Galileo, Galilei

From Encyclopediak

GaVileo 1564-1642, the name usually applied to Galileo Galilei, mathematician, physicist, philosopher and astronomer, born at Pisa, Italy, and educated in a monastery near Florence and later 1581-1585 at the University of Pisa. While a student at Pisa he was attracted one day by the swinging of the great lamp in the roof of the cathedral there. His study of this movement resulted in his application of the pendulum to the measurement of time. In 1585 he was obliged to leave his university course unfinished for lack of funds. But he pursued in private the study of Archimedes, which led to his invention of the hydrostatic balance. He continued the study of mathematics and natural science while teaching these subjects in Pisa University from 1589 to 1591, at the same time lecturing on some of the newer phases of science which he had discovered. These lectures were thought by the people of his day to conflict with the teaching of the Bible, and he found it advisable to resign his position. He continued his studies and lectures, however, and in 1592 was called to a chair in Padua University, where he remained for 18 years.

In 1609 Galileo perfected the telescope, and the next year he discovered the satellites of Jupiter and observed the peculiarities of Saturn, which were later more clearly defined and called "rings." During the same year he discovered spots on the sun, and, noting their movements from west to east, he worked out the theory of the rotation of the sun on an axis and determined its inclination to the ecliptic. He also discovered the phases of Mercury, Venus and Mars, and the librations of the moon. His lectures upon his discoveries, such as the laws of falling bodies, the thermometer, interesting action of magnets, and the results of his astronomical researches spread his fame throughout Europe. He accepted the view of Copernicus concerning the movements of the heavenly bodies, and this led to his persecution by the Church, though he was not punished. During the last years of his life he was blind, but he continued his work. His service to modern science is notable, for he laid the foundation upon which later scientists have built. See ASTRONOMY, TELESCOPE.