1 00:00:03,870 --> 00:00:06,384 The greatest triumph of civilization 2 00:00:06,384 --> 00:00:09,585 is often seen as our mastery of heat. 3 00:00:12,478 --> 00:00:16,224 Yet our conquest of cold is an equally epic journey, 4 00:00:16,225 --> 00:00:20,225 from dark beginnings, to an ultra cool frontier. 5 00:00:21,785 --> 00:00:25,463 For centuries, cold remained a perplexing mystery 6 00:00:25,464 --> 00:00:27,802 Nobody had any idea what it was. 7 00:00:27,803 --> 00:00:30,383 Much less how to harness its effects. 8 00:00:30,830 --> 00:00:33,305 Yet in the last 100 years, 9 00:00:34,000 --> 00:00:36,765 cold has transformed the way we live and work. 10 00:00:38,605 --> 00:00:42,374 Imagine homes or supermarkets without fridges and frozen foods 11 00:00:42,575 --> 00:00:45,277 or skyscrapers without air-conditioning, 12 00:00:45,278 --> 00:00:48,048 or hospitals without liquid oxygen. 13 00:00:51,244 --> 00:00:53,218 We take for granted the technology of cold, 14 00:00:53,219 --> 00:00:56,884 yet it has enabled us to explore outer space 15 00:00:56,885 --> 00:00:59,405 and the inner depths of our brain. 16 00:01:00,644 --> 00:01:03,404 And as we develop new ultra cold technology 17 00:01:03,405 --> 00:01:06,365 to create quantum computers and high-speed networks, 18 00:01:06,805 --> 00:01:10,645 it may even change the way we think and interact. 19 00:01:13,805 --> 00:01:15,164 This is the story of 20 00:01:15,165 --> 00:01:18,805 how scientists and dreamers over the past four centuries 21 00:01:19,185 --> 00:01:22,345 plunged lower and lower down the temperature scale 22 00:01:22,445 --> 00:01:25,382 to conquer the cold, enrich our lives 23 00:01:25,583 --> 00:01:29,040 and attempt to reach the ultimate limit of cold. 24 00:01:29,065 --> 00:01:32,545 A Holy Grail as elusive as the speed limit of light: 25 00:01:33,425 --> 00:01:35,465 absolute zero. 26 00:01:49,870 --> 00:01:52,184 Extreme cold has always held 27 00:01:52,185 --> 00:01:54,465 a special place in our imagination. 28 00:01:55,020 --> 00:01:57,984 For thousands of years, it seemed like a malevolent force 29 00:01:57,985 --> 00:02:00,984 associated with death and darkness. 30 00:02:00,985 --> 00:02:04,344 Cold was an unexplained phenomenon. 31 00:02:06,385 --> 00:02:11,035 Was it a substance, a process, or some special state of being? 32 00:02:11,036 --> 00:02:14,023 Back in the 17th century, no one knew, 33 00:02:14,024 --> 00:02:15,863 but they certainly felt its effects 34 00:02:15,864 --> 00:02:18,444 in the freezing London winters. 35 00:02:20,912 --> 00:02:23,080 (Simon Schaffer) 17th-century England was in the middle 36 00:02:23,081 --> 00:02:25,282 of what's now called "the little Ice Age." 37 00:02:25,583 --> 00:02:27,250 It was fantastically cold by modern standards. 38 00:02:27,251 --> 00:02:29,720 You have to imagine a world lit by fire 39 00:02:29,721 --> 00:02:32,239 in which most people are cold most of the time. 40 00:02:32,290 --> 00:02:35,292 Cold would've felt like a real presence, 41 00:02:35,493 --> 00:02:39,939 a kind of positive agent that was affecting how people felt. 42 00:02:40,239 --> 00:02:41,699 And not fitted nicely 43 00:02:41,899 --> 00:02:44,879 with the most orthodox received view, 44 00:02:44,880 --> 00:02:47,479 that natural philosophers inherited from the greeks, 45 00:02:47,679 --> 00:02:50,637 from Aristotle, hundreds of years earlier, 46 00:02:50,860 --> 00:02:53,119 that there are two agents in the world: 47 00:02:53,419 --> 00:02:54,979 hot and cold. 48 00:02:55,139 --> 00:02:57,339 They function symetrically. 49 00:02:58,060 --> 00:02:59,220 They can combine 50 00:02:59,539 --> 00:03:01,039 or separate. 51 00:03:03,764 --> 00:03:06,868 Back then, people felt at the mercy of cold. 52 00:03:08,269 --> 00:03:10,880 This was a time when such natural forces 53 00:03:10,939 --> 00:03:13,641 were viewed with awe as acts of God. 54 00:03:15,942 --> 00:03:21,147 So anyone attempting to tamper with cold did so at their peril. 55 00:03:21,648 --> 00:03:25,552 The first to try was an alchemist, Cornelius Drebbel. 56 00:03:28,170 --> 00:03:30,323 On a hot summer's day in 1620, 57 00:03:30,924 --> 00:03:32,898 King James I and his entourage 58 00:03:32,899 --> 00:03:36,349 arrived to experience an unearthly event. 59 00:03:38,364 --> 00:03:41,166 Drebbel, who was also the court magician, 60 00:03:41,367 --> 00:03:42,902 had a wager with the King 61 00:03:42,903 --> 00:03:45,705 that he could turn summer into winter. 62 00:03:46,406 --> 00:03:48,079 He would attempt to chill the air 63 00:03:48,080 --> 00:03:51,520 in the largest interior space in the British Isles: 64 00:03:52,239 --> 00:03:54,513 the great hall of Westminster. 65 00:03:57,650 --> 00:04:02,159 Drebbel hoped to shake the King to his core. 66 00:04:04,924 --> 00:04:06,980 (Andrew Szydlo) He had a phenomenally fertile mind. 67 00:04:07,059 --> 00:04:08,780 He was an inventor par excellence. 68 00:04:09,280 --> 00:04:12,009 His whole world was steeped in the world of alchemy, 69 00:04:12,633 --> 00:04:14,558 of perpetual motion machines, 70 00:04:14,559 --> 00:04:16,270 of the idea of time, space, 71 00:04:16,720 --> 00:04:18,720 planets, moon, sun, gods. 72 00:04:19,160 --> 00:04:20,800 He was a fervently religious man. 73 00:04:21,119 --> 00:04:25,019 He was a person for whom nature presented 74 00:04:25,219 --> 00:04:28,720 a phenomenal... a galaxy of possibilities. 75 00:04:31,240 --> 00:04:33,251 Dr. Andrew Szydlo, a chemist 76 00:04:33,252 --> 00:04:35,359 with a lifelong fascination for Drebbel, 77 00:04:35,360 --> 00:04:39,439 enjoys his reincarnation as the great court magician. 78 00:04:41,460 --> 00:04:44,720 Like most alchemists, Drebbel kept his method secret. 79 00:04:45,065 --> 00:04:47,180 Dr. Szydlo wants to test his ideas 80 00:04:47,220 --> 00:04:50,400 on how Drebbel created artificial cold. 81 00:04:56,676 --> 00:04:58,040 When Drebbel was trying to achieve 82 00:04:58,111 --> 00:05:00,520 the lowest temperature possible, he knew that ice, of course, 83 00:05:00,581 --> 00:05:03,700 was the freezing point, or the coldest you could get normally. 84 00:05:04,118 --> 00:05:05,520 But he would've been aware of the facts 85 00:05:05,587 --> 00:05:08,820 through his experience that mixing ice with different salts 86 00:05:08,956 --> 00:05:11,240 could get you a colder temperature. 87 00:05:12,200 --> 00:05:15,662 Salts will lower the temperature at which ice melts. 88 00:05:16,263 --> 00:05:20,160 Dr. Szydlo thinks Drebbel probably used common table salt, 89 00:05:20,200 --> 00:05:22,268 which gives the biggest temperature drop. 90 00:05:25,169 --> 00:05:27,494 But salt and ice alone would not be enough 91 00:05:27,495 --> 00:05:29,758 to cool down such a large interior. 92 00:05:30,611 --> 00:05:33,880 Drebbel was famous for designing elaborate contraptions, 93 00:05:33,881 --> 00:05:36,716 a passion shared by Dr. Szydlo, 94 00:05:36,717 --> 00:05:39,586 who has an idea for the alchemist's machine. 95 00:05:41,887 --> 00:05:44,623 So here, we would've had a fan, 96 00:05:44,624 --> 00:05:45,990 which would've been turned over 97 00:05:46,019 --> 00:05:50,700 blowing warm air over the cold vessels there, 98 00:05:50,797 --> 00:05:54,601 and as the air blows over these cold jars, 99 00:05:54,702 --> 00:05:55,870 we would've had, in effect, 100 00:05:56,280 --> 00:05:59,629 the world's first air-conditioning unit. 101 00:06:02,309 --> 00:06:05,477 But could this really turn summer into winter? 102 00:06:07,130 --> 00:06:10,215 (Dr. Szydlo) The idea was to stir it in as well as possible 103 00:06:10,216 --> 00:06:12,920 in the 5 seconds that you have to do it. 104 00:06:14,430 --> 00:06:17,480 Dr. Szydlo stacks the jars of freezing mixture 105 00:06:17,490 --> 00:06:20,740 to create cold corridors for the air to pass through. 106 00:06:25,765 --> 00:06:27,733 We can feel it's very cold, 107 00:06:27,834 --> 00:06:30,100 in fact I could feel cold air 108 00:06:30,137 --> 00:06:32,239 actually falling on my hands, 109 00:06:32,272 --> 00:06:35,608 because cold air, of course, is denser than warm air, 110 00:06:35,609 --> 00:06:38,339 and one can feel it quite clearly on the fingers. 111 00:06:41,348 --> 00:06:43,000 The vital question: 112 00:06:43,083 --> 00:06:45,960 would the gust of warm air become cold? 113 00:06:52,259 --> 00:06:56,529 I can feel certainly a blast of cold air hitting me 114 00:06:56,530 --> 00:06:58,720 as that 2nd cover was released. 115 00:06:59,099 --> 00:07:02,068 Well, temperature, we're on 14 at the moment. 116 00:07:02,269 --> 00:07:05,400 Yes, keep it going. That's definitely the right direction. 117 00:07:05,750 --> 00:07:10,800 I think possibily even closer still would give us the best of... 118 00:07:15,320 --> 00:07:17,291 So, how would the King have reacted 119 00:07:17,292 --> 00:07:19,318 to this encounter with man-made cold? 120 00:07:20,520 --> 00:07:21,399 He would've been shocked, 121 00:07:21,400 --> 00:07:22,779 he wouln't have known what's happening, 122 00:07:22,780 --> 00:07:24,400 he could've in fact been wondering 123 00:07:24,401 --> 00:07:26,178 whether there was some action of gods 124 00:07:26,420 --> 00:07:28,132 or some sort of forces, 125 00:07:28,233 --> 00:07:31,158 demonological forces, which were in action 126 00:07:31,160 --> 00:07:35,580 and he would have let pacefully freezing as he did so. 127 00:07:36,790 --> 00:07:39,183 Had Drebbel written up his great stunt, 128 00:07:39,184 --> 00:07:40,590 he might've gone down in history 129 00:07:40,653 --> 00:07:43,000 as the inventor of the air-conditioning. 130 00:07:43,022 --> 00:07:45,059 Yet it would be almost 3 centuries 131 00:07:45,060 --> 00:07:47,720 before this idea eventually took off. 132 00:07:49,100 --> 00:07:51,600 To advance knowledge and conquer the cold 133 00:07:51,910 --> 00:07:55,160 required men with a very different mind set. 134 00:07:57,260 --> 00:08:00,159 King James' Lord Chancellor Francis Bacon 135 00:08:00,160 --> 00:08:02,820 was the first to apply the scientific method 136 00:08:02,880 --> 00:08:04,600 to the study of heat and cold. 137 00:08:04,860 --> 00:08:07,819 He believed it was important to conduct experiments 138 00:08:07,820 --> 00:08:09,258 and analyze the results 139 00:08:09,558 --> 00:08:13,360 rather than rely on the established wisdom of the ancients. 140 00:08:14,458 --> 00:08:17,859 For Francis Bacon, heat and cold turned out to be 141 00:08:17,860 --> 00:08:21,357 right at the center of his world view. 142 00:08:21,358 --> 00:08:23,458 One way of understanding why that's so 143 00:08:23,658 --> 00:08:29,358 is think why heat and cold matter to human beings. 144 00:08:29,458 --> 00:08:31,800 They really matter in XVII century for two reasons: 145 00:08:32,200 --> 00:08:35,440 one is the weather and one is disease. 146 00:08:35,558 --> 00:08:39,080 There was after all an obvious tension in everyday experience 147 00:08:39,460 --> 00:08:41,863 between the healty effects of warmth 148 00:08:41,864 --> 00:08:43,937 and the healthy effects of cold. 149 00:08:44,139 --> 00:08:46,606 Warmth made you healthy because it 150 00:08:46,907 --> 00:08:52,417 stops you radiating away the vital spirits within you. 151 00:08:52,640 --> 00:08:56,200 But cold obviously had crucial effects 152 00:08:56,400 --> 00:08:57,840 against death as well. 153 00:08:57,900 --> 00:09:00,979 It could preserve things for immensely long times 154 00:09:01,239 --> 00:09:04,840 and maybe it could preserve Francis Bacon's body too. 155 00:09:08,940 --> 00:09:11,440 Bacon rarely carried out experiments himself 156 00:09:12,040 --> 00:09:15,279 but his one foray into the preservative effects of the cold 157 00:09:15,440 --> 00:09:17,400 had disastrous consequences. 158 00:09:18,550 --> 00:09:20,300 He took a freshly killed chicken. 159 00:09:20,540 --> 00:09:22,718 and stuffed it full of ice and snow 160 00:09:22,719 --> 00:09:27,080 to investigate how much longer the chicken meat might stay fresh. 161 00:09:28,960 --> 00:09:30,819 He was impressed by the results. 162 00:09:30,960 --> 00:09:33,720 The chicken did remain fresh for many days. 163 00:09:34,060 --> 00:09:35,959 Unfortunately, during the process 164 00:09:35,960 --> 00:09:38,319 of exposing his own body to the cold 165 00:09:38,320 --> 00:09:39,859 he caught pneumonia. 166 00:09:42,020 --> 00:09:43,719 As Bacon laid dying 167 00:09:43,720 --> 00:09:46,359 it dawned on him that his fascination with the cold 168 00:09:46,360 --> 00:09:48,919 was going to cost him his life. 169 00:09:54,340 --> 00:09:57,839 The irony, tragedy of that rough sad experiment 170 00:09:58,039 --> 00:10:01,999 didn't disuade his followers from doing more experiments 171 00:10:02,000 --> 00:10:06,900 on ice and snow and its vital or preservative effects. 172 00:10:08,060 --> 00:10:10,907 The men who followed Bacon were really convinced that 173 00:10:10,908 --> 00:10:13,319 if we could understand the way in which 174 00:10:13,320 --> 00:10:16,838 motion, cold and heat fitted together 175 00:10:16,980 --> 00:10:19,240 we could save ourselves from disease, 176 00:10:19,320 --> 00:10:21,379 we'd unlock the mysteries of the universe. 177 00:10:25,273 --> 00:10:28,460 This fundamental question, "What is cold?" 178 00:10:28,777 --> 00:10:30,115 haunted Robert Boyle, 179 00:10:30,516 --> 00:10:32,840 who was born the year after Bacon died. 180 00:10:33,147 --> 00:10:35,817 The son of the Earl of Cork, a wealthy nobleman, 181 00:10:35,818 --> 00:10:39,754 Boyle used his fortune to build an extensive laboratory. 182 00:10:42,569 --> 00:10:44,093 Boyle is famous for his experiments 183 00:10:44,094 --> 00:10:45,928 on the nature of air, 184 00:10:45,929 --> 00:10:48,950 but he also became the first master of cold. 185 00:10:49,229 --> 00:10:52,170 Believing it to be an important, but neglected subject, 186 00:10:52,389 --> 00:10:54,840 he carried out hundreds of experiments. 187 00:10:57,041 --> 00:11:00,744 (Simon Schaffer) He worked through very systematically 188 00:11:00,745 --> 00:11:04,881 a series of ideas about what cold is. 189 00:11:04,882 --> 00:11:07,880 Does it come from the air? 190 00:11:08,218 --> 00:11:11,279 Does it come from the absence of light? 191 00:11:11,799 --> 00:11:15,024 Is it that there are strange, 192 00:11:15,025 --> 00:11:19,379 so-called "frigorific" cold-making particles? 193 00:11:24,199 --> 00:11:27,600 The dominant view, certainly in Boyle's lifetime, 194 00:11:27,835 --> 00:11:30,407 the view that he set out to attack, 195 00:11:30,408 --> 00:11:33,840 is that cold is a primordial substance 196 00:11:34,260 --> 00:11:36,816 that when bodies get colder 197 00:11:36,817 --> 00:11:40,198 they're sucking in this primordial cold 198 00:11:40,501 --> 00:11:43,240 and as they get warmer they expel it. 199 00:11:43,940 --> 00:11:45,756 Boyle thought that was wrong 200 00:11:46,057 --> 00:11:49,058 and he did experiments to show that it was wrong. 201 00:11:55,019 --> 00:11:59,279 Boyle was curious about the way water expanded when it turned to ice. 202 00:11:59,779 --> 00:12:01,915 He wondered whether the increase in volume 203 00:12:02,016 --> 00:12:04,598 was accompanied by an increase in weight. 204 00:12:07,480 --> 00:12:09,356 He carefully weighed a barrel of water 205 00:12:09,740 --> 00:12:11,783 and took it outside in the snow, 206 00:12:12,584 --> 00:12:14,459 leaving it to freeze overnight. 207 00:12:17,702 --> 00:12:23,196 Boyle reasoned that if once the water turned to ice the barrel weighed more, 208 00:12:23,197 --> 00:12:26,220 then perhaps cold was a substance, after all. 209 00:12:27,479 --> 00:12:29,220 But when they reweighed the barrel, 210 00:12:29,299 --> 00:12:31,900 they discovered it weighed exactly the same. 211 00:12:35,352 --> 00:12:38,199 So what must be happening, Boyle guessed, 212 00:12:38,299 --> 00:12:42,440 was that the particles of water were moving further apart, 213 00:12:43,139 --> 00:12:44,770 and that was the expansion, 214 00:12:44,960 --> 00:12:49,658 not some substance flowing into the barrel from outside. 215 00:12:52,437 --> 00:12:54,837 Boyle was becoming increasingly convinced 216 00:12:54,838 --> 00:12:56,755 that cold was not a substance 217 00:12:56,960 --> 00:12:59,753 but something that was happening to the particles, 218 00:13:00,054 --> 00:13:03,799 and began to think back to his earlier experiments with his air pump. 219 00:13:05,899 --> 00:13:10,320 Boyle's idea was that the air trapped in this glass container 220 00:13:10,600 --> 00:13:12,799 is springy, it's elastic 221 00:13:12,899 --> 00:13:15,720 and as you're trying compress it, it resists. 222 00:13:15,899 --> 00:13:19,620 Now, this is very closely linked in Boyle's program 223 00:13:19,999 --> 00:13:22,799 to the way he studies heat and cold 224 00:13:23,099 --> 00:13:24,419 because his idea was 225 00:13:24,589 --> 00:13:27,239 that as substances like the air get warmer 226 00:13:27,242 --> 00:13:28,978 they tend to expand. 227 00:13:29,159 --> 00:13:33,159 It's as though the little particles, little springs, 228 00:13:33,259 --> 00:13:36,180 out of which he imagined each air particle is made, 229 00:13:36,259 --> 00:13:37,860 were gradually unwinding, 230 00:13:37,960 --> 00:13:41,259 so they take up more space and they expand. 231 00:13:42,519 --> 00:13:44,200 Boyle's conclusion here 232 00:13:44,318 --> 00:13:49,399 was that heat is a form of motion of a particular kind 233 00:13:50,120 --> 00:13:54,960 and that as bodies cool down, they move less and less. 234 00:13:57,880 --> 00:14:00,720 Boyle's longest-published book was on the cold. 235 00:14:01,020 --> 00:14:04,470 Yet he found its study troublesome and full of hardships, 236 00:14:04,771 --> 00:14:06,921 declaring that he felt like a physician 237 00:14:06,922 --> 00:14:08,840 trying to work in a remote country 238 00:14:08,904 --> 00:14:11,837 without the benefit of instruments or medicines. 239 00:14:15,032 --> 00:14:17,801 To properly explore this country of the cold, 240 00:14:18,102 --> 00:14:20,740 Boyle lamented the lack of a vital tool: 241 00:14:21,371 --> 00:14:23,473 an accurate thermometer. 242 00:14:37,399 --> 00:14:39,657 It was not until the mid-17th century, 243 00:14:39,658 --> 00:14:41,398 that glassblowers in Florence 244 00:14:41,399 --> 00:14:44,720 began to produce accurately calibrated thermometers. 245 00:14:45,163 --> 00:14:48,660 Now it became possible to measure degrees of hot and cold. 246 00:14:52,299 --> 00:14:56,080 Because rather than mercury they used alcohol, which is much lighter, 247 00:14:56,220 --> 00:14:59,240 they made thermometers that were sometimes several meters long 248 00:14:59,579 --> 00:15:02,039 and were often wound into spirals. 249 00:15:03,655 --> 00:15:06,840 But there was still one major problem with all thermometers: 250 00:15:07,020 --> 00:15:10,440 the lack of a universally agreed temperature scale. 251 00:15:12,531 --> 00:15:15,852 There are all kinds of different ways of trying to stick numbers 252 00:15:15,853 --> 00:15:18,038 to these degrees of hot and cold, 253 00:15:18,141 --> 00:15:21,958 and they, on the whole, didn't agree with each other at all. 254 00:15:22,541 --> 00:15:27,145 So one guy in Florence makes one kind of thermometer, 255 00:15:27,346 --> 00:15:29,919 another guy in London makes a different kind, 256 00:15:30,899 --> 00:15:33,600 and they just don't even have the same scale, 257 00:15:33,799 --> 00:15:39,179 and so there was a lot of problem in trying to standardise thermometers. 258 00:15:40,779 --> 00:15:42,778 Imagine that you want to make a scale of temperature. 259 00:15:42,779 --> 00:15:43,960 What do you do? 260 00:15:44,179 --> 00:15:45,798 Well, the obvious thing to do, 261 00:15:45,799 --> 00:15:48,869 and this is well understood by instrument makers and experimentalists 262 00:15:48,870 --> 00:15:50,198 in the 17th and 18th century 263 00:15:50,200 --> 00:15:53,879 is to try to find something in nature 264 00:15:53,880 --> 00:15:56,740 which you know always has the same temperature 265 00:15:56,879 --> 00:15:59,200 and make that your fixed point. 266 00:15:59,420 --> 00:16:04,039 A better strategy even is to find two such phenomena in nature 267 00:16:04,179 --> 00:16:07,057 and then you have a lower fixed point, 268 00:16:07,058 --> 00:16:08,597 something rather cold, 269 00:16:08,679 --> 00:16:11,599 and an upper fixed point, something rather warm 270 00:16:11,600 --> 00:16:15,279 and divide the degrees of temperature between 271 00:16:15,379 --> 00:16:18,299 into say a hundred convenient bite sized chunks. 272 00:16:18,679 --> 00:16:22,579 The problem however was to find, define a phenomenon 273 00:16:22,679 --> 00:16:25,200 whose temperature you guessed was fixed. 274 00:16:25,679 --> 00:16:28,720 So for the lower fixed point you might choose 275 00:16:28,920 --> 00:16:32,320 the temperature of ice. just as it's melting. 276 00:16:33,920 --> 00:16:36,440 And then there's an almost indefinite range 277 00:16:36,520 --> 00:16:40,080 of possible candidates for your upper fixed point. 278 00:16:43,739 --> 00:16:45,862 And Isaac Newton, for example, 279 00:16:45,863 --> 00:16:50,438 worked rather hard on constructing what he called the Scale of Heat. 280 00:16:50,519 --> 00:16:53,679 He, for example, defined 281 00:16:53,900 --> 00:16:58,299 the temperature which a human can only just tolerate 282 00:16:58,400 --> 00:17:01,640 if they plunge their hand into warm water. 283 00:17:03,100 --> 00:17:06,100 It could be the normal human underarm, 284 00:17:06,640 --> 00:17:08,559 the temperature of the human blood, 285 00:17:09,000 --> 00:17:11,600 the temperature of wax just as it's melting. 286 00:17:15,577 --> 00:17:17,938 The first temperature scale to be widely adopted 287 00:17:17,939 --> 00:17:20,160 was devised by Daniel Fahrenheit, 288 00:17:20,260 --> 00:17:21,970 an accomplished instrument maker 289 00:17:21,971 --> 00:17:24,557 who made thermometers for doctors in Holland. 290 00:17:25,894 --> 00:17:29,640 He used a mixture of ice, water, and salt for his 0 degrees; 291 00:17:30,699 --> 00:17:33,480 ice melting in water at 32 degrees 292 00:17:33,903 --> 00:17:35,484 and for his upper fixed point, 293 00:17:35,485 --> 00:17:38,485 the temperature of the human body, at 96 degrees, 294 00:17:38,586 --> 00:17:40,557 which is close to the modern value. 295 00:17:41,844 --> 00:17:44,519 (Hasok Chang) One of the things that Fahrenheit was able to achieve 296 00:17:45,815 --> 00:17:48,039 was to make thermometers quite small, 297 00:17:48,651 --> 00:17:50,799 and that he did by using mercury 298 00:17:51,321 --> 00:17:55,880 as opposed to alcohol or air, which other people had used. 299 00:17:55,959 --> 00:17:58,640 And because mercury thermometers are compact, 300 00:17:59,880 --> 00:18:03,479 clearly if you're trying to use it for clinical purposes, 301 00:18:03,480 --> 00:18:06,520 you don't want some big thing sticking out of the patient! 302 00:18:08,020 --> 00:18:11,119 So the fact that he could make them small and convenient, 303 00:18:11,608 --> 00:18:13,639 that seems to be what made Fahrenheit 304 00:18:13,840 --> 00:18:16,417 so famous and so influential. 305 00:18:18,980 --> 00:18:21,660 It was a Swedish astronomer, Anders Celsius, 306 00:18:21,816 --> 00:18:24,299 who came up with the idea of dividing the scale 307 00:18:24,300 --> 00:18:26,039 into 100 divisions. 308 00:18:27,290 --> 00:18:31,680 The original scale used by Celsius was upside down, 309 00:18:32,060 --> 00:18:35,600 so he had the boiling point of water as zero 310 00:18:36,365 --> 00:18:38,360 and the freezing point as 100, 311 00:18:39,034 --> 00:18:41,440 with numbers just continuing to increase 312 00:18:41,637 --> 00:18:43,400 as we go below freezing. 313 00:18:44,240 --> 00:18:49,151 And this is another little mystery in the history of the thermometer 314 00:18:49,152 --> 00:18:51,377 that we just don't know for sure. 315 00:18:51,380 --> 00:18:55,140 What was he thinking when he labeled it this way? 316 00:18:55,380 --> 00:18:58,240 And it was the botanist Linnaeus, 317 00:18:59,260 --> 00:19:01,940 who was then the president of the Swedish Academy, 318 00:19:02,591 --> 00:19:06,319 who after a few years said, "We need to stop this nonsense," 319 00:19:06,496 --> 00:19:07,960 and inverted the scale 320 00:19:07,964 --> 00:19:11,799 to give us what we now call "Celsius scale" today. 321 00:19:17,273 --> 00:19:18,739 A question nobody thought to ask 322 00:19:18,839 --> 00:19:23,319 when devising temperature scales was "how low can you go?". 323 00:19:23,580 --> 00:19:26,679 Is there an absolute lower limit of temperature? 324 00:19:28,440 --> 00:19:30,180 The idea that there might be 325 00:19:30,260 --> 00:19:33,240 would become a turning point in the history of cold. 326 00:19:37,158 --> 00:19:40,880 The story begins with the French physicist Guillaume Amontons. 327 00:19:41,463 --> 00:19:46,698 He was doing experiments on heating and cooling bodies of air 328 00:19:46,699 --> 00:19:48,880 to see how they expand and contract. 329 00:19:49,980 --> 00:19:53,580 - We're now going to put ice around that bulb and see what happens. 330 00:19:53,758 --> 00:19:58,479 And he was noticing that, well, when you cool a body of air, 331 00:19:58,480 --> 00:20:01,460 the volume or the pressure would go down. 332 00:20:01,740 --> 00:20:04,663 And he speculated "Well, what would happen 333 00:20:04,664 --> 00:20:06,657 if we just kept cooling it?" 334 00:20:07,759 --> 00:20:10,319 By plotting temperature against pressure, 335 00:20:10,480 --> 00:20:13,240 Amontons saw that as the temperature dropped, 336 00:20:13,380 --> 00:20:17,640 so did the pressure, and this gave him an extraordinary idea. 337 00:20:18,199 --> 00:20:20,880 Amontons started to consider the possibility 338 00:20:21,052 --> 00:20:24,479 "What would happen if you projected this line back 339 00:20:24,480 --> 00:20:26,119 until the pressure was zero?" 340 00:20:26,219 --> 00:20:29,959 And this was the first time in the course of history 341 00:20:29,960 --> 00:20:31,879 that people actually considered 342 00:20:31,880 --> 00:20:35,060 the concept of an absolute zero of temperature. 343 00:20:35,240 --> 00:20:38,219 Zero pressure, zero temperature. 344 00:20:38,837 --> 00:20:42,100 It was quite the revolutionary idea when you think about it 345 00:20:42,200 --> 00:20:44,759 because you wouldn't just think 346 00:20:44,760 --> 00:20:49,960 that temperature has a limit of lower bound, or zero, 347 00:20:50,039 --> 00:20:54,119 because in the upper end, it can go on forever, 348 00:20:54,180 --> 00:20:57,319 we think, until it's hotter and hotter and hotter. 349 00:20:57,379 --> 00:20:59,990 But somehow, maybe there's 350 00:21:00,060 --> 00:21:02,519 a zero point where this all begins. 351 00:21:02,780 --> 00:21:06,440 So you could actually give a calculation 352 00:21:06,519 --> 00:21:10,039 of where this zero point would be. 353 00:21:10,520 --> 00:21:13,519 Amontons didn't do that calculation himself, 354 00:21:13,520 --> 00:21:16,959 but some other people did later on, and when you do it, 355 00:21:16,960 --> 00:21:19,120 you get a value that's actually not that far 356 00:21:19,200 --> 00:21:24,139 from the modern value of roughly minus 273 °C. 357 00:21:27,919 --> 00:21:30,439 In one stroke, Amontons had realized 358 00:21:30,440 --> 00:21:33,255 that although temperatures might go on rising forever, 359 00:21:33,256 --> 00:21:37,293 they could only fall as far as this absolute point. 360 00:21:37,697 --> 00:21:40,159 For him, this was a theoretical limit, 361 00:21:40,160 --> 00:21:42,903 not a goal to attempt to reach. 362 00:21:44,804 --> 00:21:48,440 Before scientists could venture towards this zero point, 363 00:21:48,541 --> 00:21:50,960 far beyond the coldest temperatures on Earth, 364 00:21:51,145 --> 00:21:54,359 they needed to resolve a fundamental question. 365 00:21:57,048 --> 00:21:59,960 By now, for most scientists, the penny had dropped 366 00:22:00,060 --> 00:22:03,160 that cold was simply the absence of heat. 367 00:22:03,188 --> 00:22:07,756 But what was actually happening as substances warmed or cooled 368 00:22:07,957 --> 00:22:10,017 was still hotly debated. 369 00:22:10,928 --> 00:22:12,918 The argument of men like Amontons 370 00:22:12,919 --> 00:22:16,659 relied completely on the idea that heat is a form of motion, 371 00:22:16,960 --> 00:22:20,780 and that particles move more and more closely together 372 00:22:20,839 --> 00:22:23,299 as the substance in which they're in 373 00:22:23,300 --> 00:22:25,119 gets cooler and cooler. 374 00:22:26,844 --> 00:22:29,199 Unfortunately, the science of cold 375 00:22:29,200 --> 00:22:31,880 was about to suffer a serious setback. 376 00:22:32,216 --> 00:22:35,911 The idea that cooling was caused by particles slowing down 377 00:22:35,912 --> 00:22:37,718 began to go out of fashion. 378 00:22:39,880 --> 00:22:41,838 At the end of the 18th century, 379 00:22:41,839 --> 00:22:44,399 a rival theory of heat and cold emerged 380 00:22:44,400 --> 00:22:48,059 that was tantalizingly appealing, but completely wrong. 381 00:22:49,600 --> 00:22:52,039 It was called "The Caloric Theory" 382 00:22:52,240 --> 00:22:54,799 and its principal advocate was the great French chemist 383 00:22:54,960 --> 00:22:56,680 Antoine Lavoisier. 384 00:23:01,913 --> 00:23:03,640 Like most scientists at the time, 385 00:23:03,880 --> 00:23:07,319 Lavoisier was a rich aristocrat who funded his own research. 386 00:23:07,800 --> 00:23:10,082 He and his wife, Madame Lavoisier, 387 00:23:10,083 --> 00:23:12,317 who assisted with his experiments, 388 00:23:12,419 --> 00:23:15,120 even commissioned the celebrated painter David 389 00:23:15,327 --> 00:23:16,820 to paint their portrait. 390 00:23:19,864 --> 00:23:21,932 Lavoisier carried out experiments 391 00:23:21,933 --> 00:23:26,159 to support the erroneous idea that heat was a substance, 392 00:23:26,160 --> 00:23:29,880 a weightless fluid that he called "caloric." 393 00:23:30,474 --> 00:23:33,720 He thought in the solid state of matter, 394 00:23:33,919 --> 00:23:36,540 molecules were just packed close in together, 395 00:23:36,800 --> 00:23:39,959 and when you added more and more caloric to this, 396 00:23:40,139 --> 00:23:42,519 the caloric would insinuate itself 397 00:23:42,600 --> 00:23:46,200 between these particles of matter and loosen them up. 398 00:23:47,858 --> 00:23:51,038 So the basic notion was that caloric was this fluid 399 00:23:51,039 --> 00:23:54,420 that was, as he put it, "self-repulsive." 400 00:23:54,600 --> 00:23:58,620 It just tended to break things apart from each other. 401 00:23:59,220 --> 00:24:02,420 And that's his basic notion of heat, 402 00:24:02,540 --> 00:24:06,200 as the cold is just the absence of caloric, 403 00:24:06,279 --> 00:24:08,360 or the relative lack of caloric. 404 00:24:11,415 --> 00:24:14,600 Lavoisier even had an apparatus to measure caloric, 405 00:24:14,853 --> 00:24:16,720 which he called a "calorimeter." 406 00:24:17,289 --> 00:24:19,559 He packed the outer compartment with ice. 407 00:24:20,025 --> 00:24:23,628 Inside, he conducted experiments that generated heat. 408 00:24:23,829 --> 00:24:25,930 Sometimes from chemical reactions, 409 00:24:26,031 --> 00:24:27,765 sometimes from animals, 410 00:24:27,766 --> 00:24:30,735 to determine how much caloric was released. 411 00:24:33,236 --> 00:24:35,559 He collected the water from the melting ice 412 00:24:35,659 --> 00:24:37,158 and weighed it to calculate 413 00:24:37,208 --> 00:24:40,410 the amount of caloric generated from each source. 414 00:24:42,046 --> 00:24:44,880 (Robert Fox) I think the most striking thing about Lavoisier 415 00:24:45,039 --> 00:24:47,440 is that he sees caloric as a substance 416 00:24:47,519 --> 00:24:51,039 which is exactly comparable with ordinary matter, 417 00:24:51,320 --> 00:24:53,519 to the point that he includes caloric 418 00:24:53,800 --> 00:24:55,619 in his list of the elements. 419 00:24:56,719 --> 00:24:59,720 It's very easy to talk about the quantity of heat 420 00:24:59,820 --> 00:25:01,960 and to think of it, as a fluid, 421 00:25:02,219 --> 00:25:04,245 whereas the talk about the quantity of heat 422 00:25:04,246 --> 00:25:05,878 and to think that it's a vibration 423 00:25:06,319 --> 00:25:09,218 of the particles of matter, which was the other alternative, 424 00:25:09,219 --> 00:25:11,619 that's much more difficult, conceptually. 425 00:25:11,819 --> 00:25:15,559 It's a very hard model to refute 426 00:25:15,759 --> 00:25:18,266 because if you can accept there's a substance 427 00:25:18,267 --> 00:25:19,717 that doesn't have any weight 428 00:25:20,029 --> 00:25:23,852 (indeed, for Lavoisier, heat, caloric, is an element. 429 00:25:24,053 --> 00:25:27,519 Is an element like oxygen or nitrogen. 430 00:25:28,068 --> 00:25:32,960 Oxygen gas is made of oxygen + caloric 431 00:25:33,480 --> 00:25:34,779 and if you take the caloric away, 432 00:25:34,780 --> 00:25:36,876 presumably the oxygen might liquify.), 433 00:25:37,477 --> 00:25:42,140 that's a very hard model to shift because it explains so much, 434 00:25:42,340 --> 00:25:44,400 and indeed, Lavoisier's chemistry 435 00:25:44,419 --> 00:25:47,400 was so otherwise extraordinarily successful. 436 00:25:47,454 --> 00:25:52,319 However, Lavoisier's story about caloric was soon undermined. 437 00:25:56,595 --> 00:25:59,880 There was one man who was convinced Lavoisier was wrong 438 00:25:59,960 --> 00:26:03,080 and was determined to destroy the caloric theory. 439 00:26:04,200 --> 00:26:07,120 His name was Count Rumford. 440 00:26:13,240 --> 00:26:15,440 Count Rumford had a colourful past. 441 00:26:15,719 --> 00:26:17,120 He was born in America, 442 00:26:17,279 --> 00:26:19,720 spied for the British during the Revolution, 443 00:26:20,040 --> 00:26:21,799 and after being forced into exile 444 00:26:21,919 --> 00:26:25,479 became an influential government minister in Bavaria. 445 00:26:28,161 --> 00:26:31,960 Among his varied responsibilities was the artillery works, 446 00:26:31,994 --> 00:26:33,878 and it was here in the 1790s 447 00:26:34,234 --> 00:26:37,764 that he began to think about how he might be able to disprove 448 00:26:37,765 --> 00:26:40,757 the caloric theory using cannon boring. 449 00:26:44,440 --> 00:26:46,318 Rumford had noticed that the friction 450 00:26:46,319 --> 00:26:50,039 from boring out a cannon barrel generated a lot of heat. 451 00:26:50,960 --> 00:26:54,619 He decided to carry out experiments to measure how much. 452 00:26:55,960 --> 00:26:59,160 He adapted the machine to produce even more heat 453 00:26:59,260 --> 00:27:01,199 by installing a blunt borer 454 00:27:01,200 --> 00:27:04,759 that had one end submerged in a jacket of water. 455 00:27:06,279 --> 00:27:08,440 As the cannon turned against the borer, 456 00:27:08,519 --> 00:27:12,759 the temperature of the water increased and eventually boiled. 457 00:27:13,839 --> 00:27:16,759 The longer he bored, the more heat was produced. 458 00:27:18,519 --> 00:27:20,200 For Rumford, what this showed was 459 00:27:20,839 --> 00:27:22,880 that heat must be a form of motion, 460 00:27:23,960 --> 00:27:25,579 and heat is not a substance, 461 00:27:25,880 --> 00:27:27,318 because you could generate 462 00:27:27,319 --> 00:27:29,600 indefinitely large amounts of heat 463 00:27:29,780 --> 00:27:32,560 simply by turning the cannon. 464 00:27:34,280 --> 00:27:36,760 Despite Count Rumford's best efforts, 465 00:27:36,860 --> 00:27:39,180 Lavoisier's caloric theory remained dominant 466 00:27:39,600 --> 00:27:41,279 until the end of the 18th-century. 467 00:27:43,103 --> 00:27:45,138 His prestige as a scientist 468 00:27:45,139 --> 00:27:47,899 meant that few dared challenge his ideas. 469 00:27:48,442 --> 00:27:50,279 Sadly this did not protect him 470 00:27:50,280 --> 00:27:52,798 from the revolutionary turmoil in France, 471 00:27:52,799 --> 00:27:55,140 which was about to interrupt his research. 472 00:27:56,116 --> 00:27:58,039 At the height of the reign of terror, 473 00:27:58,339 --> 00:28:01,960 Lavoisier was arrested and eventually guillotined. 474 00:28:03,960 --> 00:28:07,060 The reason he was guillotined was not because of his science 475 00:28:07,160 --> 00:28:09,133 but because he helped run 476 00:28:09,134 --> 00:28:13,960 the privatized income tax service of the French state. 477 00:28:14,060 --> 00:28:17,960 There's nothing more unpopular, even in France, 478 00:28:18,160 --> 00:28:21,319 than a privatized tax collector. 479 00:28:22,200 --> 00:28:25,126 Once he was guillotined, his wife left France 480 00:28:25,319 --> 00:28:28,279 and eventually met Rumford 481 00:28:28,440 --> 00:28:31,680 when he moved to Western Europe in the early 1800s. 482 00:28:32,260 --> 00:28:34,060 Rumford then married her. 483 00:28:34,139 --> 00:28:36,119 So he'd married the widow of the man 484 00:28:36,120 --> 00:28:38,480 who'd founded the theory that he destroyed. 485 00:28:40,940 --> 00:28:42,359 The marriage was short-lived. 486 00:28:42,360 --> 00:28:46,039 After a tormented year, Rumford left Madame Lavoisier 487 00:28:46,320 --> 00:28:50,120 and devoted the rest of his life to his first love, science. 488 00:28:51,839 --> 00:28:53,540 It would be nearly 50 years 489 00:28:53,619 --> 00:28:57,640 before his theory of heat and cold was finally accepted. 490 00:29:00,159 --> 00:29:02,395 A founder of the Royal Institution, 491 00:29:02,596 --> 00:29:06,160 Rumford continued to support the pursuit of science. 492 00:29:06,760 --> 00:29:09,219 And it was here that the next major breakthrough 493 00:29:09,220 --> 00:29:11,519 in the conquest of cold would occur. 494 00:29:16,520 --> 00:29:18,859 Michael Faraday, who later became famous 495 00:29:18,860 --> 00:29:21,400 for his work on electricity and magnetism, 496 00:29:21,519 --> 00:29:23,559 unwittingly carried out an experiment 497 00:29:23,759 --> 00:29:27,600 that would begin the long descent towards absolute zero. 498 00:29:27,680 --> 00:29:30,060 He was asked to explore the properties 499 00:29:30,160 --> 00:29:33,559 of a newly discovered pungent gas called chlorine. 500 00:29:34,440 --> 00:29:36,600 This experiment was potentially explosive, 501 00:29:37,080 --> 00:29:39,200 which is perhaps why it was left to Faraday 502 00:29:40,660 --> 00:29:43,039 and perhaps also why Dr. Andrew Szydlo 503 00:29:43,200 --> 00:29:45,319 is curious to repeat it today. 504 00:29:47,759 --> 00:29:49,200 We are about to undertake 505 00:29:49,319 --> 00:29:51,039 an exceedingly dangerous experiment 506 00:29:51,200 --> 00:29:55,880 in which Michael Faraday in 1823 heated this substance here, 507 00:29:55,980 --> 00:29:59,160 the hydrates of chlorine, in a sealed tube. 508 00:30:03,079 --> 00:30:03,760 Is that sealed? 509 00:30:04,000 --> 00:30:05,000 (man) That's sealed, Andrew. 510 00:30:05,079 --> 00:30:05,920 (Andrew) That's absolutely brilliant! 511 00:30:08,200 --> 00:30:09,440 In the original experiment, 512 00:30:09,519 --> 00:30:12,519 Faraday took the sealed tube and heated the end 513 00:30:12,600 --> 00:30:14,120 containing the crystals. 514 00:30:14,880 --> 00:30:16,960 He put the other end in an ice bath. 515 00:30:18,360 --> 00:30:21,880 Soon he noticed yellow chlorine gas being given off. 516 00:30:24,440 --> 00:30:26,279 (Andrew) Because the gas is being produced, 517 00:30:26,660 --> 00:30:28,000 pressure's building up. 518 00:30:29,400 --> 00:30:32,039 But because this side is so very cold, 519 00:30:32,100 --> 00:30:33,799 hopefully what we'll see 520 00:30:33,800 --> 00:30:38,948 is some tiny oily droplets of chlorine, liquid chlorine, being produced. 521 00:30:38,949 --> 00:30:41,200 It's the pressure which is causing this. 522 00:30:42,759 --> 00:30:44,759 Ray, this is where it starts to get dangerous, 523 00:30:45,360 --> 00:30:48,120 so if you'll now take a few steps back... 524 00:30:50,180 --> 00:30:53,879 When Faraday did the experiment, a visitor, Dr. Paris, 525 00:30:53,880 --> 00:30:55,860 called him to see what he was up to. 526 00:30:57,200 --> 00:31:00,559 Paris pointed out some oily matter in the bottom of the tube. 527 00:31:01,560 --> 00:31:05,160 Faraday was curious and decided to break open the tube. 528 00:31:07,600 --> 00:31:10,039 Right, so let's have a look inside here. 529 00:31:17,360 --> 00:31:20,220 The explosion sent shards of glass flying. 530 00:31:20,880 --> 00:31:22,560 With the sudden release of pressure, 531 00:31:22,619 --> 00:31:24,220 the oily liquid vanished. 532 00:31:29,360 --> 00:31:30,600 And there we are. Is that what happened? 533 00:31:30,779 --> 00:31:32,039 Yes, that's exactly what happened. 534 00:31:32,139 --> 00:31:33,839 It popped open, glass flew. 535 00:31:35,559 --> 00:31:36,579 And can you detect 536 00:31:36,580 --> 00:31:38,559 the strong smell of chlorine? - I can now. 537 00:31:38,680 --> 00:31:41,319 Absolutely. Well, he detected the strong smell of chlorine 538 00:31:41,619 --> 00:31:45,479 and this was a major mystery for him. 539 00:31:46,619 --> 00:31:49,360 Faraday soon realized the increased pressure 540 00:31:49,440 --> 00:31:53,039 inside the sealed tube had caused the gas to liquify. 541 00:31:53,739 --> 00:31:57,319 Later, he used the same technique to liquify ammonia gas. 542 00:31:57,939 --> 00:32:01,880 He noticed that on releasing the pressure, the liquid evaporated, 543 00:32:02,139 --> 00:32:04,720 triggering a dramatic drop in temperature. 544 00:32:05,439 --> 00:32:08,799 He predicted that one day this cooling might be useful: 545 00:32:10,039 --> 00:32:13,759 "There is great reason to believe that this cooling technique with ammonia 546 00:32:13,880 --> 00:32:16,039 may be successfully employed 547 00:32:16,139 --> 00:32:19,039 for the preservation of animal and vegetable substances 548 00:32:19,260 --> 00:32:21,240 for the purposes of food." 549 00:32:23,040 --> 00:32:26,625 But Faraday's idea of using ammonia as a refrigerant 550 00:32:26,626 --> 00:32:27,880 was ahead of its time. 551 00:32:28,120 --> 00:32:31,360 Besides, he had no interest in commercial exploitation. 552 00:32:35,300 --> 00:32:36,619 Across the Atlantic, 553 00:32:36,800 --> 00:32:40,039 a Yankee entrepreneur had a very different philosophy. 554 00:32:40,239 --> 00:32:43,119 and was about to commercialize cold. 555 00:32:45,020 --> 00:32:47,639 Frederic Tudor had a chance conversation with his brother 556 00:32:47,640 --> 00:32:48,960 that led him on a path 557 00:32:49,039 --> 00:32:51,200 to become one of the richest men in America. 558 00:32:59,880 --> 00:33:01,440 (Dennis Picard) The story goes, at the dinner table 559 00:33:01,819 --> 00:33:04,740 they were trying to decide what they had on their father's farm 560 00:33:04,759 --> 00:33:05,959 they could make money off of. 561 00:33:05,960 --> 00:33:07,680 And certainly there was a lot of rocks, 562 00:33:07,839 --> 00:33:09,120 but people weren't going to pay for that, 563 00:33:09,479 --> 00:33:11,519 so they came up with the idea of maybe ice, 564 00:33:11,600 --> 00:33:13,200 'cause some areas did not have ice. 565 00:33:13,640 --> 00:33:17,400 And it seemed kind of crazy at first, but it paid off. 566 00:33:19,779 --> 00:33:22,960 When Tudor began harvesting ice from New England ponds, 567 00:33:23,120 --> 00:33:25,880 he soon realised he needed specialised tools 568 00:33:25,960 --> 00:33:27,600 to keep up with the huge demand. 569 00:33:28,080 --> 00:33:29,700 (Dennis Picard) We had the saws, 570 00:33:30,039 --> 00:33:34,279 and the saws were an improvement over the old wood saws. 571 00:33:34,440 --> 00:33:36,680 They have teeth that are sharpened on both sides 572 00:33:36,959 --> 00:33:39,959 and set, so it cuts on both the up and the down stroke. 573 00:33:43,360 --> 00:33:47,440 The crew could clear a 3-acre pond easily in a couple of days. 574 00:33:55,839 --> 00:33:58,519 Tudor's dream to make ice available to all 575 00:33:58,600 --> 00:34:00,279 was not confined to New England. 576 00:34:00,960 --> 00:34:02,980 He wanted to ship ice to hot parts of the world 577 00:34:03,180 --> 00:34:05,440 like the Caribbean and the deep South. 578 00:34:07,519 --> 00:34:10,399 (Dennis Picard) When Tudor first tried to convince shipmasters 579 00:34:10,480 --> 00:34:13,399 to put his load of frozen water into the ships, 580 00:34:13,660 --> 00:34:15,479 they all refused, 'cause they told him 581 00:34:15,480 --> 00:34:17,799 that water belonged outside the hull, not inside. 582 00:34:18,179 --> 00:34:22,159 So he had to go find other investors to get the money 583 00:34:22,160 --> 00:34:24,159 to buy his own ship, and he bought a ship 584 00:34:24,160 --> 00:34:25,239 by the name of the "Favorite." 585 00:34:29,640 --> 00:34:32,519 New England became the refrigerator for the world, 586 00:34:32,799 --> 00:34:34,580 with ice shipments to the Caribbean, 587 00:34:34,640 --> 00:34:37,239 the coast of South America and Europe. 588 00:34:38,019 --> 00:34:40,440 Tudor even reached India and China. 589 00:34:41,879 --> 00:34:44,580 Watching the ice cutters working Walden Pond, 590 00:34:44,860 --> 00:34:48,339 Henry Thoreau marveled that water from his bathing beach 591 00:34:48,599 --> 00:34:50,499 was traveling halfway around the globe 592 00:34:50,680 --> 00:34:53,899 to end up in the cup of an East Indian philosopher. 593 00:34:56,640 --> 00:34:59,640 Tudor, who soon became known as the "Ice King," 594 00:34:59,820 --> 00:35:03,660 began using horses and huge teams of workers to harvest 595 00:35:03,740 --> 00:35:07,519 larger and larger lakes as the demand for ice grew. 596 00:35:10,740 --> 00:35:14,318 During the latter half of the 19th century, the ice industry 597 00:35:14,319 --> 00:35:17,599 eventually employed tens of thousands of people. 598 00:35:24,319 --> 00:35:28,239 (Dennis Picard) Tudor became the largest distributor of ice, 599 00:35:28,319 --> 00:35:31,239 and he became one of the first American millionaires. 600 00:35:31,619 --> 00:35:33,160 And we're talking about one of his ships 601 00:35:33,239 --> 00:35:37,239 going to the Caribbean giving him a profit of $6,000! 602 00:35:37,319 --> 00:35:39,720 Now, this is in a time period when people were earning 603 00:35:39,799 --> 00:35:42,560 $200 to $300 a year, the average family. 604 00:35:42,640 --> 00:35:45,799 So someone earning thousands of dollars was just inconceivable, 605 00:35:45,979 --> 00:35:50,080 and that would be losing 20% of your ice when it got there. 606 00:35:50,160 --> 00:35:51,899 There was still huge amounts of profit. 607 00:35:55,720 --> 00:35:56,879 Tudor's success was based 608 00:35:57,000 --> 00:35:59,599 on an extraordinary physical property of ice: 609 00:36:00,080 --> 00:36:02,920 it takes the same amount of heat to melt a block of ice 610 00:36:03,099 --> 00:36:05,640 as it does to heat a similar quantity of water 611 00:36:05,920 --> 00:36:08,519 to around 80 °C. 612 00:36:08,599 --> 00:36:11,499 This meant that ice took a long time to melt, 613 00:36:11,799 --> 00:36:13,799 even when shipped to hotter climates. 614 00:36:23,799 --> 00:36:26,399 What started out as a small family enterprise 615 00:36:26,480 --> 00:36:28,000 turned into a global business. 616 00:36:28,680 --> 00:36:31,280 Frederic Tudor had industrialised cold 617 00:36:31,660 --> 00:36:32,399 in the same way 618 00:36:32,480 --> 00:36:35,339 the great pioneers of steam had harnessed heat. 619 00:36:40,000 --> 00:36:43,920 By the 1830s, the Industrial Revolution was in full swing. 620 00:36:45,399 --> 00:36:48,740 Yet ironically, it was not until a small group of scientists 621 00:36:49,280 --> 00:36:50,879 worked out the underlying principles 622 00:36:51,100 --> 00:36:54,319 of how steam engines convert heat into motion 623 00:36:54,699 --> 00:36:57,780 that the next step in the conquest of cold could be made. 624 00:36:58,539 --> 00:37:01,300 Only after solving this riddle of heat engines 625 00:37:01,380 --> 00:37:03,720 could the first cold engines be made 626 00:37:03,799 --> 00:37:06,380 to produce artificial refrigeration. 627 00:37:11,639 --> 00:37:13,200 How much useful work 628 00:37:13,260 --> 00:37:16,680 can you get out of a given amount of heat? 629 00:37:17,199 --> 00:37:20,040 By the early 1800s, that had become 630 00:37:20,320 --> 00:37:24,740 the single most important economic problem in Europe. 631 00:37:27,879 --> 00:37:32,079 To make a profit was to convert heat into motion 632 00:37:32,080 --> 00:37:34,399 efficiently, without wasting heat, 633 00:37:34,880 --> 00:37:38,560 and getting the maximum amount of mechanical effect. 634 00:37:47,239 --> 00:37:49,720 The first person to really engage with this problem 635 00:37:49,899 --> 00:37:53,239 was a young French artillery engineer, Sadi Carnot. 636 00:37:54,160 --> 00:37:56,959 He thought that improving the efficiency of steam engines 637 00:37:57,180 --> 00:37:59,319 might help France's flagging economy 638 00:37:59,399 --> 00:38:01,160 after defeat at Waterloo in 1815. 639 00:38:01,239 --> 00:38:05,000 Working at the Conservatoire des Arts et Mètiers, 640 00:38:05,080 --> 00:38:07,160 he began to analyze how a steam engine 641 00:38:07,239 --> 00:38:10,380 was able to turn heat into mechanical work. 642 00:38:13,120 --> 00:38:17,799 The originality of Carnot's treatement, in my eyes, 643 00:38:17,979 --> 00:38:23,399 is essentially that he shows that in order to extract energy, 644 00:38:23,480 --> 00:38:25,640 to extract work from the heat engine, 645 00:38:25,820 --> 00:38:29,959 you need a high temperature source, which is the boiler, 646 00:38:30,300 --> 00:38:33,720 and you need a low temperature, which is that of the condenser. 647 00:38:34,099 --> 00:38:36,799 And the essence of the heat engine for Carnot 648 00:38:37,179 --> 00:38:41,080 is that heat passes from the high temperature of the boiler 649 00:38:41,160 --> 00:38:43,799 to the low temperature of the condenser. 650 00:38:45,559 --> 00:38:48,159 In steam engines, it looks as though 651 00:38:48,257 --> 00:38:51,660 heat is flowing around the engine, 652 00:38:51,861 --> 00:38:55,864 and as it flows, the engine does mechanical work. 653 00:39:01,499 --> 00:39:02,980 The implication there 654 00:39:03,060 --> 00:39:07,119 is that heat is neither consumed nor destroyed. 655 00:39:07,299 --> 00:39:10,699 You simply circulate it around, and it does work. 656 00:39:10,799 --> 00:39:14,799 So, there the analogy would be between heat, in a steam engine, 657 00:39:14,899 --> 00:39:17,799 and water, in a water wheel. 658 00:39:18,099 --> 00:39:19,799 It's though it's the flow of heat 659 00:39:20,299 --> 00:39:23,840 that's actually getting the work done in the standard steam engine. 660 00:39:26,160 --> 00:39:28,319 Carnot likened this flow of heat 661 00:39:28,399 --> 00:39:30,560 to the flow of water over a waterwheel. 662 00:39:33,300 --> 00:39:35,799 He saw that the amount of mechanical work produced 663 00:39:35,979 --> 00:39:38,319 depended on how far the water fell. 664 00:39:42,879 --> 00:39:46,399 His novel idea was that steam engines worked in a similar way, 665 00:39:46,680 --> 00:39:49,319 except this fall was a fall in temperature 666 00:39:49,599 --> 00:39:52,399 from the hottest to the coldest part of the engine. 667 00:39:53,160 --> 00:39:54,640 The greater the temperature difference, 668 00:39:54,920 --> 00:39:56,480 the more work was produced. 669 00:40:00,100 --> 00:40:02,419 Carnot distilled these profound ideas 670 00:40:02,499 --> 00:40:04,720 into an accessible book for general readers, 671 00:40:04,999 --> 00:40:07,799 which meant it was largely ignored by scientists 672 00:40:08,219 --> 00:40:10,640 instead of being heralded as a classic. 673 00:40:12,780 --> 00:40:13,560 Well, this is the book. 674 00:40:13,640 --> 00:40:15,640 It's Carnot's only publication. 675 00:40:15,799 --> 00:40:18,560 "Reflections on the Motive Power of Fire" of 1824, 676 00:40:19,399 --> 00:40:21,720 a small book, 118 pages only, 677 00:40:21,879 --> 00:40:24,160 published just 600 copies, 678 00:40:24,539 --> 00:40:28,020 and in his own lifetime, it's virtually unknown. 679 00:40:28,399 --> 00:40:30,559 Twenty years after the publication, 680 00:40:30,560 --> 00:40:33,699 William Thompson, the Scottish physicist, 681 00:40:34,119 --> 00:40:37,000 is absolutely intent on finding a copy. 682 00:40:37,080 --> 00:40:40,720 He's here in Paris, and the accounts we have suggest 683 00:40:40,799 --> 00:40:42,879 that he spends a great deal of time 684 00:40:43,000 --> 00:40:46,399 visiting bookshops, visiting the bouquinistes 685 00:40:46,599 --> 00:40:48,319 on the banks of the Seine 686 00:40:48,699 --> 00:40:51,000 looking, always asking for the book, 687 00:40:51,080 --> 00:40:55,080 and the booksellers tell him they've never even heard of it. 688 00:41:00,799 --> 00:41:04,319 Back then, William Thompson, who would later become Lord Kelvin, 689 00:41:04,599 --> 00:41:07,319 a giant in this new field of thermodynamics, 690 00:41:07,699 --> 00:41:11,000 was impressed by Carnot's idea that the movement of heat 691 00:41:11,200 --> 00:41:13,599 produced useful work in the machine. 692 00:41:14,840 --> 00:41:15,874 But when he returned home, 693 00:41:16,079 --> 00:41:18,155 he heard about an alternative theory 694 00:41:18,260 --> 00:41:21,160 from a Manchester brewer called James Joule. 695 00:41:23,899 --> 00:41:27,160 Joule had this notion that Carnot was wrong, 696 00:41:27,539 --> 00:41:32,180 that heat wasn't producing work just by its movement. 697 00:41:32,360 --> 00:41:35,560 Heat was actually turning into mechanical work, 698 00:41:35,660 --> 00:41:38,959 which is a very strange idea when you think about it. 699 00:41:39,000 --> 00:41:41,559 We're all now used to thinking about energy 700 00:41:41,560 --> 00:41:43,920 and how it can take all different forms, 701 00:41:43,899 --> 00:41:46,239 but it was a revolutionary idea 702 00:41:46,319 --> 00:41:50,180 that heat and something like mechanical energy 703 00:41:50,260 --> 00:41:53,000 were, at bottom, the same kind of thing. 704 00:41:57,319 --> 00:41:59,560 The experiment that convinced Joule of this 705 00:41:59,640 --> 00:42:01,720 was set up in the cellar of his brewery. 706 00:42:02,099 --> 00:42:04,799 It converted mechanical movement into heat, 707 00:42:04,979 --> 00:42:07,519 almost like a steam engine in reverse. 708 00:42:13,319 --> 00:42:14,959 He used falling weights 709 00:42:15,000 --> 00:42:17,999 to drive paddles around the drum of water. 710 00:42:18,760 --> 00:42:20,480 The friction from this process 711 00:42:20,660 --> 00:42:22,640 generated a minute amount of heat. 712 00:42:25,860 --> 00:42:28,719 Only brewers had thermometers accurate enough 713 00:42:28,720 --> 00:42:31,000 to register this tiny temperature increase 714 00:42:31,360 --> 00:42:34,179 caused by a measured amount of mechanical work. 715 00:42:35,940 --> 00:42:39,799 Joule's work mattered because it was the first time 716 00:42:40,279 --> 00:42:43,079 that anyone had convincingly measured 717 00:42:43,300 --> 00:42:48,080 the exchange rate between movement and heat. 718 00:42:49,780 --> 00:42:53,798 He proved the existence of something 719 00:42:53,799 --> 00:42:58,160 that converts between heat and motion. 720 00:42:59,600 --> 00:43:02,300 That something was going to be called "energy" 721 00:43:02,680 --> 00:43:06,680 and it's for that reason that the basic unit of energy 722 00:43:06,860 --> 00:43:09,000 in the new International System of Units 723 00:43:09,180 --> 00:43:11,380 is named after him: the Joule. 724 00:43:13,419 --> 00:43:16,481 This apparent contradiction between Joule and Carnot 725 00:43:16,482 --> 00:43:18,517 was eventually resolved by Thomson 726 00:43:18,640 --> 00:43:21,959 in what would later become known as "the laws of thermodynamics". 727 00:43:23,919 --> 00:43:26,480 The first law, from Joule's work, states 728 00:43:26,560 --> 00:43:29,639 that, "Energy can be converted from one form to another, 729 00:43:29,640 --> 00:43:32,799 but can never be created or destroyed." 730 00:43:34,480 --> 00:43:37,480 The 2nd law, from Carnot's theory, states that, 731 00:43:37,560 --> 00:43:41,699 "Heat flows in one direction only, from hot to cold." 732 00:44:07,260 --> 00:44:09,160 In the 2nd half of the 19th century, 733 00:44:09,239 --> 00:44:12,920 this new concept of energy paved the way for steam power 734 00:44:12,999 --> 00:44:15,079 to artificially produce cold. 735 00:44:17,179 --> 00:44:19,339 The flow of heat, from hot to cold, 736 00:44:19,340 --> 00:44:21,077 drives any refrigeration cycle 737 00:44:21,379 --> 00:44:22,978 whether it's a modern fridge 738 00:44:22,979 --> 00:44:25,758 or a steam powered ice-making machine. 739 00:44:32,959 --> 00:44:34,319 In the first stage of this cycle, 740 00:44:34,399 --> 00:44:38,280 gigantic pistons compress ammonia gas into a hot liquid. 741 00:44:40,480 --> 00:44:43,959 The hot liquified ammonia is pumped into a condenser 742 00:44:45,119 --> 00:44:46,699 where it is cooled 743 00:44:49,160 --> 00:44:52,079 and fed into pipes beneath the water tanks. 744 00:44:57,860 --> 00:45:00,499 In the next stage the liquid ammonia re-evaporates, 745 00:45:00,760 --> 00:45:02,260 and the temperature drops. 746 00:45:04,399 --> 00:45:07,419 As the ammonia re-absorbs heat from the surrounding water, 747 00:45:07,599 --> 00:45:11,360 gradually, the tanks of water become blocks of ice. 748 00:45:14,879 --> 00:45:17,480 By the 1880's, many towns across America 749 00:45:17,560 --> 00:45:19,239 had ice plants like this one, 750 00:45:19,319 --> 00:45:22,619 which could produce 150 tons of ice a day. 751 00:45:24,280 --> 00:45:27,000 For the first time, artificially produced ice 752 00:45:27,080 --> 00:45:29,480 was threatening the natural ice trade 753 00:45:29,560 --> 00:45:31,560 created by Frederic Tudor. 754 00:45:35,640 --> 00:45:38,380 America's appetite for ice was insatiable. 755 00:45:39,319 --> 00:45:40,879 Slaughterhouses, breweries, 756 00:45:40,959 --> 00:45:43,620 and food warehouses, all needed ice. 757 00:45:44,579 --> 00:45:47,439 Animals were disassembled on production lines in Chicago 758 00:45:47,939 --> 00:45:50,560 and the meat was loaded into ice-cooled boxcars 759 00:45:50,640 --> 00:45:52,239 to be shipped by railroad. 760 00:45:53,560 --> 00:45:54,799 Livestock on its way 761 00:45:54,979 --> 00:45:57,020 to the great meat-packing centers of the nation, 762 00:45:57,560 --> 00:45:58,480 to markets everywhere. 763 00:45:59,399 --> 00:46:00,560 Food of every sort 764 00:46:00,640 --> 00:46:03,519 safely and quickly delivered in refrigerator cars. 765 00:46:04,399 --> 00:46:06,319 From New York to Los Angeles 766 00:46:06,599 --> 00:46:08,318 restaurants were able to serve 767 00:46:08,319 --> 00:46:12,640 thousands of miles from where their meals once roamed. 768 00:46:14,159 --> 00:46:16,959 As fruit and vegetables became available out of season, 769 00:46:17,300 --> 00:46:20,319 urban diets improved, making city dwellers 770 00:46:20,599 --> 00:46:22,399 the best-fed people in the world. 771 00:46:25,160 --> 00:46:26,560 And to keep everything fresh at home, 772 00:46:26,840 --> 00:46:29,000 the iceman made his weekly delivery 773 00:46:29,380 --> 00:46:31,000 to recharge the refrigerator. 774 00:46:35,480 --> 00:46:38,202 (Tom Schachtman) Refrigeration makes a tremendous difference in people's lives. 775 00:46:38,203 --> 00:46:39,078 First of all, in the diet, 776 00:46:39,079 --> 00:46:41,000 what is possible for them to eat. 777 00:46:42,080 --> 00:46:43,080 They can go to the store once a week. 778 00:46:43,160 --> 00:46:44,480 They don't have to go every day. 779 00:46:44,720 --> 00:46:46,319 They can obtain at that store 780 00:46:47,239 --> 00:46:49,000 foods that are from almost anywhere in the world 781 00:46:49,319 --> 00:46:51,080 that have been transported and kept cool, 782 00:46:51,399 --> 00:46:53,179 and then they can keep them in their own home. 783 00:46:54,480 --> 00:46:56,599 Eventually the iceman disappeared 784 00:46:56,680 --> 00:46:59,560 as more and more households bought electric fridges. 785 00:47:02,560 --> 00:47:04,778 These used the same basic principles 786 00:47:04,779 --> 00:47:06,879 as the old ice-making machines. 787 00:47:07,299 --> 00:47:08,727 Heat from the food inside 788 00:47:08,728 --> 00:47:10,998 is drained away by the evaporating coolant 789 00:47:11,080 --> 00:47:13,239 and is dumped, at the back. 790 00:47:13,439 --> 00:47:15,839 The electric pump drives this cycle 791 00:47:15,840 --> 00:47:18,797 of compression, evaporation and condensation. 792 00:47:20,239 --> 00:47:22,560 And that's how the fridge got its hum. 793 00:47:24,720 --> 00:47:27,180 The electric power companies loved refrigerators 794 00:47:27,360 --> 00:47:29,000 because they ran all day and all night. 795 00:47:29,380 --> 00:47:31,639 They may not have used that much power for each hour, 796 00:47:31,640 --> 00:47:33,160 but they continued to use that. 797 00:47:33,239 --> 00:47:36,239 So one of the ways that they sold rural electrification 798 00:47:36,319 --> 00:47:39,080 was the possibility of having your own refrigerator. 799 00:47:40,879 --> 00:47:41,799 In the early days, 800 00:47:41,879 --> 00:47:45,080 the fridge's icebox was used to freeze water, nothing else. 801 00:47:45,699 --> 00:47:47,339 Freezing was seen as having 802 00:47:47,419 --> 00:47:49,539 the same damaging effects as frost. 803 00:47:55,480 --> 00:47:57,959 The man who would change this idea forever 804 00:47:58,200 --> 00:48:02,519 was a scientist and explorer called Clarence Birdseye. 805 00:48:03,160 --> 00:48:07,099 In 1912, Birdseye set off on an expedition to Labrador, 806 00:48:08,840 --> 00:48:12,380 and the temperature dropped to 40 degrees below freezing. 807 00:48:22,319 --> 00:48:25,480 The Inuit had taught Birdseye how to ice fish. 808 00:48:28,600 --> 00:48:31,158 He cut a hole down in the ice which could be several feet thick, 809 00:48:31,159 --> 00:48:33,160 the fish were on the pool and lined down below, 810 00:48:33,280 --> 00:48:34,319 bring the fish up. 811 00:48:34,399 --> 00:48:35,640 And as he did that, 812 00:48:35,720 --> 00:48:38,679 he found that they'd freezed in this terribly cold air, 813 00:48:39,160 --> 00:48:40,720 almost before they hit the shoulder. 814 00:48:42,879 --> 00:48:44,640 (Tom Schachtman) When you went to cook this fish, 815 00:48:44,820 --> 00:48:46,560 it tasted just as good as if fresh, 816 00:48:47,000 --> 00:48:48,160 and he couldn't figure that out, 817 00:48:48,239 --> 00:48:50,280 because when he froze fish at home, 818 00:48:51,319 --> 00:48:52,539 they would taste terrible. 819 00:48:53,239 --> 00:48:54,480 So when he got back home, 820 00:48:54,560 --> 00:48:56,640 he finally tried to figure out what was the difference 821 00:48:56,820 --> 00:48:59,840 between this quick freezing and the usual freezing. 822 00:49:05,319 --> 00:49:06,720 Under closer examination, 823 00:49:06,999 --> 00:49:09,460 he could see what was happening to the fish cells. 824 00:49:12,000 --> 00:49:15,560 With slow freezing, large ice crystals formed, 825 00:49:15,640 --> 00:49:18,100 which distorted and ruptured the cells. 826 00:49:18,640 --> 00:49:20,720 When thawed, the tissue collapsed 827 00:49:20,799 --> 00:49:23,860 and all the nutrients and flavor washed away. 828 00:49:25,679 --> 00:49:27,580 That's the "mushy strawberry" syndrome. 829 00:49:27,880 --> 00:49:29,865 A people's fruit, the freezed strawberries 830 00:49:29,866 --> 00:49:31,478 that they picked in their garden, 831 00:49:32,080 --> 00:49:34,679 and they put them out on the table the next day 832 00:49:34,680 --> 00:49:36,920 and they, they're collapsed, they're all mushy. 833 00:49:37,959 --> 00:49:39,080 But with fast freezing, 834 00:49:39,239 --> 00:49:42,319 only tiny ice crystals were formed inside the cells, 835 00:49:42,399 --> 00:49:44,319 and these caused little damage. 836 00:49:45,599 --> 00:49:48,239 It was all down to the speed of the freezing zone. 837 00:49:50,339 --> 00:49:54,078 What Birdseye found out is that you can get through this zone very quickly: 838 00:49:54,079 --> 00:49:55,997 flash freezing or quick freezing. 839 00:49:56,300 --> 00:49:58,160 You'll avoid this ice crystalization. 840 00:49:58,640 --> 00:50:03,490 And that made it possible for the food, when it's unfrozen and cooked, 841 00:50:03,891 --> 00:50:05,738 to taste just as good as fresh. 842 00:50:07,799 --> 00:50:11,319 The basic concept was simple, but it took Clarence Birdseye 843 00:50:11,399 --> 00:50:13,080 another 10 years to perfect 844 00:50:13,160 --> 00:50:15,720 a commercial fast-freezing technique 845 00:50:15,799 --> 00:50:19,679 that would mimic the natural process he'd experienced in Labrador. 846 00:50:21,480 --> 00:50:24,459 In 1924, he opened a flash freezing plant 847 00:50:24,460 --> 00:50:26,159 in Gloucester, Massachusetts 848 00:50:26,160 --> 00:50:30,159 that froze freshly landed fish at minus 45 degrees. 849 00:50:33,160 --> 00:50:36,059 He then extended that to all sorts of other kinds of meats 850 00:50:36,080 --> 00:50:39,480 and products and vegetables and almost single-handedly 851 00:50:39,760 --> 00:50:41,780 invented the frozen food industry. 852 00:50:43,080 --> 00:50:46,640 Fridges and freezers would eventually become icons of modern living, 853 00:50:47,319 --> 00:50:49,639 but there was a less visible cold transformation 854 00:50:49,640 --> 00:50:51,160 happening at the same time. 855 00:50:52,080 --> 00:50:55,080 This would also have a huge impact on urban living: 856 00:50:56,480 --> 00:50:58,680 the cooling of the air itself. 857 00:51:00,480 --> 00:51:03,319 Three centuries had passed since Cornelius Drebbel 858 00:51:03,399 --> 00:51:06,000 had shaken King James in Westminster. 859 00:51:06,560 --> 00:51:08,640 Now at the dawn of the 20th century, 860 00:51:08,720 --> 00:51:12,080 air cooling was about to shake the world. 861 00:51:13,319 --> 00:51:16,480 Tell me, what is the low down on this air-conditioning thing? 862 00:51:16,879 --> 00:51:18,799 Now you've started something by asking me that. 863 00:51:24,399 --> 00:51:27,160 Air-conditioning was about to transform America, 864 00:51:27,519 --> 00:51:30,279 and the person responsible was Willis Carrier, 865 00:51:30,679 --> 00:51:35,259 whose important breakthrough passed into comfort cooling mythology. 866 00:51:37,400 --> 00:51:39,340 Let's go back to that foggy night, 867 00:51:39,341 --> 00:51:41,663 when the young engineer named Willis Carrier 868 00:51:41,764 --> 00:51:43,517 sought the answer to a problem. 869 00:51:44,000 --> 00:51:48,100 The effects of humidity, of moist air, on industrial production. 870 00:51:48,400 --> 00:51:50,920 "Fog! Maybe that's the answer. 871 00:51:51,899 --> 00:51:52,938 Let's see. 872 00:51:53,580 --> 00:51:55,840 Fog is water vapour, that's been condensed. 873 00:51:56,100 --> 00:51:58,652 That's because the air has become cooler 874 00:51:58,653 --> 00:52:01,599 and cool air can't hold as much moisture as warm air. 875 00:52:02,300 --> 00:52:04,599 Maybe that's the way to reduce humidity. 876 00:52:05,000 --> 00:52:07,840 Cool the air and condense the moisture. 877 00:52:08,500 --> 00:52:09,600 It might work." 878 00:52:11,200 --> 00:52:13,840 Control the humidity through control the temperature. 879 00:52:14,140 --> 00:52:16,399 That was Willis Carrier's idea. 880 00:52:19,879 --> 00:52:24,720 (Marsha Ackermann) Carrier is sent to Brooklyn for a very special job in 1902. 881 00:52:25,720 --> 00:52:30,319 The company that publishes the magazine "Judge", 882 00:52:30,399 --> 00:52:35,000 one of the most popular full-color magazines in America 883 00:52:35,100 --> 00:52:38,160 at this particular time, is having a huge problem. 884 00:52:38,539 --> 00:52:43,678 It's July in Brooklyn and the ink which they use 885 00:52:43,679 --> 00:52:46,920 on their beautiful covers is sliding off the pages. 886 00:52:47,099 --> 00:52:50,160 It will not stick because the humidity is too high. 887 00:52:53,319 --> 00:52:56,720 Carrier, using some principles that he's been developing 888 00:52:56,799 --> 00:53:00,999 as a young new employee of this fan company, finds a way 889 00:53:01,079 --> 00:53:05,280 to get out the July 1902 run of the "Judge" magazine, 890 00:53:05,560 --> 00:53:07,640 and from there he begins 891 00:53:07,720 --> 00:53:10,599 to eventually build his air-conditioning empire. 892 00:53:14,019 --> 00:53:16,720 The demand for air-conditioning gradually grew. 893 00:53:17,499 --> 00:53:19,316 In the 1920's, movie houses 894 00:53:19,317 --> 00:53:22,000 were among the first to promote the benefits. 895 00:53:22,380 --> 00:53:25,920 People would flock there in summer to shelter from the heat. 896 00:53:26,939 --> 00:53:30,080 (Marsha Ackermann) The movies are wildly popular, and the air-conditioning 897 00:53:30,160 --> 00:53:32,160 certainly helps to attract an audience, 898 00:53:32,239 --> 00:53:34,239 especially if they happen to be walking down the street 899 00:53:34,319 --> 00:53:37,000 on a horribly hot day and they duck into this movie theater 900 00:53:37,080 --> 00:53:38,480 and have this wonderful experience. 901 00:53:42,799 --> 00:53:46,319 Air-conditioning became increasingly common in the workplace too, 902 00:53:46,399 --> 00:53:50,000 particularly in the South, where textile and tobacco factories 903 00:53:50,080 --> 00:53:52,799 were almost unbearable without cooling. 904 00:53:54,720 --> 00:53:57,560 (man) When employees breath good air and feel comfortable, 905 00:53:57,860 --> 00:54:00,519 they work faster and do a better job. 906 00:54:00,780 --> 00:54:01,559 I think some people think 907 00:54:01,560 --> 00:54:04,599 that these were nice compassionate employers 908 00:54:04,679 --> 00:54:06,939 who were cooling down the workplace for the workers, 909 00:54:07,039 --> 00:54:09,080 but of course, nothing could be further from the truth. 910 00:54:09,160 --> 00:54:12,560 That was an inadvertent by-product, 911 00:54:12,640 --> 00:54:16,160 but actually this was a quality control device 912 00:54:16,239 --> 00:54:19,720 to control the breaking of fibers in cotton mills 913 00:54:19,999 --> 00:54:24,959 to get consistent quality control in these various industries 914 00:54:25,000 --> 00:54:27,160 to control the dust that had bedeviled 915 00:54:27,239 --> 00:54:31,319 tobacco stemming room workers for decades. 916 00:54:32,080 --> 00:54:35,860 I mean, I think the workers obviously went home 917 00:54:36,079 --> 00:54:39,860 and to their unair-conditioned shacks in most cases 918 00:54:39,920 --> 00:54:44,840 and talked about how nice and cool it was working during the day. 919 00:54:45,740 --> 00:54:48,440 Well, as anybody will tell you who's lived here for very long. 920 00:54:48,740 --> 00:54:51,058 Even today, on the age of the air conditioning 921 00:54:51,059 --> 00:54:54,000 we've so plenty of sun and sweat and humidity 922 00:54:54,101 --> 00:54:55,679 it's something you just have to deal with. 923 00:54:55,980 --> 00:54:57,620 It's silly to suffer from the heat 924 00:54:57,699 --> 00:55:00,499 when you can afford the modest cost of air-conditioning. 925 00:55:01,539 --> 00:55:04,839 By the 1950's, people were air-conditioning their homes 926 00:55:04,840 --> 00:55:08,399 with stand-alone window units that could be easily installed. 927 00:55:09,080 --> 00:55:10,840 This wasn't just an appliance; 928 00:55:11,120 --> 00:55:13,680 it offered a new, cool way of life. 929 00:55:26,239 --> 00:55:29,080 (Raymond Arsenault) Walking down a typical Southern street 930 00:55:29,360 --> 00:55:31,360 prior to the air-conditioning revolution, 931 00:55:31,760 --> 00:55:35,519 you would have seen families, individuals, outside. 932 00:55:35,520 --> 00:55:37,078 They would have been on their porches, 933 00:55:37,079 --> 00:55:38,839 on each other's porches. 934 00:55:38,840 --> 00:55:41,599 There was a visiting tradition, a real sense of community. 935 00:55:46,000 --> 00:55:47,720 Well, I think all that changes with air-conditioning. 936 00:55:48,120 --> 00:55:51,479 You walk down that same street and basically what you'll hear 937 00:55:51,480 --> 00:55:53,798 are not the voices of people talking on the porch; 938 00:55:53,799 --> 00:55:55,440 you'll hear the whirr of the compressors. 939 00:56:00,000 --> 00:56:01,080 Guess what we've got! 940 00:56:02,899 --> 00:56:04,959 An RCA room air conditioner. 941 00:56:05,780 --> 00:56:09,238 I'm a woman, and I know how much pure air means to mother 942 00:56:09,239 --> 00:56:12,180 in keeping our rooms clean and free from dust and dirt. 943 00:56:20,640 --> 00:56:23,480 Control of the cold has transformed city life. 944 00:56:25,959 --> 00:56:28,840 Refrigeration helped cities expand outwards 945 00:56:29,319 --> 00:56:31,000 by enabling large numbers of people 946 00:56:31,080 --> 00:56:33,640 to live at great distances from their source of food. 947 00:56:39,699 --> 00:56:43,080 Air-conditioning enabled cities to expand upwards. 948 00:56:44,080 --> 00:56:48,079 Beyond 20 stories, high winds make open windows impractical, 949 00:56:49,060 --> 00:56:50,719 but with air-conditioning, 950 00:56:50,720 --> 00:56:53,439 100-story skyscrapers were possible. 951 00:56:59,319 --> 00:57:01,560 (Simon Schaffer) Technologies emerged, 952 00:57:01,640 --> 00:57:03,399 which not only worked 953 00:57:03,680 --> 00:57:08,080 to insulate human society against the evils of cold, 954 00:57:08,460 --> 00:57:11,160 but turned cold into a productive, 955 00:57:11,239 --> 00:57:14,239 manageable, effective resource. 956 00:57:14,879 --> 00:57:16,879 On the one hand, the steam engine; 957 00:57:17,259 --> 00:57:19,239 on the other, the refrigerator, 958 00:57:20,000 --> 00:57:23,760 those 2 great symbols of 19th-century world, 959 00:57:24,239 --> 00:57:28,640 which completely changed the society and economy of the planet. 960 00:57:30,760 --> 00:57:33,319 All that is part of, I think, 961 00:57:33,399 --> 00:57:36,020 what we could call bringing cold to market. 962 00:57:36,239 --> 00:57:39,699 Turning it from an evil agent that you feared 963 00:57:40,000 --> 00:57:43,399 into a force of nature from which you could profit. 964 00:57:46,560 --> 00:57:48,879 The explosive growth of the modern world 965 00:57:49,000 --> 00:57:50,560 over the last two centuries 966 00:57:50,640 --> 00:57:52,879 owes much to the conquest of cold. 967 00:57:53,640 --> 00:57:54,999 But this is only the beginning 968 00:57:55,000 --> 00:57:57,399 of the journey down the temperature scale. 969 00:57:58,399 --> 00:58:00,720 Going lower would be even harder, 970 00:58:01,160 --> 00:58:02,799 but would produce greater wonders 971 00:58:02,979 --> 00:58:06,200 that promise extraordinary innovations for the future. 972 00:58:08,680 --> 00:58:11,720 With rival scientists racing towards the final frontier, 973 00:58:12,160 --> 00:58:15,840 the pace quickens and the molecular dance slows 974 00:58:16,560 --> 00:58:21,319 as they approach the Holy Grail of cold: absolute zero.