Galileo Galilei was an Italian mathematician, inventor and astronomer. Born in Pisa, Italy in 1564, Galileo studied and invented many things society now takes for granted. Though he never received a college degree, he was granted teaching positions at multiple universities after making many scientific discoveries. He fashioned one of the first telescopes in order to see the moon and faraway unknown planets. http://galileo.rice.edu/bio/narrative_6.html

His studies of space led him to believe that the Earth revolves around the Sun, contradicting the theory condoned by the Catholic Church that the Earth was the center of the universe. Even though he was brought before the pope on multiple occasions to account for his disregard of the Bible's teachings, he continued writing, discovering and teaching things that would help to eventually prove his theory. http://www.fordham.edu/halsall/mod/1630galileo.html His studies of space also helped to create a consistent yearly calendar in the 1600s. http://www.smithsonianmag.com/science-nature/Galileos-Vision.html

In 2010, there are only two of the telescopes made by Galileo left in existence. They are cycled through museums all over the world in exhibits on astronomy. http://www.smithsonianmag.com/science-nature/Galileos-Vision.html

• Galileo's first telescope not only led to the discovery that the earth revolves around the sun, it also helped him to study sunspots, the Moon, the four satellites of Jupiter, the phases of Venus, and to observe a supernova. http://galileo.rice.edu/bio/narrative_6.html He wrote about his discovers in his many pamphlets he published while teaching in Siena, Pisa and Padua.
• Due to his money troubles, and responsibility for his sister's dowries, Galileo had to make extra money outside of his modest teaching salary. To do this he invented many small contraptions like a pump to lift water from the ground, a thermoscope (one of the first versions of a thermometer) and a rudimentary compass. http://galileo.rice.edu/bio/narrative_4.html He sold these items to people all over Italy to support his family.http://brunelleschi.imss.fi.it/museum/esim.asp?c=300251
• While teaching at the University of Pisa, Galileo investigated the laws of gravity. He discovered that all objects fall at the same rate despite their density. Today we call this the law of uniform acceleration. He recorded his findings in his book called De Motu, meaning on motion. http://galileo.rice.edu/bio/narrative_3.html
• Galileo's study of isochronism, through the swinging of a pendulum, led to the creation of pendulum clocks. http://galileo.rice.edu/bio/narrative_2.html

As early at 1616, Galileo was chastised by the Catholic Church for his belief and teachings of Copernicus's theory that the Earth revolves around the Sun. In 1624 he was assured by Pope Urban VIII that he could continue his studies as long as he treated them as mathematical theories and not fact. With the publishing of his book Dialogue Concerning the Two Chief World Systems in 1633 he was summoned to Rome on heresy charges against the church. He was found guilty of heresy and punished with house arrest at his home in Florence for the rest of his life. http://galileo.rice.edu/bio/narrative_2.html

• 1564: Galileo is born.
• 1581: He is studying mathematics at the University of Pisa.
• 1583: He discovers the isochronism of the pendulum.
• 1585: He returns to Florence, and his family, without a degree.
• 1586: Begins to give lessons in mathematics to students in Florence and Siena.
• 1587: Discovers properties of gravitational forces that go beyond the work of others.
• 1588: Lectures on the dimesions of Hell based on Dante's Inferno."
• 1589: Obtains teaching positions at the Universities of Siena, Pisa, Padua and Bologna.
• 1592: Is made the chair of mathematics at the University of Padua.
• 1593: Invents a pump to raise water, pulled by horses.
• 1595: Writes and theory on tides and how they affect the motion of the Earth.
• 1597: Invents a military and geometric compass.
• 1606: Invents the Thermoscope, a rudimentary version of the Thermometer.
• 1609: Galileo invents a telescope, after hearing rumors of one made in Holland. Then observes the moon through it.
• 1615: After writing many books about what was observed through the telepscope, Galileo is accused of heresy against the church, since the observations contradict the Bible.
• 1618-1624: Galileo has many audience with the Pope, attempting to defend his observations. The Pope declares that Galileo can write the theories as long as they are presented as a mathematical hypotheses.
• 1624: Invents the compound microscope.
• 1632: Dialouge Concerning the Two Chief World Systems is published.
• 1633: Galileo is summoned to Rome to face heresy charges. Is pronounced guilty and sentenced to house arrest for the remainder of his life.
• 1642: Galileo dies on January 8, 1642.http://galileo.rice.edu/chron/galileo.html