Galileo Galilei Learning Objective: By the end of the period I will be able to describe the discoveries and inventions of Galileo as well as how his discoveries conflicted with church teachings by filling in my Slot Notes.

Childhood Galileo was born in February 15, 1564, near the town of Pisa, Italy. His father Vincenzo was a musician and teacher. He studied the science of music and he may have helped to develop opera. Galileo was sent to a monastery school at thirteen.

Education At seventeen, Galileo returned to Pisa to study at the university there. He studied medicine to make his father happy, but his real interest lie in mathematics. Galileo befriended two important scholars, Guidobaldo del Monte (a student of mechanics) and Christopher Clavius (a priest and mathematician).

Teaching In 1592, Galileo was given a position as a Professor of Mathematics at the University of Padua in Venice.  At the university he became very interested in the way objects fell through the air.  He is said to have proven his theories by dropping cannonballs from the Leaning Tower of Pisa.  At the university, some professors found him pushy and his views shocking.

Discoveries and Inventions 1597 – invented a device he called the “geometric and military compass” for making calculations 1609 – created a telescope by improving on the work of Hans Lippershy observed the surface of the moon using his new telescope 1610 – observed the planet Jupiter and discovered four of its’ moons

Discoveries and Inventions (cont.) 1610 – observed Venus and recognized that it orbited the sun (supporting the teachings of Copernicus) 1610 – wrote about his discoveries with the telescope in a book called, Sidereus Nuncius (Starry Messenger) 1612 – observed spots on the sun

In Trouble With The Church The Catholic Church taught that the Earth was the center of God’s creation. Copernicus’s teaching that the sun was the center of the universe challenged this teaching. It got him (and others who agreed into a lot of trouble with the Church). Galileo tried to convince the Church of the truth of Copernicus’s teachings, but was unsuccessful.

In Trouble With The Church (cont.) Galileo was ordered to stop teaching Copernican Theory. He knew he walked a fine line (another supporter of Copernicus named Giordano Bruno had been burned at the stake) with the Church. In 1632, his book, Dialogue of the Two Principal Systems of the World, was published. It was meant to show a discussion between supporters of Aristotle and Copernicus.

Spanish Inquisition Trial Enemies of Galileo stirred up trouble for him with Pope Urban VIII. His book was banned by the Church and he was brought before the Spanish Inquisition on charges of heresy. He was found guilty of heresy on June 21, On June 22 he was forced to denounce his beliefs (or face death).

Final Years Galileo was ultimately sentenced to live out the rest of his life under house arrest. While under house arrest, he wrote another book, Discourses and Mathematical Demonstrations Concerning Two New Sciences Pertaining to Mechanics and Local Motions, which dealt with his interest in falling objects. He is said to have gone completely blind from a combination of glaucoma and cataracts by 1638.