1 00:00:01,320 --> 00:00:04,240 Speaker 1: Welcome to Stuff you missed in History Class, A production 2 00:00:04,400 --> 00:00:14,080 Speaker 1: of iHeartRadio. Hello, and welcome to the podcast. I'm Holly 3 00:00:14,120 --> 00:00:18,120 Speaker 1: Frye and I'm Tracy V. Wilson. Hey. This is yet 4 00:00:18,160 --> 00:00:22,480 Speaker 1: another instance of one episode tangentially inspiring another that happens 5 00:00:22,520 --> 00:00:24,720 Speaker 1: a lot. It does lately, it happens a lot more 6 00:00:24,720 --> 00:00:30,520 Speaker 1: than usual. I don't know why that is. I first 7 00:00:30,560 --> 00:00:35,200 Speaker 1: came into contact with Frenelle lenses in college, but then 8 00:00:36,040 --> 00:00:40,280 Speaker 1: because I worked, you know, I have a theater degree, 9 00:00:40,720 --> 00:00:43,320 Speaker 1: and they come up in lighting, right, which you had 10 00:00:43,320 --> 00:00:46,560 Speaker 1: to do. Even though I was largely working in acting, 11 00:00:46,600 --> 00:00:49,920 Speaker 1: I did a lot of set stuff as well. But 12 00:00:50,040 --> 00:00:52,800 Speaker 1: then while I was working on our episode on TV remotes, 13 00:00:52,880 --> 00:00:55,640 Speaker 1: Fornelle lenses came up again in relation to one of 14 00:00:55,680 --> 00:00:58,760 Speaker 1: Eugene Polly's patents, and that, of course reminded me of him. 15 00:00:59,320 --> 00:01:02,960 Speaker 1: Because August Stint Franelle is pretty interesting to me. He 16 00:01:03,080 --> 00:01:06,240 Speaker 1: did not live a long life, but in his relatively 17 00:01:06,240 --> 00:01:10,560 Speaker 1: short life, he contributed significantly both to the understanding of 18 00:01:10,760 --> 00:01:14,120 Speaker 1: light and related to that, to the safety of coastlines. 19 00:01:14,400 --> 00:01:16,400 Speaker 1: But what I love most about his story is that 20 00:01:16,480 --> 00:01:19,360 Speaker 1: neither of those accomplishments had anything to do with his 21 00:01:19,480 --> 00:01:24,160 Speaker 1: chosen career that you can talk about a little more 22 00:01:24,280 --> 00:01:26,240 Speaker 1: behind the scenes. But we're going to talk about Augustin 23 00:01:26,280 --> 00:01:30,920 Speaker 1: Franell today. Augustin Jean Frenelle was born on May tenth, 24 00:01:31,000 --> 00:01:35,399 Speaker 1: seventeen eighty eight, in Brolyi, France, which sits roughly seventy 25 00:01:35,440 --> 00:01:39,120 Speaker 1: five miles or one hundred and twenty kilometers west of Paris. 26 00:01:39,840 --> 00:01:43,200 Speaker 1: His mother was Augustine Mary May and his father was 27 00:01:43,440 --> 00:01:48,000 Speaker 1: Jacques Frenelle, who was an architect, and Jacques was very successful. 28 00:01:48,240 --> 00:01:52,040 Speaker 1: He took on projects like restoring and expanding chateau for 29 00:01:52,120 --> 00:01:57,840 Speaker 1: the aristocracy. After Augustin was born, the Frenelles moved to Scherbourg, 30 00:01:57,960 --> 00:02:00,480 Speaker 1: which sits on the northern point of the coast line 31 00:02:00,560 --> 00:02:04,320 Speaker 1: bordering the English Channel. This was being built up as 32 00:02:04,400 --> 00:02:07,840 Speaker 1: a port city and Jacques Frenelle was part of that 33 00:02:08,120 --> 00:02:12,200 Speaker 1: expansion project. If you have ever seen the movie Parapluis 34 00:02:12,200 --> 00:02:16,840 Speaker 1: de Cherbourg, which was spectacular, Catherine din a vehicle. You 35 00:02:16,960 --> 00:02:19,200 Speaker 1: like me, hear that name and go ja tem gee, 36 00:02:20,320 --> 00:02:24,560 Speaker 1: I can't help it forever forever. Augustin was born at 37 00:02:24,600 --> 00:02:28,320 Speaker 1: a pivotal point in French history. He was still a baby. 38 00:02:28,360 --> 00:02:31,640 Speaker 1: For example, when the Bastille was stormed in seventeen eighty nine, 39 00:02:31,680 --> 00:02:34,360 Speaker 1: and he was not yet five years old when Louis 40 00:02:34,440 --> 00:02:37,680 Speaker 1: the sixteenth was beheaded and the Reign of Terror began, 41 00:02:38,600 --> 00:02:42,120 Speaker 1: And although his parents were not directly involved in the revolution, 42 00:02:42,560 --> 00:02:45,840 Speaker 1: the family was of course impacted by it. The most 43 00:02:45,880 --> 00:02:48,920 Speaker 1: obvious result was that the work at Cherbourg stopped and 44 00:02:49,000 --> 00:02:51,760 Speaker 1: Jacques took Augustine and Augustin to live in a small 45 00:02:51,840 --> 00:02:56,239 Speaker 1: village north of cont called Matthieu. After the family moved there, 46 00:02:56,360 --> 00:03:00,080 Speaker 1: Jacques and Augustine had two morph sons, Leonard and Fauje. 47 00:03:01,280 --> 00:03:05,399 Speaker 1: This was a deeply religious family. The Frenelles were followers 48 00:03:05,400 --> 00:03:09,000 Speaker 1: of the teachings of sixteenth and seventeenth century Dutch Catholic 49 00:03:09,040 --> 00:03:14,400 Speaker 1: bishop Cornelius otto Jansen, who led the Jansenist reform movement 50 00:03:14,480 --> 00:03:18,840 Speaker 1: in the Roman Catholic Church. Yansonism focused on ideas of 51 00:03:18,919 --> 00:03:21,959 Speaker 1: free will and God's grace, and that the fate of 52 00:03:22,080 --> 00:03:25,200 Speaker 1: humans is largely out of their hands, as those who 53 00:03:25,440 --> 00:03:29,280 Speaker 1: God gives grace to will be saved by it, and 54 00:03:29,360 --> 00:03:34,040 Speaker 1: those without it are doomed to sin. This faction of 55 00:03:34,120 --> 00:03:37,680 Speaker 1: the church was controversial. A lot of Catholics rejected it 56 00:03:37,720 --> 00:03:40,680 Speaker 1: as not really being part of the denomination at all, 57 00:03:41,200 --> 00:03:43,720 Speaker 1: although that sentiment may have had less to do with 58 00:03:43,840 --> 00:03:47,720 Speaker 1: theology and more to do with power struggles within the church. 59 00:03:48,400 --> 00:03:52,760 Speaker 1: But the Frenelles were devout, and Augustin remained so for 60 00:03:52,840 --> 00:03:56,400 Speaker 1: the rest of his life. As a young child, Augustin 61 00:03:56,600 --> 00:04:00,240 Speaker 1: was educated at home. Although he was not considered to 62 00:04:00,280 --> 00:04:03,480 Speaker 1: be especially smart by his parents because he struggled with 63 00:04:03,520 --> 00:04:06,280 Speaker 1: his studies and he actually couldn't read at all until 64 00:04:06,280 --> 00:04:09,600 Speaker 1: he was about eight years old, other children thought he 65 00:04:09,680 --> 00:04:12,680 Speaker 1: was absolutely a genius. All of the energy that he 66 00:04:12,760 --> 00:04:15,400 Speaker 1: was not putting into his studies seemed to go into 67 00:04:15,440 --> 00:04:20,000 Speaker 1: his own experiments and to sometimes building dangerous toys like 68 00:04:20,040 --> 00:04:23,440 Speaker 1: projectile shooters for the village children. There's a story that 69 00:04:23,480 --> 00:04:25,560 Speaker 1: he built them all canons to play with, to the 70 00:04:25,560 --> 00:04:28,640 Speaker 1: point that parents were like, oh my goodness, hey, for nels, 71 00:04:28,680 --> 00:04:31,359 Speaker 1: can you control your kids? I was wondering when I 72 00:04:31,480 --> 00:04:34,960 Speaker 1: read this, like, what kind of projectiles are we talking 73 00:04:35,000 --> 00:04:38,000 Speaker 1: about here? Yeah, they weren't like fuse lit canons. They 74 00:04:38,000 --> 00:04:40,680 Speaker 1: were more like, you know, simple machine type things that 75 00:04:40,720 --> 00:04:43,600 Speaker 1: could shoot things. But yeah, he was apparently a little 76 00:04:43,600 --> 00:04:46,400 Speaker 1: scamp in that regard, and when he was twelve he 77 00:04:46,480 --> 00:04:50,760 Speaker 1: started studying AT's Eco Central School, and he got his 78 00:04:50,800 --> 00:04:54,400 Speaker 1: first taste of science and mathematics there and he really 79 00:04:54,600 --> 00:04:58,119 Speaker 1: loved it, and with subject matter that engaged his brain, 80 00:04:58,200 --> 00:05:01,560 Speaker 1: he actually did very well in school. He pretty quickly 81 00:05:01,560 --> 00:05:04,599 Speaker 1: decided that an engineering career was his goal, as it 82 00:05:04,720 --> 00:05:08,280 Speaker 1: incorporated both of those things. So at the age of sixteen, 83 00:05:08,640 --> 00:05:11,679 Speaker 1: he moved to Paris to study at the Ecole Polytechnique. 84 00:05:12,320 --> 00:05:14,600 Speaker 1: He studied there for two years, and then he advanced 85 00:05:14,600 --> 00:05:17,520 Speaker 1: to the Ecole des Pont de Chose, the School of 86 00:05:17,520 --> 00:05:20,160 Speaker 1: Bridges and Roads, and he studied there for three years 87 00:05:20,480 --> 00:05:24,440 Speaker 1: before receiving his credentials as a civil engineer. In his 88 00:05:24,560 --> 00:05:29,200 Speaker 1: mid twenties, Frenelle settled into a career path not dissimilar 89 00:05:29,279 --> 00:05:33,080 Speaker 1: from his father's. He worked as an engineer on public works. 90 00:05:33,720 --> 00:05:36,640 Speaker 1: In eighteen oh four, the same year that Napoleon became 91 00:05:36,839 --> 00:05:40,119 Speaker 1: Emperor of the French, he was hired by the Corps 92 00:05:40,160 --> 00:05:43,880 Speaker 1: of Bridges and Roads to expand the country's roadways, starting 93 00:05:44,040 --> 00:05:48,440 Speaker 1: m Bondei on the west coast of France. His first 94 00:05:48,480 --> 00:05:52,520 Speaker 1: assignment was in Larouchurion, which was a town that Napoleon 95 00:05:52,680 --> 00:05:55,880 Speaker 1: renamed after himself and then built up as an administrative 96 00:05:55,920 --> 00:05:59,800 Speaker 1: seat of government in the region, and Frenelle's job was 97 00:05:59,800 --> 00:06:03,120 Speaker 1: to create an infrastructure of roadways that would give La 98 00:06:03,240 --> 00:06:07,159 Speaker 1: Rochetrion easier access to the rest of Vonde, and he 99 00:06:07,880 --> 00:06:12,320 Speaker 1: hated it. He liked solving problems, but he was put 100 00:06:12,360 --> 00:06:15,800 Speaker 1: in a position where he had to manage people, which 101 00:06:16,000 --> 00:06:18,360 Speaker 1: is the last thing on earth that he wanted to do. 102 00:06:18,680 --> 00:06:22,359 Speaker 1: So he kept himself busy studying various things that just 103 00:06:22,400 --> 00:06:26,120 Speaker 1: tickled his fancy in his free time. Yeah, his writings 104 00:06:26,160 --> 00:06:28,640 Speaker 1: back to his family are basically about how much he 105 00:06:28,720 --> 00:06:31,919 Speaker 1: dislikes management. How he's one of those people that I 106 00:06:31,960 --> 00:06:36,280 Speaker 1: suspect may not have been an amazing communicator of his 107 00:06:36,440 --> 00:06:39,320 Speaker 1: ideas because he talks about often having to step in 108 00:06:39,360 --> 00:06:42,440 Speaker 1: and do the work himself, which, listen, I have that 109 00:06:42,480 --> 00:06:46,000 Speaker 1: same disease, so I understand it. But I think he 110 00:06:46,120 --> 00:06:49,640 Speaker 1: just maybe wasn't always great at communicating what he was after. 111 00:06:50,480 --> 00:06:54,040 Speaker 1: In eighteen twelve, Frenell moved into another large scale public 112 00:06:54,080 --> 00:06:57,640 Speaker 1: works project, this time building a roadway that would connect 113 00:06:57,720 --> 00:07:00,360 Speaker 1: Spain in Italy and it had to pass through grants, 114 00:07:00,640 --> 00:07:04,160 Speaker 1: particularly through mountainous areas, and this was once again a 115 00:07:04,240 --> 00:07:06,680 Speaker 1: job assignment that came at the same time as a 116 00:07:06,720 --> 00:07:11,840 Speaker 1: significant development in Napoleon's story, and that story impacts Ranel. 117 00:07:12,000 --> 00:07:13,680 Speaker 1: So we're going to quickly review a little bit of 118 00:07:13,680 --> 00:07:17,480 Speaker 1: French history here. In the summer of eighteen twelve, the 119 00:07:17,480 --> 00:07:20,600 Speaker 1: Emperor Napoleon, acting on fears that Russia was about to 120 00:07:20,640 --> 00:07:24,840 Speaker 1: ally with England, invaded Russia after first parking his troops 121 00:07:24,840 --> 00:07:27,960 Speaker 1: in Poland along the border for a while. This pretty 122 00:07:28,000 --> 00:07:31,960 Speaker 1: famously did not go well. In the very simplest terms, 123 00:07:32,240 --> 00:07:35,480 Speaker 1: the Russian army mostly refused to battle, which made Napoleon's 124 00:07:35,640 --> 00:07:38,760 Speaker 1: entire effort look sort of foolish. There was only one 125 00:07:38,800 --> 00:07:41,840 Speaker 1: major battle that happened as a result of this, at Borodino, 126 00:07:41,920 --> 00:07:45,240 Speaker 1: which Napoleon did win, and that enabled the French to 127 00:07:45,280 --> 00:07:48,120 Speaker 1: advance to Moscow, but the city had already been sacked 128 00:07:48,160 --> 00:07:51,680 Speaker 1: by Russian forces, so that Napoleon's army would find nothing 129 00:07:51,720 --> 00:07:56,000 Speaker 1: to gain there. Furthermore, Zar Alexander the First refused to 130 00:07:56,080 --> 00:08:00,000 Speaker 1: negotiate with Napoleon, and as winter closed in, things got 131 00:08:00,200 --> 00:08:03,720 Speaker 1: dire and Napoleon was forced to retreat to Paris, where 132 00:08:03,720 --> 00:08:07,760 Speaker 1: he actually found rumors circulating that he was dead. He had, 133 00:08:07,840 --> 00:08:10,560 Speaker 1: in returning to Paris, left behind most of his troops, 134 00:08:10,600 --> 00:08:14,560 Speaker 1: which dwindled from a starting number estimated at seven hundred 135 00:08:14,560 --> 00:08:17,600 Speaker 1: thousand to a mere one hundred thousand by the end 136 00:08:17,600 --> 00:08:21,760 Speaker 1: of the Russian campaign. Napoleon's failure was such a complete 137 00:08:21,760 --> 00:08:25,680 Speaker 1: disaster that allies began to abandon him, and some of 138 00:08:25,720 --> 00:08:30,320 Speaker 1: them actually joined forces with Russia. As countries expelled French 139 00:08:30,360 --> 00:08:34,640 Speaker 1: troops and Napoleon's power shrink, he was eventually completely overthrown 140 00:08:34,720 --> 00:08:37,600 Speaker 1: and the French monarchy was restored with Louis the eighteenth 141 00:08:37,640 --> 00:08:41,440 Speaker 1: as king. Napoleon was exiled to Elba in the spring 142 00:08:41,520 --> 00:08:46,680 Speaker 1: of eighteen fourteen. That same year, Frenelle started studying the 143 00:08:46,760 --> 00:08:49,520 Speaker 1: area that would make his name famous, which was optics. 144 00:08:50,360 --> 00:08:53,720 Speaker 1: He had some optics education at university, but it was 145 00:08:53,800 --> 00:08:57,760 Speaker 1: pretty rudimentary and soufre Now it seemed like the principles 146 00:08:57,800 --> 00:09:01,920 Speaker 1: he was taught didn't really explained the behaviors of light 147 00:09:02,160 --> 00:09:06,440 Speaker 1: very effectively. Newton's ideas about light were included. We'll talk 148 00:09:06,520 --> 00:09:09,400 Speaker 1: more about those inan a moment, but again that felt 149 00:09:09,440 --> 00:09:13,120 Speaker 1: limited to him. He did not feel compelled to start 150 00:09:13,120 --> 00:09:16,280 Speaker 1: to do his own experimenting until the eighteen teens, and 151 00:09:16,360 --> 00:09:20,080 Speaker 1: he didn't actually start his scientific study as a hobby 152 00:09:20,559 --> 00:09:24,080 Speaker 1: working in light or optics. He kind of messed around 153 00:09:24,080 --> 00:09:27,600 Speaker 1: with a few different things until he landed there. For 154 00:09:27,720 --> 00:09:31,600 Speaker 1: a while, he thought that light and heat transmission might 155 00:09:31,720 --> 00:09:36,000 Speaker 1: happen through quote the vibrations of a special fluid. He 156 00:09:36,040 --> 00:09:39,960 Speaker 1: wrote about this idea to his brother Leonor. He was 157 00:09:40,120 --> 00:09:43,559 Speaker 1: just really excited. It seems to have projects that let 158 00:09:43,640 --> 00:09:47,880 Speaker 1: him try to solve problems creatively. He eventually worked on 159 00:09:47,960 --> 00:09:53,240 Speaker 1: various experiments to explain the behaviors of light, including reflection, refraction, 160 00:09:53,440 --> 00:09:57,400 Speaker 1: and polarization. And coming up, we're going to talk about 161 00:09:57,480 --> 00:10:00,760 Speaker 1: exactly how Napoleon impacted for Nell's work, but first we 162 00:10:00,800 --> 00:10:03,280 Speaker 1: will hear from the sponsors. They keep the show going. 163 00:10:12,800 --> 00:10:17,160 Speaker 1: When Napoleon returned from Elba suddenly in eighteen fifteen, everything 164 00:10:17,200 --> 00:10:21,119 Speaker 1: in the French government was upended, including public works projects. 165 00:10:21,760 --> 00:10:25,080 Speaker 1: Frenelle was very dismayed. When Napoleon landed at cann on 166 00:10:25,200 --> 00:10:30,079 Speaker 1: March first, eighteen fifteen. The exiled emperor had seven ships 167 00:10:30,080 --> 00:10:34,960 Speaker 1: of soldiers with him and intended to reclaim France. Frenelle 168 00:10:35,160 --> 00:10:38,680 Speaker 1: thought this was literally an attack on civilization, that is 169 00:10:38,720 --> 00:10:41,960 Speaker 1: what he called it, and he left his job to 170 00:10:41,960 --> 00:10:45,480 Speaker 1: go fight for the king. But Napoleon did manage to 171 00:10:45,520 --> 00:10:48,359 Speaker 1: make his way to Paris, with people joining his military 172 00:10:48,440 --> 00:10:51,199 Speaker 1: as he passed through the country, and on March twentieth 173 00:10:51,240 --> 00:10:54,920 Speaker 1: he walked into Tuilerie and began his second rule, which 174 00:10:55,120 --> 00:10:59,560 Speaker 1: of course famously lasted exactly one hundred days. Because Frenelle 175 00:10:59,640 --> 00:11:04,320 Speaker 1: had against Napoleon, his position as a civil engineer was 176 00:11:04,360 --> 00:11:07,800 Speaker 1: of course no longer available to him, so he was 177 00:11:07,880 --> 00:11:11,000 Speaker 1: unemployed and viewed as an enemy of the state, and 178 00:11:11,160 --> 00:11:14,720 Speaker 1: so he was also surveilled. He moved back to his 179 00:11:14,880 --> 00:11:18,840 Speaker 1: village of Matthieu and took advantage of his unemployed free 180 00:11:18,880 --> 00:11:22,800 Speaker 1: time to continue his study of optics. One of the 181 00:11:22,840 --> 00:11:25,680 Speaker 1: things that he wanted to figure out was why the 182 00:11:25,840 --> 00:11:30,480 Speaker 1: shadow around a thin edged object like a knife would 183 00:11:30,559 --> 00:11:34,640 Speaker 1: have a fringed edge, or why light that passed through 184 00:11:34,679 --> 00:11:37,719 Speaker 1: a slit in a card would have dark spots in it. 185 00:11:38,440 --> 00:11:42,400 Speaker 1: He was after the cause of light diffraction. In some ways, 186 00:11:42,440 --> 00:11:45,679 Speaker 1: he had to catch up to the contemporary discussions already 187 00:11:45,720 --> 00:11:48,520 Speaker 1: happening in the science of light. He had no idea 188 00:11:48,640 --> 00:11:53,160 Speaker 1: about the work and the controversy around Thomas Young and 189 00:11:53,280 --> 00:11:57,520 Speaker 1: Young's wave theory of light. Thomas Young was an English 190 00:11:57,520 --> 00:12:02,360 Speaker 1: physician and physicist originally from some England, and Young achieved 191 00:12:02,400 --> 00:12:04,920 Speaker 1: a lot of noteworthy things in his life. He could 192 00:12:04,920 --> 00:12:07,760 Speaker 1: easily be an episode in the future. But germane to 193 00:12:07,880 --> 00:12:12,000 Speaker 1: Frenelle's story is his wave theory of light. He developed 194 00:12:12,040 --> 00:12:15,560 Speaker 1: this theory through an experiment that involved sunlight passing through 195 00:12:15,600 --> 00:12:19,559 Speaker 1: two small slits in a card, and when Young observed 196 00:12:19,600 --> 00:12:22,040 Speaker 1: the light that had passed through the card onto the 197 00:12:22,080 --> 00:12:25,160 Speaker 1: wall beyond it, he noted that it appeared not as 198 00:12:25,280 --> 00:12:29,120 Speaker 1: two spots of light, but as a series of vertical lines, 199 00:12:29,440 --> 00:12:33,720 Speaker 1: and that evidenced an interference pattern, and that was important 200 00:12:33,760 --> 00:12:37,079 Speaker 1: because it supported the idea that light traveled in waves. 201 00:12:37,920 --> 00:12:40,480 Speaker 1: This challenged the idea that had been put forth by 202 00:12:40,520 --> 00:12:44,080 Speaker 1: Sir Isaac Newton that light traveled as a particle, what 203 00:12:44,280 --> 00:12:48,640 Speaker 1: was known as the corpuscular theory. The corpuscular theory of 204 00:12:48,760 --> 00:12:52,480 Speaker 1: light came about as the scientific world was struggling to 205 00:12:52,520 --> 00:12:56,400 Speaker 1: get a handle on what exactly light was and how 206 00:12:56,440 --> 00:13:00,240 Speaker 1: it moved throughout the world. In seventeen oh four, or 207 00:13:00,280 --> 00:13:04,520 Speaker 1: Sir Isaac Newton proposed the corpuscular theory. Newton's take on 208 00:13:04,679 --> 00:13:07,440 Speaker 1: light was that it was made up of tiny particles 209 00:13:07,480 --> 00:13:12,600 Speaker 1: what he called corpusals. These particles were emitted from various sources, 210 00:13:12,760 --> 00:13:17,080 Speaker 1: obviously the sun, but also things like candles, stars, et cetera. 211 00:13:18,160 --> 00:13:24,320 Speaker 1: Different luminous objects produce differently sized corpusles, and that accounts 212 00:13:24,320 --> 00:13:28,120 Speaker 1: for different colors of light, and per Newton's theories, these 213 00:13:28,160 --> 00:13:31,120 Speaker 1: particles moved at a very high velocity and always in 214 00:13:31,160 --> 00:13:34,600 Speaker 1: a straight line. So if one hit an opaque object 215 00:13:34,720 --> 00:13:37,240 Speaker 1: and could not pass through it, it would be reflected 216 00:13:37,320 --> 00:13:40,640 Speaker 1: away at an angle and continue to travel in a 217 00:13:40,800 --> 00:13:45,280 Speaker 1: straight line. That's reflective light. But if light hits a 218 00:13:45,320 --> 00:13:49,560 Speaker 1: medium it can pass through. These particles are attracted at 219 00:13:49,559 --> 00:13:52,480 Speaker 1: the surface, and if the medium is denser than the 220 00:13:52,520 --> 00:13:56,760 Speaker 1: medium that the light had been traveling through, like traveling 221 00:13:56,840 --> 00:14:00,960 Speaker 1: from air into a prism, the dense nature of the 222 00:14:01,000 --> 00:14:04,000 Speaker 1: prism will speed up the light and cause the directional shift. 223 00:14:04,000 --> 00:14:08,800 Speaker 1: And in this theory, vision is explained as light hitting 224 00:14:08,840 --> 00:14:13,000 Speaker 1: the eye to produce imagery. Yeah, so that was Isaac 225 00:14:13,040 --> 00:14:16,760 Speaker 1: Newton's take. Obviously some of that is incorrect. I'll talk 226 00:14:16,800 --> 00:14:21,040 Speaker 1: about that some more. Frenell had started his own experiments 227 00:14:21,040 --> 00:14:24,080 Speaker 1: in this area even before he knew about Young's work. 228 00:14:24,480 --> 00:14:27,840 Speaker 1: He wasn't entirely flying blind though he was basing his 229 00:14:27,960 --> 00:14:31,520 Speaker 1: experiments on the work of another scientist, Danish mathematician and 230 00:14:31,560 --> 00:14:35,200 Speaker 1: astronomer Chris John Huygens, who he had learned about in school. 231 00:14:36,080 --> 00:14:39,880 Speaker 1: Huygen's principle regarding wave motion states quote, every point on 232 00:14:39,960 --> 00:14:43,480 Speaker 1: a wavefront is in itself the source of spherical wavelets, 233 00:14:43,680 --> 00:14:46,400 Speaker 1: which spread out in the forward directions at the speed 234 00:14:46,440 --> 00:14:50,960 Speaker 1: of light. The sum of these spherical wavelets forms the wavefront, 235 00:14:51,240 --> 00:14:56,000 Speaker 1: and Forrenell eventually expanded on Huygen's adding that these secondary 236 00:14:56,040 --> 00:15:00,200 Speaker 1: wavelets would then interfere with one another. Where Huygen's had 237 00:15:00,200 --> 00:15:03,840 Speaker 1: described those secondary wavelets as enveloping the initial wave and 238 00:15:03,880 --> 00:15:08,120 Speaker 1: carrying it forward, Frenell's explanations suggested that they overlapped and 239 00:15:08,240 --> 00:15:11,480 Speaker 1: interfered with one another, and that that was what formed 240 00:15:11,520 --> 00:15:14,600 Speaker 1: the wavefront. This, by the way, I should say, is 241 00:15:14,680 --> 00:15:19,040 Speaker 1: my very rudimentary understanding. Holly is not a physicist. But 242 00:15:19,160 --> 00:15:21,760 Speaker 1: this amended version of Huygen's work came to be known 243 00:15:21,800 --> 00:15:26,479 Speaker 1: as the Huygen's Frenelle principle. Frenelle also worked on explaining 244 00:15:26,600 --> 00:15:30,160 Speaker 1: the dark spots that appeared in pools of light. Sometimes. 245 00:15:30,800 --> 00:15:33,520 Speaker 1: He came to the conclusion that two light waves that 246 00:15:33,640 --> 00:15:37,840 Speaker 1: perfectly lined up peak to trough would yield darkness as 247 00:15:37,880 --> 00:15:40,680 Speaker 1: they interfered with one another. But if they were lined 248 00:15:40,720 --> 00:15:43,720 Speaker 1: up peak to peak and trough to trough, they would 249 00:15:43,800 --> 00:15:48,320 Speaker 1: amplify into a larger wave. The earliest of these ideas 250 00:15:48,400 --> 00:15:51,560 Speaker 1: was put into an essay which got lost, but through 251 00:15:51,640 --> 00:15:55,880 Speaker 1: an uncle, Augustin was introduced to Francois Arago, who would 252 00:15:55,920 --> 00:16:00,120 Speaker 1: become an important collaborator and front But Frenell did did 253 00:16:00,240 --> 00:16:03,160 Speaker 1: not get to work on his special interest projects forever 254 00:16:03,800 --> 00:16:06,040 Speaker 1: because he got his job with the Corps des ponte 255 00:16:06,160 --> 00:16:10,000 Speaker 1: Chaise back after Napoleon was exiled for the second time 256 00:16:10,280 --> 00:16:13,280 Speaker 1: to the island of Saint Helena, and Forrenell was sent 257 00:16:13,320 --> 00:16:17,520 Speaker 1: tourin to resume work on the roads. This slowed Fernelle's 258 00:16:17,560 --> 00:16:21,400 Speaker 1: scientific work quite a bit. His work in optics was 259 00:16:21,480 --> 00:16:24,000 Speaker 1: relegated to these small amounts of free time that his 260 00:16:24,040 --> 00:16:27,760 Speaker 1: work afforded him, or to times when he took vacation 261 00:16:27,960 --> 00:16:30,920 Speaker 1: or leave, and he made a lot of requests for 262 00:16:31,080 --> 00:16:34,680 Speaker 1: time off, each time heading to Paris to continue his 263 00:16:34,800 --> 00:16:39,160 Speaker 1: scientific studies. These frequent leaves from work would not have 264 00:16:39,240 --> 00:16:42,560 Speaker 1: been approved had it not been for high ranking members 265 00:16:42,600 --> 00:16:47,000 Speaker 1: of the scientific establishment, like Francois Arago advocating with the 266 00:16:47,040 --> 00:16:51,520 Speaker 1: Bridges and Roads Department on his behalf. Because Forrenell had 267 00:16:51,640 --> 00:16:55,480 Speaker 1: a strong mathematical background, he was able to back up 268 00:16:55,560 --> 00:16:58,400 Speaker 1: a lot of his ideas about lightweight theory with it. 269 00:16:58,960 --> 00:17:02,160 Speaker 1: But it also took a lot of time. As we mentioned, 270 00:17:02,280 --> 00:17:04,240 Speaker 1: he worked out a lot of his early ideas and 271 00:17:04,320 --> 00:17:07,560 Speaker 1: formulas before he even knew about other scientists working on 272 00:17:07,600 --> 00:17:11,240 Speaker 1: the problem of light The thing about Fornell's work that 273 00:17:11,400 --> 00:17:13,560 Speaker 1: was unique was that a lot of it, or work 274 00:17:13,680 --> 00:17:17,320 Speaker 1: closely related to it, had happened already. So in a way, 275 00:17:17,840 --> 00:17:21,639 Speaker 1: this young public works engineer was actually working in his 276 00:17:21,720 --> 00:17:26,080 Speaker 1: spare time to verify earlier theories and experiments without even 277 00:17:26,160 --> 00:17:30,000 Speaker 1: knowing it, and that was a huge challenge. He believed 278 00:17:30,000 --> 00:17:33,159 Speaker 1: that elementary waves were generated all along the arc of 279 00:17:33,200 --> 00:17:36,119 Speaker 1: the wave and interacted with one another. Okay, to a 280 00:17:36,200 --> 00:17:39,080 Speaker 1: lay person, that kind of makes sense, I'll be frank, 281 00:17:39,119 --> 00:17:42,000 Speaker 1: it's easier when you look at diagrams. But for me 282 00:17:42,240 --> 00:17:45,280 Speaker 1: and probably a lot of listeners, imagine having to come 283 00:17:45,359 --> 00:17:48,280 Speaker 1: up with the math that supports that idea. To me, 284 00:17:48,359 --> 00:17:51,879 Speaker 1: this seems like superhero stuff. I can't even fathom it. 285 00:17:52,240 --> 00:17:55,399 Speaker 1: And Fornell, who was very good at maths, still needed 286 00:17:55,480 --> 00:17:59,280 Speaker 1: months to puzzle it all out. In eighteen sixteen, Fornell 287 00:17:59,359 --> 00:18:03,480 Speaker 1: published his first paper about this work, but he acknowledged 288 00:18:03,520 --> 00:18:06,040 Speaker 1: that he was still in the early stages of working 289 00:18:06,119 --> 00:18:09,720 Speaker 1: everything out and included a plea to readers to understand 290 00:18:09,720 --> 00:18:14,399 Speaker 1: the situation. And he also for a while joined forces 291 00:18:14,440 --> 00:18:18,000 Speaker 1: with Francois Arago, who was two years older than Frenell 292 00:18:18,080 --> 00:18:21,480 Speaker 1: and was the chair of analytic geometry at the Paris 293 00:18:21,560 --> 00:18:26,520 Speaker 1: Ecole Polytechnique. Together the two of them studied interference as 294 00:18:26,560 --> 00:18:31,359 Speaker 1: it applied to polarized light. Frenelle may have continued to 295 00:18:31,400 --> 00:18:35,119 Speaker 1: focus on polarized light, had a high profile opportunity to 296 00:18:35,160 --> 00:18:38,040 Speaker 1: show his work in light waves not have come up, 297 00:18:38,720 --> 00:18:41,240 Speaker 1: But he learned that the Academy of Sciences was going 298 00:18:41,280 --> 00:18:45,240 Speaker 1: to make diffraction the topic of their eighteen nineteen Grand Prix. 299 00:18:45,640 --> 00:18:47,879 Speaker 1: And as we've just mentioned, he had worked a long 300 00:18:48,000 --> 00:18:50,480 Speaker 1: time on the mathematical side of this theory, and he 301 00:18:50,640 --> 00:18:54,400 Speaker 1: really believed that his work was solid, so he hustled 302 00:18:54,400 --> 00:18:57,120 Speaker 1: to get an entry ready. He wrote, quote, I think 303 00:18:57,160 --> 00:19:00,520 Speaker 1: I have proved that light is propagated by the unguls 304 00:19:00,640 --> 00:19:04,199 Speaker 1: of an infinitely subtle fluid diffused in space, and it 305 00:19:04,280 --> 00:19:06,960 Speaker 1: is to the demonstration of this great principle that I 306 00:19:06,960 --> 00:19:10,600 Speaker 1: have been particularly attached. It is the end towards which 307 00:19:10,640 --> 00:19:14,720 Speaker 1: I have directed all my efforts. Though Atrago had tried 308 00:19:14,760 --> 00:19:17,560 Speaker 1: to promote the work of Frenelle to the scientific establishment 309 00:19:17,600 --> 00:19:20,520 Speaker 1: in both France and England, most of the people who 310 00:19:20,600 --> 00:19:24,159 Speaker 1: heard about what this young civil engineer was doing assumed 311 00:19:24,200 --> 00:19:26,680 Speaker 1: that he was just copying Thomas Young, and they really 312 00:19:26,680 --> 00:19:29,040 Speaker 1: didn't give his work a whole lot of additional attention. 313 00:19:30,080 --> 00:19:33,000 Speaker 1: Eighteen nineteen would prove to be a big year for 314 00:19:33,160 --> 00:19:36,280 Speaker 1: Augustin Frannell, and we will talk about why after we 315 00:19:36,400 --> 00:19:49,400 Speaker 1: pause for a sponsor break. In eighteen nineteen, Augustin Frenelle 316 00:19:49,480 --> 00:19:52,960 Speaker 1: presented his work with light waves and diffraction to France's 317 00:19:53,040 --> 00:19:58,600 Speaker 1: Academy of Sciences under the title Natures simplexefagunda Nature simple 318 00:19:58,680 --> 00:20:02,879 Speaker 1: and Fertile, and this offered twenty five cases of ways 319 00:20:02,880 --> 00:20:07,800 Speaker 1: diffraction might appear, along with mathematical formulas to explain each 320 00:20:07,840 --> 00:20:12,159 Speaker 1: of those cases. This competition was intended to bring the 321 00:20:12,240 --> 00:20:16,360 Speaker 1: smartest minds in the country science community together to discuss 322 00:20:16,440 --> 00:20:19,920 Speaker 1: the true nature of light. But because Farnell's work ran 323 00:20:20,040 --> 00:20:23,639 Speaker 1: counter to the widely accepted work of Newton. There was 324 00:20:23,680 --> 00:20:27,520 Speaker 1: a lot of resistance to what he presented. The next 325 00:20:27,520 --> 00:20:30,640 Speaker 1: figure who's important to this particular part of the story 326 00:20:30,800 --> 00:20:35,399 Speaker 1: is a man named Simeon Denis Poisson. Poissant was a 327 00:20:35,440 --> 00:20:38,920 Speaker 1: mathematician who had become known for his work in probability 328 00:20:39,400 --> 00:20:43,600 Speaker 1: and who was very influential on France's scientific education system. 329 00:20:44,119 --> 00:20:46,720 Speaker 1: He was also one of the competition judges for the 330 00:20:46,760 --> 00:20:51,520 Speaker 1: Academy of Sciences, and he thought Frenelle was talking absolute nonsense. 331 00:20:52,600 --> 00:20:56,920 Speaker 1: One particular example in Fernell's paper really rankled Poisson, and 332 00:20:56,960 --> 00:20:59,280 Speaker 1: he pointed it out as proof that this person didn't 333 00:20:59,280 --> 00:21:02,479 Speaker 1: know what they were doing. This was an instance where 334 00:21:02,920 --> 00:21:06,480 Speaker 1: Frenell suggested that the shadow of a circular disc would 335 00:21:06,520 --> 00:21:09,600 Speaker 1: actually have a bright spot of light in the center, 336 00:21:10,000 --> 00:21:13,080 Speaker 1: and Poisson was adamant that this just simply could not happen. 337 00:21:13,720 --> 00:21:16,720 Speaker 1: But Arago, who really believed in his friend and saw 338 00:21:16,760 --> 00:21:19,760 Speaker 1: that there was bias against his work, managed to get 339 00:21:19,800 --> 00:21:22,840 Speaker 1: the right instruments to do the experiment there with the 340 00:21:22,880 --> 00:21:26,080 Speaker 1: competition judges, so that they could see if Frenell was 341 00:21:26,200 --> 00:21:30,240 Speaker 1: correct and he was the shadow that he produced had 342 00:21:30,280 --> 00:21:33,640 Speaker 1: a bright spot in the center. And although the judges 343 00:21:33,680 --> 00:21:37,280 Speaker 1: who favored the Newtonian theory of light didn't exactly believe 344 00:21:37,320 --> 00:21:40,159 Speaker 1: in Frenelle's work, it had proven out and they couldn't 345 00:21:40,200 --> 00:21:44,359 Speaker 1: deny that, and so he won the prize as an aside. 346 00:21:45,440 --> 00:21:49,560 Speaker 1: Eventually it was recognized that elements of both Newton's corpuscular 347 00:21:49,640 --> 00:21:53,880 Speaker 1: theory and Frenelle's work were true regarding the nature of light. 348 00:21:54,640 --> 00:21:58,320 Speaker 1: Corpuscular theory is kind of the proto version of our 349 00:21:58,520 --> 00:22:04,080 Speaker 1: understanding of photon. Newton's take had some incorrect ideas, specifically 350 00:22:04,200 --> 00:22:09,359 Speaker 1: different sized light particles causing color difference, light levels, traveling 351 00:22:09,400 --> 00:22:12,840 Speaker 1: faster and denser media, and the idea that media could 352 00:22:12,840 --> 00:22:16,600 Speaker 1: attract or repel light. That also didn't offer an explanation 353 00:22:16,640 --> 00:22:21,280 Speaker 1: for things like polarization or diffraction. Eventually, humans came to 354 00:22:21,400 --> 00:22:25,280 Speaker 1: understand that diffraction was the result of light waves passing 355 00:22:25,320 --> 00:22:28,400 Speaker 1: through a small opening the size of or smaller than 356 00:22:28,440 --> 00:22:32,800 Speaker 1: the wavelength, or when a light wave bends and spreads 357 00:22:32,800 --> 00:22:36,600 Speaker 1: as it passes around an obstacle. Today, the idea of 358 00:22:36,800 --> 00:22:41,640 Speaker 1: wave particle duality is accepted to understand the nature of light. 359 00:22:42,280 --> 00:22:45,120 Speaker 1: That means that sometimes it does travel like a particle 360 00:22:45,359 --> 00:22:47,480 Speaker 1: of fox time in a straight line, but at other 361 00:22:47,560 --> 00:22:51,200 Speaker 1: times it behaves like a wave, enabling it to bend 362 00:22:51,880 --> 00:22:55,680 Speaker 1: a thing that I remember from physics class. I don't 363 00:22:55,680 --> 00:22:57,960 Speaker 1: remember a whole lot from physics class. We can talk 364 00:22:58,000 --> 00:23:01,159 Speaker 1: about what a weak physics student I was on Friday, 365 00:23:01,160 --> 00:23:04,840 Speaker 1: if you like. Frenelle still longed for a position where 366 00:23:04,840 --> 00:23:07,800 Speaker 1: he could work on his scientific studies full time so 367 00:23:07,840 --> 00:23:10,080 Speaker 1: he wouldn't have to juggle it in his free time 368 00:23:10,160 --> 00:23:13,920 Speaker 1: alongside a public works engineering job that he just clearly 369 00:23:13,920 --> 00:23:18,000 Speaker 1: did not like, and starting in eighteen nineteen, Frenelle did 370 00:23:18,080 --> 00:23:22,000 Speaker 1: begin working alongside Francois at Agau in a national project 371 00:23:22,240 --> 00:23:25,400 Speaker 1: that was intended to improve upon the lighthouses of France, 372 00:23:25,920 --> 00:23:29,320 Speaker 1: first by working to perform a series of tests on them. 373 00:23:29,920 --> 00:23:33,359 Speaker 1: And this project was precipitated by the ongoing problem of 374 00:23:33,359 --> 00:23:38,160 Speaker 1: shipwrecks being caused by vessels simply running aground unexpectedly or 375 00:23:38,520 --> 00:23:42,320 Speaker 1: slamming into rocks that were near the land. France had 376 00:23:42,320 --> 00:23:45,359 Speaker 1: been a buzz after a high profile shipwreck of a 377 00:23:45,400 --> 00:23:48,800 Speaker 1: French ship off the coast of Africa, and this had 378 00:23:48,880 --> 00:23:51,640 Speaker 1: led to a high level of interest in fortifying their 379 00:23:51,680 --> 00:23:57,159 Speaker 1: own coastline against similar accidents. At this time, there were 380 00:23:57,200 --> 00:24:01,560 Speaker 1: a number of ways that lighthouses provided light. Lighthouses have 381 00:24:01,600 --> 00:24:05,359 Speaker 1: been around since at least two eighty five BCE, maybe 382 00:24:05,400 --> 00:24:09,560 Speaker 1: even longer. That example is one of the Seven Wonders 383 00:24:09,560 --> 00:24:13,560 Speaker 1: of the World, built in Alexandria, Egypt. There were Roman 384 00:24:13,640 --> 00:24:16,840 Speaker 1: lighthouses spread throughout Europe during the time of the Holy 385 00:24:16,920 --> 00:24:22,360 Speaker 1: Roman Empire. Early lighthouses used beacon fires. Some of these 386 00:24:22,400 --> 00:24:24,840 Speaker 1: fires were protected by a roof and others were in 387 00:24:24,880 --> 00:24:28,840 Speaker 1: the open air. Eventually, coal and then candles, and then 388 00:24:28,920 --> 00:24:33,560 Speaker 1: oil lamps replaced the fires. In the twelfth century. Lighthouses 389 00:24:33,840 --> 00:24:37,160 Speaker 1: became more common as the dark ages ended and new 390 00:24:37,200 --> 00:24:41,480 Speaker 1: trade routes were established, fostering a need for near shore lights. 391 00:24:42,480 --> 00:24:46,679 Speaker 1: The earliest modern lighthouses appeared sometime around the beginning of 392 00:24:46,720 --> 00:24:51,520 Speaker 1: the eighteenth century. In seventeen eighty, Ami are Gone invented 393 00:24:51,560 --> 00:24:55,560 Speaker 1: a clean burning oil lamp that became standard in lighthouses. 394 00:24:56,200 --> 00:25:00,000 Speaker 1: These are sometimes combined with reflectors that consisted of large 395 00:25:00,280 --> 00:25:04,879 Speaker 1: glass discs with spherical coatings to reflect the light. A 396 00:25:04,920 --> 00:25:08,719 Speaker 1: glass cutter from London had actually created a lighthouse lens 397 00:25:08,800 --> 00:25:11,440 Speaker 1: in the seventeen eighties that was twenty one inches across 398 00:25:11,480 --> 00:25:14,840 Speaker 1: in five and a half inches thick. That glass cutter 399 00:25:14,960 --> 00:25:19,120 Speaker 1: Thomas Rogers implemented these lenses in a couple of lighthouses, 400 00:25:19,560 --> 00:25:22,879 Speaker 1: but they were made of green glass and had some imperfections, 401 00:25:22,920 --> 00:25:25,320 Speaker 1: so they did not really throw the light as far 402 00:25:25,680 --> 00:25:29,199 Speaker 1: as was hoped. Then there were developments that led to 403 00:25:29,359 --> 00:25:34,080 Speaker 1: rotating parabolic reflectors, a couple of which were combined with lenses. 404 00:25:35,080 --> 00:25:38,800 Speaker 1: The lenses actually made the lighthouse less effective and they 405 00:25:38,880 --> 00:25:42,679 Speaker 1: were abandoned. I kind of want to do a history 406 00:25:42,680 --> 00:25:45,720 Speaker 1: of lighthouses. It's on the list. Yeah, a lot of 407 00:25:45,760 --> 00:25:49,680 Speaker 1: interesting stuff there and a lot of science, So we'll 408 00:25:49,720 --> 00:25:53,359 Speaker 1: see if my brain can handle it. Because Frenelle had 409 00:25:53,440 --> 00:25:56,080 Speaker 1: already done so much study of light, he was kind 410 00:25:56,080 --> 00:25:58,800 Speaker 1: of the perfect man for this challenge, and as he 411 00:25:58,840 --> 00:26:02,320 Speaker 1: had been helping Arago performed tests on the existing lighthouse 412 00:26:02,320 --> 00:26:06,280 Speaker 1: setups in the country, he immediately began to brainstorm the 413 00:26:06,280 --> 00:26:09,000 Speaker 1: ways that they could be improved, although to be clear, 414 00:26:09,080 --> 00:26:11,240 Speaker 1: that was not a task he had been given. At 415 00:26:11,240 --> 00:26:15,680 Speaker 1: that point. Fornell realized that reflective mirrors could be replaced 416 00:26:15,680 --> 00:26:18,760 Speaker 1: with lenses that bent the light instead of reflecting it, 417 00:26:19,280 --> 00:26:21,840 Speaker 1: and this was something that had been tried. We just 418 00:26:21,960 --> 00:26:24,880 Speaker 1: mentioned it in some of those efforts, But Forrenell tried 419 00:26:24,880 --> 00:26:27,600 Speaker 1: to figure out ways to fix the problems that previous 420 00:26:27,680 --> 00:26:31,480 Speaker 1: lenses had. At one point he actually considered something I 421 00:26:31,480 --> 00:26:34,119 Speaker 1: found quite charming, which is creating a lens by filling 422 00:26:34,160 --> 00:26:37,600 Speaker 1: a glass container with wine. Obviously that would be a 423 00:26:37,680 --> 00:26:41,800 Speaker 1: white wine. But he abandoned it, and then he had 424 00:26:41,800 --> 00:26:45,040 Speaker 1: the idea to create a giant lens that did not 425 00:26:45,320 --> 00:26:49,119 Speaker 1: have to be impenetrably thick in the middle. Instead, it 426 00:26:49,119 --> 00:26:51,639 Speaker 1: would have a series of prisms that could bend and 427 00:26:51,680 --> 00:26:54,679 Speaker 1: focus the light into a beam. And he called his 428 00:26:54,800 --> 00:27:00,640 Speaker 1: design lentil Eeschlan or Lenses by Steps. But the Lighthouse 429 00:27:00,680 --> 00:27:03,400 Speaker 1: Commission was kind of a ho hum on this idea 430 00:27:04,040 --> 00:27:07,159 Speaker 1: and compared it to a similar one created by another 431 00:27:07,280 --> 00:27:11,359 Speaker 1: person some years earlier. But Frenell really thought he was 432 00:27:11,400 --> 00:27:14,399 Speaker 1: onto something. He knew though that he would have to 433 00:27:14,600 --> 00:27:17,560 Speaker 1: make it to show them what he was talking about. 434 00:27:18,400 --> 00:27:20,440 Speaker 1: He did manage to get some grant money from the 435 00:27:20,480 --> 00:27:25,440 Speaker 1: commission to help with the cost of construction. Like any prototype, 436 00:27:25,440 --> 00:27:28,840 Speaker 1: this one had some problems, but Frenell worked with craftsmen 437 00:27:28,920 --> 00:27:33,119 Speaker 1: to refine them. A specialist named Francois so they was 438 00:27:33,320 --> 00:27:36,800 Speaker 1: crucial to the construction of a glass panel that looked 439 00:27:36,840 --> 00:27:40,640 Speaker 1: like a square containing a bull's eye, with concentric rings 440 00:27:40,720 --> 00:27:44,840 Speaker 1: formed around a central circle to form a polygonal lens. 441 00:27:45,600 --> 00:27:48,920 Speaker 1: It had ninety seven different pieces of glass in it. 442 00:27:49,760 --> 00:27:52,639 Speaker 1: In an actual functioning lighthouse, he planned for there to 443 00:27:52,680 --> 00:27:56,760 Speaker 1: be eight such panels combined together in an octagonal shape 444 00:27:56,800 --> 00:28:00,280 Speaker 1: surrounding the light source, but for this test, one would 445 00:28:00,320 --> 00:28:03,240 Speaker 1: have to do. He combined it with a lamp that 446 00:28:03,359 --> 00:28:06,480 Speaker 1: used several small wicks instead of one large one, and 447 00:28:06,560 --> 00:28:09,080 Speaker 1: when he tested it in front of the Commission, those 448 00:28:09,119 --> 00:28:14,439 Speaker 1: in attendance were, in Frenelle's account, dazzled. But while a 449 00:28:14,520 --> 00:28:18,399 Speaker 1: full version of this design was requested, Frenelle was not 450 00:28:18,480 --> 00:28:21,200 Speaker 1: getting a full green light to go ahead with this project. 451 00:28:21,600 --> 00:28:26,680 Speaker 1: Two other people were also presenting fully assembled attempted solutions 452 00:28:26,720 --> 00:28:31,680 Speaker 1: to the lighthouse problem. Both of those other competitors used reflectors, 453 00:28:32,119 --> 00:28:35,280 Speaker 1: and the final test of these three models was public. 454 00:28:35,400 --> 00:28:39,240 Speaker 1: It was held at the Paris Observatory, and Forrenell was 455 00:28:39,280 --> 00:28:42,400 Speaker 1: the very clear winner by a mile. Nobody could deny 456 00:28:42,840 --> 00:28:46,120 Speaker 1: that what he had achieved far out shown not to 457 00:28:46,160 --> 00:28:48,920 Speaker 1: be punny. The work that everyone had been doing with 458 00:28:49,000 --> 00:28:52,719 Speaker 1: reflectors From there, he was commissioned to build a lens 459 00:28:52,800 --> 00:28:56,880 Speaker 1: for France's oldest continuously operating lighthouse, which was known as 460 00:28:56,960 --> 00:29:01,240 Speaker 1: Cordouin between the successful test of that lens and its 461 00:29:01,320 --> 00:29:05,680 Speaker 1: final installation, which was postponed due to winter weather, Frenell 462 00:29:05,800 --> 00:29:09,080 Speaker 1: continued to work on his work in light theory and 463 00:29:09,440 --> 00:29:13,400 Speaker 1: refining and formalizing any theoretical points that had been involved 464 00:29:13,440 --> 00:29:17,040 Speaker 1: in his earlier work with mathematics. He also wrote an 465 00:29:17,200 --> 00:29:21,040 Speaker 1: entry on refraction for Encyclopedia Britannica at the behest of 466 00:29:21,120 --> 00:29:24,920 Speaker 1: none other than Thomas Young. When the winter was over, 467 00:29:25,040 --> 00:29:28,240 Speaker 1: the final installation of the lens that Cordoine was completed, 468 00:29:28,440 --> 00:29:32,720 Speaker 1: and Forrenell's place in French scientific history was cemented. For 469 00:29:32,880 --> 00:29:35,840 Speaker 1: all of his work, Frenelle became an elected member of 470 00:29:35,880 --> 00:29:39,720 Speaker 1: the Academy of Sciences in eighteen twenty three. He also 471 00:29:39,840 --> 00:29:43,400 Speaker 1: received the French Legion of Honor, and the Royal Society 472 00:29:43,400 --> 00:29:46,480 Speaker 1: of London inducted Frenelle as a member in eighteen twenty four, 473 00:29:47,120 --> 00:29:51,040 Speaker 1: and that same year he was assigned to France's lighthouse commission. 474 00:29:51,760 --> 00:29:55,320 Speaker 1: The French government was so pleased with Frenell's lenses that 475 00:29:55,360 --> 00:29:58,840 Speaker 1: it developed a plan to illuminate the entire French coastline 476 00:29:58,840 --> 00:30:02,120 Speaker 1: with them. Arnell himself created a map of a planned 477 00:30:02,160 --> 00:30:05,160 Speaker 1: fifty one lighthouses for the country that would create a 478 00:30:05,200 --> 00:30:09,800 Speaker 1: continuous network of light. He also improved on his lens 479 00:30:09,880 --> 00:30:13,000 Speaker 1: design as he worked. Yeah, at that time there were 480 00:30:13,040 --> 00:30:16,640 Speaker 1: thirteen of those fifty one lighthouses that existed, so a 481 00:30:16,720 --> 00:30:19,040 Speaker 1: huge number we're going to have to be built from scratch, 482 00:30:19,120 --> 00:30:22,240 Speaker 1: and those thirteen were going to have to be significantly updated. 483 00:30:23,120 --> 00:30:27,000 Speaker 1: In eighteen twenty seven, Frenell received the Rumford Medal. That's 484 00:30:27,040 --> 00:30:29,840 Speaker 1: a metal bestowed by the Royal Society of London quote 485 00:30:29,840 --> 00:30:33,200 Speaker 1: for important discoveries in the field of thermal or optical 486 00:30:33,240 --> 00:30:37,320 Speaker 1: properties of matter and their applications. For some reason, just 487 00:30:37,400 --> 00:30:40,520 Speaker 1: if you go looking the Royal Society site, say this 488 00:30:40,560 --> 00:30:43,080 Speaker 1: happened in eighteen twenty four, that is the year he 489 00:30:43,160 --> 00:30:46,400 Speaker 1: was inducted. But based on ratings of other people involved 490 00:30:46,440 --> 00:30:49,600 Speaker 1: in the nomination and the award itself, this did happen 491 00:30:49,600 --> 00:30:53,760 Speaker 1: in eighteen twenty seven. Forrenell had not been especially healthy 492 00:30:53,800 --> 00:30:55,920 Speaker 1: at any point in his life, but as he got 493 00:30:55,960 --> 00:30:59,800 Speaker 1: into his late thirties he declined really rapidly. All through 494 00:30:59,840 --> 00:31:02,160 Speaker 1: him life, he'd been one of those people who worked 495 00:31:02,280 --> 00:31:07,000 Speaker 1: constantly up to and through the point of exhaustion. Many 496 00:31:07,040 --> 00:31:10,760 Speaker 1: biographies cite his deeply held religious faith as the source 497 00:31:10,800 --> 00:31:15,160 Speaker 1: of his drive. He believed his service to society was important, 498 00:31:15,520 --> 00:31:18,040 Speaker 1: and he pursued it to the exclusion of everything else. 499 00:31:18,720 --> 00:31:22,640 Speaker 1: Sometimes he characterized as being aware that he probably wouldn't 500 00:31:22,640 --> 00:31:25,800 Speaker 1: live a long life, and consequently he felt compelled to 501 00:31:25,800 --> 00:31:28,680 Speaker 1: do as much as he could in whatever time he had. 502 00:31:29,640 --> 00:31:32,120 Speaker 1: Just as his scientific work was taking off, he was 503 00:31:32,240 --> 00:31:36,640 Speaker 1: warned against overworking and had to prioritize what projects he 504 00:31:36,760 --> 00:31:40,280 Speaker 1: felt were the most important, and Forrenell did have a 505 00:31:40,320 --> 00:31:43,840 Speaker 1: short life. In the summer of eighteen twenty seven, he 506 00:31:44,000 --> 00:31:46,600 Speaker 1: was ill and was taken to a family property in 507 00:31:46,760 --> 00:31:49,120 Speaker 1: Vis d' roy in the hopes that fresh air would 508 00:31:49,160 --> 00:31:52,880 Speaker 1: help his health improve. His friend Arago traveled there to 509 00:31:52,920 --> 00:31:55,520 Speaker 1: see him and to give him the Rumford medal he 510 00:31:55,560 --> 00:31:58,760 Speaker 1: had been awarded, and Arago was quite distressed at just 511 00:31:58,840 --> 00:32:03,040 Speaker 1: how sick his friend was. Regarding the metal Frenelle, who 512 00:32:03,080 --> 00:32:06,040 Speaker 1: was incredibly weak, is said to have told Arago quote, 513 00:32:06,240 --> 00:32:09,040 Speaker 1: the most beautiful crown means little when it is laid 514 00:32:09,120 --> 00:32:12,680 Speaker 1: on the grave of a friend. He died of tuberculosis 515 00:32:12,680 --> 00:32:16,520 Speaker 1: on July fourteenth, eighteen twenty seven. His mother was with 516 00:32:16,640 --> 00:32:20,440 Speaker 1: him when he died, and he was thirty nine. His brother, 517 00:32:20,560 --> 00:32:24,440 Speaker 1: Leonor continued his work on the lighthouse project. The Frenelle 518 00:32:24,520 --> 00:32:28,680 Speaker 1: lens quickly became the standard in lighthouses around the world. 519 00:32:29,720 --> 00:32:32,240 Speaker 1: One of the ways that Frenell contributed to the world 520 00:32:32,240 --> 00:32:36,320 Speaker 1: of science, beyond his specific work in light waves and lenses, 521 00:32:36,720 --> 00:32:39,560 Speaker 1: was that his approach to his work helped to establish 522 00:32:39,600 --> 00:32:42,800 Speaker 1: the ways in which questions of physics would be examined 523 00:32:42,880 --> 00:32:46,440 Speaker 1: going forward. The idea of physics as a branch of 524 00:32:46,480 --> 00:32:50,239 Speaker 1: science hadn't really solidified yet when Frenelle was conducting his 525 00:32:50,320 --> 00:32:54,840 Speaker 1: experiments and developing his formulas. The word physics was kind 526 00:32:54,840 --> 00:32:58,200 Speaker 1: of a nebulous term that referred to almost any study 527 00:32:58,240 --> 00:33:01,800 Speaker 1: of the natural world. There were efforts in the decades 528 00:33:01,880 --> 00:33:05,840 Speaker 1: leading up to Augustine Farnell's birth and beyond to try 529 00:33:05,880 --> 00:33:08,960 Speaker 1: to formalize the more specific definition, but it had been 530 00:33:09,040 --> 00:33:13,800 Speaker 1: problematic in some ways. Other specialties had managed to carve 531 00:33:13,880 --> 00:33:17,120 Speaker 1: out their own identities, and physics was made up of 532 00:33:17,160 --> 00:33:20,800 Speaker 1: the science that was unclaimed by the other disciplines. There 533 00:33:20,800 --> 00:33:24,560 Speaker 1: were two branches of physics that developed general encompassed things 534 00:33:24,600 --> 00:33:27,840 Speaker 1: to do with the mechanics of the world and universe 535 00:33:27,880 --> 00:33:31,920 Speaker 1: as it was understood at the time, so things like gravity, inertia, movement, 536 00:33:32,120 --> 00:33:36,880 Speaker 1: et cetera. Particular physics dealt with the various characteristics of 537 00:33:36,960 --> 00:33:42,280 Speaker 1: matter like heat, light, and magnetism. Former podcast subject Antoine 538 00:33:42,360 --> 00:33:46,240 Speaker 1: Lavoisier had introduced the idea of physics as a recognized 539 00:33:46,280 --> 00:33:49,040 Speaker 1: branch of science to the Academy of Science just three 540 00:33:49,120 --> 00:33:53,760 Speaker 1: years before Frenell was born. But Frenelle's very careful methodology 541 00:33:53,960 --> 00:33:57,560 Speaker 1: of performing experiments and then developing the math to both 542 00:33:57,680 --> 00:34:00,520 Speaker 1: verify and explain the results was a huge step forward, 543 00:34:00,560 --> 00:34:04,520 Speaker 1: and it set the bar for physics, theory and proofs. Yeah, 544 00:34:04,560 --> 00:34:07,320 Speaker 1: he's interesting. I feel like we left so much out, 545 00:34:07,320 --> 00:34:09,279 Speaker 1: but I honestly can't parsel a lot of his work. 546 00:34:11,680 --> 00:34:15,600 Speaker 1: Don't ask me to explain the math. I love math 547 00:34:15,600 --> 00:34:17,719 Speaker 1: and theory, I'm just bad at it. I have a 548 00:34:17,760 --> 00:34:19,480 Speaker 1: listener mail that I hope won't make me cry, but 549 00:34:19,520 --> 00:34:22,399 Speaker 1: it might because it's quite beautiful. Ah. This is from 550 00:34:22,400 --> 00:34:25,120 Speaker 1: our listener Jen who writes high Holly and Tracy. I 551 00:34:25,200 --> 00:34:28,000 Speaker 1: recently listened to your behind the scenes episode on spray 552 00:34:28,040 --> 00:34:30,040 Speaker 1: Paint and I think it was Holly who was saying 553 00:34:30,040 --> 00:34:31,800 Speaker 1: in her youth, there was an area that it was 554 00:34:31,840 --> 00:34:33,960 Speaker 1: a rite of passage for the young people to tag 555 00:34:34,360 --> 00:34:37,680 Speaker 1: with spray paint, and that it would periodically get painted over. 556 00:34:38,200 --> 00:34:41,360 Speaker 1: It reminded me of my small town growing up. We 557 00:34:41,400 --> 00:34:43,719 Speaker 1: actually had a rather high level of deaths of high 558 00:34:43,760 --> 00:34:46,719 Speaker 1: school students for the size of our town. Death is 559 00:34:46,760 --> 00:34:49,760 Speaker 1: always hard to process, but especially for kids, and especially 560 00:34:49,800 --> 00:34:52,839 Speaker 1: when it is someone so young. Anyway, there was a 561 00:34:52,880 --> 00:34:55,319 Speaker 1: barn in the area that was unused, and after a 562 00:34:55,400 --> 00:34:57,520 Speaker 1: death the friends of the student would go out there 563 00:34:57,560 --> 00:35:01,680 Speaker 1: and paint a eulogy of sorts, obviously sometimes more artistically 564 00:35:01,719 --> 00:35:04,600 Speaker 1: than others, depending on who was present, but the point 565 00:35:04,640 --> 00:35:07,520 Speaker 1: wasn't really the art of it, as the grief processing 566 00:35:07,600 --> 00:35:10,600 Speaker 1: it allowed. The memorial would stay until the next high 567 00:35:10,600 --> 00:35:12,800 Speaker 1: schooler died, and then it would be covered by the 568 00:35:12,840 --> 00:35:15,839 Speaker 1: next group. It was a haunting, beautiful reminder each time 569 00:35:15,880 --> 00:35:19,239 Speaker 1: you drove by. The barn continued to fall into disrepair 570 00:35:19,280 --> 00:35:21,239 Speaker 1: over the years, and it has now been torn down, 571 00:35:21,280 --> 00:35:24,160 Speaker 1: but I sometimes wish something similar everywhere to allow for 572 00:35:24,200 --> 00:35:27,640 Speaker 1: this kind of public and personalized memorial in a way 573 00:35:27,640 --> 00:35:29,880 Speaker 1: for young people to work out some of their grief 574 00:35:30,520 --> 00:35:32,880 Speaker 1: as pet tax I have attached a short video of 575 00:35:32,880 --> 00:35:35,279 Speaker 1: my three year old son rolling around with our seven 576 00:35:35,360 --> 00:35:37,880 Speaker 1: year old rescue met scuttle Butt thanks to the podcast. 577 00:35:37,880 --> 00:35:41,240 Speaker 1: I always enjoy it. This is such a beautiful thing. Yeah, 578 00:35:41,520 --> 00:35:43,520 Speaker 1: I get very choked up over it. It's so lovely 579 00:35:44,840 --> 00:35:48,160 Speaker 1: and it is very insightful about people trying to process laws. 580 00:35:48,640 --> 00:35:51,680 Speaker 1: So Jim, thank you. I'm crying. It's lovely. If you 581 00:35:51,800 --> 00:35:53,600 Speaker 1: have an email that you would like to make me 582 00:35:53,640 --> 00:35:56,799 Speaker 1: cry with, feel free take it as challenge. It's not 583 00:35:56,840 --> 00:35:59,400 Speaker 1: a very hard one. You could do that at History 584 00:35:59,440 --> 00:36:03,279 Speaker 1: podcast iHeartRadio dot com. You can also subscribe to the 585 00:36:03,320 --> 00:36:07,040 Speaker 1: show wherever you listen to your favorite podcasts, including the 586 00:36:07,120 --> 00:36:15,000 Speaker 1: iHeartRadio app. Stuff You Missed in History Class is a 587 00:36:15,040 --> 00:36:19,440 Speaker 1: production of iHeartRadio. For more podcasts from iHeartRadio, visit the 588 00:36:19,440 --> 00:36:22,960 Speaker 1: iHeartRadio app, Apple Podcasts, or wherever you listen to your 589 00:36:22,960 --> 00:36:23,680 Speaker 1: favorite shows.