1 00:00:01,920 --> 00:00:06,520 Speaker 1: Welcome to brain Stuff, a production of iHeart Radio, Hey 2 00:00:06,559 --> 00:00:11,959 Speaker 1: brain Stuff Lauren Bogelbaum here today. Italian astronomer, physicist, and 3 00:00:12,039 --> 00:00:15,840 Speaker 1: author Galileo Galilei, who lived from fifteen sixty four to 4 00:00:15,960 --> 00:00:19,560 Speaker 1: sixteen forty two, might be most famous for having been 5 00:00:19,560 --> 00:00:22,400 Speaker 1: put on trial for heresy by the Roman Inquisition in 6 00:00:22,520 --> 00:00:26,159 Speaker 1: sixteen thirty three. That event has come to symbolize the 7 00:00:26,200 --> 00:00:30,120 Speaker 1: conflict between adherence to religious dogma and the intellectual freedom 8 00:00:30,200 --> 00:00:35,440 Speaker 1: required by science. Galileo's trouble with authorities actually stemmed not 9 00:00:35,600 --> 00:00:38,080 Speaker 1: from his own work, but from his advocacy of Polish 10 00:00:38,120 --> 00:00:42,600 Speaker 1: astronomer Nicolas Copernicus's heliocentric theory that the Sun, not the Earth, 11 00:00:43,000 --> 00:00:46,720 Speaker 1: was the object around which the planets revolved. Galileo was 12 00:00:46,800 --> 00:00:49,840 Speaker 1: forced to renounce those views to avoid torture and execution, 13 00:00:50,280 --> 00:00:52,160 Speaker 1: and had to spend the last years of his life 14 00:00:52,280 --> 00:00:56,960 Speaker 1: under house arrest. Even so, Galileo ultimately won the argument. 15 00:00:57,600 --> 00:01:00,400 Speaker 1: Three and a half centuries later, Pope John Paul Second 16 00:01:00,480 --> 00:01:02,560 Speaker 1: gave a speech in which he not only said that 17 00:01:02,600 --> 00:01:05,840 Speaker 1: the Church's persecution of Galileo had been a mistake, but 18 00:01:05,959 --> 00:01:09,320 Speaker 1: also praised him as a brilliant mind who quote practically 19 00:01:09,480 --> 00:01:15,200 Speaker 1: invented the experimental method. But all of that bruhaha, isn't 20 00:01:15,319 --> 00:01:18,880 Speaker 1: the most important thing about Galileo, a scientific giant whose 21 00:01:18,880 --> 00:01:22,560 Speaker 1: discoveries forever changed humans views of both the cosmos and 22 00:01:22,680 --> 00:01:25,640 Speaker 1: the physical world in which we live, and helped establish 23 00:01:25,720 --> 00:01:29,520 Speaker 1: the way in which modern scientists do science. He also 24 00:01:29,600 --> 00:01:33,360 Speaker 1: became one of the first celebrities scientist authors, whose sixteen 25 00:01:33,400 --> 00:01:38,720 Speaker 1: ten book Starry Messenger became a sensation. We spoke by 26 00:01:38,800 --> 00:01:42,760 Speaker 1: email with Paula Finland, the Ubaldo Pierratti, Professor of Italian 27 00:01:42,880 --> 00:01:45,600 Speaker 1: history and co director of the Patrick Soupy Center for 28 00:01:45,680 --> 00:01:49,240 Speaker 1: the History and Philosophy of Science at Stanford University. She 29 00:01:49,360 --> 00:01:53,800 Speaker 1: said Galileo is an interesting example of a versatile Renaissance mind. 30 00:01:54,400 --> 00:01:57,480 Speaker 1: He loves literature, art and music as well as science. 31 00:01:57,840 --> 00:01:59,720 Speaker 1: He knows how to draw, and he certainly knows how 32 00:01:59,800 --> 00:02:03,080 Speaker 1: to fight with eloquence. He's fascinated with how things work 33 00:02:03,440 --> 00:02:06,480 Speaker 1: and visits artisans to know more. I see him as 34 00:02:06,520 --> 00:02:09,160 Speaker 1: one of the culminating products of the Renaissance, living in 35 00:02:09,200 --> 00:02:11,959 Speaker 1: the age of the Reformation. Yet what he does with 36 00:02:12,080 --> 00:02:15,680 Speaker 1: his knowledge launches a new age of science and observation. 37 00:02:17,200 --> 00:02:20,440 Speaker 1: Galileo was born in Pisa, Italy, in fifteen sixty four, 38 00:02:20,960 --> 00:02:23,560 Speaker 1: one of six or seven children of a musician named 39 00:02:23,639 --> 00:02:28,160 Speaker 1: Vincenzo Galilei. In Galileo's youth, his family moved to Florence. 40 00:02:29,120 --> 00:02:32,079 Speaker 1: After getting his early education at a monastery. Galileo was 41 00:02:32,120 --> 00:02:34,359 Speaker 1: sent by his father in fifteen eighty one to the 42 00:02:34,440 --> 00:02:36,919 Speaker 1: University of Pisa, where he was supposed to earn a 43 00:02:36,960 --> 00:02:40,640 Speaker 1: medical degree, but Galileo didn't have much interest in healing 44 00:02:40,720 --> 00:02:44,000 Speaker 1: the human body. Instead, he was curious about the world 45 00:02:44,080 --> 00:02:47,760 Speaker 1: around him and started physics experiments, some of them challenging 46 00:02:47,800 --> 00:02:51,560 Speaker 1: the views of the classical Greek philosopher Aristotle. In fifteen 47 00:02:51,600 --> 00:02:54,280 Speaker 1: eighty five, he left the university without earning a degree 48 00:02:54,600 --> 00:02:58,760 Speaker 1: and began teaching mathematics, another of his interests. Eventually, his 49 00:02:58,880 --> 00:03:02,000 Speaker 1: reputation grew so much that in fifteen eighty nine he 50 00:03:02,120 --> 00:03:05,040 Speaker 1: was invited back to the university to head the math department. 51 00:03:06,480 --> 00:03:09,600 Speaker 1: In fifteen ninety two, Galileo moved to Venice and took 52 00:03:09,639 --> 00:03:12,440 Speaker 1: a better paying post at the University of Padua, where 53 00:03:12,480 --> 00:03:15,440 Speaker 1: he spent the next eighteen years teaching math in astronomy. 54 00:03:16,320 --> 00:03:18,720 Speaker 1: During that time, he began a relationship with a woman 55 00:03:18,840 --> 00:03:22,120 Speaker 1: named Marina Gamba, with whom he eventually had two daughters 56 00:03:22,200 --> 00:03:26,000 Speaker 1: and a son. In sixteen o nine, while still at 57 00:03:26,040 --> 00:03:29,280 Speaker 1: the university, Galileo heard about a Dutchman who had visited 58 00:03:29,360 --> 00:03:33,480 Speaker 1: Venice and showed off a new invention, the telescope. Galileo 59 00:03:33,560 --> 00:03:36,040 Speaker 1: decided to make his own version and taught himself how 60 00:03:36,120 --> 00:03:40,640 Speaker 1: to grind lenses to an even higher magnification. But we 61 00:03:40,760 --> 00:03:44,080 Speaker 1: also spoke by email with Alan Hirschfeld, a physics professor 62 00:03:44,160 --> 00:03:47,320 Speaker 1: and director of the U Mass Dartmouth Observatory and the 63 00:03:47,400 --> 00:03:52,040 Speaker 1: author of the book Starlight Detectives, How Astronomers, inventors, and 64 00:03:52,160 --> 00:03:56,640 Speaker 1: Eccentrics Discovered the modern Universe. He said he was an 65 00:03:56,720 --> 00:03:59,920 Speaker 1: excellent craftsman who read descriptions of the instrument and made 66 00:04:00,040 --> 00:04:03,120 Speaker 1: the most powerful telescopes at the time. He could see 67 00:04:03,200 --> 00:04:07,240 Speaker 1: what others could not, and therefore his observations were groundbreaking. 68 00:04:08,920 --> 00:04:12,920 Speaker 1: Perhaps the most important of Galileo's astronomical discoveries were his 69 00:04:13,040 --> 00:04:17,000 Speaker 1: revelations about the Moon's topography and how its mountains, valleys, 70 00:04:17,000 --> 00:04:20,960 Speaker 1: and plains are comparable to those on Earth. Hirschfeld explained, 71 00:04:21,440 --> 00:04:25,200 Speaker 1: it's a material world in space, not some special celestial 72 00:04:25,240 --> 00:04:30,200 Speaker 1: body made of divine substance. Galileo's discovery of Jupiter's moons 73 00:04:30,240 --> 00:04:34,480 Speaker 1: and their movement was another breakthrough. Hirschfeld said, they keep 74 00:04:34,600 --> 00:04:37,160 Speaker 1: up with Jupiter as it moves, whether it moves around 75 00:04:37,160 --> 00:04:39,560 Speaker 1: the Earth or around the Sun, depending on one's beliefs, 76 00:04:39,920 --> 00:04:43,120 Speaker 1: but Jupiter's moons do not get left behind, as critics 77 00:04:43,160 --> 00:04:46,120 Speaker 1: of Copernicus claimed our moon would if Earth were moving 78 00:04:46,160 --> 00:04:49,440 Speaker 1: around the Sun. Jupiter and its moons provide a model 79 00:04:49,560 --> 00:04:52,599 Speaker 1: of what the Solar System is like small bodies orbiting 80 00:04:52,800 --> 00:04:57,920 Speaker 1: the larger body. Galileo also observed the Milky Way consists 81 00:04:58,000 --> 00:05:00,560 Speaker 1: of stars, most of which are you faint to be 82 00:05:00,640 --> 00:05:05,080 Speaker 1: seen individually by unassisted human eyes, meaning that we learned 83 00:05:05,200 --> 00:05:09,200 Speaker 1: that there are more stars and indeed more cosmos out 84 00:05:09,240 --> 00:05:13,720 Speaker 1: there than anyone had previously thought. He also discovered that 85 00:05:13,720 --> 00:05:17,880 Speaker 1: the planet Venus has changing crescent phases. But we spoke 86 00:05:17,960 --> 00:05:21,120 Speaker 1: by email with Larry Marshall, and emeritus professor of physics 87 00:05:21,160 --> 00:05:25,160 Speaker 1: at Gettysburg College. He said the observation that Venus went 88 00:05:25,240 --> 00:05:28,040 Speaker 1: through a full cycle of phases from new to crescent 89 00:05:28,160 --> 00:05:31,839 Speaker 1: to full and back was totally incompatible with the geocentric 90 00:05:31,880 --> 00:05:34,760 Speaker 1: model of the universe. It could only be explained if 91 00:05:34,880 --> 00:05:37,080 Speaker 1: Venus went around the Sun in an orbit that was 92 00:05:37,200 --> 00:05:40,160 Speaker 1: smaller than the Earth's orbit around the Sun, in other words, 93 00:05:40,240 --> 00:05:45,720 Speaker 1: the Copernican model. Though his astronomical discoveries made him a 94 00:05:45,760 --> 00:05:50,159 Speaker 1: scientific celebrity, Galileo also made important discoveries in physics, going 95 00:05:50,240 --> 00:05:52,720 Speaker 1: back to his early years at the University of Pisa. 96 00:05:53,720 --> 00:05:58,160 Speaker 1: For example, Galileo disproved the Greek philosopher Aristotle's belief that 97 00:05:58,279 --> 00:06:01,920 Speaker 1: heavier objects fall faster than lighter ones, and instead showed 98 00:06:01,960 --> 00:06:04,120 Speaker 1: that objects tend to fall at the same speed no 99 00:06:04,279 --> 00:06:07,000 Speaker 1: matter what their weight or shape, which became known as 100 00:06:07,080 --> 00:06:11,400 Speaker 1: the law of falling bodies. In legend, Galileo accomplished this 101 00:06:11,520 --> 00:06:13,840 Speaker 1: by dropping a cannon and a musket ball from the 102 00:06:13,920 --> 00:06:17,520 Speaker 1: leaning Tower of Pisa, though modern historians have cast doubt 103 00:06:17,640 --> 00:06:21,520 Speaker 1: upon that story. Galileo also discovered that the time taken 104 00:06:21,600 --> 00:06:25,360 Speaker 1: for a pendulum to complete complete one swing was independent 105 00:06:25,520 --> 00:06:27,800 Speaker 1: of the length of the ark, which led him to 106 00:06:27,880 --> 00:06:32,560 Speaker 1: create a design for pendulum clock. But his most important 107 00:06:32,560 --> 00:06:36,160 Speaker 1: breakthrough may have been discovering the concept of inertia that 108 00:06:36,320 --> 00:06:39,880 Speaker 1: bodies at rest tend to remain at rest, which eventually 109 00:06:40,080 --> 00:06:42,640 Speaker 1: became the first of the three laws of motion described 110 00:06:42,720 --> 00:06:47,200 Speaker 1: by British physicist and mathematician Isaac Newton. In the process, 111 00:06:47,360 --> 00:06:51,560 Speaker 1: Galileo also helped establish the way that today's scientists do science. 112 00:06:52,200 --> 00:06:57,400 Speaker 1: Hirschfeld said he fostered the paradigm of physical experiment, precise measurement, 113 00:06:57,680 --> 00:07:01,560 Speaker 1: and objective observation. Let nature speak as the saying goes, 114 00:07:01,920 --> 00:07:06,080 Speaker 1: as opposed to logical inference based on preconceived notions about nature. 115 00:07:06,880 --> 00:07:09,920 Speaker 1: The language of nature, he wrote, is mathematical, and one 116 00:07:10,040 --> 00:07:18,360 Speaker 1: must learn to understand that language. Today's episode was written 117 00:07:18,360 --> 00:07:21,040 Speaker 1: by Patrick J. Tiger and produced by Tyler Playing. For 118 00:07:21,160 --> 00:07:23,280 Speaker 1: more on this and lots of other weighty topics, visit 119 00:07:23,320 --> 00:07:25,840 Speaker 1: how stuff works dot com. Brain Stuff is production of 120 00:07:25,920 --> 00:07:28,800 Speaker 1: I Heart Radio or more podcasts. My heart Radio visit 121 00:07:28,840 --> 00:07:31,480 Speaker 1: the iHeart Radio app, Apple Podcasts, or wherever you listen 122 00:07:31,600 --> 00:07:32,480 Speaker 1: to your favorite shows.