Welcome to brain Stuff, a production of iHeart Radio, Hey brain Stuff Lauren Bogelbaum here today. Italian astronomer, physicist, and author Galileo Galilei, who lived from fifteen sixty four to sixteen forty two, might be most famous for having been put on trial for heresy by the Roman Inquisition in sixteen thirty three. That event has come to symbolize the conflict between adherence to religious dogma and the intellectual freedom
required by science. Galileo's trouble with authorities actually stemmed not from his own work, but from his advocacy of Polish astronomer Nicolas Copernicus's heliocentric theory that the Sun, not the Earth, was the object around which the planets revolved. Galileo was forced to renounce those views to avoid torture and execution, and had to spend the last years of his life under house arrest. Even so, Galileo ultimately won the argument.
Three and a half centuries later, Pope John Paul Second gave a speech in which he not only said that the Church's persecution of Galileo had been a mistake, but also praised him as a brilliant mind who quote practically invented the experimental method. But all of that bruhaha, isn't the most important thing about Galileo, a scientific giant whose discoveries forever changed humans views of both the cosmos and the physical world in which we live, and helped establish
the way in which modern scientists do science. He also became one of the first celebrities scientist authors, whose sixteen ten book Starry Messenger became a sensation. We spoke by email with Paula Finland, the Ubaldo Pierratti, Professor of Italian history and co director of the Patrick Soupy Center for the History and Philosophy of Science at Stanford University. She said Galileo is an interesting example of a versatile Renaissance mind. He loves literature, art and music as well as science.
He knows how to draw, and he certainly knows how to fight with eloquence. He's fascinated with how things work and visits artisans to know more. I see him as one of the culminating products of the Renaissance, living in the age of the Reformation. Yet what he does with his knowledge launches a new age of science and observation. Galileo was born in Pisa, Italy, in fifteen sixty four, one of six or seven children of a musician named
Vincenzo Galilei. In Galileo's youth, his family moved to Florence. After getting his early education at a monastery. Galileo was sent by his father in fifteen eighty one to the University of Pisa, where he was supposed to earn a medical degree, but Galileo didn't have much interest in healing the human body. Instead, he was curious about the world around him and started physics experiments, some of them challenging
the views of the classical Greek philosopher Aristotle. In fifteen eighty five, he left the university without earning a degree and began teaching mathematics, another of his interests. Eventually, his reputation grew so much that in fifteen eighty nine he was invited back to the university to head the math department. In fifteen ninety two, Galileo moved to Venice and took a better paying post at the University of Padua, where he spent the next eighteen years teaching math in astronomy.
During that time, he began a relationship with a woman named Marina Gamba, with whom he eventually had two daughters and a son. In sixteen o nine, while still at the university, Galileo heard about a Dutchman who had visited Venice and showed off a new invention, the telescope. Galileo decided to make his own version and taught himself how
to grind lenses to an even higher magnification. But we also spoke by email with Alan Hirschfeld, a physics professor and director of the U Mass Dartmouth Observatory and the author of the book Starlight Detectives, How Astronomers, inventors, and Eccentrics Discovered the modern Universe. He said he was an excellent craftsman who read descriptions of the instrument and made
the most powerful telescopes at the time. He could see what others could not, and therefore his observations were groundbreaking. Perhaps the most important of Galileo's astronomical discoveries were his revelations about the Moon's topography and how its mountains, valleys, and plains are comparable to those on Earth. Hirschfeld explained, it's a material world in space, not some special celestial body made of divine substance. Galileo's discovery of Jupiter's moons
and their movement was another breakthrough. Hirschfeld said, they keep up with Jupiter as it moves, whether it moves around the Earth or around the Sun, depending on one's beliefs, but Jupiter's moons do not get left behind, as critics of Copernicus claimed our moon would if Earth were moving around the Sun. Jupiter and its moons provide a model of what the Solar System is like small bodies orbiting
the larger body. Galileo also observed the Milky Way consists of stars, most of which are you faint to be seen individually by unassisted human eyes, meaning that we learned that there are more stars and indeed more cosmos out there than anyone had previously thought. He also discovered that the planet Venus has changing crescent phases. But we spoke by email with Larry Marshall, and emeritus professor of physics
at Gettysburg College. He said the observation that Venus went through a full cycle of phases from new to crescent to full and back was totally incompatible with the geocentric model of the universe. It could only be explained if Venus went around the Sun in an orbit that was smaller than the Earth's orbit around the Sun, in other words,
the Copernican model. Though his astronomical discoveries made him a scientific celebrity, Galileo also made important discoveries in physics, going back to his early years at the University of Pisa. For example, Galileo disproved the Greek philosopher Aristotle's belief that heavier objects fall faster than lighter ones, and instead showed that objects tend to fall at the same speed no matter what their weight or shape, which became known as
the law of falling bodies. In legend, Galileo accomplished this by dropping a cannon and a musket ball from the leaning Tower of Pisa, though modern historians have cast doubt upon that story. Galileo also discovered that the time taken for a pendulum to complete complete one swing was independent of the length of the ark, which led him to
create a design for pendulum clock. But his most important breakthrough may have been discovering the concept of inertia that bodies at rest tend to remain at rest, which eventually became the first of the three laws of motion described by British physicist and mathematician Isaac Newton. In the process, Galileo also helped establish the way that today's scientists do science. Hirschfeld said he fostered the paradigm of physical experiment, precise measurement,
and objective observation. Let nature speak as the saying goes, as opposed to logical inference based on preconceived notions about nature. The language of nature, he wrote, is mathematical, and one must learn to understand that language. Today's episode was written by Patrick J. Tiger and produced by Tyler Playing. For more on this and lots of other weighty topics, visit how stuff works dot com. Brain Stuff is production of
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