1 00:00:00,040 --> 00:00:04,800 Speaker 1: Hey y'all, we're rerunning two episodes today. Enjoy the show. Hi, 2 00:00:05,360 --> 00:00:08,879 Speaker 1: I'm Eves, and Welcome to This Day in History Class, 3 00:00:09,280 --> 00:00:12,440 Speaker 1: a show that uncovers history one day at a time. 4 00:00:21,200 --> 00:00:25,880 Speaker 1: The day was May twenty ninth, nineteen nineteen. A total 5 00:00:25,960 --> 00:00:30,440 Speaker 1: solar eclipse lasted for more than six minutes, casting darkness 6 00:00:30,480 --> 00:00:35,720 Speaker 1: from South America to Africa. German physicist Albert Einstein had 7 00:00:35,800 --> 00:00:39,199 Speaker 1: recently published his general theory of relativity, but it was 8 00:00:39,320 --> 00:00:44,479 Speaker 1: not yet proven. During the eclipse, British astronomer Arthur Eddington 9 00:00:44,720 --> 00:00:47,720 Speaker 1: led an experiment to test the deflection of light by 10 00:00:47,720 --> 00:00:52,360 Speaker 1: a gravitational field. Eddington's research teams found that their eclipse 11 00:00:52,360 --> 00:00:58,720 Speaker 1: measurements confirmed Einstein's predictions about general relativity. Einstein, a professor 12 00:00:58,720 --> 00:01:02,600 Speaker 1: in Berlin, had yet to achieve worldwide fame, but after 13 00:01:02,640 --> 00:01:08,240 Speaker 1: the eclipse experiment, Einstein rose to prominence. In nineteen fifteen, 14 00:01:08,240 --> 00:01:12,200 Speaker 1: Einstein published four papers describing his general theory of relativity. 15 00:01:13,800 --> 00:01:17,000 Speaker 1: At the time, Isaac Newton's model of classical mechanics and 16 00:01:17,080 --> 00:01:21,360 Speaker 1: law of universal gravitation ruled, but Einstein's work was at 17 00:01:21,360 --> 00:01:26,040 Speaker 1: odds with Newton's theory. According to Newton, space was inert 18 00:01:26,160 --> 00:01:29,399 Speaker 1: and gravity was a force step pulled objects together. But 19 00:01:29,560 --> 00:01:34,040 Speaker 1: Einstein's special theory of relativity, proposed in nineteen o five, 20 00:01:34,600 --> 00:01:38,039 Speaker 1: said that space and time were relative informed of four 21 00:01:38,080 --> 00:01:42,560 Speaker 1: dimensional continuum called space time, and his general theory of 22 00:01:42,560 --> 00:01:46,000 Speaker 1: relativity posed gravity as a distortion in the fabric of 23 00:01:46,080 --> 00:01:50,840 Speaker 1: space caused by the presence of massive objects. Einstein and 24 00:01:50,920 --> 00:01:55,640 Speaker 1: Newton's views on how gravity influences light also differed. Classical 25 00:01:55,720 --> 00:01:58,680 Speaker 1: dynamics says that the gravity of a star can deflect 26 00:01:58,720 --> 00:02:02,880 Speaker 1: the path of a photon or a quantum of electromagnetic radiation, 27 00:02:03,520 --> 00:02:07,320 Speaker 1: but Einstein predicted that light curves while traveling through spacetime 28 00:02:07,400 --> 00:02:12,600 Speaker 1: near the warp induced by an object's gravitational field. So 29 00:02:12,840 --> 00:02:16,160 Speaker 1: both scientists predicted that light would bend due to gravity, 30 00:02:16,560 --> 00:02:19,080 Speaker 1: though newt end predicted it would do so by only 31 00:02:19,200 --> 00:02:22,960 Speaker 1: half as much as Einstein's theory did, but the difference 32 00:02:23,000 --> 00:02:26,480 Speaker 1: in measurements was small, and the two theories made similar 33 00:02:26,480 --> 00:02:31,560 Speaker 1: predictions for tests of gravity and light. Figuring out which 34 00:02:31,600 --> 00:02:34,639 Speaker 1: theory was more accurate seemed pointless at a time when 35 00:02:34,639 --> 00:02:37,640 Speaker 1: it seemed like science did not have the capability to 36 00:02:37,720 --> 00:02:41,320 Speaker 1: measure such a tiny curvature. But the more massive an 37 00:02:41,360 --> 00:02:44,280 Speaker 1: object is the bigger the warp, and the more its 38 00:02:44,280 --> 00:02:48,520 Speaker 1: gravity can bend light. Einstein realized that the Sun was 39 00:02:48,639 --> 00:02:52,160 Speaker 1: massive enough to measure such a subtle effect. As the 40 00:02:52,240 --> 00:02:55,640 Speaker 1: Sun moved towards a background star, it would bend the 41 00:02:55,639 --> 00:02:59,160 Speaker 1: stars light and the star would appear to move. This 42 00:02:59,280 --> 00:03:01,520 Speaker 1: kind of observed sation would have to be made when 43 00:03:01,520 --> 00:03:04,440 Speaker 1: the Sun was out, but its light was blocked, so 44 00:03:04,520 --> 00:03:08,280 Speaker 1: stars were visible, and eclipse was the perfect time to 45 00:03:08,320 --> 00:03:14,040 Speaker 1: carry out tests of Einstein's theory. German astronomer Erwin Finlay 46 00:03:14,080 --> 00:03:18,119 Speaker 1: Fronleech attempted to prove Einstein's theory, but war broke out 47 00:03:18,160 --> 00:03:20,440 Speaker 1: and he was arrested as a spy as he was 48 00:03:20,480 --> 00:03:25,720 Speaker 1: preparing to experiment during an eclipse in nineteen fourteen. Astronomers 49 00:03:25,760 --> 00:03:30,080 Speaker 1: from California's Lick Observatory also attempted to photograph the eclipse 50 00:03:30,120 --> 00:03:34,080 Speaker 1: from near Kiev, but cloud's got in the way. Around 51 00:03:34,080 --> 00:03:37,600 Speaker 1: this time, Einstein realized his calculations about how much the 52 00:03:37,600 --> 00:03:41,600 Speaker 1: stars would move was incorrect, and he published his completed 53 00:03:41,760 --> 00:03:46,320 Speaker 1: General Theory of Relativity in nineteen fifteen. World War One 54 00:03:46,440 --> 00:03:50,000 Speaker 1: kept Einstein's work isolated, and people in the science community 55 00:03:50,000 --> 00:03:53,680 Speaker 1: pushed back against the new theory, but Sir Arthur Eddington, 56 00:03:53,920 --> 00:03:58,360 Speaker 1: director of the Cambridge Observatory, supported Einstein's theory and wanted 57 00:03:58,440 --> 00:04:02,240 Speaker 1: to lead an experiment to test it. The nineteen nineteen 58 00:04:02,320 --> 00:04:06,240 Speaker 1: total solar eclipse presented an opportunity to carry out tests. 59 00:04:07,200 --> 00:04:12,440 Speaker 1: Britain's astronomer, Royal Sir Frank W. Dyson, proposed an expedition 60 00:04:12,480 --> 00:04:15,800 Speaker 1: to experiment during the solar eclipse, set to occur on 61 00:04:15,880 --> 00:04:20,359 Speaker 1: May twenty ninth, nineteen nineteen. If scientists measured the position 62 00:04:20,400 --> 00:04:23,279 Speaker 1: of the stars during the eclipse and compared them to 63 00:04:23,320 --> 00:04:26,799 Speaker 1: their normal positions, the tests could confirm the general theory 64 00:04:26,800 --> 00:04:32,240 Speaker 1: of relativity. Eddington would lead the expedition. He took measurements 65 00:04:32,320 --> 00:04:35,159 Speaker 1: of the stars in the Hyades cluster in January and 66 00:04:35,200 --> 00:04:38,760 Speaker 1: February of nineteen nineteen, since the sun would cross that 67 00:04:38,800 --> 00:04:42,400 Speaker 1: cluster during the eclipse, and the Royal Society in Royal 68 00:04:42,400 --> 00:04:47,599 Speaker 1: Astronomical Society organized expeditions to Principal, An Island off the 69 00:04:47,640 --> 00:04:52,039 Speaker 1: coast of West Africa, and to sober All, Brazil. The 70 00:04:52,120 --> 00:04:55,400 Speaker 1: May twenty nine eclipse was one of the longest in centuries, 71 00:04:55,800 --> 00:04:59,760 Speaker 1: and despite that, weather in Principe for a period astronomers 72 00:04:59,800 --> 00:05:02,440 Speaker 1: had a considerable amount of time to take photos of 73 00:05:02,440 --> 00:05:07,200 Speaker 1: the location of the stars and the Hyades cluster. Months later, 74 00:05:07,360 --> 00:05:10,040 Speaker 1: the team had measured the precise position of the stars 75 00:05:10,080 --> 00:05:13,400 Speaker 1: that were visible on the photographic plates. They found that 76 00:05:13,440 --> 00:05:18,520 Speaker 1: their measurements were consistent with Einstein's predictions. The expedition's results 77 00:05:18,520 --> 00:05:22,839 Speaker 1: became front page news in Einstein became famous for his theory. 78 00:05:23,880 --> 00:05:28,600 Speaker 1: On November six, nineteen nineteen, Eddington and Dyson presented their 79 00:05:28,600 --> 00:05:31,719 Speaker 1: findings at a joint meeting of the Royal Society and 80 00:05:31,760 --> 00:05:36,279 Speaker 1: the Royal Astronomical Society in England. Not everyone accepted or 81 00:05:36,360 --> 00:05:41,880 Speaker 1: understood Einstein's theory, and Einstein himself had detractors, but later 82 00:05:41,960 --> 00:05:47,840 Speaker 1: eclipses corroborated Einstein's predictions. By the nineteen sixties, most physicists 83 00:05:47,839 --> 00:05:51,039 Speaker 1: had accepted the validity of the general theory of relativity. 84 00:05:51,839 --> 00:05:54,960 Speaker 1: The deflection of light passing near a massive object is 85 00:05:55,000 --> 00:05:59,640 Speaker 1: now called gravitational lensing. Gravitational lensing has been used to 86 00:05:59,680 --> 00:06:05,719 Speaker 1: map dark matter and discovered distant galaxies. I'm Eves Decote 87 00:06:05,760 --> 00:06:08,480 Speaker 1: and hopefully you know a little more about history today 88 00:06:08,800 --> 00:06:12,240 Speaker 1: than you did yesterday. And if you'd like to follow 89 00:06:12,320 --> 00:06:15,160 Speaker 1: us on social media, you can find us at T 90 00:06:15,720 --> 00:06:21,160 Speaker 1: D I h C Podcast on Twitter, Instagram, and Facebook. 91 00:06:22,279 --> 00:06:31,920 Speaker 1: Thanks for showing up. We'll meet here again tomorrow. Hey y'all, 92 00:06:31,920 --> 00:06:34,800 Speaker 1: I'm Eves and welcome to This Day in History Class, 93 00:06:34,800 --> 00:06:37,320 Speaker 1: a podcast that brings you a little nugget of history 94 00:06:37,480 --> 00:06:48,320 Speaker 1: every day. The day was made fourteen fifty three, Constantinople, 95 00:06:48,600 --> 00:06:51,640 Speaker 1: the capital of the Byzantine Empire, was captured by the 96 00:06:51,680 --> 00:06:55,440 Speaker 1: Ottoman Empire. The fall of Constantinople marked the end of 97 00:06:55,480 --> 00:07:00,320 Speaker 1: the Byzantine Empire. Roman Emperor Constantine the first into the 98 00:07:00,400 --> 00:07:06,080 Speaker 1: city of Constantinople in three Constantinople served as the capital 99 00:07:06,120 --> 00:07:10,000 Speaker 1: of the Eastern Roman Empire, later known as the Byzantine Empire. 100 00:07:11,120 --> 00:07:13,840 Speaker 1: The city survived as the empire's capital for more than 101 00:07:13,960 --> 00:07:19,119 Speaker 1: one thousand years, lasting through attacks and rebellions. In twelve 102 00:07:19,160 --> 00:07:23,080 Speaker 1: o four CE, nights of the Fourth Crusade captured Constantinople. 103 00:07:23,640 --> 00:07:27,080 Speaker 1: The Crusaders founded the Latin Empire on lands that captured, 104 00:07:27,440 --> 00:07:29,760 Speaker 1: while the rest of the Byzantine Empire split into the 105 00:07:29,800 --> 00:07:34,080 Speaker 1: Empire of Nicea, the Empire of Trebizond, and the Despotate 106 00:07:34,200 --> 00:07:39,160 Speaker 1: of Epirus. In twelve sixty one, the Nicenes regained control 107 00:07:39,200 --> 00:07:43,800 Speaker 1: of Constantinople from the Crusaders. Michael the Eighth polio Logos 108 00:07:43,880 --> 00:07:48,400 Speaker 1: repaired and restored the capital, rebuilding monasteries and other buildings, 109 00:07:49,440 --> 00:07:53,720 Speaker 1: but the Byzantine Empire was declining. Reconstruction was expensive and 110 00:07:53,920 --> 00:07:58,720 Speaker 1: devalued Byzantine currency. The Empire's population was decreasing and its 111 00:07:58,800 --> 00:08:02,679 Speaker 1: territory was contracting. The Black Death killed a large chunk 112 00:08:02,720 --> 00:08:06,560 Speaker 1: of the population in Constantinople, and a civil war took 113 00:08:06,560 --> 00:08:09,400 Speaker 1: place in the empire from thirteen forty one to thirteen 114 00:08:09,440 --> 00:08:13,120 Speaker 1: forty seven. The Byzantine Empire also faced attacks from the 115 00:08:13,160 --> 00:08:17,800 Speaker 1: Bulgarians and the Serbians. At the same time, the Ottoman Empire, 116 00:08:18,160 --> 00:08:21,840 Speaker 1: founded in the late thirteenth century, was expanding. The Ottoman 117 00:08:21,880 --> 00:08:24,800 Speaker 1: Empire captured Borsa from the Byzantines and made it the 118 00:08:24,840 --> 00:08:29,800 Speaker 1: capital city. The Empire also invaded Thrace and captured Adrian Noble, 119 00:08:30,240 --> 00:08:34,360 Speaker 1: making it the new Ottoman capital. It captured Thessaloniki from 120 00:08:34,400 --> 00:08:37,760 Speaker 1: the Venetians, and after the Ottomans emerged victorious in the 121 00:08:37,760 --> 00:08:41,120 Speaker 1: Battle of Kosovo in thirteen eighty nine, the Serbians fell 122 00:08:41,160 --> 00:08:44,280 Speaker 1: out of power in the region. By this point, the 123 00:08:44,320 --> 00:08:47,800 Speaker 1: Byzantine Empire had become a vassal to the Ottomans. While 124 00:08:47,800 --> 00:08:50,440 Speaker 1: the Byzantine Empire was on the verge of collapse, the 125 00:08:50,480 --> 00:08:55,520 Speaker 1: Ottoman Empire was closing in on Constantinople. In fourteen fifty one, 126 00:08:55,679 --> 00:08:58,800 Speaker 1: Sultan Mehmed the Second took the Ottoman throne for the 127 00:08:58,880 --> 00:09:02,520 Speaker 1: second time. The Byzantine emperor at the time was Constantine 128 00:09:02,520 --> 00:09:07,000 Speaker 1: the eleventh. When the Ottoman threat was imminent, Constantine appealed 129 00:09:07,040 --> 00:09:10,199 Speaker 1: to Pope Nicholas the Fifth for aid. The Pope did 130 00:09:10,240 --> 00:09:13,200 Speaker 1: seek help from the West, but many Western states were 131 00:09:13,240 --> 00:09:15,720 Speaker 1: tied up in their own conflicts and didn't have the 132 00:09:15,760 --> 00:09:19,800 Speaker 1: people or money to send help to Constantinople. Venice and 133 00:09:19,840 --> 00:09:22,720 Speaker 1: Genoa sent military support to the city, but the help 134 00:09:22,800 --> 00:09:26,360 Speaker 1: that the Byzantines did get was no match for Ottoman forces. 135 00:09:27,400 --> 00:09:30,079 Speaker 1: The siege of the city began on April six, fourteen 136 00:09:30,080 --> 00:09:34,280 Speaker 1: fifty three. The Ottoman army likely had between sixty and 137 00:09:34,360 --> 00:09:37,679 Speaker 1: eighty thousand people. There were likely less than ten thousand 138 00:09:37,760 --> 00:09:41,320 Speaker 1: Byzantine forces. On top of that, the Ottomans had plenty 139 00:09:41,360 --> 00:09:45,680 Speaker 1: of cannon. Mohammed's plan was to blockade Constantinople on all 140 00:09:45,679 --> 00:09:49,720 Speaker 1: sides while attacking the Theodosian walls. The defensive walls that 141 00:09:49,800 --> 00:09:52,960 Speaker 1: fortified the city, but the Byzantines were able to repair 142 00:09:53,080 --> 00:09:56,160 Speaker 1: a lot of the damage. Between the cannon shots, the 143 00:09:56,200 --> 00:10:00,760 Speaker 1: Ottomans began constructing tunnels, but the Byzantines intercepted them. The 144 00:10:00,800 --> 00:10:03,880 Speaker 1: attack went on for weeks with some effective resistance from 145 00:10:03,920 --> 00:10:08,040 Speaker 1: the Byzantine side, despite being outnumbered. Near the end of May, 146 00:10:08,240 --> 00:10:11,280 Speaker 1: Mahemmed offered to lift the siege if the Byzantines gave 147 00:10:11,360 --> 00:10:15,760 Speaker 1: him the city, but Constantine refused to surrender. Mehemmed called 148 00:10:15,760 --> 00:10:18,400 Speaker 1: a council of war and the Ottomans prepared for a 149 00:10:18,480 --> 00:10:22,959 Speaker 1: final assault. In the early hours of May nine, Mahammed 150 00:10:23,120 --> 00:10:28,600 Speaker 1: launched a coordinated artillery infantry enable assault on Constantinople. By 151 00:10:28,640 --> 00:10:31,520 Speaker 1: the third wave of the attack, women and children were 152 00:10:31,559 --> 00:10:36,319 Speaker 1: defending the walls. Ottoman troops fledded into the city. Thousands 153 00:10:36,320 --> 00:10:39,720 Speaker 1: of people were killed, died by suicide, or were shipped 154 00:10:39,720 --> 00:10:42,959 Speaker 1: away to be enslaved. Buildings like the Ia Sophia were 155 00:10:42,960 --> 00:10:47,640 Speaker 1: looted for their treasures and destroyed. That afternoon, Mahammed entered 156 00:10:47,679 --> 00:10:49,760 Speaker 1: the city and called for an end to the looting. 157 00:10:50,280 --> 00:10:53,000 Speaker 1: He also called for the Ia Sophia to be converted 158 00:10:53,000 --> 00:10:58,959 Speaker 1: into a mosque. Constantinople renamed Istanbul, became the new Ottoman capital, 159 00:10:59,200 --> 00:11:02,040 Speaker 1: and what was left of the Byzantine Empire soon became 160 00:11:02,080 --> 00:11:06,760 Speaker 1: part of the Ottoman Empire. The fall of Constantinople removed 161 00:11:06,840 --> 00:11:10,920 Speaker 1: mainland Europe's defense against Ottoman expansion and marked the end 162 00:11:11,000 --> 00:11:14,960 Speaker 1: of the old Roman Empire. Over time, the city's population 163 00:11:15,080 --> 00:11:19,320 Speaker 1: increased and the harbor became an important trade center. Is 164 00:11:19,360 --> 00:11:22,199 Speaker 1: Stanbol remained the capital of the Ottoman Empire until this 165 00:11:22,320 --> 00:11:27,480 Speaker 1: date was dissolved in I'm eve Jeff Cote, and hopefully 166 00:11:27,720 --> 00:11:30,080 Speaker 1: you know a little more about history today than you 167 00:11:30,120 --> 00:11:33,520 Speaker 1: did yesterday. And if you have any comments or suggestions 168 00:11:33,559 --> 00:11:36,160 Speaker 1: for future episodes, you can send them to us at 169 00:11:36,480 --> 00:11:39,360 Speaker 1: this day at iHeart Media dot com. You can also 170 00:11:39,440 --> 00:11:41,800 Speaker 1: hit us up on social media where at t D 171 00:11:41,800 --> 00:11:45,120 Speaker 1: I h C podcast. Thanks so much for listening to 172 00:11:45,120 --> 00:11:56,280 Speaker 1: the show and we'll see you tomorrow. 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