WEBVTT - The Inventor who Almost Ended the World (Classic) 0:00:15.410 --> 0:00:15.890 Pushkin. 0:00:24.930 --> 0:00:29.210 Thomas Midgley Junior was born on College Hill in Beaver Falls, Pennsylvania, 0:00:29.370 --> 0:00:33.730 May eighteenth, eighteen eighty nine. His father, Thomas Midgley Senior, 0:00:33.930 --> 0:00:37.010 was a prolific inventor in a variety of fields, but 0:00:37.210 --> 0:00:40.530 notably that of automobile times and his mother. 0:00:41.490 --> 0:00:45.890 A eulogy for an inventor, a hero of industrial science 0:00:46.170 --> 0:00:50.770 who changed the world, and who died tragically young, aged 0:00:51.090 --> 0:00:56.450 just fifty five. Thomas Midgley Junior studied mechanical engineering, but 0:00:56.530 --> 0:00:59.890 he was just as fascinated by chemistry. As a young 0:00:59.930 --> 0:01:04.170 researcher employed by General Motors, Midgley took to carrying a 0:01:04.210 --> 0:01:07.370 copy of the Periodic Table around in his pocket to 0:01:07.450 --> 0:01:11.210 inform his quest for new ideas. By the end of 0:01:11.250 --> 0:01:16.490 his life, Midgley had accumulated over one hundred patents. We're 0:01:16.530 --> 0:01:19.690 going to hear about three of his inventions. 0:01:20.730 --> 0:01:24.130 In nineteen sixteen, Midgley became a member of our research 0:01:24.130 --> 0:01:27.410 staff and began then his long association with me and 0:01:27.490 --> 0:01:30.290 his remarkably productive career in research. 0:01:30.690 --> 0:01:35.570 The eulogist is Charles Boss Kettering, himself an inventor of 0:01:35.650 --> 0:01:39.850 some renown. Kettering was Thomas Midgley's boss in the General 0:01:39.890 --> 0:01:45.050 Motors Research department. He went on to become a lifelong friend, mentor, 0:01:45.370 --> 0:01:49.850 and business associate as the two men built lucrative careers 0:01:49.890 --> 0:01:52.610 with General Motors and the DuPont Corporation. 0:01:53.330 --> 0:01:54.610 What do you want me to do next? 0:01:54.650 --> 0:01:55.010 Boss? 0:01:55.850 --> 0:01:58.730 That simple question and the answer to it turned out 0:01:58.730 --> 0:02:01.050 to be the beginning of a great adventure in the 0:02:01.130 --> 0:02:02.970 life of a most versatile man. 0:02:03.370 --> 0:02:08.090 Versatile Indeed, the brain children of Thomas Midgley touched many 0:02:08.250 --> 0:02:12.970 areas of life. Life. This pudgy, bespectacled inventor seemed to 0:02:13.170 --> 0:02:18.610 personify the mid twentieth century ideal of progress, as summed 0:02:18.690 --> 0:02:23.130 up by DuPont in their famous nineteen thirties advertising slogan 0:02:23.530 --> 0:02:28.650 better things for better living, living through chemistry Hemistry. In 0:02:28.690 --> 0:02:34.010 his eulogy, Boss Kettering runs through Midgley's long list of accomplishments. 0:02:34.770 --> 0:02:39.410 President of the American Chemical Society, winner of the Nichols Medal, 0:02:39.770 --> 0:02:44.050 the Perkin Medal, the Priestly Medal, the Willard Gibbs Medal, 0:02:44.530 --> 0:02:48.770 the Longstreth Medal, honorary doctorates from the College of Wooster 0:02:49.570 --> 0:02:54.690 and the Ohio State University. Kettering quotes the citation from 0:02:54.690 --> 0:02:55.610 Ohio State. 0:02:56.250 --> 0:03:00.090 Midgley contributed so greatly to more pleasant and efficient living. 0:03:00.690 --> 0:03:03.690 He has made science a liberator, and we rejoice with 0:03:03.770 --> 0:03:06.770 him at the satisfactions that must be his In seeing 0:03:06.810 --> 0:03:13.210 the fruits of his labor, Asterity will acknowledge their permanent value. 0:03:13.770 --> 0:03:18.450 Posterity alas, was not as kind to Midgley as his 0:03:18.610 --> 0:03:23.810 many admirers had expected, but they were absolutely right to 0:03:23.930 --> 0:03:28.530 say that he would change the world. He did, he 0:03:28.610 --> 0:03:36.050 made it much much worse. I'm Tim Harford and you're 0:03:36.090 --> 0:04:08.050 listening to cautionary tales? 0:04:16.370 --> 0:04:17.970 What do you want me to do? An next bus? 0:04:18.650 --> 0:04:22.810 One day, when Thomas Midgley asked that question of Charles Kettering, 0:04:23.130 --> 0:04:25.810 the boss had a problem he wanted Midgley to solve. 0:04:26.250 --> 0:04:30.050 The problem had to do with refrigeration. At the time, 0:04:30.490 --> 0:04:33.810 people didn't have fridges at home. It was too dangerous. 0:04:34.490 --> 0:04:37.530 The chemicals you needed for the cooling coils were either 0:04:37.610 --> 0:04:42.730 toxic or flammable, so refrigeration was mainly used in industrial 0:04:42.770 --> 0:04:49.330 settings by trained personnel. Even then, accidents were common. Kettering 0:04:49.490 --> 0:04:54.530 wanted Midgley to invent away to cool things safely. Midgley 0:04:54.610 --> 0:04:58.930 took the periodic table out of his pocket. He soon 0:04:59.170 --> 0:05:03.170 zeroed in on fluorine as a promising element for creating 0:05:03.210 --> 0:05:07.290 a compound that might have the right properties. As Kettering's 0:05:07.330 --> 0:05:08.970 eulogy recalls. 0:05:09.370 --> 0:05:14.410 He and his helpers prepared such a compound, dichloridy fluoromethane. 0:05:14.850 --> 0:05:17.690 It proved to have just the properties required. It is 0:05:17.770 --> 0:05:22.130 highly stable, non inflammable, and altogether without harmful effects on 0:05:22.250 --> 0:05:23.370 man or animals. 0:05:25.010 --> 0:05:29.850 Dichloro difluoromethane it did seem to be all together without 0:05:29.970 --> 0:05:34.570 harmful effects. Midgeley tested this by replacing all the nitrogen 0:05:34.650 --> 0:05:40.930 in air with dichlorodifluoromethane and seeing what happened to animals 0:05:40.930 --> 0:05:45.010 who breathed it in. Happily, for the animals, they were 0:05:45.010 --> 0:05:49.970 completely fine. Midgeley wasn't just an inventor, He was a showman. 0:05:50.450 --> 0:05:54.170 He presented his new product in a dramatic lecture to 0:05:54.210 --> 0:05:59.450 the American Chemical Society. Midgeley lights a candle. He produces 0:05:59.490 --> 0:06:05.050 a container of di chlorodfluoromethane. He sucks it in a long, 0:06:05.530 --> 0:06:13.290 deep gulp, filling his lungs. Then slowly and gently he 0:06:13.450 --> 0:06:19.490 breathes out over the candle. The flame goes out. It's 0:06:19.650 --> 0:06:26.010 a bravura performance. Dichlorodifluoromethane belongs to a class of chemicals 0:06:26.050 --> 0:06:33.210 called CFCs, or chlorofluora carbons. Under Midgley's guidance, General Motors 0:06:33.210 --> 0:06:36.450 and the DuPont Corporation start to produce a whole range 0:06:36.490 --> 0:06:40.170 of CFCs. They give them the trade name free On. 0:06:40.930 --> 0:06:45.050 Thanks to these new non hazardous coolants, people soon had 0:06:45.090 --> 0:06:48.690 refrigerators in their own homes. That was a game changer. 0:06:49.450 --> 0:06:53.330 Food stayed fresh. The housewives of America could spend less 0:06:53.370 --> 0:06:58.530 time endlessly shopping for groceries. Food poisoning was easier to avoid, 0:06:59.010 --> 0:07:03.370 and it wasn't just fridges. Air conditioners too. Even better, 0:07:03.690 --> 0:07:07.570 it soon turned out that CFCs had uses beyond cooling. 0:07:08.090 --> 0:07:13.330 They were ideal for making aerosol sprays, insect repellance, air freshness, 0:07:13.450 --> 0:07:18.770 hair spray deodorance. It was just like DuPont said, better 0:07:18.850 --> 0:07:25.690 things for better living through chemistry. In the summer of 0:07:25.810 --> 0:07:31.290 nineteen seventy three, nearly three decades after Thomas Midgley's untimely death, 0:07:31.690 --> 0:07:36.410 a chemistry professor named Sherwood Roland welcomes a new postdoctoral 0:07:36.450 --> 0:07:41.290 researcher to his team at the University of California, Irvine. 0:07:41.410 --> 0:07:45.170 Mario Molina is from Mexico. He's thirty years old, and 0:07:45.330 --> 0:07:48.570 he needs Professor Roland to give him a project to 0:07:48.650 --> 0:07:52.890 work on. Roland recalls something he heard over coffee at 0:07:52.930 --> 0:07:57.250 a conference the previous year about a precise new way 0:07:57.370 --> 0:08:03.290 of measuring trace gases in the atmosphere, gases like dichlorodifluoromethane. 0:08:03.850 --> 0:08:06.410 It turns out that CFCs are present in the air 0:08:06.530 --> 0:08:10.410 around US at two hundred and thirty parts per trillion. 0:08:10.810 --> 0:08:14.370 That's like detecting a drop of gin in a swimming 0:08:14.370 --> 0:08:18.570 pool of tonic. Roland is intrigued to hear that, not 0:08:18.690 --> 0:08:21.890 because the amount sounds so small to him, but because 0:08:22.090 --> 0:08:25.290 it sounds so big. He knows that it's only a 0:08:25.330 --> 0:08:29.570 few decades since CFCs started to be manufactured on an 0:08:29.610 --> 0:08:33.970 industrial scale, not much more than that dropful can ever 0:08:34.050 --> 0:08:38.730 have been produced. Roland is a radio chemist. He studies 0:08:38.810 --> 0:08:43.210 how particles react and decay. Most chemicals break down in 0:08:43.250 --> 0:08:47.850 the environment sooner or later that CFCs just seemed to 0:08:47.850 --> 0:08:52.570 be hanging around, So he makes a suggestion to Mario Molina, 0:08:53.370 --> 0:08:57.850 why don't you look into CFCs. Molina recalls, we thought 0:08:57.890 --> 0:09:02.010 it would be a nice, interesting academic exercise. We both 0:09:02.050 --> 0:09:05.130 knew that these CFCs were rather stable, so there was 0:09:05.170 --> 0:09:08.330 nothing obvious that would damage them soon after they'd be released. 0:09:09.170 --> 0:09:11.130 That's about as much as I knew at the time. 0:09:11.650 --> 0:09:15.370 If CFCs aren't interacting much with anything in the atmosphere 0:09:15.370 --> 0:09:20.050 close to Earth, Molina reasoned, they'll eventually drift upwards to 0:09:20.090 --> 0:09:24.530 the stratosphere, where the air is thinner. It would take decades, 0:09:24.810 --> 0:09:28.770 but they'd get there. When they did, they'd encounter more 0:09:29.010 --> 0:09:33.690 ultraviolet BE waves from the Sun, and maybe that would 0:09:33.690 --> 0:09:37.330 cause the CFCs to break down. Because UVB waves are 0:09:37.370 --> 0:09:41.330 pretty destructive. They're the main reason why too much sunshine 0:09:41.330 --> 0:09:44.690 can give you skin cancer. In fact, if the Earth 0:09:44.730 --> 0:09:49.130 had no protection from UVB radiation, life on land might 0:09:49.210 --> 0:09:56.290 not be possible. What does protect the Earth the ozone layer. 0:09:56.970 --> 0:10:00.610 Ozone is a gas made from oxygen atoms up in 0:10:00.650 --> 0:10:04.450 the stratosphere. A thin layer of ozone blocks most of 0:10:04.490 --> 0:10:08.890 the Sun's UVB radiation. Mario Molina sat down to work 0:10:08.930 --> 0:10:12.090 out what would happen to a CFC molecule when it 0:10:12.170 --> 0:10:15.610 drifts up to the stratosphere. It would get hit by 0:10:15.610 --> 0:10:19.050 a wave of UVB radiation that would knock off the 0:10:19.130 --> 0:10:23.570 chlorine atom. The chlorine atom would soon meet an ozone molecule. 0:10:24.010 --> 0:10:27.530 When it did, it would split the ozone apart and 0:10:27.650 --> 0:10:32.290 form oxygen and chlorine monoxide instead. But that's not the 0:10:32.410 --> 0:10:36.330 end of the story. Because chlorine monoxide isn't stable. It 0:10:36.370 --> 0:10:40.290 breaks down quickly. That frees up the chlorine atom again 0:10:40.810 --> 0:10:45.170 to take out another ozone molecule, and the cycle repeats, 0:10:45.770 --> 0:10:50.730 chlorine atoms pinballing around the stratosphere, popping ozone as they go. 0:10:54.330 --> 0:10:58.170 Melina was intrigued by this, but not alarmed. After all, 0:10:58.530 --> 0:11:01.890 there weren't that many CFC molecules in the atmosphere. It 0:11:01.930 --> 0:11:04.650 was a drop in a swimming pool. They couldn't possibly 0:11:04.690 --> 0:11:08.330 destroy enough of the ozone layer to cause a problem, 0:11:08.610 --> 0:11:13.490 could they. Molina got the data showing how much CFC 0:11:13.570 --> 0:11:17.050 gas had been produced. He sat down with a pencil, 0:11:17.530 --> 0:11:22.010 paper and a calculator and did the sums. Oh, that 0:11:22.050 --> 0:11:24.970 can't be right. He checked them. He checked them again, 0:11:25.170 --> 0:11:29.010 and again. He checked them a dozen times. That night. 0:11:29.450 --> 0:11:32.690 When he got home, Molina's wife asked how his day 0:11:32.730 --> 0:11:37.290 had been. The work's going well, Molina said, but it 0:11:37.290 --> 0:11:48.530 looks like the end of the world. Cautionary tales will 0:11:48.570 --> 0:11:57.930 be back in a moment. At the University of California, Irvine, 0:11:58.290 --> 0:12:01.850 Maria and Melina tracks down Sherwood Roland and may have 0:12:01.850 --> 0:12:07.890 found something important. Roland checks Molina's sums. He checks them again. 0:12:08.090 --> 0:12:11.890 That can't be right, but it was. The CFCs drifting 0:12:12.050 --> 0:12:16.050 slowly up towards the stratosphere were a ticking time bomb. 0:12:16.890 --> 0:12:21.250 Barely forty years had passed since DuPont started to manufacture 0:12:21.290 --> 0:12:25.650 their CFCs under the free On brand on an industrial scale. 0:12:26.530 --> 0:12:29.690 That wasn't long enough to expect any obvious impacts yet, 0:12:30.650 --> 0:12:33.970 but more and more CFCs were being produced every year. 0:12:34.970 --> 0:12:38.770 If that continued, what might it mean by say, the 0:12:38.810 --> 0:12:43.450 middle of the twenty first century. Molina and Roland calculated 0:12:43.450 --> 0:12:47.690 that up to half the ozone layer could disappear. As 0:12:47.730 --> 0:12:50.930 Molina had put it, it looked like the end of 0:12:50.930 --> 0:12:55.530 the world. The two scientists wrote up their research. They 0:12:55.570 --> 0:12:59.290 published it in Nature in the summer of nineteen seventy four, 0:13:00.290 --> 0:13:05.050 and hardly anyone noticed. A few reporters got in touch 0:13:05.130 --> 0:13:09.050 from local newspapers. That was nice, but this wasn't really 0:13:09.170 --> 0:13:14.970 a local story. An executive from DuPont phoned Sherwood Roland, I. 0:13:14.930 --> 0:13:17.050 Read your paper. I was appalled. 0:13:17.650 --> 0:13:20.770 Thanks for getting in touch. It is appalling. 0:13:20.730 --> 0:13:23.730 Throughout your paper. You talk about Freon. Don't you know 0:13:23.850 --> 0:13:27.330 that Freon's are DuPont registered brand name. You need to 0:13:27.370 --> 0:13:31.610 refer to CFC's generically, not Freeon specifically. I have to 0:13:31.650 --> 0:13:33.650 tell you we take this very seriously. 0:13:34.730 --> 0:13:37.210 Uh oh okay. 0:13:38.050 --> 0:13:42.690 Roland and Molina were dispirited. They'd discovered the end of 0:13:42.730 --> 0:13:47.650 the world and nobody cared. They looked for another opportunity 0:13:47.690 --> 0:13:51.490 to get attention. The Annual meeting of the American Chemical 0:13:51.530 --> 0:13:55.410 Society was coming up, the very same event that Thomas 0:13:55.450 --> 0:13:59.370 Midgley had wowed forty four years earlier by filling his 0:13:59.450 --> 0:14:04.850 lungs with die chlorod fluomethane and softly extinguishing a candle. 0:14:06.330 --> 0:14:10.010 Roland and Melina submitted their paper to the annual meeting, 0:14:10.490 --> 0:14:13.730 but lots of papers get submitted, so it's the job 0:14:13.770 --> 0:14:17.770 of the American Chemical Society's news manager to decide which 0:14:17.850 --> 0:14:23.090 papers to publicize. Her name was Dorothy Smith. She decided 0:14:23.130 --> 0:14:27.770 to go big, much to the displeasure of DuPont. 0:14:28.770 --> 0:14:31.890 Hello, I've just seen your press release. You're making a 0:14:31.930 --> 0:14:34.210 big thing of this paper on CFC's and. 0:14:34.170 --> 0:14:36.850 Ozone yes, it seems important. 0:14:37.410 --> 0:14:39.650 We think it's an insignificant story. 0:14:39.890 --> 0:14:41.530 A lot of people are interested. 0:14:42.690 --> 0:14:46.970 Dorothy Smith stood her ground. She put Roland and Melina 0:14:47.170 --> 0:14:50.650 on stage at a press conference, and finally their work 0:14:50.770 --> 0:14:55.410 started to gain some traction. Environmental activists called for a 0:14:55.450 --> 0:14:59.210 ban on CFCs. A few politicians took up the cause, 0:15:00.090 --> 0:15:04.650 but the industry fought back. Yes, the scientific theory seemed sound, 0:15:04.730 --> 0:15:10.490 but that's all it was theory. No ozone depletion has 0:15:10.570 --> 0:15:15.450 ever been detected, despite the most sophisticated analysis. All ozone 0:15:15.490 --> 0:15:19.210 depletion figures to date are computer projections based on a 0:15:19.290 --> 0:15:24.970 series of uncertain assumptions. The initial burst of attention slowly 0:15:25.010 --> 0:15:29.570 began to fade. Roland and Molina kept speaking out that 0:15:29.730 --> 0:15:34.570 fewer and fewer people were bothering to listen. Progress towards 0:15:34.610 --> 0:15:38.970 banning CFC's ground to a halt. It was clear that 0:15:39.010 --> 0:15:43.090 only one thing might reboot the interest of the world's governments, 0:15:43.770 --> 0:15:48.130 hard evidence of damage to the ozone layer. But if 0:15:48.170 --> 0:15:52.090 it took decades for CFCs to drift up to the stratosphere, 0:15:52.530 --> 0:15:55.610 the first ones to be manufactured would only just be 0:15:55.690 --> 0:16:00.370 making it there. Would the evidence come in time to 0:16:00.490 --> 0:16:08.650 avert disaster. We'll pick up the story of CFC's and 0:16:08.690 --> 0:16:13.730 the oz But I promised you three inventions by Thomas Midgley, 0:16:14.170 --> 0:16:18.410 and as we'll see, those three inventions have a theme. 0:16:18.970 --> 0:16:25.170 That theme on anticipated consequences. I mentioned that Thomas Midgley 0:16:25.250 --> 0:16:31.330 died young. How did he die exactly? Bossquttering's eulogy tiptoed 0:16:31.370 --> 0:16:33.170 around that delicate question. 0:16:33.730 --> 0:16:36.890 In the early fall of nineteen forty, Midgley was struck 0:16:36.930 --> 0:16:40.610 by an acute attack of poliomylidis, which deprived him of 0:16:40.650 --> 0:16:43.290 the use of his legs and made him a semi invalid. 0:16:44.050 --> 0:16:48.210 Middley died unexpectedly on November two, nineteen forty four, at 0:16:48.210 --> 0:16:49.530 the age of fifty five. 0:16:50.570 --> 0:16:54.610 Confined to his bed by polio. Midgley had applied his 0:16:54.730 --> 0:16:59.010 inventive mind to devising a series of pulleys and ropes 0:16:59.090 --> 0:17:03.530 by which he could move himself around. He died unexpectedly 0:17:03.970 --> 0:17:07.130 when a rope in this device got wrapped around his 0:17:07.250 --> 0:17:14.650 neck and strangled him. So one of Mitchelly's inventions had 0:17:14.770 --> 0:17:18.130 ended up killing him, and another was going to destroy 0:17:18.170 --> 0:17:21.890 the ozone layer and fry the planet. It's fair to 0:17:21.930 --> 0:17:27.210 say that unanticipated consequences is the right description for both 0:17:27.290 --> 0:17:33.090 these inventions. The phrase unanticipated consequences was coined a few 0:17:33.250 --> 0:17:37.530 years before Mitchelly's death in a much cited article by 0:17:37.530 --> 0:17:43.130 the great American sociologist Robert K. Murton. That article was 0:17:43.130 --> 0:17:50.770 called The Unanticipated Consequences of Purposive Social Action. Throughout history, 0:17:50.970 --> 0:17:56.650 Merton argued, philosophers have grappled with the idea of unanticipated consequences, 0:17:57.130 --> 0:18:01.130 using various different words to describe it, but nobody had 0:18:01.170 --> 0:18:07.730 thought systematically about how unanticipated consequences come about. Merton set 0:18:07.810 --> 0:18:11.370 himself the task of categorizing all the possible ways in 0:18:11.410 --> 0:18:15.290 which our actions might backfire. Simple error is one way 0:18:15.330 --> 0:18:18.850 we might get unanticipated consequences. We think we know what 0:18:18.890 --> 0:18:23.170 will happen, but we're wrong. Another is what Merton called 0:18:23.450 --> 0:18:28.610 the imperious immediacy of interest. Roughly speaking, we're so keen 0:18:28.690 --> 0:18:31.410 to solve some pressing problem that we don't much care 0:18:31.490 --> 0:18:35.290 what else might happen down the line. And then there's 0:18:35.610 --> 0:18:38.610 ignorance when we don't have the knowledge that would be 0:18:38.690 --> 0:18:43.290 necessary to anticipate what might happen. In some cases, that 0:18:43.410 --> 0:18:46.010 might be because we haven't put in the time and 0:18:46.210 --> 0:18:49.530 energy that would be necessary to get that knowledge, or 0:18:49.610 --> 0:18:52.770 maybe the situation is so novel we can't imagine what 0:18:52.890 --> 0:18:56.250 we might need to know. That's a good description of 0:18:56.250 --> 0:18:59.930 what happened with CFCs. Midgley had tried to get some 0:19:00.090 --> 0:19:05.650 knowledge about potential risks by making animals breathe in dichlorodifluomethane, 0:19:06.250 --> 0:19:10.570 but the interaction with ozone came completely out of the blue. 0:19:10.770 --> 0:19:16.450 This phrase of Robert K. Merton, unanticipated consequences has a twist. 0:19:16.890 --> 0:19:19.610 To find out what it is, we need to turn 0:19:19.690 --> 0:19:25.010 to the third of Thomas Midgley's disastrous brain waves, arguably 0:19:25.530 --> 0:19:30.450 the worst of all. It came again from that fateful question, 0:19:31.370 --> 0:19:35.090 what do you want me to do next? Boss? This time, 0:19:35.370 --> 0:19:40.930 the problem Charles Kettering wanted Midgley to solve was engine knock. 0:19:42.170 --> 0:19:44.650 When you read your car and it sounds like you're 0:19:44.730 --> 0:19:49.210 firing a machine gun. It's not a common sound nowadays, 0:19:49.250 --> 0:19:53.330 but it blighted the lives of early motorists. General motors 0:19:53.370 --> 0:19:56.690 wanted to invent a product that would stop it, but 0:19:56.890 --> 0:20:01.090 nobody even understood why it happened. Thomas Midgley worked it out. 0:20:01.570 --> 0:20:05.250 In an internal combustion engine, A piston in a cylinder 0:20:05.610 --> 0:20:09.690 compresses a mixture of air and fuel until a spark 0:20:09.770 --> 0:20:14.010 plug ignites it. Engine knock happens when the mixture explodes 0:20:14.450 --> 0:20:18.770 before the piston has compressed it fully. It's not just 0:20:18.810 --> 0:20:25.210 an unpleasant noise, it can damage the engine. But where 0:20:25.210 --> 0:20:28.770 would you even start to look for a solution? Ketoing 0:20:28.890 --> 0:20:30.450 and Midgeley talked it over. 0:20:31.370 --> 0:20:34.330 We thought that maybe if the fuel were colored red, 0:20:34.490 --> 0:20:38.170 it would absorb more radiant heat and evaporate more completely, 0:20:38.570 --> 0:20:42.690 thus preventing the rough combustion. This theory came to us then, 0:20:42.890 --> 0:20:44.930 because we both happened to know that the leaves of 0:20:45.010 --> 0:20:48.250 the trailing arbuddhis are red on the back, and that 0:20:48.330 --> 0:20:50.610 they grow and bloom under the snow. 0:20:51.730 --> 0:20:55.050 Midgley went to a chemist's shop and brought iodine. He 0:20:55.130 --> 0:20:58.010 put the iodine in some fuel, which turned it red, 0:20:58.650 --> 0:21:03.210 and he ran the engine no knock. Midgeley and Kettering 0:21:03.370 --> 0:21:06.810 were astonished, But was it really the color red that 0:21:06.930 --> 0:21:10.650 was stopping the knock. Midgeley try other ways of dyeing fuel, 0:21:11.130 --> 0:21:14.970 but with no success. Apparently it wasn't the red color, 0:21:15.330 --> 0:21:18.250 but something else about the iodine. The leaves of the 0:21:18.290 --> 0:21:23.330 trailing arbutus had been a red herring. Midgley then tried 0:21:23.610 --> 0:21:29.090 ethyl iodide, which has iodine but no color. It stopped 0:21:29.090 --> 0:21:35.130 the knock just as well. Unfortunately, it also corroded the engine. Underterreed, 0:21:35.410 --> 0:21:39.050 Midgeley pulled the periodic table from his pocket and began 0:21:39.130 --> 0:21:40.410 to work his way through it. 0:21:41.090 --> 0:21:44.930 Many anti Knoch agents were discovered along the way, compounds 0:21:44.930 --> 0:21:50.530 of iodine, of nitrogen, of phosphorus, of arsenic, of antimony, 0:21:50.890 --> 0:21:56.250 of selenium, of tillurium, But everyone had some limitation or 0:21:56.330 --> 0:21:59.770 shortcoming which prevented it from being used in a practical way. 0:22:00.850 --> 0:22:05.730 Eventually, Thomas Midgley's perseverance paid off. He discovered something that 0:22:05.810 --> 0:22:10.370 he could add to gasoline that would stop engine without 0:22:10.890 --> 0:22:16.370 damaging the engine, tetra ethyl lead. Thomas Midley had invented 0:22:17.010 --> 0:22:23.450 leaded gasoline because of Midgeley's invention. I'm about five iq 0:22:23.770 --> 0:22:27.770 points stupider than I would otherwise have been, and so 0:22:27.850 --> 0:22:30.650 are you if you're around my age or older, because 0:22:30.890 --> 0:22:34.770 you too, will have spent your childhood inhaling fumes of 0:22:34.850 --> 0:22:39.130 leaded gasoline from car exhausts. The air pollution messed up 0:22:39.170 --> 0:22:42.810 brain development for whole generations of kids, and it caused 0:22:42.850 --> 0:22:47.890 cancers and heart disease and strokes. It's estimated that leaded 0:22:47.930 --> 0:22:54.530 gasoline hastened tens of millions of deaths. Leaded gasoline completes 0:22:54.650 --> 0:22:59.570 an astonishing trifector. Thomas Midgley invented a rope and pulley 0:22:59.610 --> 0:23:03.250 device that killed him, an additive for fuel that killed 0:23:03.290 --> 0:23:06.330 lots of other people, and a refrigerant that was on 0:23:06.490 --> 0:23:11.210 course to wipe out life on earth all together. How 0:23:11.450 --> 0:23:23.370 unlucky can one man be? That luck isn't the whole story. 0:23:24.170 --> 0:23:28.130 In the early nineteen eighties, the radio chemist Sherwood Rowland 0:23:28.250 --> 0:23:31.770 and his colleague Mario Molina kept on talking about the 0:23:31.850 --> 0:23:36.370 danger of CFC's to the ozone layer. Nobody wanted to listen. 0:23:36.970 --> 0:23:39.730 Roland became more and more exasperated. 0:23:39.930 --> 0:23:42.250 What's the use of having developed a science well enough 0:23:42.250 --> 0:23:45.850 to make predictions if in the end all we're willing 0:23:45.890 --> 0:23:47.810 to do is stand around and wait for them to 0:23:47.810 --> 0:23:48.850 come true. 0:23:48.930 --> 0:23:52.810 The predictions, however, were all too easy for the industry 0:23:52.850 --> 0:23:58.330 to dismiss. Remember the line from DuPont All ozone depletion 0:23:58.450 --> 0:24:02.610 figures to date are computer projections based on a series 0:24:02.650 --> 0:24:08.290 of uncertain assumptions. Only actual evidence of damage to the 0:24:08.330 --> 0:24:12.410 ozone layer would get CFCs back on the agenda, but 0:24:12.490 --> 0:24:15.690 the evidence would be hard to come by. The first 0:24:15.730 --> 0:24:19.690 CFCs to be produced decades earlier would only just have 0:24:19.770 --> 0:24:23.050 reached the stratosphere. If they were starting to reduce the 0:24:23.130 --> 0:24:26.410 levels of ozone, that might be hard to see for 0:24:26.490 --> 0:24:31.690 a couple of reasons. First, ozone levels fluctuate naturally. Second, 0:24:32.090 --> 0:24:35.050 there are different ways to measure ozone from the ground, 0:24:35.130 --> 0:24:39.570 from satellites, from special instruments tied to helium balloons, which 0:24:39.610 --> 0:24:44.370 were most accurate, No one was entirely sure. Tantalizing hints 0:24:44.370 --> 0:24:49.130 of evidence began to emerge. Some Japanese researchers sent balloons 0:24:49.170 --> 0:24:53.530 to the stratosphere. The ozone readings came back worryingly low 0:24:54.010 --> 0:24:57.130 that you really needed a long term series of data 0:24:57.170 --> 0:25:00.610 points to establish there was a trend. The Japanese team 0:25:00.650 --> 0:25:05.770 didn't have that, but someone else did. For twenty five years, 0:25:06.050 --> 0:25:11.170 an obscure organization called the British Antarctic Survey had been 0:25:11.290 --> 0:25:14.890 toiling away on a shoe string budget, sending researchers to 0:25:14.930 --> 0:25:19.250 a remote outpost in Antarctica to measure all sorts of things. 0:25:19.890 --> 0:25:23.170 They weren't looking for anything in particular, They just liked 0:25:23.170 --> 0:25:26.250 to collect data. In case it ever happened to show 0:25:26.290 --> 0:25:31.890 anything interesting. For twenty five years, it never had. Now, 0:25:32.010 --> 0:25:36.530 in the early nineteen eighties, it did. The ozone measurements 0:25:36.530 --> 0:25:40.370 were all over the place. The researchers suspected that their 0:25:40.410 --> 0:25:44.250 instruments had gone haywire. They send new ones to Antarctica, 0:25:44.690 --> 0:25:48.210 but the data came back the same. At first, it 0:25:48.290 --> 0:25:51.770 seemed random, but when the researchers looked more closely, they 0:25:51.810 --> 0:25:55.330 realized there was a pattern to the unusually low readings, 0:25:55.810 --> 0:26:00.570 a pattern related to the seasons, a pattern that reactions 0:26:00.570 --> 0:26:06.210 with chlorine could plausibly explain. NASA's satellites had also picked 0:26:06.290 --> 0:26:10.930 up some surprisingly low readings over the Antarctic solo. The 0:26:10.970 --> 0:26:16.050 computers had initially thrown them out as obvious anomalies. Now 0:26:16.090 --> 0:26:19.090 it was clear that something was happening. There was still 0:26:19.170 --> 0:26:22.730 room to doubt. Why was it really a chemical reaction 0:26:23.010 --> 0:26:27.930 caused by chlorofluorocarbons, or was it solar activities or wind 0:26:28.850 --> 0:26:32.250 There was only one way to be sure. NASA rushed 0:26:32.250 --> 0:26:35.370 to put together a team of scientists and flew them 0:26:35.410 --> 0:26:38.890 to Antarctica. In charge of the mission was thirty year 0:26:38.930 --> 0:26:44.410 old Dr Susan Solomon, an atmospheric chemist. Solomon had never 0:26:44.450 --> 0:26:47.770 been to Antarctica before, and she didn't have the right equipment. 0:26:48.410 --> 0:26:51.730 Her team had brought instruments to analyze light from the Moon, 0:26:52.130 --> 0:26:54.250 but they hadn't had time to build a tracking device 0:26:54.330 --> 0:26:58.330 to focus the Moon's rays. Instead, someone had to sit 0:26:58.490 --> 0:27:01.810 on the laboratory roof at night holding a mirror at 0:27:01.930 --> 0:27:05.450 just the right angle. The first time Solomon took the 0:27:05.530 --> 0:27:10.610 roof shift, she squinted to direct the mirror's reflect found 0:27:10.690 --> 0:27:14.850 that her eye had frozen shut. For the results of 0:27:14.890 --> 0:27:20.290 the experiments pointed only in one direction. On October the twentieth, 0:27:20.410 --> 0:27:24.530 nineteen eighty six, journalists gathered in Washington, d C. To 0:27:24.570 --> 0:27:29.330 hear Solomon relay her team's preliminary findings over a crackly 0:27:29.410 --> 0:27:31.250 satellite link from Antarctica. 0:27:32.570 --> 0:27:35.930 At present, we have not conclusively established the cause. 0:27:35.690 --> 0:27:36.570 Of the oath on whole. 0:27:37.050 --> 0:27:41.490 However, we have strong evidence against theories that upward wins 0:27:41.650 --> 0:27:45.490 or high solar activities caused the deplete it. We suspect 0:27:45.530 --> 0:27:49.610 a chemical process is fundamentally responsible for the formation of 0:27:49.650 --> 0:27:50.010 the whole. 0:27:51.210 --> 0:27:57.210 Solomon was right. More experiments confirmed it. The world's leaders 0:27:57.410 --> 0:28:02.010 acted with commendable speed. In nineteen eighty seven, they agreed 0:28:02.090 --> 0:28:07.610 the Montreal Protocol to phase out CFC's Sherwood Rowland and 0:28:07.690 --> 0:28:11.890 Mario Molina share and Nobel Prize. The end of the 0:28:11.930 --> 0:28:18.010 world was averted. By now, the impacts of leaded gasoline 0:28:18.010 --> 0:28:22.010 on human health were equally plain to see. Governments around 0:28:22.050 --> 0:28:26.450 the world were banning that too, albeit more slowly. As 0:28:26.450 --> 0:28:32.090 for Thomas Midgley, well with hindsight, Boss Ketowing's eulogy sounds 0:28:32.130 --> 0:28:32.850 a little different. 0:28:33.450 --> 0:28:37.570 Midgeley contributed so greatly to more pleasant and efficient living. 0:28:38.330 --> 0:28:44.130 So he did. Safe refrigerators, air assaults, smoothly running gas engines, 0:28:44.530 --> 0:28:51.690 pleasant and efficient, just deadly too. Seventy years after Ketoing's eulogy, 0:28:52.050 --> 0:28:56.450 the New Scientist looked back on Midgeley's life, memorably describing 0:28:56.530 --> 0:29:01.850 him as a one man environmental disaster, far from the 0:29:01.890 --> 0:29:05.650 epitome of industrial progress. He starts to look more like 0:29:05.690 --> 0:29:09.050 a byword for that phrase coined by the great sociologist 0:29:09.490 --> 0:29:19.450 Robert K. Merton, unanticipated consequences and yet unanticipated consequences isn't 0:29:19.450 --> 0:29:22.170 a phrase you hear much anymore. It's given way to 0:29:22.570 --> 0:29:27.850 unintended consequences. Merton himself switched from using one phrase to 0:29:27.890 --> 0:29:31.010 the other. They might sound like synonyms, but they're not. 0:29:31.650 --> 0:29:36.130 A professor of political science named Frank Dejevart points out 0:29:36.130 --> 0:29:40.850 that this shift in language obscures a whole category of impacts, 0:29:41.250 --> 0:29:45.970 ones that you don't intend but you might nonetheless anticipate. 0:29:46.970 --> 0:29:50.010 Think of a doctor prescribing a drug that often has 0:29:50.050 --> 0:29:53.610 side effects. She doesn't want you to suffer the side effects, 0:29:53.730 --> 0:29:57.570 but she does foresee the possibility, or at least she should, 0:29:58.330 --> 0:30:01.570 and she should be honest about it too. We expect 0:30:01.690 --> 0:30:05.970 doctors to speak truthfully about risks and trade offs. Other 0:30:06.010 --> 0:30:09.850 decision makers might not when they stand to gain while 0:30:09.850 --> 0:30:13.930 the risks fall on others. In cases like that, says Dejerrat, 0:30:14.330 --> 0:30:20.170