Galileo,Italian Philosopher, Astronomer & Mathematician

Galileo

ITALIAN PHILOSOPHER, ASTRONOMER, AND MATHEMATICIAN

Galileo, in full Galileo Galilei, (born February 15, 1564, Pisa [Italy] —died January 8, 1642, Arcetri, near Florence), Italian natural philosopher, astronomer, and mathematician who made fundamental contributions to the sciences of motion, astronomy, and strength of materials and to the development of the scientific method. His formulation of (circular) inertia, the law of falling bodies, and parabolic trajectories marked the beginning of a fundamental change in the study of motion. His insistence that the book of nature was written in the language of mathematics changed natural philosophy from a verbal, qualitative account to a mathematical one in which experimentation became a recognized method for discovering the facts of nature. Finally, his discoveries with the telescope revolutionized astronomy and paved the way for the acceptance of the Copernican heliocentric system, but his advocacy of that system eventually resulted in an Inquisition process against him.

• What did Galileo do?

Galileo was a natural philosopher, astronomer, and mathematician who made fundamental contributions to the sciences of motion, astronomy, and strength of materials and to the development of the scientific method.

• What did Galileo invent?

Among other things, Galileo improved upon the telescope and invented an early type of the thermometer.

• Did the Roman catholic church execute Galileo?

For his heresy in claiming that Earth orbits the Sun, Galileo was sentenced to life imprisonment by the Roman Catholic Church. He served his sentence under house arrest and died at home after an illness.

• What discoveries did Galileo make?

Galileo discovered the four biggest moons of Jupiter (now called the Galilean moons) and the rings of Saturn.

• What influences did Galileo have on science today???

Galileo influenced scientists for decades to come, not least in his willingness to stand up to the church to defend his findings. His improvements to the telescope led to various strides in the field of astronomy. Sir Isaac Newton, the great physicist, later expanded on Galileo's work when coming up with his own theories.

Telescopic Discoveries

At this point, however, Galileo’s career took a dramatic turn. In the spring of 1609, he heard that in the Netherlands an instrument had been invented that showed distant things as though they were nearby. By trial and error, he quickly figured out the secret of the invention and made his own three-powered spyglass from lenses for sale in spectacle makers’ shops. 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 1609, Galileo began observing the heavens with instruments that magnified up to 20 times. In December he drew the Moon’s phases as seen through the telescope, showing that the Moon’s surface is not smooth, as had been thought, but is rough and uneven. In January 1610 he discovered four moons revolving around Jupiter. He also found that the telescope showed many more stars that are visible with the naked eye. These discoveries were earthshaking, and Galileo quickly produced a little book, Sidereus Nuncius (The Sidereal Messenger), in which he described them. He dedicated the book to Cosimo II de Medici (1590–1621), the grand duke of his native Tuscany, whom he had tutored in mathematics for several summers, and he named the moons of Jupiter After the Medici family: the Sidera Medicea, or “Medicean Stars.” Galileo was rewarded with an appointment as mathematician and philosopher of the grand duke of Tuscany, and in the fall of 1610, he returned in triumph to his native land.

Galileo was now a courtier and lived the life of a gentleman. Before he left Padua he had discovered the puzzling appearance of Saturn, later 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 the Earth is a planet orbiting the Sun, they undermined Aristotelian cosmology: the absolute difference between the corrupt earthly region and the perfect and unchanging heavens was proved wrong by the mountainous surface of the Moon, the moons of Jupiter showed that there had to be more than one center of motion in the universe, and the phases of Venus showed that it (and, by implication, Mercury) revolves around the Sun. 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 center of the universe and that the Earth is a planet, as Copernicus had argued. Galileo’s conversion to Copernicanism would be a key turning point in the scientific revolution.

After a brief controversy about floating bodies, Galileo again turned his attention to the heavens and entered a debate with Christoph Scheiner (1573–1650), a German Jesuit and professor of mathematics at Ingolstadt, about the nature of sunspots (of which Galileo was an independent discoverer). This controversy resulted in Galileo’s Istoria e dimostrazioni intorno alle macchie solari e loro accidenti (“History and Demonstrations Concerning Sunspots and Their Properties,” or “Letters on Sunspots”), which appeared in 1613. Against Scheiner, who, in an effort to save the perfection of the Sun, argued that sunspots are satellites of the Sun, Galileo argued that the spots are on or near the Sun’s surface, and he bolstered his argument with a series of detailed engravings of his observations.

Galileo Galilei Quotes

• All truths are easy to understand once they are discovered; the point is to discover them.
• The laws of nature are written by the hand of God in the language of mathematics.
• You can't teach anybody anything, only make them realize the answers are already inside them.
• I have never met a man so ignorant that I couldn't learn something from him.
• In the sciences, the authority of thousands of opinions is not worth as much as one tiny spark of reason in an individual man.
• To understand the Universe, you must understand the language in which it's written, the language of Mathematics.
• Knowing thyself, that is the greatest wisdom.
• I do not feel obliged to believe that the same God who has endowed us with senses, reason, and intellect has intended us to forego their use.
• The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do.
• To be humane, we must ever be ready to pronounce that wise, ingenious and modest statement 'I do not know'.
• Nonetheless, it moves.
• Measure what can be measured, and make measureable what cannot be measured.
• Two truths cannot contradict one another.
• There are those who reason well, but they are greatly outnumbered by those who reason badly.
• Mathematics is the language with which God has written the universe.
• In my studies of astronomy and philosophy I hold this opinion about the universe, that the Sun remains fixed in the centre of the circle of heavenly bodies, without changing its place; and the Earth, turning upon itself, moves round the Sun.
• The Bible shows the way to go to heaven, not the way the heavens go.
• The prohibition of science would be contrary to the Bible, which in hundreds of places teaches us how the greatness and the glory of God shine forth marvelously in all His works, and is to be read above all in the open book of the heavens.
• And who can doubt that it will lead to the worst disorders when minds created free by God are compelled to submit slavishly to an outside will? When we are told to deny our senses and subject them to the whim of others? When people devoid of whatsoever competence are made judges over experts and are granted authority to treat them as they please? These are the novelties which are apt to bring about the ruin of commonwealths and the subversion of the state.
• The greatest wisdom is to get to know oneself.
• Wine is sunlight, held together by water.
• Where the senses fail us, reason must step in.
• Science proceeds more by what it has learned to ignore than what it takes into account.
• Being infinitely amazed, so do I give thanks to God, Who has been pleased to make me the first observer of marvelous things, unrevealed to bygone ages.
• E pur si muove. "Albeit It does move". (That's what Galileo purportedly muttered after torturers forced him to recant his theory that the earth orbits the sun.)