Galileo
1564-1642 Italian physicist and astronomer who improved the telescope and had a famous dispute with the Catholic Church.
Until the sixteenth century, the prevailing view was that the Sun, Moon, stars and planets circled the Earth. Puzzled astronomers noticed that Mars, Jupiter and Saturn sometimes seemed to move backwards, but their motions were well predicted by Ptolemy's theory. A Polish astronomer, Nicolaus Copernicus (1473-1543), published a model of the solar system in which the earth and other planets circled the sun, with Catholic Church approval. The scientific evidence was inconclusive.
Galileo tested Aristotle's theory that heavy objects fall faster than light ones and found it was a consequence of air resistance, not gravity. By making careful measurements he found he could use mathematics to predict how things fell and the movements of pendulums and tides. His theory of tides turned out to be mistaken.
In June or July of 1609, word reached Galileo the telescope, which had been invented in Holland. Without knowing the technical details of the construction of the device, he managed to create one for himself. With it, he was able to witness a supernova, observe our Moon, and document the phases of Venus. He also located sunspots. Some of these discoveries helped support a heliocentric system.
Because Galileo overstated the scientific case for the heliocentric theory, the Catholic Church decided against Galileo in 1616 and said that 1) the immobility of the Sun at the center of the universe was absurd in philosophy and formally heretical, and that 2) the mobility of Earth was absurd in philosophy and at least erroneous in theology. [1] In 1632 Galileo published a book about tides, and against the Church's instructions he advocated the heliocentric theory. He also ridiculed the Pope. Church authorities arrested him, and forced him to say he was mistaken. Galileo went back to studying motion and mechanics.
Galileo's work is often cited as an early example of the use of the scientific method, involving testing a theory by experiment and observation.
In 1741, many years after Galileo's death, the Church under Pope Benedict XIV bid the Holy Office grant an imprimatur to the first edition of the Complete Works of Galileo.[2]
Stillman Drake of the University of Toronto [1] was for the last decades of his life the most original and important scholar to study this seventeenth-century physicist.[3] == References ==