Galileo Galilei (1564-1642) was an Italian physicist, astronomer, philosopher, engineer and mathematician. He was a critical figure in the scientific revolution of the 17th century. Galileo is perhaps most synonymous with the invention of the modern telescope which has since helped man to discover countless things about the universe.
In regard to astronomy, Galileo is erroneously credited with the discovery of the first telescope. His contribution was carrying out massive improvements on the existing telescopes. In 1609, Galileo learnt about the spyglass which was crudely used in ordinary life to view distant places on the land. Galileo began to grind and polish his own lenses thereby making his own telescope that had a magnification 8 to ten times that of the existing spyglass that had a magnification of three. Armed with the new telescope, Galileo pointed it upwards and improved it to view heavenly bodies. He managed to see craters on the moon as well as discover sunspots. He also viewed and documented the rings on planet Saturn, and Venus’s phases. In addition, Galileo observed that moon did not emit its own light but it reflected light from the sun back to the earth. Galileo was able to show the moon as having a mountainous surface with numerous craters. He also stated that the Milky Way was made up of several stars inside the Milky Way.
Some people credit Galileo with the discovery of planet Neptune although it was officially documented 2 centuries after Galileo first saw it. Galileo also saw and documented about a supernova.
Galileo is most famous for his unique and outstanding discovery that Jupiter had four moons which were late named; Europa, Lo, Ganymede and Callisto. These moons are now called Galilean Moons. Indeed, when NASA sent an exploration expedition to Jupiter, they named it Galileo in honor of Galileo’s great astronomical works in relation to Jupiter.
Galileo is also famous for his discovery of the Copernican System. The Copernican System states that the Earth and the other planets revolve around the sun. In the 1600s, all celestial bodies were believed to orbit around the earth and the Catholic Church declared it a heresy for anyone to teach the contrary. Galileo carried out further research to show that Jupiter’s moons did not orbit the massive planet and this led to great support for the Copernican System. Galileo held this claim about astronomy even when he was summoned to Rome and warned against propagating his controversial theory. In 1632, Galileo wrote about the issue by treating it as a mathematical proposition. In building his theory on the Copernican System, Galileo built upon the findings previously made by Kepler and Brahe. Previously, the Catholic Church had made the Science community to believe that the Earth was supposed to the centre of all human activity. It is on this that Galileo proclaimed the Earth was a mere small planet that revolved around the sun. Initially, Galileo thought that the bodies revolving around the sun moved in a circle but he later proved that they did so in an elliptical shape as previously shown by astronomer Johann Kepler.
In the last ten year of his life Galileo was placed under house arrest but within that time he wrote several publications on astronomy, science, Mathematics and philosophy. Although the church was against Galileo’s Copernican theory he boldly proclaimed what he had observed repeatedly. Modern scientists, philosophers and astronomers believed Galileo since they could verify assertions by observing the heavens though Galileo’s telescopes.
References
Redd, N. T. (2012, May 8). Galileo Galilei: Biography, Inventions & Other Facts. Retrieved January 25, 2017 , from http://www.space.com/15589-galileo-galilei.html
