1 00:00:03,127 --> 00:00:07,928 The history of light is the history of human cunning. 2 00:00:09,272 --> 00:00:13,763 Ingenious humans have manipulated and turned light to build 3 00:00:13,764 --> 00:00:17,955 optical tools of the most extraordinary sophistication. 4 00:00:20,103 --> 00:00:24,953 Optical tools which could allow navigators to travel on earth and sea, 5 00:00:25,032 --> 00:00:29,787 which could allow artists to make the most amazingly realistic pictures, 6 00:00:29,993 --> 00:00:32,718 which could allow us to see the almost 7 00:00:32,719 --> 00:00:36,159 infinitely distant and the unimaginably small. 8 00:00:37,890 --> 00:00:42,509 These tools have had really surprising effects. 9 00:00:43,550 --> 00:00:50,187 They've taken us deep into the heavens and reveal the very origin of the universe. 10 00:00:52,546 --> 00:00:56,993 But as light told us more about God's creation, 11 00:00:56,994 --> 00:01:01,811 it's forced us to face new and dangerous questions, 12 00:01:03,640 --> 00:01:10,438 It's even made us ask whether God himself actually exists. 13 00:01:27,061 --> 00:01:31,678 The journey to a new understanding of light begins here 14 00:01:31,679 --> 00:01:36,212 in the Baltic sea around northern Europe in the 1500s. 15 00:01:36,350 --> 00:01:43,470 And it begins not with scholars or scientists, but with traders and navigators. 16 00:01:50,760 --> 00:01:54,205 In the 16th century, these waters were some 17 00:01:54,206 --> 00:01:57,885 of the very busiest trade routes in the world. 18 00:01:57,886 --> 00:02:04,618 Navigator's horizons had expended enormously to China, and Indies, and south America. 19 00:02:04,680 --> 00:02:07,837 The trade goods that float through the 20 00:02:07,838 --> 00:02:11,824 Baltic were amber and skins, wheat and timber. 21 00:02:11,898 --> 00:02:18,554 And for that trade to flow, what was required was confident, expert navigation. 22 00:02:18,574 --> 00:02:23,771 and the expertise of navigators relied on their understanding of light. 23 00:02:26,579 --> 00:02:32,383 Baltic navigators built the best tools yet to gaze the stars. And 24 00:02:32,384 --> 00:02:38,539 on this island, in their mist, lived an astrologer called Tyco Brahe. 25 00:02:43,983 --> 00:02:48,413 He used scaled up versions of navigators' tools to 26 00:02:48,414 --> 00:02:53,452 conduct an extraordinarily systematic study of the stars. 27 00:02:57,324 --> 00:03:04,306 But Tyco was no ethereal scholar. He was tough and argumentative. 28 00:03:05,648 --> 00:03:09,577 Tyco was a street fighting man. When he was a student, he 29 00:03:09,578 --> 00:03:13,438 kept on ending up in brawls. One brawl was almost fatal. 30 00:03:14,150 --> 00:03:19,942 The fight began when someone dare to challenge Tyco's astrological predictions. 31 00:03:19,977 --> 00:03:24,798 In the ensuing duel, the bridge of his nose was sliced off. 32 00:03:25,357 --> 00:03:31,414 Tyco was not abashed, what he did was to commission a metal replacement. 33 00:03:31,504 --> 00:03:34,899 It was made of cooper, if it is like everyday 34 00:03:34,900 --> 00:03:38,220 use, and then gold for ceremonial occasions. 35 00:03:38,271 --> 00:03:42,990 Tyco's nose was of scar, he was proud to wear. 36 00:03:43,079 --> 00:03:46,694 It was a sign that he wouldn't suffer fools. 37 00:03:46,695 --> 00:03:50,631 There is his metal badge of his noble pugnacity. 38 00:03:52,990 --> 00:03:58,092 Here, on Hven, Tyco wanted to make a better map of the heavens, 39 00:03:59,587 --> 00:04:05,431 a map that would let him predict exactly the future of humans living on Earth. 40 00:04:07,895 --> 00:04:11,264 Tyco took astrology very seriously. 41 00:04:11,340 --> 00:04:15,790 He reckoned that there was the lights streaming down from the stars and 42 00:04:15,791 --> 00:04:20,302 planets which allowed the heavens to control what happens here on Earth. 43 00:04:20,582 --> 00:04:26,756 So Tyco made predictions of the weather, of the life and death of kings. 44 00:04:26,854 --> 00:04:31,558 He flattered the king of Denmark, Frederick II, with these predictions, 45 00:04:31,655 --> 00:04:36,453 and in return, the king gave him the entire island of Hven on 46 00:04:36,454 --> 00:04:41,484 which to build an observatory, where Tyco could study the stars. 47 00:04:46,612 --> 00:04:50,194 Tyco's observatory was state of the art. 48 00:04:50,295 --> 00:04:55,533 He filled it with exquisitely engineered quadrels and clocks, 49 00:04:55,673 --> 00:05:00,162 and used them to make the most accurate star charts to date. 50 00:05:02,090 --> 00:05:06,275 Now all that is left are Tyco's most surprising 51 00:05:06,276 --> 00:05:10,809 observational tools: the flower beds of his garden. 52 00:05:12,681 --> 00:05:17,478 And the best way to see them is from above. 53 00:05:21,418 --> 00:05:25,822 Tyco plotted it out to represent the signs of the 54 00:05:25,823 --> 00:05:30,403 zodiac and help him map the positions of the stars. 55 00:05:37,327 --> 00:05:42,310 It is just extraordinarily moving to be here, floating above Tyco's 56 00:05:42,311 --> 00:05:47,512 observatory, looking down from the heavens with which he was obsessed. 57 00:05:49,289 --> 00:05:54,341 The layout of the observatory is perfectly symmetrical, so there are two long 58 00:05:54,342 --> 00:05:59,198 axis, one run in exactly north and south, the other exactly west and east, 59 00:05:59,297 --> 00:06:04,969 with the big observatory building in the center, with large walls surrounding it, 60 00:06:04,977 --> 00:06:09,640 And in between, a garden, a herb garden, an astrological garden in which 61 00:06:09,889 --> 00:06:14,163 each medicinal herb was planted towards the point of the 62 00:06:14,164 --> 00:06:18,811 astrological zodiac, which controlled the power of that herb. 63 00:06:18,849 --> 00:06:22,465 Hyssop and balsam, roses and chrysanthemums. 64 00:06:22,630 --> 00:06:28,007 The whole thing, reflecting the astronomical order that was going to be 65 00:06:28,008 --> 00:06:33,310 revealed from this extraordinarily beautiful astronomical observatory. 66 00:06:37,367 --> 00:06:43,342 And then, while out observing on 13th of November 1577, Tyco saw 67 00:06:43,343 --> 00:06:49,408 something that would completely change the model of the universe. 68 00:06:50,483 --> 00:06:57,243 There appeared in the skies above his head a comet, moving across the sky. 69 00:07:01,922 --> 00:07:05,663 Tyco was transfixed by the sight. 70 00:07:06,445 --> 00:07:10,152 Night after night, he tracked the comet with the 71 00:07:10,153 --> 00:07:14,691 relentlessness of a hunter, taking meticulous measurements. 72 00:07:16,740 --> 00:07:21,176 Tyco didn't know it yet, but this was dangerous data, data 73 00:07:21,177 --> 00:07:25,988 that challenged the very nature of the universe created by God. 74 00:07:32,905 --> 00:07:36,608 The church asserted as absolute truth that God 75 00:07:36,609 --> 00:07:40,468 had put the Earth at the center of the universe, 76 00:07:40,549 --> 00:07:46,125 and around it, embedded a series of vast crystal spheres, 77 00:07:46,225 --> 00:07:53,464 He placed the Moon, the Sun, the planets, and ultimately the stars. 78 00:07:54,240 --> 00:07:59,362 These spheres were impenetrable, and nothing could move through them. 79 00:07:59,412 --> 00:08:05,036 Yet all these was about to be challenged by Tyco's comet. 80 00:08:05,273 --> 00:08:09,705 Now, people knew that comets were moving in the heavens, 81 00:08:10,403 --> 00:08:15,639 but if there were crystal spheres, the comets couldn't move through them, so 82 00:08:15,640 --> 00:08:21,012 comets must be nearer to the Earth, nearer to the Earth even than the Moon is. 83 00:08:23,847 --> 00:08:29,890 As the comet blazed across the sky, Tyco measured its movement so accurately 84 00:08:29,891 --> 00:08:36,326 that it was possible for the first time to calculate its distance from the Earth. 85 00:08:39,387 --> 00:08:45,520 The method Tyco used was based on a property of light called parallax, 86 00:08:45,540 --> 00:08:48,905 it was a technique very common amongst navigators. 87 00:08:48,946 --> 00:08:53,565 Imagine two boats out at the sea moving at the same speed, 88 00:08:53,607 --> 00:08:57,446 one boat if it is further away will seem to 89 00:08:57,447 --> 00:09:01,721 move much more slowly than the nearby boat will. 90 00:09:02,555 --> 00:09:09,351 Well, if the comet is near the Earth, if it is moving between the Earth and the Moon, 91 00:09:09,382 --> 00:09:13,574 then it should move fairly rapidly across the sky, 92 00:09:13,633 --> 00:09:16,471 but that is not what Tyco saw 93 00:09:16,523 --> 00:09:20,561 What he saw, was the comet moving really pretty 94 00:09:20,562 --> 00:09:24,262 slowly against the background of the stars. 95 00:09:24,372 --> 00:09:27,685 And that could only mean one thing: 96 00:09:27,727 --> 00:09:33,087 the comet must be moving much further away than the Moon, 97 00:09:33,135 --> 00:09:36,926 it must be moving in the area of the heavens which 98 00:09:36,927 --> 00:09:40,569 people imagined was full of crystalline spheres. 99 00:09:41,019 --> 00:09:45,051 Tyco checked his observations, the comet was 100 00:09:45,052 --> 00:09:49,172 very far away. 6 times further than the Moon. 101 00:09:49,241 --> 00:09:52,486 It was moving through celestial space. 102 00:09:52,514 --> 00:09:58,971 Tyco's comet had completely overthrown the basic model of the universe. 103 00:09:59,012 --> 00:10:04,371 If there were any crystal spheres, then the comet would have smashed through them. 104 00:10:13,148 --> 00:10:17,532 Tyco have made observations of the most extraordinary precision, 105 00:10:17,567 --> 00:10:20,834 and what they'd shown was that the church's 106 00:10:20,835 --> 00:10:24,397 traditional view of the universe must be wrong. 107 00:10:24,437 --> 00:10:26,912 There were no crystal spheres. 108 00:10:27,004 --> 00:10:32,840 The distances of the stars, the planets, of comets were unimaginably vast. 109 00:10:33,235 --> 00:10:37,221 All this brought a crisis in cosmology. 110 00:10:37,375 --> 00:10:40,405 A new world view seemed to be required. 111 00:10:44,191 --> 00:10:51,330 This wasn't just bad news for the church, ultimately, it was bad news for Tyco. 112 00:10:51,705 --> 00:10:55,444 For this big beery aggressive Danish astronomer, 113 00:10:55,445 --> 00:10:58,802 things in the end didn't work out too well. 114 00:10:58,980 --> 00:11:02,602 He completely blew his relations with the Danish king 115 00:11:02,603 --> 00:11:06,224 and he had to move away from his beloved observatory. 116 00:11:07,371 --> 00:11:10,889 He died soon afterwards of a bladder infection 117 00:11:10,890 --> 00:11:14,258 acquired after a particularly drunken feast. 118 00:11:15,531 --> 00:11:18,869 But Tyco had made his mark. He was the first 119 00:11:18,870 --> 00:11:22,429 person accurately to measure and map the stars. 120 00:11:22,519 --> 00:11:27,825 And this work had put the claims of the church on shaky ground. 121 00:11:29,371 --> 00:11:34,144 But that was nothing compared to what would happen next. 122 00:11:42,313 --> 00:11:45,871 Glass would change everything. 123 00:11:50,145 --> 00:11:54,878 When people began to stare at the heavens through this everyday 124 00:11:54,879 --> 00:11:59,980 stuff, they would undermine hundreds of years of religious doctrine. 125 00:12:03,923 --> 00:12:11,017 And it all began with a revolution in glass making in 16th century Venice. 126 00:12:27,934 --> 00:12:30,646 Venetian glass was money glass. 127 00:12:30,789 --> 00:12:34,871 It was a way of displaying the wealth of the great Venetian 128 00:12:34,872 --> 00:12:39,293 merchants who dominated the trade routes from their watery city. 129 00:12:39,322 --> 00:12:44,541 And it was gorgeous glass. From the 16th century, Venetians could 130 00:12:44,542 --> 00:12:49,681 make Crystallo, a glass of unparalleled beauty and transparency. 131 00:12:50,721 --> 00:12:56,091 And people noticed that glass has unique and magical properties. 132 00:13:01,995 --> 00:13:05,686 Glass is strange and spooky stuff. 133 00:13:05,829 --> 00:13:09,511 It makes light bend and change direction. 134 00:13:09,680 --> 00:13:13,313 As it changes direction, it refracts. 135 00:13:13,683 --> 00:13:17,699 Now people knew that well, they'd already started to use 136 00:13:17,700 --> 00:13:21,856 lenses to make reading easier, to bring things into focus. 137 00:13:22,329 --> 00:13:27,963 And the mastery of this extraordinary property of glass would 138 00:13:27,964 --> 00:13:33,688 indeed change the way human beings could see the world around. 139 00:13:36,471 --> 00:13:43,967 But in renaissance Venice, glass was seen as a decoration, a trinket, a toy. 140 00:13:46,625 --> 00:13:52,765 So when in 1609, there was a rumor of a device for sale, a spy glass that 141 00:13:52,766 --> 00:13:59,071 use lenses to make distant objects appear nearer, no one took it seriously, 142 00:13:59,217 --> 00:14:04,552 except an impoverished math professor Galileo Galilei. 143 00:14:08,294 --> 00:14:13,448 Galileo first got news of the spy glass which was roughly the summer of 1609, 144 00:14:13,529 --> 00:14:18,662 he was extremely clever, very well informed and broke, 145 00:14:18,808 --> 00:14:24,927 he wanted a much better job than the badly paying university job that he had, 146 00:14:25,037 --> 00:14:30,875 and he knew, brilliantly, that if he could make a wonder, a marvel, a 147 00:14:30,876 --> 00:14:37,046 new piece of technology that he could offer on the market or to a patron, 148 00:14:37,075 --> 00:14:41,549 his name, his reputation, and his income would be made, 149 00:14:41,632 --> 00:14:46,187 and this is what the news of the spy glass offered him. 150 00:14:46,982 --> 00:14:53,536 But there was a problem, tricky bits of glass were usually sold by conman. 151 00:14:57,905 --> 00:15:01,675 Charlatan is an Italian word. It means, or at least it 152 00:15:01,676 --> 00:15:06,200 originally meant, the guys who got up on a platform in the middle 153 00:15:06,201 --> 00:15:10,382 of the piazza and sold you snake oil, weird stuff, things to 154 00:15:10,383 --> 00:15:14,701 cure syphilis, and things to make women fall in love with you. 155 00:15:15,072 --> 00:15:18,639 And in between this charming, rather bizarre, but 156 00:15:18,640 --> 00:15:22,419 definitely financial game, they showed you machines, 157 00:15:22,420 --> 00:15:26,343 tricks, bits of glass, they showed you glass that make 158 00:15:26,344 --> 00:15:30,194 things colored, it was called the science of miracles 159 00:15:30,224 --> 00:15:35,090 What Galileo had to do was to exploit what the charmans was 160 00:15:35,091 --> 00:15:39,793 doing and then make sure that no one mistook him for one. 161 00:15:41,771 --> 00:15:45,308 Despite its tawdry reputation, Galileo was 162 00:15:45,309 --> 00:15:49,749 convinced the spy glass could make him a fast ducket. 163 00:15:51,159 --> 00:15:55,044 He realized that an instrument that could make distant 164 00:15:55,045 --> 00:15:59,423 bodies appear very nearby could be much more than just a toy. 165 00:15:59,550 --> 00:16:05,239 For a military and commercial power like Venice, it could be invaluable. 166 00:16:05,321 --> 00:16:10,768 The Venetian navy could see its enemies hours before they arrived, and traders 167 00:16:10,769 --> 00:16:16,283 could spot goods that were coming into port and adjust their price accordingly. 168 00:16:16,420 --> 00:16:19,797 And of course, Galileo himself could racket in. 169 00:16:20,500 --> 00:16:26,197 Galileo at once got hold of some good lenses from his local glassworks. 170 00:16:26,237 --> 00:16:30,972 And he took them away to test, to play with. 171 00:16:31,364 --> 00:16:36,866 The result of Galileo's games with these lenses would change astronomy forever. 172 00:16:40,730 --> 00:16:46,232 Now, Galileo set about making a better spy glass than the existing one. 173 00:16:47,785 --> 00:16:54,761 The spy glass showed things upside down, and it could only magnify 2 or 3 times. 174 00:16:54,801 --> 00:16:57,790 But what Galileo did was to use a very 175 00:16:57,791 --> 00:17:01,566 strong concave lens which he put near his eye, 176 00:17:01,618 --> 00:17:07,479 and then at a determined distance further off, along the tube, a convex lens. 177 00:17:07,548 --> 00:17:12,651 Now with that arrangement, Galileo's device could show things 178 00:17:12,652 --> 00:17:17,754 the right way up and they showed them magnified 8 or 9 times. 179 00:17:19,585 --> 00:17:23,907 Galileo's telescope was a technical marvel. 180 00:17:24,659 --> 00:17:30,446 He was convinced he would make his fortune by selling it to the Venetian government. 181 00:17:32,400 --> 00:17:37,252 But first, he had to convince them he wasn't a charlatan. 182 00:17:38,731 --> 00:17:43,488 So he would bring skeptics up here to the top of the bell tower 183 00:17:43,489 --> 00:17:47,947 in Venice, and showed them the familiar sights of the city. 184 00:17:48,058 --> 00:17:52,951 And then he get them to look through the telescope, and 185 00:17:52,952 --> 00:17:58,281 agree that he just did magnify and that it could be trusted. 186 00:17:58,876 --> 00:18:04,370 What he was setting out to do was to get people to accept that light 187 00:18:04,371 --> 00:18:09,864 traveling through a telescope was a reliable carrier of information. 188 00:18:11,942 --> 00:18:17,431 Finally the Venetian government were persuaded that it wasn't just a 189 00:18:17,432 --> 00:18:22,921 trick and they accepted Galileo's offer and rewarded him handsomely. 190 00:18:24,860 --> 00:18:30,279 Galileo was extremely cunning in dealing with the Venetian government, 191 00:18:30,303 --> 00:18:35,422 in exchange for offering them a monopoly over the manufacture 192 00:18:35,423 --> 00:18:40,458 of his new spy glasses, he wanted a serious salary increase. 193 00:18:42,253 --> 00:18:45,682 And he got it. Unfortunately, the very next day, 194 00:18:45,683 --> 00:18:49,390 he was found out that government discovered that spy 195 00:18:49,391 --> 00:18:53,099 glasses sold by charlatans in the markets of Venice. 196 00:18:53,100 --> 00:18:57,087 They are not as good, were a lot cheaper than Galileo's, 197 00:18:57,169 --> 00:19:00,676 and they refused to increase his salary ever again. 198 00:19:04,717 --> 00:19:09,156 But now Galileo had what he needed, some money, and more 199 00:19:09,157 --> 00:19:13,518 importantly, a tool to manipulate light: the telescope. 200 00:19:16,152 --> 00:19:19,677 Here, the balcony of his house, Galileo turned 201 00:19:19,678 --> 00:19:23,203 his telescope to the skies for the first time, 202 00:19:24,629 --> 00:19:28,431 What he saw amazed him. He saw a world that 203 00:19:28,432 --> 00:19:32,406 people had never dreamt could possibly exist. 204 00:19:35,829 --> 00:19:39,251 Over the next few months, he became obsessed 205 00:19:39,252 --> 00:19:42,977 by what he could see on the surface of the Moon, 206 00:19:42,988 --> 00:19:46,471 it was rugged, it had craters and mountains, he even 207 00:19:46,472 --> 00:19:50,151 managed to measure the height of some of the mountains. 208 00:19:50,240 --> 00:19:52,881 They were 4 mils high. 209 00:19:52,958 --> 00:19:57,818 He saw far more stars than you can see with the naked eye. 210 00:19:59,770 --> 00:20:05,955 Nobody had ever seen these things before, the telescope revealed a 211 00:20:05,956 --> 00:20:12,232 universe far bigger and more complex than anyone had ever imagined. 212 00:20:14,633 --> 00:20:19,932 Galileo worked hard to publish his findings just as soon as he could. 213 00:20:20,052 --> 00:20:24,428 He quickly released a book called the Starry Messenger. 214 00:20:24,545 --> 00:20:29,211 Now the book was an absolute revelation. Although the public 215 00:20:29,212 --> 00:20:33,494 read it avidly, they found it disturbing and confusing. 216 00:20:33,500 --> 00:20:38,005 It showed hundreds of stars invisible to the naked eye. 217 00:20:38,149 --> 00:20:42,714 It showed mountains on the Moon, carters and seas. 218 00:20:42,790 --> 00:20:46,093 It showed stars never before imagined. 219 00:20:46,153 --> 00:20:53,725 The whole universes seemed to be in flux, and all these because of a simple telescope. 220 00:20:53,801 --> 00:20:56,911 But hidden in the Starry Messenger was the 221 00:20:56,912 --> 00:21:00,237 most explosive of all Galileo's observations. 222 00:21:00,325 --> 00:21:03,690 These tiny sketches would ignite one of the greatest 223 00:21:03,691 --> 00:21:07,118 controversies in the history of the Christian church. 224 00:21:07,601 --> 00:21:12,666 They refer to the observations he started on the 10th of June 225 00:21:12,667 --> 00:21:17,894 1610, the night he trained his telescope on the planet Jupiter. 226 00:21:18,081 --> 00:21:23,773 He saw 3, and then 4 moons orbiting round the planet. 227 00:21:24,877 --> 00:21:31,238 This would shake the world view that it held sway for 500 years. 228 00:21:44,307 --> 00:21:48,918 Throughout the ages, people had considered themselves to be special, 229 00:21:49,118 --> 00:21:52,503 to hold a pivotal position on Earth 230 00:21:53,691 --> 00:21:58,797 After all, the book of genesis said that God made man in his 231 00:21:58,798 --> 00:22:03,902 own image, and place him on Earth at the center of universe. 232 00:22:11,642 --> 00:22:16,352 It was believed that all the planets were rotating 233 00:22:16,353 --> 00:22:20,878 round the Earth, and this even included the Sun. 234 00:22:21,270 --> 00:22:27,558 But Galileo's telescope-suggested things were very different. 235 00:22:28,423 --> 00:22:34,311 What Galileo had shown with his discovery of the moons orbiting around Jupiter was that: 236 00:22:34,326 --> 00:22:41,375 here were bodies orbiting round somewhere else, around another planet. 237 00:22:41,530 --> 00:22:47,202 And that made it much more plausible that there were many objects 238 00:22:47,203 --> 00:22:53,046 in motion in the universe, each revolving around different centers. 239 00:22:53,163 --> 00:22:57,527 Above all, I think, it made it really plausible that 240 00:22:57,528 --> 00:23:01,726 the Earth was moving, that the Earth was a planet. 241 00:23:07,674 --> 00:23:11,341 Galileo's work was evidence for a startling new 242 00:23:11,342 --> 00:23:15,160 model of the universe with the Sun at the center. 243 00:23:17,563 --> 00:23:22,319 Now, the Earth might be just another planet orbiting round the Sun. 244 00:23:24,674 --> 00:23:30,696 Suddenly, the church's creationist model of the universe was in big trouble. 245 00:23:30,934 --> 00:23:37,735 Men had lost his special divinely appointed position at the center of everything. 246 00:23:54,936 --> 00:24:01,143 The position of the church as all knowing, and all powerful was under threat. 247 00:24:03,427 --> 00:24:08,657 Yet the last thing Galileo had intended was to damage the church. 248 00:24:09,531 --> 00:24:13,526 Galileo was a religious man, who simply wanted 249 00:24:13,527 --> 00:24:17,776 the church to get it right, and not look foolish. 250 00:24:18,500 --> 00:24:22,790 And he openly said the bible who may tell you how to 251 00:24:22,791 --> 00:24:27,160 get to heaven, but it doesn't you how the heavens go. 252 00:24:31,348 --> 00:24:37,472 By mastering the telescope, Galileo had revealed how the heavens go. 253 00:24:37,548 --> 00:24:41,280 Galileo had made his telescope just to make money. 254 00:24:41,364 --> 00:24:48,268 Yet unwittingly, using light, he dealt a damaging blow to God's supremacy. 255 00:24:56,284 --> 00:25:01,315 After the success of Galileo's telescope, the lens's market boomed. 256 00:25:01,469 --> 00:25:07,983 Lenses become an almost universal technology and reached into every aspect of life. 257 00:25:19,748 --> 00:25:25,449 Art would also be affected by the combination of light and lenses. 258 00:25:25,460 --> 00:25:30,896 A dramatic change would take place in ways of painting, and drawing, 259 00:25:30,897 --> 00:25:36,648 and a new kind of realism would enter the way of representing the world. 260 00:25:40,912 --> 00:25:45,232 For the first time, the ordinary, the everyday 261 00:25:45,233 --> 00:25:49,001 became subjects for the artist's canvas. 262 00:25:51,892 --> 00:25:57,336 And all that happened through a set up called the Camera Obscura. 263 00:25:57,396 --> 00:26:01,058 with the light from the subject passes through a 264 00:26:01,059 --> 00:26:04,944 lens, so it is projected into the painter's canvas. 265 00:26:07,532 --> 00:26:12,007 Philip Steadman is an expert on the camera obscura. 266 00:26:12,345 --> 00:26:17,473 What we got here is that I am in the camera obscura, of this half 267 00:26:17,474 --> 00:26:22,368 of the studio that I am sitting in is pretty much in the dark, 268 00:26:23,376 --> 00:26:28,193 and between you in the middle is the lens, you are very brightly lit and the 269 00:26:28,194 --> 00:26:33,198 image comes through the lens onto this translucent screen that I am working it, 270 00:26:33,233 --> 00:26:35,185 I am tracing around the other side of it. 271 00:26:45,645 --> 00:26:48,520 Obviously, one of the things about the images 272 00:26:48,521 --> 00:26:51,520 is that I am upside down. Why am I upside down? 273 00:26:51,592 --> 00:26:54,450 Well, you are upside down because we got 274 00:26:54,451 --> 00:26:57,809 very simple camera arrangement here. Just the 275 00:26:57,810 --> 00:27:04,097 lens between you and me and the screen, and the rays of lights, cross over in the lens, 276 00:27:04,161 --> 00:27:06,794 and so the, as well the bottom half of you becomes the top half of the picture. 277 00:27:09,361 --> 00:27:14,380 So the lens focuses the rays of light coming from me straight on to the 278 00:27:14,381 --> 00:27:19,329 canvas. It is the same principal and the basis of modern film cameras. 279 00:27:23,854 --> 00:27:27,303 Artists started to become interested in camera 280 00:27:27,304 --> 00:27:30,825 obscura with lenses in the middle 17th century. 281 00:27:30,912 --> 00:27:33,465 The outstanding example is Vermeer. 282 00:27:33,685 --> 00:27:36,488 Vermeer seems to have become interested in 283 00:27:36,489 --> 00:27:39,617 the camera obscura in the middle of his career. 284 00:27:39,618 --> 00:27:43,522 There is a definite date when he changes completely. 285 00:27:45,818 --> 00:27:51,698 And you really can see the difference that using a lens makes to Vermeer's work. 286 00:27:51,786 --> 00:27:55,716 the 3 characters in the first painting have heads of the same 287 00:27:55,717 --> 00:27:59,962 size despite the fact there were very different distances from us. 288 00:28:00,078 --> 00:28:05,474 But the perspective in the second painting is exact and photographic, 289 00:28:05,514 --> 00:28:10,487 the soldier's head is twice the size of the girl's cause he is much closer. 290 00:28:10,498 --> 00:28:13,350 But it is not just the perspective that's 291 00:28:13,351 --> 00:28:16,746 changed. Vermeer was moved from painting mythical 292 00:28:16,747 --> 00:28:19,395 religious scenes of angels and icons to 293 00:28:19,396 --> 00:28:22,994 portraying the real world of soldiers and servants. 294 00:28:25,746 --> 00:28:27,433 So here is the finished product. 295 00:28:27,554 --> 00:28:30,154 Oh well done, that is magnificent. 296 00:28:30,327 --> 00:28:34,105 I think it does more than justice to the sitter. 297 00:28:34,134 --> 00:28:37,229 You are very kind. It is of course done extremely 298 00:28:37,230 --> 00:28:40,881 quickly. Yeah. I mean, this is only half done of its work. 299 00:28:40,982 --> 00:28:45,963 The use of lenses had created a new art of describing the world. 300 00:28:46,014 --> 00:28:50,657 What lens technology and the camera obscura meant was that artists set 301 00:28:50,658 --> 00:28:55,235 out to make realistic images of the world as they saw it around them. 302 00:28:57,915 --> 00:29:02,646 The telescope had completely changed people's relationship 303 00:29:02,647 --> 00:29:06,495 with the world, of the great, and of the small. 304 00:29:06,503 --> 00:29:12,181 And now, the camera obscura had put people into perspective, giving 305 00:29:12,182 --> 00:29:17,859 them an account of the world that was realistic, that was accurate. 306 00:29:21,719 --> 00:29:28,907 In 17th century Europe, lenses were used to explore every aspect of the world, 307 00:29:29,151 --> 00:29:34,739 not just up into the heaves, but down towards the Earth. 308 00:29:42,831 --> 00:29:48,203 London in the 1660s was booming. It was the commercial headquarters of the world. 309 00:29:48,259 --> 00:29:51,794 Here and now was the birthplace of capitalism. 310 00:29:53,439 --> 00:29:56,459 As the British empire was expanding through 311 00:29:56,460 --> 00:29:59,754 trade, scholars were also exploring new worlds. 312 00:30:01,547 --> 00:30:07,812 It was fashionable to be curious, and no one was more curious than Robert Hooke. 313 00:30:11,148 --> 00:30:16,123 He was the engineer who designed London street after the fire 314 00:30:16,124 --> 00:30:21,339 of 1666, and the man who will lead the next revolution in light. 315 00:30:21,444 --> 00:30:29,552 The brilliant, if slightly warped, Hooke was constantly experimenting, often on himself. 316 00:30:30,212 --> 00:30:34,459 I have drunk lead, which somewhat benumbed my head. 317 00:30:34,511 --> 00:30:39,816 To cure of vertigo, I let my blood 7 ounces. The vertigo continued, 318 00:30:39,836 --> 00:30:43,888 but upon snuffing ginger, I was much relieved 319 00:30:43,889 --> 00:30:47,940 by blowing out my nose a lump of thick jelly, 320 00:30:48,093 --> 00:30:50,291 and to treat the stomach, I have 321 00:30:50,292 --> 00:30:53,587 experimented with volatile spirit of wormwood, 322 00:30:53,660 --> 00:30:59,843 which made me very sick and disturb me all the night and purged me in the morning. 323 00:30:59,864 --> 00:31:03,412 This is certainly a great discovery in physic. 324 00:31:07,644 --> 00:31:12,316 Hooke was intensively inquisitive about how everything worked. 325 00:31:12,368 --> 00:31:19,373 Anatomy, engineering, philosophy, everything was greased to Robert Hooke's meal. 326 00:31:20,196 --> 00:31:24,885 Hooke's greatest passion was light, 327 00:31:24,916 --> 00:31:29,255 and he had exactly the right tools and skills to make the most 328 00:31:29,256 --> 00:31:33,800 of this passion because Hooke was also a master of glass working. 329 00:31:33,936 --> 00:31:38,428 He had really skilled allies in the London glass trade. 330 00:31:38,476 --> 00:31:42,909 And these men were capable of making the very finest lenses. 331 00:31:42,965 --> 00:31:47,926 But Hooke's genius was to turn the same technique which had 332 00:31:47,927 --> 00:31:53,052 worked in telescopic astronomy towards designing microscopes. 333 00:31:53,144 --> 00:31:57,563 Because the same principle of magnification would work, not 334 00:31:57,564 --> 00:32:01,909 just on the very large and distant, but on the very small. 335 00:32:02,357 --> 00:32:10,077 What Hooke saw through the lenses of his microscope was an absolute revelation. 336 00:32:16,212 --> 00:32:22,645 For the first time, he was unlocking the machinery of creation. 337 00:32:24,404 --> 00:32:28,822 Here was a world of beauty and of terror, insects 338 00:32:28,823 --> 00:32:33,771 that looked like aliens, hideous monsters in miniature, 339 00:32:33,772 --> 00:32:36,476 nothing was as it seemed. 340 00:32:39,972 --> 00:32:44,467 Hooke recorded every minute detail with exquisite drawings. 341 00:32:49,819 --> 00:32:56,453 And in 1665, he published the extraordinary book: Micrographia. 342 00:32:58,173 --> 00:33:04,886 When Samuel Pepys got his copy, he stayed up until 2 in the morning, engrossed by it, 343 00:33:04,921 --> 00:33:09,982 and called it the most ingenious book that ever I read in my life. 344 00:33:13,669 --> 00:33:20,007 Hooke's microscopic world was wonderful, but it was also extremely threatening, 345 00:33:20,190 --> 00:33:27,382 because what it meant was that the Earth had opened at the feet of Hooke's readers. 346 00:33:27,422 --> 00:33:32,063 They saw beneath them in an unimaginable, and otherwise 347 00:33:32,064 --> 00:33:37,118 invisible world. Something minute but of immense complexity. 348 00:33:37,234 --> 00:33:42,182 Agents, beings, and structures they had never dreamt of before were there. 349 00:33:42,499 --> 00:33:48,790 All around them, inside their bodies, in their hair, under their skin. 350 00:33:48,870 --> 00:33:52,710 A world of life and structure which they didn't 351 00:33:52,711 --> 00:33:56,230 understand, whose purposes was not obvious. 352 00:33:58,930 --> 00:34:03,413 After these great successes, Robert Hooke eventually died of the 353 00:34:03,414 --> 00:34:07,759 damage caused to his body by his obsessive self experimenting. 354 00:34:07,949 --> 00:34:10,387 And his legacy was also disturbing. 355 00:34:10,474 --> 00:34:13,712 People were troubled by the micro world Hooke 356 00:34:13,713 --> 00:34:17,655 unveiled cause they no longer seemed unique or special. 357 00:34:17,786 --> 00:34:21,301 They began to question whether they have been 358 00:34:21,302 --> 00:34:25,199 chosen by God, and whether there was a God at all. 359 00:34:25,994 --> 00:34:29,105 Robert Hooke's work with microscope completely 360 00:34:29,106 --> 00:34:31,951 changed the boundaries of natural history. 361 00:34:32,071 --> 00:34:37,559 In fact, in the 18th century, naturalists became rather a craze throughout Europe. 362 00:34:37,619 --> 00:34:42,003 People began collecting specimens of animals, vegetables, and plants, 363 00:34:42,004 --> 00:34:46,638 to try work out what species they were, and how they could be classified. 364 00:34:48,887 --> 00:34:53,387 In the 1700s, classification was one of the hottest words 365 00:34:53,388 --> 00:34:57,887 of the day, and the hottest place to discuss it was Bath. 366 00:35:18,976 --> 00:35:22,927 Bath was the Las Vegas of the 18th century, 367 00:35:22,964 --> 00:35:27,048 it was rich, it was boomtown. It was slightly seedy. 368 00:35:27,128 --> 00:35:31,012 Not only did the eel come here, but the intellectuals as 369 00:35:31,013 --> 00:35:35,032 well. They gossiped in the coffeehouse and around the spa. 370 00:35:35,044 --> 00:35:39,968 They shared ideas about life, the universe, and everything. 371 00:35:43,042 --> 00:35:46,798 Among the clever gents was William Herschel. A 372 00:35:46,799 --> 00:35:51,033 musician from Germany who came to Bath to play here. 373 00:35:52,429 --> 00:35:55,810 Herschel would transform the understanding of 374 00:35:55,811 --> 00:35:59,338 light more dramatically than anyone before him. 375 00:35:59,545 --> 00:36:03,761 As he mixed with Bath's philosophers in salon, he 376 00:36:03,762 --> 00:36:07,977 rapidly got drawn into the classification debate. 377 00:36:15,005 --> 00:36:20,801 Herschel made his name in Bath intellectual society by studying this: coral. 378 00:36:20,904 --> 00:36:24,865 The big problem was: is this animal, or vegetable? 379 00:36:25,149 --> 00:36:30,760 Herschel got hold of a microscope and began to study coral very closely. 380 00:36:37,673 --> 00:36:42,321 Herschel applied light and lenses to the problem. 381 00:36:43,646 --> 00:36:50,481 And what he saw were thin cell walls, this could mean only one thing: 382 00:36:53,117 --> 00:36:59,705 Coral, which previously been thought to be a plant, was in fact, an animal. 383 00:37:08,474 --> 00:37:12,322 Herschel made a huge leap of imagination, 384 00:37:12,381 --> 00:37:17,431 if this approach with light and lenses work for things 385 00:37:17,432 --> 00:37:22,114 on Earth, maybe it will also work for the heavens. 386 00:37:25,761 --> 00:37:31,265 Herschel will treat the stars the way living species are treated. 387 00:37:31,309 --> 00:37:34,425 He decided to classify them. 388 00:37:36,238 --> 00:37:39,708 What you needed to do that, Herschel reckoned, 389 00:37:39,709 --> 00:37:43,251 was huge telescopes which by penetrating deeply 390 00:37:43,252 --> 00:37:46,795 into space would be able to classify what kinds 391 00:37:46,796 --> 00:37:50,634 of things stars, nebulae, and galaxies really were. 392 00:37:50,671 --> 00:37:54,401 He would become the first natural historian of the heavens. 393 00:37:55,874 --> 00:38:00,682 But there was a problem with building huge telescopes. 394 00:38:00,690 --> 00:38:05,754 Since Galileo's spy glasses, people have built longer and longer telescopes, 395 00:38:05,846 --> 00:38:09,721 which proved almost impossible to manage, and possess 396 00:38:09,722 --> 00:38:14,098 lenses which could never bring the image into perfect focus. 397 00:38:17,643 --> 00:38:20,618 Herschel had a different idea. 398 00:38:20,662 --> 00:38:23,917 He realized he could apply one of Newton's 399 00:38:23,918 --> 00:38:27,627 cleverest ideas and replace lenses with mirrors. 400 00:38:27,711 --> 00:38:32,491 A curved mirror magnifies rather the way a lens does, 401 00:38:32,510 --> 00:38:39,810 but most importantly, mirrors grasp much more star light than any comparable lens. 402 00:38:40,979 --> 00:38:45,746 Trouble was: no one had ever made mirrors this big before, 403 00:38:45,866 --> 00:38:50,694 they would have to be curved with exquisite precision to focus the light. 404 00:38:55,071 --> 00:38:58,315 So Herschel took matters into his own hands, 405 00:38:58,442 --> 00:39:01,752 he turned his kitchen into a factory to make mirrors, 406 00:39:01,783 --> 00:39:07,015 and would spend up to 16 hours a day painstakingly polishing them 407 00:39:07,016 --> 00:39:12,010 to get them to just the right curved shape to focus the light. 408 00:39:17,956 --> 00:39:24,252 He was obsessive about this and became the world's best maker of mirrors. 409 00:39:30,304 --> 00:39:37,168 Once he perfected his mirrors, he put them to use inside his telescopes. 410 00:39:40,604 --> 00:39:46,392 Herschel dreamt up a cunning scheme to allow you to see the mirrors' image. 411 00:39:46,410 --> 00:39:50,042 Light entering the telescope will reflect off a big 412 00:39:50,043 --> 00:39:53,744 curved mirror onto a smaller mirror set at an angle. 413 00:39:54,964 --> 00:39:58,427 Looking into the second mirror allows you to see 414 00:39:58,428 --> 00:40:02,102 the brightly illuminated image without blocking it. 415 00:40:08,394 --> 00:40:13,435 With this new telescope, Herschel soon made an amazing discovery. 416 00:40:13,575 --> 00:40:19,987 On the 13th of March 1781, he saw, what he thought at first was a new comet, but very 417 00:40:19,988 --> 00:40:23,193 soon, it emerged that it was a new planet, 418 00:40:23,194 --> 00:40:26,771 that first ever discovered in recorded history. 419 00:40:27,819 --> 00:40:31,884 As an attempt to get patronage out of king George III, Herschel 420 00:40:31,885 --> 00:40:35,631 and his friends decided to name this object George's star, 421 00:40:35,679 --> 00:40:40,476 but no one else decided to call it that, so it is known to us as Uranus. 422 00:40:40,540 --> 00:40:44,187 It was an extraordinary triumph for Herschel's astronomy. 423 00:40:48,162 --> 00:40:54,771 Simply by finding this planet, Herschel had doubled the size of the known universe. 424 00:41:01,796 --> 00:41:07,879 King George rewarded Herschel with a life pension and a house in Slough, 425 00:41:07,880 --> 00:41:13,628 making him by far the most successful amateur astronomer in history. 426 00:41:17,724 --> 00:41:23,207 But Herschel's next discoveries would be even greater, even grander, 427 00:41:23,208 --> 00:41:28,452 and they'd hinge upon a fundamental property of light, its speed. 428 00:41:32,343 --> 00:41:36,151 The question of whether light takes any time at all to travel 429 00:41:36,152 --> 00:41:39,652 was an ancient one. It had been discussed by the Greeks. 430 00:41:39,744 --> 00:41:43,418 But it is a major puzzle. It doesn't seem at all 431 00:41:43,419 --> 00:41:47,092 obvious that light does take any time to travel. 432 00:41:47,133 --> 00:41:49,835 When I look at some really distant object 433 00:41:49,836 --> 00:41:52,795 like that tree. To look it is to see it, it's 434 00:41:52,796 --> 00:41:58,263 as though light is instantly switched from there to here, from the object to my eye. 435 00:41:58,312 --> 00:42:03,501 So that was a fascinating, a really urgent puzzle. 436 00:42:03,556 --> 00:42:09,988 Was there a way of working out whether light does take any time to travel? 437 00:42:10,076 --> 00:42:14,412 You couldn't hold it in your hand and measure its speed. 438 00:42:23,385 --> 00:42:26,234 The answer lay in the motions of the solar 439 00:42:26,235 --> 00:42:29,282 system, and in particular, the motions of the 440 00:42:29,283 --> 00:42:32,132 moons round Jupiter. Just those moons that 441 00:42:32,133 --> 00:42:35,245 Galileo had first observed with his telescope. 442 00:42:35,325 --> 00:42:38,897 Now in 1676, a brilliant young Danish astronomer, 443 00:42:38,898 --> 00:42:41,826 here on Earth, Ole Roemer, was observing 444 00:42:41,827 --> 00:42:45,399 the moons of Jupiter because he wanted to measure 445 00:42:45,400 --> 00:42:48,685 the times they took to go round their planet. 446 00:42:48,764 --> 00:42:51,933 And he spotted something very surprising. 447 00:42:52,017 --> 00:42:58,821 The time he was measuring depended on the distance between the Earth and Jupiter. 448 00:42:58,860 --> 00:43:03,449 When the Earth, as it orbits, was nearer Jupiter, he seemed 449 00:43:03,450 --> 00:43:07,885 to be seeing the moon going round Jupiter rather quickly. 450 00:43:07,905 --> 00:43:11,296 And when it was further away, he seems to see 451 00:43:11,297 --> 00:43:14,909 the moon going round Jupiter rather more slowly. 452 00:43:14,937 --> 00:43:17,509 And Roemer could explain the difference, 453 00:43:17,669 --> 00:43:22,891 it is due to the time it takes for light to travel from Jupiter to the 454 00:43:22,892 --> 00:43:27,965 Earth. Light does take time to travel and you can measure its speed. 455 00:43:30,489 --> 00:43:34,437 Roemer calculated a figure and got astonishingly 456 00:43:34,438 --> 00:43:38,950 close to the real speed of 300,000 kilometers a second. 457 00:43:40,821 --> 00:43:45,280 The realization that light actually does take time to travel and the 458 00:43:45,281 --> 00:43:50,126 exact measurement of the speed of light were the most amazing discoveries. 459 00:43:50,200 --> 00:43:55,222 It was a building block for an entirely new kind of physics. 460 00:43:56,112 --> 00:44:01,928 William Herschel was cunning enough and intelligent enough to realize 461 00:44:01,929 --> 00:44:07,245 just what the finite speed of light meant for him and his work. 462 00:44:07,398 --> 00:44:10,465 when you look at the Sun, you are not seeing the 463 00:44:10,466 --> 00:44:13,782 Sun as it is now, but as it was about 8 minutes ago. 464 00:44:13,877 --> 00:44:17,886 Because it takes light about 8 minutes to reach us from the Sun. 465 00:44:17,930 --> 00:44:23,721 but Herschel's telescopes allowed him to see much further away than that. 466 00:44:24,345 --> 00:44:30,386 To galaxies unimaginably distant, and when Herschel did the calculations, 467 00:44:30,498 --> 00:44:35,037 he realized that light must have taken millions of years 468 00:44:35,038 --> 00:44:39,258 to reach his reflectors from those distant galaxies. 469 00:44:39,339 --> 00:44:43,662 So Herschel's telescopes were like time machines. 470 00:44:43,722 --> 00:44:47,403 They were devices that allowed him to travel 471 00:44:47,404 --> 00:44:51,821 backwards in time to the immense vastnesses of space. 472 00:45:08,327 --> 00:45:13,227 The implications of Herschel's discoveries were genuinely shattering. 473 00:45:13,320 --> 00:45:17,495 and they were going to turn him into a world famous celebrity. 474 00:45:20,676 --> 00:45:24,719 Actors took to the stage in London's west end to tell 475 00:45:24,720 --> 00:45:28,912 an enthralled public about William Herschel's findings. 476 00:45:38,203 --> 00:45:46,143 The honorable William Herschel has looked further into the heaven than any man before, 477 00:45:46,169 --> 00:45:48,440 and what he has found 478 00:45:48,703 --> 00:45:52,452 is most remarkable. 479 00:45:52,980 --> 00:45:56,902 It might seem extraordinary to us that William Herschel's 480 00:45:56,903 --> 00:46:01,568 astronomy became a theatrical event, but that is just what happened. 481 00:46:01,591 --> 00:46:06,238 People flood to west the end in droves to theaters like this to 482 00:46:06,239 --> 00:46:11,031 be shown what it was that Herschel was saying about the universe. 483 00:46:11,131 --> 00:46:13,841 And it made him an immediate star, a 484 00:46:13,842 --> 00:46:17,755 personality, the most famous astronomer in Europe. 485 00:46:18,619 --> 00:46:25,240 Having seen so many stars through his excellent telescopes, 486 00:46:25,383 --> 00:46:30,967 Mr. Herschel has charted the entire Milky 487 00:46:30,968 --> 00:46:37,083 Way, enlarging the universe, many times over. 488 00:46:37,155 --> 00:46:41,907 Now traditionally, the world had been understood as limited to the solar system. 489 00:46:41,940 --> 00:46:45,873 But for Herschel, the solar system was just 490 00:46:45,874 --> 00:46:49,984 one of many systems inside of vast Milky Way. 491 00:46:50,079 --> 00:46:53,664 The size of the universe had been expanded enormously. 492 00:46:55,207 --> 00:47:01,152 Herschel realized what is he looked through a vastly sized universe, 493 00:47:01,396 --> 00:47:06,047 he was also looking through a vastly old universe. 494 00:47:06,504 --> 00:47:12,902 Mr. Herschel has observed stars whose light, it can be 495 00:47:12,903 --> 00:47:19,184 proved, must take 2 million years to reach the Earth. 496 00:47:19,484 --> 00:47:24,033 And these 2 discoveries, the great size and age of 497 00:47:24,034 --> 00:47:28,849 the universe let Herschel to his biggest idea of all. 498 00:47:28,987 --> 00:47:43,167 He believes, that just as befits a dog, or a tree, a star must be born, grow and die. 499 00:47:46,124 --> 00:47:51,296 Not only did Herschel believed that the universe was enormous and bounded, 500 00:47:51,384 --> 00:47:56,640 But he also believed what is even more dramatic. There was in many ways, a life. 501 00:47:56,732 --> 00:48:00,251 As you looked through his telescope, out into 502 00:48:00,252 --> 00:48:04,153 the space, you were like a botanist, a naturalist, 503 00:48:04,169 --> 00:48:08,001 looking backwards over the whole life cycle 504 00:48:08,002 --> 00:48:12,181 of an immensely old, an unimaginably old plant. 505 00:48:15,016 --> 00:48:19,512 So as he looked through his telescopes, back in time, 506 00:48:19,669 --> 00:48:25,376 he could see the universe and its contents in various stages of development. 507 00:48:27,113 --> 00:48:30,853 The occupants of the universe, the stars, the nebulae, and 508 00:48:30,854 --> 00:48:34,593 the planets themselves have life cycles just like animals. 509 00:48:34,608 --> 00:48:37,136 They would come into being and pass away. 510 00:48:37,205 --> 00:48:43,162 And the key, he thought, to these life cycles of the stars was light itself. 511 00:48:43,289 --> 00:48:50,609 He has determined stars in the furtherment, grow from light. 512 00:48:56,042 --> 00:49:00,348 It seems to me that in many ways, Herschel's ideas must have 513 00:49:00,349 --> 00:49:04,584 struck a lot of his contemporaries as absolutely appalling. 514 00:49:04,609 --> 00:49:08,738 Not just revolutionary, because what this meant was, that the 515 00:49:08,739 --> 00:49:12,734 Earth become a completely trivial occupant of the universe. 516 00:49:12,953 --> 00:49:16,257 It wasn't of course, the center of the solar system, 517 00:49:16,378 --> 00:49:23,006 but the solar system was just a minor star in the western spiral arm of the Milky Way. 518 00:49:23,206 --> 00:49:27,913 And within the milky way, within the universe, there were 519 00:49:27,914 --> 00:49:33,106 unaccountably many nebulae, each of them vast numbers of stars. 520 00:49:33,189 --> 00:49:37,946 This was a sublime idea, but dangerous, and threatening, 521 00:49:38,045 --> 00:49:41,410 because it undermine the uniqueness of humanity. 522 00:49:41,426 --> 00:49:45,786 It made the universe, perhaps, a larger and older, but 523 00:49:45,787 --> 00:49:50,226 also in a way more threatening place for human to live. 524 00:50:02,386 --> 00:50:06,099 William Herschel had shown that the universe is very 525 00:50:06,100 --> 00:50:09,602 big, and very old, and it is constantly evolving. 526 00:50:09,661 --> 00:50:13,753 Now that was shocking enough to many people, but worse was to come. 527 00:50:13,826 --> 00:50:18,879 What Herschel had said was that clouds of light evolving 528 00:50:18,880 --> 00:50:23,754 to stars, and then suns, and then our Sun, our planet. 529 00:50:25,046 --> 00:50:32,326 This idea of constant gradual change had an enormous and unanticipated impact. 530 00:50:32,346 --> 00:50:37,422 It directly inspired a young naturalist called Charles Darwin to 531 00:50:37,423 --> 00:50:42,654 come up with the most dangerous scientific idea of all: evolution. 532 00:50:48,812 --> 00:50:53,815 In the early decades of the 19th century, evolution became thinkable. 533 00:50:53,818 --> 00:50:57,613 It became possible to imagine that there was a 534 00:50:57,614 --> 00:51:02,055 natural law like story telling how the great diversity 535 00:51:02,056 --> 00:51:05,447 of life had emerged on our planet without 536 00:51:05,448 --> 00:51:09,726 creation, without miracles, effectively without God. 537 00:51:11,208 --> 00:51:16,738 And in 1859, Charles Darwin printed this book: 538 00:51:16,854 --> 00:51:19,999 On the origins of species by natural selection. 539 00:51:20,011 --> 00:51:24,373 The boldest attempt yet to replace creationism 540 00:51:24,374 --> 00:51:28,271 with something more natural and law like. 541 00:51:28,391 --> 00:51:31,335 Now there were those who were seduced by 542 00:51:31,336 --> 00:51:34,795 those idea, but most found this book obscene, 543 00:51:35,007 --> 00:51:41,862 as though the wonders of creation, and above all, humanity itself were a kind of random 544 00:51:41,863 --> 00:51:45,212 throw of the dice that they emerged by the 545 00:51:45,213 --> 00:51:48,795 law of higoudi pigoudi. This was intolerable. 546 00:51:52,544 --> 00:51:55,659 The war over evolution began. 547 00:51:55,824 --> 00:52:00,017 Victorian physicists and engineers got theory men all 548 00:52:00,018 --> 00:52:04,443 of them couldn't stand Darwin's anti-creationist theory. 549 00:52:04,456 --> 00:52:07,011 And they had a good way of proving him wrong. 550 00:52:08,319 --> 00:52:12,432 Light, sunlight, was at the heart of the battle. 551 00:52:14,548 --> 00:52:17,978 Darwin's theory of evolution needed hundreds 552 00:52:17,979 --> 00:52:21,484 of millions of years in order for it to work, 553 00:52:21,647 --> 00:52:25,566 and the greatest British physicists Lord Calvin 554 00:52:25,567 --> 00:52:29,485 simply wasn't prepared to give him enough time. 555 00:52:29,516 --> 00:52:35,174 Calvin believed that physics proved creation, and his reasoning 556 00:52:35,175 --> 00:52:41,273 was based on the Sun, that extraordinary source of energy and light. 557 00:52:41,440 --> 00:52:44,662 Scientists had realized that of all the things 558 00:52:44,663 --> 00:52:47,952 necessary for life, light was the most crucial. 559 00:52:48,016 --> 00:52:51,841 Sunlight powers all life by fueling the growth of 560 00:52:51,842 --> 00:52:56,355 plants, it creates foods for all other animals to feed of. 561 00:52:59,577 --> 00:53:02,841 But imagine, as Lord Calvin did, 562 00:53:02,848 --> 00:53:08,633 that the Sun was made of the very best fuel you could get at the time, something 563 00:53:08,634 --> 00:53:14,704 like good old British coal condensing under gravity, how long could such a Sun burn? 564 00:53:17,632 --> 00:53:22,576 Now if you do the sums that Calvin did, you quickly find out that 565 00:53:22,577 --> 00:53:27,820 the Sun could only of be burning for a few tens of millions of years, 566 00:53:27,980 --> 00:53:33,399 There just wasn't enough time. This great big British physicist was saying 567 00:53:33,400 --> 00:53:38,529 for the processes of evolution to work the way Darwin said they would. 568 00:53:38,536 --> 00:53:42,423 That was just fine for Calvin. He was a creationist, he 569 00:53:42,424 --> 00:53:46,658 thought the world was rational, orderly and designed by God. 570 00:53:46,701 --> 00:53:50,364 His physics and his religion fitted together nicely. 571 00:53:51,837 --> 00:53:55,840 Sunlight had given round one to the creationists, 572 00:53:55,841 --> 00:54:00,244 and Darwin died with no comeback to Calvin's argument. 573 00:54:00,332 --> 00:54:04,118 It seemed that evolution, this incredibly elegant 574 00:54:04,119 --> 00:54:07,677 and revolutionary idea might remain just that, 575 00:54:07,764 --> 00:54:09,197 an idea. 576 00:54:10,901 --> 00:54:16,660 A man in 1904, a brilliant young New Zealand physicist turned up in London to give a 577 00:54:16,661 --> 00:54:19,506 big lecture at the royal institution on a 578 00:54:19,507 --> 00:54:22,758 major new discovery he had made: Radioactivity. 579 00:54:22,785 --> 00:54:26,470 Calvin was there. He was dozing a bit in the audience, 580 00:54:26,471 --> 00:54:29,753 but he woke up when Rutherford started to speak. 581 00:54:29,886 --> 00:54:34,931 Because what Rutherford was saying was that here in radioactivity was a new 582 00:54:34,932 --> 00:54:40,374 kind of energy which could keep the Sun going for thousands of millions of years. 583 00:54:40,425 --> 00:54:44,390 More than enough time for the processes that Darwin needed. 584 00:54:47,246 --> 00:54:51,734 Physics paid off for the evolutionists. By the middle 585 00:54:51,735 --> 00:54:56,554 of 20th century, nuclear physics could explain how stars, 586 00:54:56,614 --> 00:54:59,867 in their cores were fusing, generating enormous 587 00:54:59,868 --> 00:55:03,187 amounts of energy which reaches us as starlight. 588 00:55:03,257 --> 00:55:09,430 The answer to evolution's time scale was the nuclear physics of starlight. 589 00:55:12,606 --> 00:55:16,322 Light had won the case for evolution. 590 00:55:16,462 --> 00:55:21,781 Evolution shifted from being merely a possible story about the 591 00:55:21,782 --> 00:55:27,438 emergence and history of life to becoming probable, authoritative. 592 00:55:27,523 --> 00:55:31,479 Light provided the evidence for a history of 593 00:55:31,480 --> 00:55:35,698 the world that required no God and no miracles. 594 00:55:36,442 --> 00:55:41,669 For the first time, there was a powerful and effective 595 00:55:41,670 --> 00:55:46,895 alternative account of how the world and life emerged. 596 00:55:56,935 --> 00:56:00,860 Now, light can take us back in time through 597 00:56:00,861 --> 00:56:05,231 billions of years to the origin of the universe. 598 00:56:10,266 --> 00:56:15,647 The Hubble space telescope is the most powerful telescope we have. 599 00:56:15,698 --> 00:56:19,440 Inside it is a giant mirror, 2.4 meters wide, 600 00:56:19,441 --> 00:56:23,263 of which Herschel himself would have be proud. 601 00:56:24,084 --> 00:56:28,215 Scientists have just used it to reveal something 602 00:56:28,216 --> 00:56:32,599 truly astonishing: the oldest starlight in the sky. 603 00:56:36,258 --> 00:56:40,743 These latest photographs from Hubble showed 604 00:56:40,744 --> 00:56:45,431 galaxies and stars over 13 billion years old. 605 00:56:45,503 --> 00:56:49,567 Stars born just after the big bang. 606 00:56:52,971 --> 00:57:00,803 Finally we can look back in time and see the origin of the universe. 607 00:57:03,208 --> 00:57:07,466 Scientists have used light as a tool to reveal 608 00:57:07,467 --> 00:57:12,177 the scientific story of the beginning of our world. 609 00:57:21,807 --> 00:57:26,547 We used to think that the universe was incomprehensible, 610 00:57:26,548 --> 00:57:29,956 miraculous, the result of an act of God. 611 00:57:30,168 --> 00:57:33,121 But by the manipulation of light with 612 00:57:33,122 --> 00:57:36,951 instruments, the monuments of human ingenuity, 613 00:57:37,028 --> 00:57:40,483 we have completely changed our model of the world. 614 00:57:40,576 --> 00:57:47,680 Galileo's telescopes, Robert Hooke's microscopes, William Herschel's vast mirrors 615 00:57:47,736 --> 00:57:52,236 made the universe a place which could be explained, 616 00:57:52,367 --> 00:57:58,345 a place which could be understood, using the light of reason. 617 00:58:03,836 --> 00:58:10,256 Next, on light fantastic, the journey from the light bulb to the nuclear bomb. 618 00:58:10,300 --> 00:58:16,440 How the quest to understand what light really is has given us the modern world.