I’ve been pals with Diana Eline since high school. She always had more brains than I do. Diana teaches high school physics. After chatting about Galileo, I asked her to contribute some thoughts to this blog. Diana was kind enough to call together an emergency meeting of the Physics Nerds Society. Here’s what she has to say:
Galileo Galilei was born in Pisa in 1564, the first of six children of Vincenzo Galilei, a musician and scholar. In 1581 he entered the University of Pisa at age 16 to study medicine, but was soon sidetracked by mathematics. He left without finishing his degree (yes, Galileo was a college dropout!). In 1583 he made his first important discovery, describing the rules that govern the motion of pendulums.
First of all, as I tell my students, that dude Aristotle screwed up science for a long time by saying all matter is composed of Earth, Water, Air or Fire. As Aristotle was such an acclaimed philosopher no one dared to disagree with him except Galileo. Aristotle also said that heavier objects fall faster to the earth than lighter objects. Which, we of course know that it is not true. In a vacuum all objects fall to the earth at an acceleration of 9.81 meters/second squared. Only due to air resistance (air is actually composed of matter—namely gas molecules—78% nitrogen and 21% oxygen) which slows down objects with a large surface-area-to-mass ratio. Galileo also discovered many stars in the Milky way. He invented the pendulum clock. He discovered Jupiter’s moons. Although he did not invent the telescope he was the first to use it systematically to observe celestial objects and record his discoveries. His book, Sidereus Nuncius or The Starry Messenger was first published in 1610 and made him famous.
Galileo thought that a ball, rolling or sliding down a hill without friction, would run up to the same height on an opposite hill. Galileo’s conclusion from this thought experiment was that no force is needed to keep an object moving with constant velocity, which led to Newton’s 3 Laws of Physics!
Galileo Galilei is considered the father of modern science and made major contributions to the fields of physics, astronomy, cosmology, mathematics and philosophy. His flair for self-promotion earned him powerful friends among Italy’s ruling elite and enemies among the Catholic Church’s leaders. Galileo’s advocacy of a heliocentric universe brought him before religious authorities in 1616 and again in 1633, when he was forced to recant and placed under house arrest for the rest of his life.
Long story short, my enthusiasm for Physics has led my oldest son to pursue a PhD in Astrophysics and continue as an underpaid scientist!
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