> 00:19:41,325 and that's the reason why the state of lowest energy 319 00:19:41,326 --> 00:19:44,703 is when gravity accumulates all this mass, 320 00:19:44,704 --> 00:19:47,242 smooths out all the imperfections 321 00:19:47,243 --> 00:19:50,326 to create a spherical star or planet. 322 00:19:51,826 --> 00:19:56,076 However, for very small objects like asteroids, 323 00:19:56,077 --> 00:19:59,940 gravity is not strong enough to smooth it out. 324 00:19:59,941 --> 00:20:02,130 In fact, if a body is less than 325 00:20:02,131 --> 00:20:04,764 a roughly 700 miles across, 326 00:20:04,765 --> 00:20:07,718 gravity is not sufficiently strong 327 00:20:07,719 --> 00:20:09,802 to create a round planet. 328 00:20:12,153 --> 00:20:14,903 Which is why Columbus is right. 329 00:20:20,079 --> 00:20:23,912 Nevertheless, the Portuguese pass on his plan. 330 00:20:28,372 --> 00:20:29,968 So, Columbus has to seek out 331 00:20:29,969 --> 00:20:32,572 fresh investors for his project, 332 00:20:32,573 --> 00:20:36,740 which he can do, because one of Europe's greatest weaknesses 333 00:20:37,650 --> 00:20:40,567 turns out to be a secret advantage. 334 00:20:41,519 --> 00:20:43,791 So, remember how Europe was 335 00:20:43,792 --> 00:20:46,329 this squabbling collection of competing states? 336 00:20:46,330 --> 00:20:48,849 Well, think about it from Columbus' point of view. 337 00:20:48,850 --> 00:20:51,388 If the Portuguese say no, he can go to the monarchs 338 00:20:51,389 --> 00:20:53,469 of England, France, or Spain, 339 00:20:53,470 --> 00:20:55,079 and he can say to each one of them, 340 00:20:55,080 --> 00:20:57,768 "If you back me, I will make you the richest ruler 341 00:20:57,769 --> 00:20:59,657 "in all of Europe." 342 00:20:59,658 --> 00:21:02,368 Of course, eventually, the king and queen of Spain 343 00:21:02,369 --> 00:21:04,154 decide to take a gamble. 344 00:21:04,155 --> 00:21:05,677 They give Columbus the funding 345 00:21:05,678 --> 00:21:08,845 for his cross-Atlantic route to China. 346 00:21:09,856 --> 00:21:11,523 On August 3rd, 1492, 347 00:21:13,529 --> 00:21:16,946 three ships set sail across the Atlantic. 348 00:21:27,874 --> 00:21:30,118 Now, from a limited point of view, 349 00:21:30,119 --> 00:21:33,445 you have an Italian commanding a Spanish commercial venture 350 00:21:33,446 --> 00:21:35,615 that's trying to get an economic advantage 351 00:21:35,616 --> 00:21:37,283 over the Portuguese. 352 00:21:39,639 --> 00:21:41,827 But think about the knowledge and the technology 353 00:21:41,828 --> 00:21:44,189 aboard those three ships. 354 00:21:48,471 --> 00:21:50,297 Columbus has studied cartography 355 00:21:50,298 --> 00:21:51,971 from ancient Greece and Rome 356 00:21:51,972 --> 00:21:54,338 that's been preserved by our scholars 357 00:21:54,339 --> 00:21:56,922 and translated back into Latin. 358 00:22:00,022 --> 00:22:03,326 He's using a compass that was invented in China 359 00:22:03,327 --> 00:22:04,694 and transmitted to Europe 360 00:22:04,695 --> 00:22:07,778 over the Middle Eastern trade routes. 361 00:22:08,841 --> 00:22:12,426 From the perspective of deep time history, 362 00:22:12,427 --> 00:22:15,282 Columbus and his men represent the sum total 363 00:22:15,283 --> 00:22:18,096 of all the extraordinary knowledge and innovation 364 00:22:18,097 --> 00:22:19,430 of Afro-Eurasia. 365 00:22:22,787 --> 00:22:25,492 Yet, because they don't know that the surface of the planet 366 00:22:25,493 --> 00:22:28,660 is divided into two major world zones, 367 00:22:29,518 --> 00:22:32,685 they have no idea where they're going. 368 00:22:36,620 --> 00:22:38,037 In spite of that, 369 00:22:40,519 --> 00:22:43,806 because of the shape of the Earth 370 00:22:43,807 --> 00:22:45,361 and geological forces unleashed 371 00:22:45,362 --> 00:22:48,112 tens of millions of years before, 372 00:22:50,524 --> 00:22:54,621 these three ships from Afro-Eurasia find land. 373 00:22:58,358 --> 00:23:01,878 An island in the Bahamas that, to this day, 374 00:23:01,879 --> 00:23:04,546 has not been clearly identified. 375 00:23:09,192 --> 00:23:11,775 It's the 12th of October, 1492. 376 00:23:28,913 --> 00:23:30,858 Columbus gives thanks to God 377 00:23:30,859 --> 00:23:34,942 for what he thinks is a successful business trip. 378 00:23:35,947 --> 00:23:40,356 In fact, he's reversed the tectonic process 379 00:23:40,357 --> 00:23:44,524 and brought Afro-Eurasia and the Americas back together. 380 00:23:47,603 --> 00:23:49,323 The world is reconnected. 381 00:23:49,324 --> 00:23:52,048 Humans rediscover each other, if you like, 382 00:23:52,049 --> 00:23:56,196 and the entire globe becomes a sort of a modern, 383 00:23:56,197 --> 00:23:57,947 metaphorical Pangaea. 384 00:23:58,962 --> 00:24:00,920 Columbus never realizes 385 00:24:00,921 --> 00:24:02,811 that he's reached the outskirts of a world 386 00:24:02,812 --> 00:24:04,562 unknown to Europeans. 387 00:24:11,422 --> 00:24:14,422 He thinks he's somewhere near India, 388 00:24:15,692 --> 00:24:19,525 and he calls the people he encounters Indians. 389 00:24:22,482 --> 00:24:25,732 In fact, these islanders are the Taino. 390 00:24:29,202 --> 00:24:32,785 Like Columbus, they came from Afro-Eurasia. 391 00:24:44,672 --> 00:24:48,767 There was this land bridge during the ice age 392 00:24:48,768 --> 00:24:51,652 that allowed waves of migrants to come 393 00:24:51,653 --> 00:24:54,653 from Asia and populate the Americas. 394 00:24:56,870 --> 00:24:58,085 Within a couple thousand years, 395 00:24:58,086 --> 00:24:58,930 they've made it right down to the 396 00:24:58,931 --> 00:25:01,239 southern tip of South America. 397 00:25:01,240 --> 00:25:04,547 With the winding of the ice age from about 12,000 years ago, 398 00:25:04,548 --> 00:25:06,965 sea levels rise dramatically. 399 00:25:06,966 --> 00:25:10,337 That bridge disappears, and these humans are now cut off, 400 00:25:10,338 --> 00:25:13,245 isolated in the Americas from Afro-Eurasia, 401 00:25:13,246 --> 00:25:17,413 and the memory of this connection is sort of lost. 402 00:25:18,807 --> 00:25:21,474 It won't be until literally 1492 403 00:25:22,926 --> 00:25:26,926 that these vast world zones will be reconnected. 404 00:25:29,744 --> 00:25:31,805 The reconnection is the start 405 00:25:31,806 --> 00:25:35,639 of what will be called the Colombian Exchange, 406 00:25:37,316 --> 00:25:39,766 a vast, ongoing transfer between 407 00:25:39,767 --> 00:25:43,053 the Americas and Afro-Eurasia of cultures, 408 00:25:43,054 --> 00:25:46,637 technologies, and especially living things. 409 00:25:49,564 --> 00:25:51,663 The breakup of the supercontinents 410 00:25:51,664 --> 00:25:53,849 was not just a geologic event. 411 00:25:53,850 --> 00:25:56,433 It was also a biological event. 412 00:25:57,562 --> 00:26:01,341 Now, technologies, plants, animals, 413 00:26:01,342 --> 00:26:05,435 diseases, and people from one land mass or the other 414 00:26:05,436 --> 00:26:09,353 will spread across oceans and around the world. 415 00:26:10,914 --> 00:26:13,130 Phase one of the exchange gets underway 416 00:26:13,131 --> 00:26:16,381 when Columbus returns to Spain in 1493. 417 00:26:18,213 --> 00:26:20,630 He has found no black pepper, 418 00:26:22,343 --> 00:26:24,582 but there are other spices 419 00:26:24,583 --> 00:26:28,750 and a strange leaf the Taino burn that they call tobacco. 420 00:26:31,966 --> 00:26:35,675 This leaf will kill hundreds of millions of people. 421 00:26:35,676 --> 00:26:38,143 Its addictive ingredient, nicotine, 422 00:26:38,144 --> 00:26:40,612 evolved as a natural insecticide, 423 00:26:40,613 --> 00:26:44,196 like the piperine molecule of black pepper. 424 00:26:45,101 --> 00:26:47,457 Even more exciting for the Spanish, 425 00:26:47,458 --> 00:26:51,326 small amounts of gold from streams and riverbeds. 426 00:26:51,327 --> 00:26:53,356 They hope to find a lot more, 427 00:26:53,357 --> 00:26:57,152 and they expect the Taino to get it for them. 428 00:26:57,153 --> 00:26:59,966 As Columbus writes in an official report, 429 00:26:59,967 --> 00:27:02,733 "The people would make good servants," 430 00:27:02,734 --> 00:27:06,484 and he brings back several of them as slaves. 431 00:27:10,276 --> 00:27:12,494 Phase two of the Colombian Exchange 432 00:27:12,495 --> 00:27:14,828 begins on January 2nd, 1494. 433 00:27:19,691 --> 00:27:23,395 Columbus returns to the Americas with 17 ships, 434 00:27:23,396 --> 00:27:26,158 European livestock like pigs and cattle, 435 00:27:26,159 --> 00:27:27,576 and a small army. 436 00:27:29,047 --> 00:27:33,002 The bloody conquest of the Americas is about to begin. 437 00:27:36,516 --> 00:27:40,683 The conquerors' most terrifying weapon is the horse. 438 00:27:44,426 --> 00:27:46,307 Imagine these early horses being brought over. 439 00:27:46,308 --> 00:27:47,413 Imagine Native American people, 440 00:27:47,414 --> 00:27:49,097 who have never seen this before, 441 00:27:49,098 --> 00:27:51,431 saying, "Wow, look at that." 442 00:27:53,404 --> 00:27:54,945 But this is another story 443 00:27:54,946 --> 00:27:57,007 with a deep time twist, 444 00:27:57,008 --> 00:28:01,175 because horses aren't really an invasive species in America. 445 00:28:03,304 --> 00:28:07,471 In fact, they're completing a 7,000-year round-trip. 446 00:28:10,257 --> 00:28:11,962 The horse, which has proven so 447 00:28:11,963 --> 00:28:13,840 important for human history, 448 00:28:13,841 --> 00:28:16,758 originally evolved in the Americas. 449 00:28:19,208 --> 00:28:22,497 Evolved and then disappeared, 450 00:28:22,498 --> 00:28:25,249 possibly hunted to extinction by the Tainos' 451 00:28:25,250 --> 00:28:26,750 ice age ancestors. 452 00:28:29,151 --> 00:28:31,269 But some horses escaped to safety 453 00:28:31,270 --> 00:28:35,437 over the bridge to Eurasia before the seas rose again. 454 00:28:37,933 --> 00:28:41,573 Those prehistoric horses spread throughout Asia and Europe, 455 00:28:41,574 --> 00:28:45,741 where they were domesticated, bred, and cross-bred. 456 00:28:49,467 --> 00:28:53,384 Now, in 1494, the horse returns to the Americas 457 00:28:54,664 --> 00:28:56,868 as a weapon of conquest. 458 00:29:02,896 --> 00:29:06,519 Horses carry the Spanish, who follow in Columbus' path, 459 00:29:06,520 --> 00:29:08,988 into Central and South America, 460 00:29:08,989 --> 00:29:13,156 where they find a new world of powerful civilizations. 461 00:29:17,422 --> 00:29:22,008 This is Mexico City, the world's 12th largest city, 462 00:29:22,009 --> 00:29:26,190 and the largest Spanish-speaking Metropolis on Earth. 463 00:29:29,634 --> 00:29:32,277 It's a hub of commerce and culture, 464 00:29:32,278 --> 00:29:34,553 but in the middle of the city 465 00:29:34,554 --> 00:29:37,387 is what remains of a great temple. 466 00:29:38,734 --> 00:29:41,764 Mexico City is built directly over the ruins 467 00:29:41,765 --> 00:29:44,765 of another great city, Tenochtitlan, 468 00:29:46,243 --> 00:29:50,584 the urban center of the Aztec empire in the early 1500s. 469 00:29:50,585 --> 00:29:54,585 Five square miles, with a population of 200,000, 470 00:29:55,681 --> 00:29:59,595 four times that of London at the time. 471 00:29:59,596 --> 00:30:01,679 It's not just the Aztecs. 472 00:30:02,798 --> 00:30:04,057 The Americas are home to 473 00:30:04,058 --> 00:30:07,623 other powerful empires and kingdoms 474 00:30:07,624 --> 00:30:10,374 including the Maya and the Incas, 475 00:30:12,956 --> 00:30:14,879 and the Spanish conquistadors 476 00:30:14,880 --> 00:30:18,190 don't have an easy time bringing them down. 477 00:30:18,191 --> 00:30:20,108 At least, not at first. 478 00:30:21,282 --> 00:30:24,615 Case in point, one summer night in 1520. 479 00:30:31,635 --> 00:30:34,246 Hernan Cortes and his men find themselves 480 00:30:34,247 --> 00:30:36,164 hunted and outnumbered, 481 00:30:39,244 --> 00:30:42,994 chased into the side streets of Tenochtitlan, 482 00:30:43,969 --> 00:30:45,911 where the spaces are too narrow 483 00:30:45,912 --> 00:30:48,245 to make use of their horses. 484 00:30:51,956 --> 00:30:56,123 Even the superior technology of guns is of little use 485 00:30:57,492 --> 00:31:01,309 against an endless rain of arrows and spears. 486 00:31:14,860 --> 00:31:19,731 As the Spanish flee with as much gold as they can carry, 487 00:31:19,732 --> 00:31:23,149 they leave behind, without knowing it, 488 00:31:23,150 --> 00:31:27,317 a weapon more powerful than gunpowder, horses, or steel. 489 00:31:30,426 --> 00:31:32,759 Inside one of Cortes' fallen 490 00:31:33,634 --> 00:31:35,717 is a biological time bomb 491 00:31:37,041 --> 00:31:39,458 brought forth from deep time. 492 00:31:44,248 --> 00:31:45,331 Months later, 493 00:31:47,110 --> 00:31:49,444 when the Spanish and anti-Aztec allies 494 00:31:49,445 --> 00:31:51,362 return to Tenochtitlan, 495 00:31:52,686 --> 00:31:55,186 they find the city in disarray 496 00:31:56,380 --> 00:31:59,630 and the streets littered with the dead. 497 00:32:00,475 --> 00:32:04,642 Smallpox is the beginning of the end of the Aztec empire. 498 00:32:07,511 --> 00:32:11,678 The disease spreads throughout Central and South America. 499 00:32:13,620 --> 00:32:15,980 The result is often catastrophic. 500 00:32:15,981 --> 00:32:17,677 But why are the European diseases 501 00:32:17,678 --> 00:32:21,457 like smallpox and measles so instantly deadly 502 00:32:21,458 --> 00:32:24,708 to the peoples of 16th century America? 503 00:32:25,868 --> 00:32:28,868 In a way, it goes back to the horse. 504 00:32:32,760 --> 00:32:35,069 Horses, and other large mammals, 505 00:32:35,070 --> 00:32:38,817 were never domesticated in North or South America, 506 00:32:38,818 --> 00:32:40,301 because by the time the descendants 507 00:32:40,302 --> 00:32:42,228 of Asian hunters settle down 508 00:32:42,229 --> 00:32:44,921 and develop civilization in the Americas, 509 00:32:44,922 --> 00:32:47,589 most large mammals had died out. 510 00:32:50,873 --> 00:32:54,699 Look at this farm on the other side of the Pacific. 511 00:32:54,700 --> 00:32:58,377 For thousands of years, people all over Afro-Eurasia 512 00:32:58,378 --> 00:33:01,527 lived with their domesticated animals, 513 00:33:01,528 --> 00:33:05,867 animals that often carried pathogens inside them. 514 00:33:05,868 --> 00:33:07,827 Over tens of centuries, 515 00:33:07,828 --> 00:33:12,000 these diseases kill hundreds of millions, 516 00:33:12,001 --> 00:33:15,164 but over the centuries, Afro-Eurasians develop 517 00:33:15,165 --> 00:33:16,998 some limited immunity. 518 00:33:19,210 --> 00:33:21,240 For the people of the Americas, 519 00:33:21,241 --> 00:33:23,908 immunity consists of two oceans. 520 00:33:26,726 --> 00:33:28,384 Early migrants to the Americas 521 00:33:28,385 --> 00:33:31,730 found themselves then sealed off in this huge world zone, 522 00:33:31,731 --> 00:33:34,843 and the disease of Afro-Eurasia 523 00:33:34,844 --> 00:33:39,444 were in no way able to make their way into the Americas. 524 00:33:39,445 --> 00:33:42,860 But when people cross the water, 525 00:33:42,861 --> 00:33:44,694 so do their pathogens. 526 00:33:47,826 --> 00:33:51,064 In just over a century after Columbus, 527 00:33:51,065 --> 00:33:52,982 between 50 and 95% 528 00:33:53,960 --> 00:33:57,293 of the Americas' native population dies. 529 00:33:59,334 --> 00:34:02,746 Some groups have descendants in the 21st century. 530 00:34:02,747 --> 00:34:04,914 Others die out completely. 531 00:34:07,732 --> 00:34:10,604 Remember, European states that are tiny in comparison 532 00:34:10,605 --> 00:34:14,718 to these great imperial states of the Aztecs and the Inca. 533 00:34:14,719 --> 00:34:16,778 But because the Europeans have got guns, 534 00:34:16,779 --> 00:34:19,648 and they've got steel, and they've got diseases, 535 00:34:19,649 --> 00:34:21,697 they're quickly able to conquer 536 00:34:21,698 --> 00:34:23,671 these very impression civilizations 537 00:34:23,672 --> 00:34:25,929 and the cultures of North America, as well, 538 00:34:25,930 --> 00:34:28,641 and turn these into great areas of 539 00:34:28,642 --> 00:34:31,511 resource acquisition for Europe. 540 00:34:31,512 --> 00:34:33,578 Resources that Europe will then use 541 00:34:33,579 --> 00:34:37,304 to finance its conquest of the rest of the world. 542 00:34:37,305 --> 00:34:39,127 Over the next 400 years, 543 00:34:39,128 --> 00:34:41,577 the Americas are utterly transformed 544 00:34:41,578 --> 00:34:45,917 by new, invasive species from Europe and Asia. 545 00:34:45,918 --> 00:34:48,386 From cattle and pigs 546 00:34:48,387 --> 00:34:50,304 to rats and earthworms, 547 00:34:51,835 --> 00:34:55,252 from apples and oranges and Midwest wheat 548 00:34:56,474 --> 00:34:58,891 to the bluegrass of Kentucky. 549 00:35:00,114 --> 00:35:02,188 There was a similar trade the other way, 550 00:35:02,189 --> 00:35:05,090 from the Americas to Western Europe, 551 00:35:05,091 --> 00:35:07,489 so what we see is a huge export 552 00:35:07,490 --> 00:35:10,326 of crops and livestock from all corners of the world 553 00:35:10,327 --> 00:35:11,969 to all corners of the world, 554 00:35:11,970 --> 00:35:14,000 thus radically transforming the ecology 555 00:35:14,001 --> 00:35:15,741 of the entire planet. 556 00:35:15,742 --> 00:35:17,161 That's because 557 00:35:17,162 --> 00:35:18,632 although the people of the Americas 558 00:35:18,633 --> 00:35:20,380 lacked large, domestic animals, 559 00:35:20,381 --> 00:35:24,548 they had bred more than half of all humanity's usable plants 560 00:35:26,248 --> 00:35:30,028 including tomatoes, squash, beans, peppers, 561 00:35:30,029 --> 00:35:33,946 chocolate, yams, avocados, peanuts, the potato, 562 00:35:35,876 --> 00:35:38,796 and a weed that became one of the world's 563 00:35:38,797 --> 00:35:42,964 most astonishing examples of genetic modification. 564 00:35:44,535 --> 00:35:46,685 What was growing successfully in the wild 565 00:35:46,686 --> 00:35:49,326 in the Americas was a plant called teosinte, 566 00:35:49,327 --> 00:35:51,660 a small, weedy sort of grass 567 00:35:52,813 --> 00:35:55,486 that it took many, many hundreds of generations 568 00:35:55,487 --> 00:35:58,482 of careful, selective breeding of teosinte 569 00:35:58,483 --> 00:36:00,248 before you could start to turn it into a crop 570 00:36:00,249 --> 00:36:02,936 that could feed large numbers of people. 571 00:36:02,937 --> 00:36:05,825 You had to essentially change the DNA of this thing 572 00:36:05,826 --> 00:36:09,134 so that it would produce a lot larger heads. 573 00:36:09,135 --> 00:36:12,091 One ear of teosinte is about the size of a finger 574 00:36:12,092 --> 00:36:15,311 with five to 12 really hard kernels. 575 00:36:15,312 --> 00:36:18,654 It's not much to look at, but 10,000 years ago, 576 00:36:18,655 --> 00:36:21,976 farmers in Mexico began planting and breeding it. 577 00:36:21,977 --> 00:36:24,130 They saw some teosinte ears were a little bigger. 578 00:36:24,131 --> 00:36:26,206 Some kernels might be slightly softer, 579 00:36:26,207 --> 00:36:27,714 and they planted those. 580 00:36:27,715 --> 00:36:30,215 Over thousands of years of selective breeding, 581 00:36:30,216 --> 00:36:32,947 the farmers of Mexico created, and that's the word, 582 00:36:32,948 --> 00:36:37,156 they created what we recognize as modern corn. 583 00:36:37,157 --> 00:36:39,324 Corn is a human invention. 584 00:36:41,238 --> 00:36:43,595 Initially, it probably gets imported into Europe 585 00:36:43,596 --> 00:36:45,872 as a novelty item, but quickly people realize 586 00:36:45,873 --> 00:36:48,373 that this is a really useful crop. 587 00:36:48,374 --> 00:36:49,969 It turns out that while the Earth 588 00:36:49,970 --> 00:36:53,983 only has a few places that can grow spices, 589 00:36:53,984 --> 00:36:57,386 it has many areas where corn can grow, 590 00:36:57,387 --> 00:37:00,970 places too dry for rice, too wet for wheat. 591 00:37:02,579 --> 00:37:05,004 It grows well in a wide range of conditions. 592 00:37:05,005 --> 00:37:06,591 It's relatively pest tolerant, 593 00:37:06,592 --> 00:37:08,322 it's relatively drought resistant, 594 00:37:08,323 --> 00:37:10,842 and it produces a large amount of carbohydrate, 595 00:37:10,843 --> 00:37:14,342 and so it quickly spreads across Europe and into Africa 596 00:37:14,343 --> 00:37:15,598 and today is the basis of both 597 00:37:15,599 --> 00:37:18,432 Europe's and Africa's food system. 598 00:37:19,894 --> 00:37:24,445 In the modern day, this has revolutionized agriculture 599 00:37:24,446 --> 00:37:26,657 across the world, and especially in places 600 00:37:26,658 --> 00:37:29,091 like the American Midwest or in China, 601 00:37:29,092 --> 00:37:32,732 where almost all of the corn that is being produced today 602 00:37:32,733 --> 00:37:35,999 ends up going into the belly of an animal 603 00:37:36,000 --> 00:37:40,167 that we then use for something else, largely for protein. 604 00:37:41,526 --> 00:37:43,587 While corn is a New World crop 605 00:37:43,588 --> 00:37:46,984 that helps transform the Old World, 606 00:37:46,985 --> 00:37:49,849 an Old World crop turns out to be the foundation 607 00:37:49,850 --> 00:37:52,350 of an empire in the New World. 608 00:37:53,506 --> 00:37:56,357 When the conquistadors first arrived in the Americas, 609 00:37:56,358 --> 00:37:58,685 they realized they were in a very conducive environment 610 00:37:58,686 --> 00:38:00,505 for growing certain crop species 611 00:38:00,506 --> 00:38:04,268 for which there is an enormous demand back in Eurasia. 612 00:38:04,269 --> 00:38:06,769 Chief amongst these was sugar. 613 00:38:07,990 --> 00:38:12,981 Sugar was the preferred drug of many, many Europeans. 614 00:38:12,982 --> 00:38:14,871 Humans have a fundamental 615 00:38:14,872 --> 00:38:17,039 deep time link with sugar. 616 00:38:19,721 --> 00:38:22,952 Because it's how we use the power of the sun. 617 00:38:33,084 --> 00:38:36,077 Through photosynthesis, plant cells use water 618 00:38:36,078 --> 00:38:40,245 and carbon dioxide to turn solar energy into oxygen 619 00:38:42,162 --> 00:38:43,829 and sugar molecules. 620 00:38:46,003 --> 00:38:49,974 Simple sugar molecules are the basis for glucose, 621 00:38:49,975 --> 00:38:53,225 which provides energy for living cells. 622 00:38:54,601 --> 00:38:57,268 So, we've evolved a sweet tooth, 623 00:38:58,292 --> 00:39:01,757 chemical receptors that make us want this energy source 624 00:39:01,758 --> 00:39:02,841 that we need. 625 00:39:05,725 --> 00:39:07,558 An early Homo sapien 626 00:39:08,540 --> 00:39:10,516 that had a strong motivation for sugar 627 00:39:10,517 --> 00:39:12,948 might have been healthier, might have been fatter, 628 00:39:12,949 --> 00:39:14,216 might have survived the winter better 629 00:39:14,217 --> 00:39:16,020 and gone on to have more children. 630 00:39:16,021 --> 00:39:18,122 Over time, this sort of evolutionary process 631 00:39:18,123 --> 00:39:21,006 would have bred a craving for sugar in us 632 00:39:21,007 --> 00:39:23,090 that we have still today. 633 00:39:24,401 --> 00:39:26,676 Sugar plantations spring up in areas 634 00:39:26,677 --> 00:39:28,601 where there's no gold to steal: 635 00:39:28,602 --> 00:39:30,777 parts of Brazil, the islands of Jamaica, 636 00:39:30,778 --> 00:39:32,778 Barbados, and elsewhere. 637 00:39:34,231 --> 00:39:36,928 Through exploration and conquest, 638 00:39:36,929 --> 00:39:38,799 Europeans have now seized something 639 00:39:38,800 --> 00:39:40,708 that the deep time history of the planet 640 00:39:40,709 --> 00:39:42,376 failed to give them: 641 00:39:43,436 --> 00:39:44,936 their own tropics. 642 00:39:47,607 --> 00:39:50,532 At first, these tropical plantations are worked 643 00:39:50,533 --> 00:39:53,504 by enslaved local peoples, 644 00:39:53,505 --> 00:39:56,048 but as we've seen, they start dying out 645 00:39:56,049 --> 00:39:58,474 from European diseases. 646 00:39:58,475 --> 00:40:01,367 So the sugar growers solved their labor shortage 647 00:40:01,368 --> 00:40:04,035 by importing slaves from Africa. 648 00:40:05,685 --> 00:40:08,367 Prince Henry the Navigator had started the slave trade 649 00:40:08,368 --> 00:40:10,934 between Africa and Europe in the 1440s. 650 00:40:10,935 --> 00:40:13,591 Now, it becomes one of the biggest businesses 651 00:40:13,592 --> 00:40:16,342 of the entire Colombian Exchange. 652 00:40:18,116 --> 00:40:20,598 Over the next 350 years, 653 00:40:20,599 --> 00:40:23,281 more than 10 million Africans 654 00:40:23,282 --> 00:40:24,864 will be shipped to the New World 655 00:40:24,865 --> 00:40:29,098 to work the sugar plantations of Brazil and the Caribbean 656 00:40:29,099 --> 00:40:31,950 and then other plantations growing tobacco, 657 00:40:31,951 --> 00:40:35,701 rice, coffee, and cotton to supply the world. 658 00:40:39,330 --> 00:40:42,973 If this looks like the beginning of globalization, 659 00:40:42,974 --> 00:40:44,724 that's because it is, 660 00:40:45,969 --> 00:40:49,730 but the substance that really connects the globe, 661 00:40:49,731 --> 00:40:53,982 linking countries around the world in a network of trade 662 00:40:53,983 --> 00:40:57,483 isn't a tropic plant but a precious metal, 663 00:40:58,441 --> 00:41:02,608 buried deep inside this extinct volcano in Bolivia 664 00:41:03,565 --> 00:41:04,898 known as Potosi. 665 00:41:08,433 --> 00:41:11,945 It's not gold, as you might think, 666 00:41:11,946 --> 00:41:13,465 but silver. 667 00:41:17,280 --> 00:41:19,325 One of the great discoveries that the conquistadors, 668 00:41:19,326 --> 00:41:21,207 the Europeans, make is the availability 669 00:41:21,208 --> 00:41:24,125 of a huge mine of silver at Potosi. 670 00:41:25,215 --> 00:41:27,633 The Europeans are very quick to exploit it. 671 00:41:27,634 --> 00:41:30,271 From the view of deep time history, 672 00:41:30,272 --> 00:41:33,689 the silver didn't really come from Potosi 673 00:41:35,975 --> 00:41:38,975 but from the death of an alien star. 674 00:41:41,645 --> 00:41:43,312 Stars make elements, 675 00:41:44,355 --> 00:41:47,351 the basic substances of the universe, 676 00:41:47,352 --> 00:41:49,871 when nuclear fusion at a star's core 677 00:41:49,872 --> 00:41:52,144 rearranges atomic nuclei 678 00:41:52,145 --> 00:41:55,145 with unimaginable pressure and heat. 679 00:41:57,362 --> 00:41:59,965 Middle-sized stars like our sun 680 00:41:59,966 --> 00:42:03,133 make very simple elements like helium. 681 00:42:05,464 --> 00:42:08,524 Larger stars make heavier elements, 682 00:42:08,525 --> 00:42:13,355 and if they die, they make more. 684 00:42:15,152 --> 00:42:19,280 When a star about 10 times more massive than our sun 685 00:42:19,281 --> 00:42:21,671 uses up its nuclear fuel, 686 00:42:21,672 --> 00:42:24,775 it collapses, and then it blows up 687 00:42:26,606 --> 00:42:30,773 in an explosion 100 million times brighter than the sun, 688 00:42:31,856 --> 00:42:34,725 creating even more elements 689 00:42:34,726 --> 00:42:37,476 and shooting them out into space. 690 00:42:38,897 --> 00:42:40,974 If the star is massive enough, 691 00:42:40,975 --> 00:42:43,642 one of those elements is silver. 692 00:42:46,374 --> 00:42:49,334 More than 4.5 billion years ago, 693 00:42:49,335 --> 00:42:52,330 gravity pulls the silver debris together 694 00:42:52,331 --> 00:42:54,248 into the forming Earth. 695 00:42:57,573 --> 00:43:00,358 You have chemicals which touch other chemicals 696 00:43:00,359 --> 00:43:02,440 and coalesce in different ways. 697 00:43:02,441 --> 00:43:05,361 So, as a consequence, silver was not distributed 698 00:43:05,362 --> 00:43:07,945 evenly across the planet Earth. 699 00:43:10,315 --> 00:43:12,626 Inside the Earth, the silver from space 700 00:43:12,627 --> 00:43:14,886 is melted and then concentrated 701 00:43:14,887 --> 00:43:17,887 in areas of extreme subsurface heat. 702 00:43:19,488 --> 00:43:23,488 In other words, where there's volcanic activity. 703 00:43:25,821 --> 00:43:28,391 So, millions of years ago in Bolivia, 704 00:43:28,392 --> 00:43:32,559 the Earth cracks open and Potosi fills with a metal 705 00:43:34,995 --> 00:43:36,936 that in the 16th century, 706 00:43:36,937 --> 00:43:40,520 the Spanish will do almost anything to get. 707 00:43:41,538 --> 00:43:44,720 When silver was discovered in the New World, 708 00:43:44,721 --> 00:43:48,221 that gave incentive for the conquistadors 709 00:43:48,222 --> 00:43:52,389 to complete the process of conquering the New World. 710 00:43:53,261 --> 00:43:56,374 So, believe it or not, events that took place 711 00:43:56,375 --> 00:43:59,336 maybe five, six billion years ago 712 00:43:59,337 --> 00:44:02,570 affected the history of the Americas 713 00:44:02,571 --> 00:44:04,571 billions of years later. 714 00:44:06,178 --> 00:44:08,746 Gold stolen from the Aztecs and Incas 715 00:44:08,747 --> 00:44:12,677 has been a huge windfall for the Spanish, 716 00:44:12,678 --> 00:44:14,962 but it's silver from Potosi 717 00:44:14,963 --> 00:44:19,617 that creates the first true international economy. 718 00:44:19,618 --> 00:44:23,201 That's because between the 1550s and 1800s, 719 00:44:24,863 --> 00:44:28,520 85% of all the silver in the world, 720 00:44:28,521 --> 00:44:31,894 from the Americas to Afro-Eurasia, 721 00:44:31,895 --> 00:44:35,035 flows from this one mountain, 722 00:44:35,036 --> 00:44:38,619 and most of it flows to one country: China. 723 00:44:42,479 --> 00:44:44,336 That's right, China. 724 00:44:44,337 --> 00:44:46,860 A few years after Columbus landed in the Bahamas, 725 00:44:46,861 --> 00:44:48,395 our old friends, the Portuguese, 726 00:44:48,396 --> 00:44:52,101 finally made it round Africa to India and then China. 727 00:44:52,102 --> 00:44:53,906 Once Portugal opened the door, 728 00:44:53,907 --> 00:44:55,860 other European countries quickly found their own ways 729 00:44:55,861 --> 00:44:57,624 into the Chinese markets. 730 00:44:57,625 --> 00:44:59,565 Spain established trades routes 731 00:44:59,566 --> 00:45:01,908 from their new territories in the Americas, 732 00:45:01,909 --> 00:45:04,026 and by the late 16th century, 733 00:45:04,027 --> 00:45:08,333 they're buying Chinese goods with the first global currency: 734 00:45:08,334 --> 00:45:10,504 the purest silver coins in the world. 735 00:45:10,505 --> 00:45:13,293 Silver from Potosi shipped to the mint in Mexico 736 00:45:13,294 --> 00:45:15,627 to create the silver dollar. 737 00:45:16,657 --> 00:45:19,416 Silver was then turned into coins or ingots. 738 00:45:19,417 --> 00:45:21,343 This was then shipped on Spanish galleons 739 00:45:21,344 --> 00:45:24,545 across the Pacific to the new Spanish colony in Manila, 740 00:45:24,546 --> 00:45:25,945 in the Philippines. 741 00:45:25,946 --> 00:45:27,541 From there, it goes on to China 742 00:45:27,542 --> 00:45:31,962 to pay for the still highly in demand Chinese luxury goods. 743 00:45:31,963 --> 00:45:34,536 This extraordinary creation of a supernova 744 00:45:34,537 --> 00:45:36,302 becomes the key medium of exchange 745 00:45:36,303 --> 00:45:38,038 during this early modern period, 746 00:45:38,039 --> 00:45:40,958 this Age of Discovery, and really marks the beginning 747 00:45:40,959 --> 00:45:45,126 of genuine global commercialization of the planet. 748 00:45:47,293 --> 00:45:49,131 500 years later, 749 00:45:49,132 --> 00:45:51,698 a lot of Potosi silver has run out, 750 00:45:51,699 --> 00:45:55,903 and the Mexican dollar is no longer a world currency. 751 00:46:03,708 --> 00:46:05,932 The effects of the global economy 752 00:46:05,933 --> 00:46:09,683 and the Colombian Exchange are all around us. 753 00:46:16,595 --> 00:46:19,448 Take a look at this very common modern meal. 754 00:46:19,449 --> 00:46:22,895 You could call it the Old World/New World combo. 755 00:46:22,896 --> 00:46:24,106 Look at the burger. 756 00:46:24,107 --> 00:46:25,240 Old World. 757 00:46:25,241 --> 00:46:27,517 The cow was domesticated in the Near East, 758 00:46:27,518 --> 00:46:28,898 then went to Western Europe 759 00:46:28,899 --> 00:46:30,872 and was taken to the Americas. 760 00:46:30,873 --> 00:46:34,410 The wheat in the bun, that was first grown in Mesopotamia. 761 00:46:34,411 --> 00:46:36,108 Lettuce, Egypt. 762 00:46:36,109 --> 00:46:38,002 The onion is Asian. 763 00:46:38,003 --> 00:46:40,784 But the tomato on the burger and in the ketchup 764 00:46:40,785 --> 00:46:42,604 comes from Mexico, 765 00:46:42,605 --> 00:46:45,334 and these french fries, New World potatoes 766 00:46:45,335 --> 00:46:47,872 named for an Old World country. 767 00:46:47,873 --> 00:46:49,660 The soda has sugar, 768 00:46:49,661 --> 00:46:51,652 which was originally from Papua New Guinea 769 00:46:51,653 --> 00:46:53,001 in the South Pacific. 770 00:46:53,002 --> 00:46:55,502 It spread through India to the Middle East, 771 00:46:55,503 --> 00:46:57,020 where Europeans acquired it 772 00:46:57,021 --> 00:46:59,702 and cultivated it in the New World. 773 00:46:59,703 --> 00:47:00,703 Oh. 774 00:47:04,254 --> 00:47:08,874 And here are packets of salt and black pepper. 775 00:47:08,875 --> 00:47:10,815 The precious exotic spice from the east 776 00:47:10,816 --> 00:47:13,438 that jump-started the Age of Discovery, 777 00:47:13,439 --> 00:47:16,588 it comes free with your meal. 778 00:47:16,589 --> 00:47:18,515 So, today, we produce black pepper 779 00:47:18,516 --> 00:47:22,225 on very large plantations at an industrial scale, 780 00:47:22,226 --> 00:47:24,815 and the cost of producing the black pepper 781 00:47:24,816 --> 00:47:27,928 are very, very small, and the cost of shipping this product 782 00:47:27,929 --> 00:47:32,375 on large container vessels is totally insignificant. 783 00:47:32,376 --> 00:47:35,138 More inexpensive food for more people? 784 00:47:35,139 --> 00:47:38,045 That's one of the legacies of the Age of Discovery. 785 00:47:38,046 --> 00:47:40,862 Other parts of that legacy are very dark, indeed. 786 00:47:40,863 --> 00:47:44,280 Violence, racism, slavery, even genocide, 787 00:47:45,204 --> 00:47:47,024 but there's something else to be said 788 00:47:47,025 --> 00:47:49,805 for the Age of Discovery. 789 00:47:49,806 --> 00:47:52,271 It altered forever the way we understood 790 00:47:52,272 --> 00:47:54,439 our place in the universe. 791 00:47:56,559 --> 00:47:57,727 There's a very clear link between 792 00:47:57,728 --> 00:48:00,452 the discoveries of these different regions, 793 00:48:00,453 --> 00:48:03,455 extraordinary land forms, life ways, and so on 794 00:48:03,456 --> 00:48:06,099 and what becomes the great Scientific Revolution, 795 00:48:06,100 --> 00:48:08,481 very much driven by trying to make sense of 796 00:48:08,482 --> 00:48:11,100 these extraordinary discoveries. 797 00:48:13,849 --> 00:48:16,206 Plunder and financial gain, 798 00:48:16,207 --> 00:48:18,932 that's why the early explorers risked their life 799 00:48:18,933 --> 00:48:20,850 to go to the New World. 800 00:48:21,700 --> 00:48:25,652 Eventually, a transformation took place. 801 00:48:25,653 --> 00:48:30,202 More and more adventurers and people who were just curious 802 00:48:30,203 --> 00:48:33,161 began to embark upon these great adventures, 803 00:48:33,162 --> 00:48:36,399 the most famous of them being Charles Darwin. 804 00:48:36,400 --> 00:48:37,715 He was curious. 805 00:48:37,716 --> 00:48:39,260 He was a naturalist. 806 00:48:39,261 --> 00:48:42,732 He wanted to write the history of life on the planet Earth, 807 00:48:42,733 --> 00:48:44,575 and the only way he could do that 808 00:48:44,576 --> 00:48:46,885 was to get on one of these boats 809 00:48:46,886 --> 00:48:49,312 and sail the ocean blue. 810 00:48:49,313 --> 00:48:52,582 So we begin to realize that even though originally 811 00:48:52,583 --> 00:48:56,816 the spirit of exploration was the spirit of 812 00:48:56,817 --> 00:49:00,094 looking for profit and commercial gain, 813 00:49:00,095 --> 00:49:01,564 eventually people went 814 00:49:01,565 --> 00:49:04,345 because they were curious about the world. 815 00:49:04,346 --> 00:49:08,513 It was the Age of Discovery in the truest sense of the word. 816 00:49:12,396 --> 00:49:14,150 In one sense, the Age of Discovery 817 00:49:14,151 --> 00:49:16,838 began with a few ships in the 15th century 818 00:49:16,839 --> 00:49:19,377 setting out for unknown shores, 819 00:49:19,378 --> 00:49:21,407 but in another sense, the Age of Discovery 820 00:49:21,408 --> 00:49:25,165 has roots in the very depths of time. 821 00:49:25,166 --> 00:49:29,211 In a land bridge that populated two continents, 822 00:49:29,212 --> 00:49:32,571 tectonic plates that ripped South America from Africa 823 00:49:32,572 --> 00:49:35,322 and created two huge world zones. 824 00:49:36,716 --> 00:49:38,906 In the molecules that formed after the collision 825 00:49:38,907 --> 00:49:40,490 that made the moon. 826 00:49:41,724 --> 00:49:43,315 And the globe-connecting element 827 00:49:43,316 --> 00:49:46,233 forged in the heat of a dying star. 828 00:49:47,166 --> 00:49:51,314 Links in the chain of events of deep time history.