Galileo became an accomplished lutenist himself and would have learned early from his father a scepticism for established authority,  the value of well-measured or quantified experimentation, an appreciation for a periodic or musical measure of time or rhythm, as well as the results expected from a combination of mathematics and experiment. Three of Galileo's five siblings survived infancy. The youngest, Michelangelo or Michelagnoloalso became a noted lutenist and composer although he contributed to financial burdens during Galileo's young adulthood.
In Italian scientist Galileo Galilei, using his own telescope, modeled on an invention recently made in the Netherlands, discovered that the Moon, far from being smooth and utterly unlike Earth, had mountains and craters. By using the lengths of their shadows, Galileo was… In Galileo applied for the chair of mathematics at the University of Bologna but was unsuccessful.
He also found some ingenious theorems on centres of gravity again, circulated in manuscript that brought him recognition among mathematicians and the patronage of Guidobaldo del Monte —a nobleman and author of several important works on mechanics.
As a result, he obtained the chair of mathematics at the University of Pisa in There, according to his first biographer, Vincenzo Viviani —Galileo demonstrated, by dropping bodies of different weights from the top of the famous Leaning Towerthat the speed of fall of a heavy object is not proportional to its weight, as Aristotle had claimed.
The manuscript tract De motu On Motionfinished during this period, shows that Galileo was abandoning Aristotelian notions about motion and was instead taking an Archimedean approach to the problem.
But his attacks on Aristotle made him unpopular with his colleagues, and in his contract was not renewed. His patrons, however, secured him the chair of mathematics at the University of Paduawhere he taught from until His university salary could not cover all his expenses, and he therefore took in well-to-do boarding students whom he tutored privately in such subjects as fortification.
He also sold a proportional compass, or sector, of his own devising, made by an artisan whom he employed in his house. Perhaps because of these financial problems, he did not marry, but he did have an arrangement with a Venetian woman, Marina Gamba, who bore him two daughters and a son.
In the midst of his busy life he continued his research on motion, and by he had determined that the distance fallen by a body is proportional to the square of the elapsed time the law of falling bodies and that the trajectory of a projectile is a parabolaboth conclusions that contradicted Aristotelian physics.
In the spring of he heard that in the Netherlands an instrument had been invented that showed distant things as though they were nearby.
Others had done the same; what set Galileo apart was that he quickly figured out how to improve the instrument, taught himself the art of lens grinding, and produced increasingly powerful telescopes.
In August of that year he presented an eight-powered instrument to the Venetian Senate Padua was in the Venetian Republic. He was rewarded with life tenure and a doubling of his salary. Galileo was now one of the highest-paid professors at the university.
In the fall of Galileo began observing the heavens with instruments that magnified up to 20 times. In January he discovered four moons revolving around Jupiter.
He also found that the telescope showed many more stars than are visible with the naked eye. These discoveries were earthshaking, and Galileo quickly produced a little book, Sidereus Nuncius The Sidereal Messengerin which he described them.
He dedicated the book to Cosimo II de Medici —the grand duke of his native Tuscanywhom he had tutored in mathematics for several summers, and he named the moons of Jupiter after the Medici family: Before he left Padua he had discovered the puzzling appearance of Saturnlater to be shown as caused by a ring surrounding it, and in Florence he discovered that Venus goes through phases just as the Moon does.
Although these discoveries did not prove that Earth is a planet orbiting the Sunthey undermined Aristotelian cosmology: As a result, Galileo was confirmed in his belief, which he had probably held for decades but which had not been central to his studies, that the Sun is the centre of the universe and that Earth is a planet, as Copernicus had argued.
Aristotle's theory of the solar system. After a brief controversy about floating bodies, Galileo again turned his attention to the heavens and entered a debate with Christoph Scheiner —a German Jesuit and professor of mathematics at Ingolstadtabout the nature of sunspots of which Galileo was an independent discoverer.
In he wrote a letter to his student Benedetto Castelli — in Pisa about the problem of squaring the Copernican theory with certain biblical passages.
Several Dominican fathers in Florence lodged complaints against Galileo in Rome, and Galileo went to Rome to defend the Copernican cause and his good name. In his Letter to the Grand Duchess Christina, Galileo discussed the problem of interpreting biblical passages with regard to scientific discoveries but, except for one example, did not actually interpret the Bible.
That task had been reserved for approved theologians in the wake of the Council of Trent —63 and the beginning of the Catholic Counter-Reformation.Dialogue Concerning the Two Chief World Systems 1, ratings Discoveries and Opinions of Galileo ratings Sidereus Nuncius, or The .
Galileo's Dialogue Concerning the Two Chief World Systems, which was published in to great popularity, was an account of conversations between a Copernican scientist, Salviati, an impartial and witty scholar named Sagredo, and a ponderous Aristotelian named Simplicio, who employed stock arguments in support of geocentricity, and was.
Watch video · This led Galileo to publish Dialogue Concerning the Two Chief World Systems in , which advocated the theory. Church reaction was swift, and Galileo was summoned to Rome. Oct 31, · But when, in , Galileo published his findings in "Dialogue Concerning the Two Chief World Systems," the work was a compelling endorsement of the Copernican system.
Galileo's book, Dialogue on the Two Chief World Systems, Ptolemaic and Copernican, comes alive for twentieth-century readers thanks to Maurice Finocchiaro's brilliant new translation and presentation.
Condemned by the Inquisition for its heretical proposition that the earth revolves around the sun, Galileo's masterpiece takes the . But the book Galileo finally published in , Dialogue Concerning the Two Chief World Systems, came off clearly in favor of the Copernican view, infuriating the pope.