1 00:00:00,040 --> 00:00:03,440 Speaker 1: Hey, y'all, we're rerunning two episodes today. Enjoy the show. 2 00:00:05,840 --> 00:00:09,360 Speaker 1: Hi there, Welcome to this day in History class, where 3 00:00:09,360 --> 00:00:12,840 Speaker 1: we sift through the artifacts of history seven days a week. 4 00:00:19,640 --> 00:00:25,680 Speaker 1: The day was February two. The journal Nature published a 5 00:00:25,760 --> 00:00:30,800 Speaker 1: letter by the English physicist James Chadwick. The letter was 6 00:00:30,880 --> 00:00:35,680 Speaker 1: called possible existence of a neutron. Up until this point, 7 00:00:36,159 --> 00:00:40,080 Speaker 1: science hill that the atom contained a positively charged nucleus 8 00:00:40,560 --> 00:00:44,879 Speaker 1: or central core, that was surrounded by negatively charged electrons, 9 00:00:45,680 --> 00:00:48,680 Speaker 1: and scientists knew that most of the mass of the 10 00:00:48,720 --> 00:00:53,680 Speaker 1: atom was at its core. But Chadwick's research confirmed the 11 00:00:53,680 --> 00:00:57,560 Speaker 1: existence of a sub atomic particle that had about the 12 00:00:57,600 --> 00:01:01,360 Speaker 1: same mass as a proton, but didn't have an electric charge. 13 00:01:02,760 --> 00:01:07,040 Speaker 1: Chadwick's findings marked a major milestone in atomic theory and 14 00:01:07,120 --> 00:01:12,800 Speaker 1: led to experimentation with developing an atomic bomb. But many 15 00:01:12,840 --> 00:01:16,319 Speaker 1: other scientists helped pave the way for Chadwick to make 16 00:01:16,400 --> 00:01:21,120 Speaker 1: his discovery. Chadwick got his master's degree in physics at 17 00:01:21,160 --> 00:01:25,320 Speaker 1: the University of Manchester, where he worked with noted physicists 18 00:01:25,319 --> 00:01:30,639 Speaker 1: and so called father of nuclear physics, Ernest Rutherford. Then 19 00:01:30,840 --> 00:01:34,560 Speaker 1: he went to Germany to study under Hans Geiger of 20 00:01:34,680 --> 00:01:39,280 Speaker 1: Geiger counter fame. After spending years in a prison camp 21 00:01:39,400 --> 00:01:43,080 Speaker 1: during the First World War, Chadwick went back to England 22 00:01:43,319 --> 00:01:47,560 Speaker 1: to study with Rutherford again, this time earning his doctorate 23 00:01:47,880 --> 00:01:53,320 Speaker 1: at the University of Cambridge, and in nineteen Chadwick was 24 00:01:53,360 --> 00:01:59,960 Speaker 1: appointed assistant director of Cambridge's Cavendish Laboratory, where Rutherford was director, 25 00:02:01,080 --> 00:02:04,480 Speaker 1: and there the two of them worked on the transmutation 26 00:02:04,560 --> 00:02:09,399 Speaker 1: of elements by bombarding them with alpha particles, and researched 27 00:02:09,440 --> 00:02:15,560 Speaker 1: the structure of the atomic nucleus. Rutherford postulated that there 28 00:02:15,560 --> 00:02:19,639 Speaker 1: had to be something else in the atomic nucleus besides protons. 29 00:02:20,320 --> 00:02:23,600 Speaker 1: Why was the atomic number for the number of protons 30 00:02:23,600 --> 00:02:29,560 Speaker 1: and adams nucleus usually about half the mass number. Rutherford 31 00:02:29,639 --> 00:02:33,720 Speaker 1: answered this question in nineteen twenty by suggesting that a 32 00:02:33,800 --> 00:02:38,680 Speaker 1: proton and electron combined to form a neutral particle that 33 00:02:38,760 --> 00:02:43,040 Speaker 1: was roughly the same mass as a proton. But this 34 00:02:43,120 --> 00:02:47,160 Speaker 1: neutral particle would be hard to detect since most techniques 35 00:02:47,200 --> 00:02:52,239 Speaker 1: at the time measured charged particles. By About a decade later, 36 00:02:52,800 --> 00:02:57,359 Speaker 1: other scientists were working on the problem. German physicist Walter 37 00:02:57,480 --> 00:03:01,960 Speaker 1: both and his student Herbert Becker. We're doing experiments bombarding 38 00:03:02,000 --> 00:03:06,800 Speaker 1: beryllium with alpha particles emitted from polonium, and they found 39 00:03:07,120 --> 00:03:11,440 Speaker 1: that the beryllium emitted a highly penetrating radiation. As a result, 40 00:03:12,639 --> 00:03:17,119 Speaker 1: they interpreted that radiation to be high energy photons, which 41 00:03:17,160 --> 00:03:22,400 Speaker 1: are particles that represent a quantum of electromagnetic radiation. But 42 00:03:22,560 --> 00:03:26,880 Speaker 1: Chadwick thought that this radiation might instead consist of the 43 00:03:26,919 --> 00:03:31,840 Speaker 1: neutral particles his mentor Rutherford had proposed, and in nineteen 44 00:03:31,880 --> 00:03:36,240 Speaker 1: thirty two Chadwick's interest was piqued when Irene and Frederic 45 00:03:36,440 --> 00:03:42,320 Speaker 1: Jolio Curie decided to study the mysterious radiation. They studied 46 00:03:42,360 --> 00:03:45,280 Speaker 1: the radiation as it hit a block of paraffin wax, 47 00:03:45,760 --> 00:03:49,640 Speaker 1: and they found that the radiation ejected protons from the 48 00:03:49,720 --> 00:03:53,800 Speaker 1: hydrogen atoms in the paraffin wax, and the protons recoiled 49 00:03:53,880 --> 00:03:58,600 Speaker 1: with the high velocity. Irene and Frederic thought that the 50 00:03:58,720 --> 00:04:03,840 Speaker 1: radiation had to be high energy gamma photons, but Chadwick 51 00:04:03,960 --> 00:04:08,120 Speaker 1: thought that since photons have no rest mass, they couldn't 52 00:04:08,160 --> 00:04:12,720 Speaker 1: possibly knock heavy protons out of the paraffin wax. So 53 00:04:12,760 --> 00:04:17,720 Speaker 1: that same year Chadwick did similar experiments at the Cavendish Laboratory. 54 00:04:18,400 --> 00:04:22,080 Speaker 1: He used paraffin wax in the experiments, but he also 55 00:04:22,279 --> 00:04:28,440 Speaker 1: used other targets like helium, nitrogen, and lithium. After comparing 56 00:04:28,480 --> 00:04:32,120 Speaker 1: the energies of the protons that were knocked out, he 57 00:04:32,279 --> 00:04:35,480 Speaker 1: was able to determine that there was likely a neutral 58 00:04:35,520 --> 00:04:39,240 Speaker 1: particle with a mass that's slightly more than a protons. 59 00:04:40,560 --> 00:04:44,960 Speaker 1: After experimenting for only a couple of weeks, Chadwick published 60 00:04:45,440 --> 00:04:50,400 Speaker 1: possible existence of a neutron, and in June n two, 61 00:04:51,080 --> 00:04:55,240 Speaker 1: Chadwick's paper titled the Existence of a Neutron was published 62 00:04:55,279 --> 00:05:00,560 Speaker 1: in the journal Proceedings of the Royal Society A. Chadwick 63 00:05:00,600 --> 00:05:03,920 Speaker 1: received the Hues Medal from the Royal Society of London 64 00:05:04,000 --> 00:05:07,680 Speaker 1: for his discovery in nineteen thirty two, and in nineteen 65 00:05:07,760 --> 00:05:10,919 Speaker 1: thirty five he got the Nobel Prize for Physics for 66 00:05:11,040 --> 00:05:15,320 Speaker 1: his discovery of the neutron. But even though his discovery 67 00:05:15,360 --> 00:05:18,599 Speaker 1: made waves in physics based on its importance to the 68 00:05:18,680 --> 00:05:23,520 Speaker 1: knowledge of atomic structure, it had implications far beyond that. 69 00:05:24,640 --> 00:05:28,000 Speaker 1: The discovery of the neutron led to the fission of 70 00:05:28,040 --> 00:05:32,520 Speaker 1: the uranium nucleus, which produced a ton of energy and 71 00:05:32,600 --> 00:05:37,880 Speaker 1: inspired the creation of nuclear weapons. During the Second World War, 72 00:05:38,640 --> 00:05:42,840 Speaker 1: Chadwick worked on the Manhattan Project, the US government research 73 00:05:42,920 --> 00:05:48,760 Speaker 1: and development endeavor that produced the first atomic bombs. I'm Eaves, 74 00:05:48,800 --> 00:05:52,400 Speaker 1: Jeffcote and hopefully you know a little more about history 75 00:05:52,480 --> 00:05:56,880 Speaker 1: today than you did yesterday. We love it if you 76 00:05:57,040 --> 00:06:01,080 Speaker 1: left us a comment on Twitter, Instagram or Facebook at 77 00:06:01,279 --> 00:06:06,800 Speaker 1: t d i h C Podcast, We'll be back with 78 00:06:06,920 --> 00:06:18,680 Speaker 1: more history tomorrow. Hey everyone, welcome to the podcast. I'm 79 00:06:18,760 --> 00:06:21,360 Speaker 1: Eves and you're listening to this Day in History class, 80 00:06:21,880 --> 00:06:24,360 Speaker 1: a podcast that really takes to heart the phrase you 81 00:06:24,480 --> 00:06:31,839 Speaker 1: learn something new every day. The day was February nineteen 82 00:06:31,960 --> 00:06:36,240 Speaker 1: seventy three. A group of a Kalala Lakota activists and 83 00:06:36,400 --> 00:06:39,800 Speaker 1: members of the American Indian Movement took control of the 84 00:06:39,880 --> 00:06:43,560 Speaker 1: town of Wounded Knee in South Dakota. The conflict that 85 00:06:43,760 --> 00:06:48,280 Speaker 1: ensued lasted for seventy one days. Wounded Knee, on the 86 00:06:48,360 --> 00:06:52,200 Speaker 1: Pine Ridge Reservation in southwestern South Dakota, is a site 87 00:06:52,240 --> 00:06:56,280 Speaker 1: of significance in the US and Native American history. In 88 00:06:56,400 --> 00:07:00,240 Speaker 1: eight members of the U. S. Army killed is of 89 00:07:00,320 --> 00:07:04,040 Speaker 1: Lakota at Wounded Knee. The site of the massacre was 90 00:07:04,160 --> 00:07:08,600 Speaker 1: designated a National Historic Landmark in nineteen sixty five. Three 91 00:07:08,680 --> 00:07:13,320 Speaker 1: years later, the American Indian Movement was founded in Minneapolis, Minnesota. 92 00:07:14,400 --> 00:07:18,120 Speaker 1: The group aimed to address the economic, cultural, and political 93 00:07:18,240 --> 00:07:21,920 Speaker 1: needs of Native American people, and it fought to restore 94 00:07:22,040 --> 00:07:26,360 Speaker 1: lands that were illegally seized from Native Americans. Many of 95 00:07:26,440 --> 00:07:29,760 Speaker 1: its protests got a lot of media attention, like the 96 00:07:29,880 --> 00:07:34,360 Speaker 1: occupation of Alcatraz from nineteen sixty nine to nineteen seventy one. 97 00:07:35,400 --> 00:07:38,960 Speaker 1: Of course, the movement had its detractors who saw its 98 00:07:39,040 --> 00:07:44,520 Speaker 1: participants as to militants. Wounded Knee was not only historically significant. 99 00:07:44,880 --> 00:07:48,600 Speaker 1: In the nineteen seventies and today, many people who lived 100 00:07:48,760 --> 00:07:53,440 Speaker 1: on the Pine Ridge Indian Reservation faced serious poverty. Richard 101 00:07:53,640 --> 00:07:57,040 Speaker 1: Dick Wilson was the tribal chairman of the Agolala Lakota 102 00:07:57,160 --> 00:08:00,640 Speaker 1: on the reservation, but many of the Agolala who lived 103 00:08:00,720 --> 00:08:04,160 Speaker 1: in Pine Ridge were unhappy with the tribal government and 104 00:08:04,280 --> 00:08:07,440 Speaker 1: thought that Wilson was a corrupt instrument of the Bureau 105 00:08:07,560 --> 00:08:12,440 Speaker 1: of Indian Affairs. Some said that he favored Lakota who assimilated, 106 00:08:13,040 --> 00:08:16,480 Speaker 1: and he shut down protests that Agolala Lakota began when 107 00:08:16,520 --> 00:08:20,440 Speaker 1: they faced racial violence. Many of the tribes people called 108 00:08:20,600 --> 00:08:24,920 Speaker 1: for Wilson's impeachment, but the effort to impeach Wilson failed. 109 00:08:26,080 --> 00:08:29,880 Speaker 1: Tribal leaders were also frustrated with the US government's failure 110 00:08:30,000 --> 00:08:33,880 Speaker 1: to fulfill treaties and its general mistreatment of Native Americans, 111 00:08:34,600 --> 00:08:37,480 Speaker 1: so some of the Agolala Lakota members looked to the 112 00:08:37,600 --> 00:08:42,160 Speaker 1: American Indian Movement for help. Tribal leaders aimed to renegotiate 113 00:08:42,280 --> 00:08:45,439 Speaker 1: the terms of past treaties and to declare Wounded me 114 00:08:45,720 --> 00:08:51,560 Speaker 1: as the independent Agolala Nation. On February seven, nineteen seventy three, 115 00:08:51,960 --> 00:08:56,160 Speaker 1: around two hundred Agolala Lakota and members of the American 116 00:08:56,240 --> 00:09:01,480 Speaker 1: Indian Movement occupied Wounded Knee. Soon the patient became violent, 117 00:09:02,120 --> 00:09:06,000 Speaker 1: The federal government set up roadblocks around the area. Federal 118 00:09:06,120 --> 00:09:09,880 Speaker 1: marshals and the National Guard traded fire with the protesters. 119 00:09:11,040 --> 00:09:14,680 Speaker 1: A ceasefire was called on March tenth, but more Agolala 120 00:09:14,800 --> 00:09:17,880 Speaker 1: Lakota supporters showed up at the site of the occupation. 121 00:09:19,120 --> 00:09:22,400 Speaker 1: The conflict continued for more than three months after it began, 122 00:09:22,960 --> 00:09:25,599 Speaker 1: and it got a lot of media coverage, But the 123 00:09:25,720 --> 00:09:29,760 Speaker 1: death of Agolala Lakota tribe member Buddy Lamont drove Mini 124 00:09:29,800 --> 00:09:33,559 Speaker 1: Agolala to put an end to the occupation. They began 125 00:09:33,640 --> 00:09:37,239 Speaker 1: negotiations with the government and on May eighth, they surrendered 126 00:09:37,360 --> 00:09:41,400 Speaker 1: once officials agreed to look into their issues. In total 127 00:09:41,640 --> 00:09:45,480 Speaker 1: to Aglala Lacoda died and several others were wounded. One 128 00:09:45,600 --> 00:09:49,280 Speaker 1: federal agent was shot and paralyzed. Many members of the 129 00:09:49,320 --> 00:09:52,960 Speaker 1: American Indian Movement left wounded me before they could be arrested, 130 00:09:53,520 --> 00:09:58,400 Speaker 1: but others, like leader Russell Means, were arrested. Nearly all 131 00:09:58,480 --> 00:10:03,120 Speaker 1: those arrested were acquitted because evidence was mishandled, but even 132 00:10:03,200 --> 00:10:07,240 Speaker 1: after the occupation ended, violent conflict between the US government 133 00:10:07,400 --> 00:10:12,440 Speaker 1: and Aklala Lakota continued. Wilson was re elected tribal chairman 134 00:10:12,520 --> 00:10:16,679 Speaker 1: in nineteen seventy four. I'm Eve Chef Coke and hopefully 135 00:10:16,760 --> 00:10:19,199 Speaker 1: you know a little more about history today than you 136 00:10:19,280 --> 00:10:23,640 Speaker 1: did yesterday. Keep up with us on Twitter, Facebook, and 137 00:10:23,920 --> 00:10:28,640 Speaker 1: Instagram at t d I h C podcast, or if 138 00:10:28,679 --> 00:10:30,480 Speaker 1: you want to get a little more fancy, you can 139 00:10:30,520 --> 00:10:33,600 Speaker 1: send us an email at this Day at I heart 140 00:10:33,720 --> 00:10:37,240 Speaker 1: media dot com. Thanks for listening. We'll see you here 141 00:10:37,320 --> 00:10:44,719 Speaker 1: again tomorrow with another episode. For more podcasts from I 142 00:10:44,840 --> 00:10:47,599 Speaker 1: Heart Radio, visit the iHeart Radio app, Apple Podcasts, or 143 00:10:47,640 --> 00:10:49,240 Speaker 1: wherever you listen to your favorite shows.