Catholic physicist and astronomer, born Pisa, Italy, 1564; died Arcetri, Italy, 1642.
One of the greatest natural philosophers of his day, he refused to accept the authority of Aristotle and arrived at his conclusions by combining calculation with experimentation.
Among his contributions to the field of science were the discovery of the isochronism of the pendulum; a demonstration of the laws of projectiles; the first satisfactory demonstration of the laws of equilibrium, and the principle of virtual velocities; an exposition of the true principle of flotation; his discovery of physical features on the moon resembling those on the earth, and the satellites of Jupiter, both of which resulted from his construction of a telescope which maguified 32 times.
He lectured at the University of Pisa, and taught mathematics at the University of Padua; 1592-1610.
His support of the heliocentric system of Copernicus in opposition to the geocentric of Ptolemy aroused antagonism among the scientists of his day.
Unfortunately, in the manner of the time, he treated his opponents too often with ridicule and contempt and thus intensified their hostility.
In 1615 Galileo came to Rome at the request of the Holy Office, which condemned the Copernican system as anti-scriptural and therefore heretical.
He promised not to spread Copernican teachings, which were as yet only hypothetical.
After leaving Rome he continued to attack the Ptolemaic system and for his dialogue, published 1632, he was summoned to trial for breach of contract.
During his imprisonment he was allowed considerable freedom and spent only 22 days in the buildings of the Holy Office.
He received the special blessing of Urban VIII before his death and was buried in consecrated ground.
In answer to those who claim that the condemnation of Galileo by the Inquisition shows that the Church was opposed to the progress of science, it must be understood that neither Paul III nor Urban VIII condemned his teachings ex cathedra, and that the Inquisition is powerless to make a dogmatic decree.
The trial of 1615 condemned the spread of Copernican propaganda as anti-scriptural, while the trial of 1633 was concerned with Galileo's breach of contract in refusing to abide by his promise made during the first trial.
New Catholic Dictionary