Galileo Galilei was an Italian astronomer, physicist, engineer, philosopher and mathematician who played a major role in the scientific revolution of the seventeenth century. He has been called the “father of observational astronomy,” “the father of modern physics,” and the “father of science.” On this date in 1610, he discovered four of Jupiter’s moons.
His contributions to observational astronomy include the telescopic confirmation of the phases of Venus, the discovery of the four largest satellites of Jupiter, and the observation and analysis of sunspots. Galileo also worked in applied science and technology, inventing an improved military compass and other instruments, including a thermoscope that was the forerunner of the thermometer and pioneering the telescope.
Galileo’s championing of “heliocentrism” (belief that earth and the planets revolved around the sun) was controversial during his lifetime; most astronomers believed that earth was the center of the solar system. The matter was investigated by the Roman Inquisition in 1615, which concluded that besides being “foolish and absurd,” it was considered “heretical since it explicitly contradicted in many places the sense of the Holy Scripture.” Galileo later defended his views, which appeared to attack the Pope. He was tried by the Inquisition and found “vehemently suspect of heresy” and forced to recant. He spent the rest of his life under house arrest.
During that time, Galileo wrote one of his best-known works that summarized work he had done some forty years earlier on the two sciences now called kinematics and strength of materials. (from Wikipedia and cute-calendar.com)