He was born into a well-to-do family, and after his father died in 1483 he was put under the guardianship of his uncle, a bishop of Warmia (Poland). He went to university in Krakow and spent a decade in Italy, studying law and mathematics. A canon of the cathedral at Frombork, Copernicus carried out administrative duties and, from his house, observed the stars and planets. For years he worked on his theory that the planets in our solar system revolved around the sun (Ptolemy of ancient Greece had explained that the universe was a closed system revolving around the earth, and the Catholic church concurred). Hesitant to publish his work for fear of being charged with heresy (which was punishable with death), Copernicus summarized it in 1530 and circulated it among Europe's scholars, where it was greeted with enthusiasm. His work was finally published in 1543, apparently just a few weeks before he died.
Because Copernicus' heliocentric theory of the planets defied 1,500 years of tradition, some historians mark the publication date of De revolutionibus as the beginning of the "scientific revolution."... It wasn't until 1835 that his work was taken off the list of books banned by the Vatican. Galileo Galilei was another scientist who got in trouble for believing that the earth moved around the sun.
Mathematics as the only key to unshakable knowledge was the paramount discovery of the sixteenth century, but it remained for an Italian mathematician, astronomer and experimental physicist, Galileo Galilei (1564-1642), to give it practical and convincing application. He played a major role in the Scientific Revolution—so much so that he has been called the “father of modern observational astronomy,” the “father of modern physics,” the father of science,” and the “Father of Modern Science.” His achievements include improvements to the telescope and consequent astronomical observations, and support for Copernicanism.
Stephen Hawking says, "Galileo, perhaps more than any other single person, was responsible for the birth of modern science." The motion of uniformly accelerated objects, taught in nearly all high school and introductory college physics courses, was studied by Galileo as the subject of kinematics. His contributions to observational astronomy include the telescopic confirmation of the phases of Venus, the discovery of the four largest satellites of Jupiter (named the Galilean moons in his honor), and the observation and analysis of sunspots. Galileo also worked in applied science and technology, inventing an improved military compass and other instruments.
Galileo's championing of Copernicanism was controversial within his lifetime, when a large majority of philosophers and astronomers still subscribed to the geocentric view that the Earth is at the centre of the universe. After 1610, when he began publicly supporting the heliocentric view, which placed the Sun at the centre of the universe, he met with bitter opposition from some philosophers and clerics, and two of the latter eventually denounced him to the Roman Inquisition early in 1615. In February 1616, although he had been cleared of any offence, the Catholic Church nevertheless condemned heliocentrism as "false and contrary to Scripture", and Galileo was warned to abandon his support for it—which he promised to do. When he later defended his views in his most famous work, Dialogue Concerning the Two Chief World Systems, published in 1632, he was tried by the Inquisition, found "vehemently suspect of heresy", forced to recant, and to spend the rest of his life under house arrest.
