Astronomy Online

Posts Tagged ‘galileo and astronomy’

Galileo was born in Pisa, Italy in the late 1500’s. He eventually became a mathematics teacher despite having no degree, and it was here that his famous future was first hinted. Galileo the math teacher made his first step into Galileo Galilei astronomy when he demonstrated to his students that Aristotle was wrong about object of different weights falling at different speeds. He wasn’t invited back to teach, and so moved to a position at the University of Padua. Galileo contributions to astronomy would come to fruition there.

In Padua, Galileo invented the compass and began studying physics. He discovered the law of falling bodies and the parabolic path of projectiles. These became very important in later Galileo Galilei astronomy. But at the time Galileo claimed to have no interest in the subject other than that he believed the work of Copernicus rather than that of Aristotle and Ptolemy. Copernicus had proposed that the solar system is heliocentric, that is that the planets rotate around the sun. Aristotle and Ptolemy held that the solar system was centered around the Earth, and even the sun rotated around our home. The model Copernicus proposed for the order of planets around the sun has been proven. And today we know Copernicus was completely correct.

Shortly after the spyglass was invented in Holland Galileo decided to make his own for peering at the night sky.  This telescope magnified objects 20 times, which was enough to make out craters and mountains on the moon.  Galileo also determined that individual stars made up what was called the Milky Way.  He went on to discover Jupiter’s four largest moons.  These discoveries brought him fame enough to earn the position of Florence’s court mathematician.  Now he could devote full time to his studies.  It took him only 9 months to discover Saturn’s phases.  This was another nail in the coffin for Ptolemy’s and Aristotle’s ideas about the solar system.

Galileo most disagreed with Aristotle.  Galileo found a great deal of support with other modern scientists who wrote of his work.  But because Aristotle’s work elevated man to key position in all the universe, the church supported his work. In 1614 a priest in Florence denounced Galileo Galilei Astronomy. Galileo responded by writing a letter proclaiming the bible irrelevant to science.  In 1616 the church censored Galileo’s books, and a cardinal instructed him to stop teaching that the Earth moves.  Respecting the church’s authority, or perhaps only its ability to enforce it, Galileo did as he was told, turning back to other interests.  It is said that Galileo had one comment after signing an agreement that the Earth does not move.  “I would say here something that was heard from an ecclesiastic of the most eminent degree; “And yet … it moves.”