One scientific anniversary stands out above all others this month: February 15, the 430th birthday of Galileo Galilei.
Born near Pisa, Italy, in 1564, Galileo entered the University of Pisa as a medical student, but found that mathematics interested him more. Though he never got a degree, he was made professor of mathematics at his alma mater in 1589. It was from Pisa’s famous leaning tower that Galileo supposedly proved that Aristotle was wrong about heavier objects falling faster than lighter ones, by dropping a heavy weight and a light weight together and observing that both hit the ground at the same moment.
Whether Galileo really conducted that experiment or not, he’d solidly embarked on a lifetime of challenging things “everyone knew” to be so. In 1604, a supernova flared and Galileo became involved in another dispute with followers of Aristotle, who held that the heavens were unchangeable. Galileo proved mathematically that the supernova was very distant, and therefore part of the “unchangeable” heavens and not an Earthly phenomenon.
After that first foray into astronomy he returned to his study of motion, but in 1609 he heard of a new Dutch invention: the telescope. Excited by its possibilities, he built his own 20-power ‘scope and with it observed mountains on the moon, the starry nature of the Milky Way and four previously unknown “planets” orbiting Jupiter. In a treatise called “The Starry Messenger” he outlined his discoveries, and as a result was named court mathematician to the Grand Duke of Tuscany in Florence. In 1610 he observed the phases of Venus, which convinced him Copernicus had been right: the Earth circles the sun, not vice versa.
This was not a good way to win friends and influence people. The Roman Catholic Church held that the Bible taught that the sun moved around the Earth. Galileo argued that empirical evidence and mathematical proofs shouldn’t be subject to doubtful scriptural interpretations, but in 1616 Rome issued an edict against Copernicus’s, and Galileo’s, belief.
In 1623, though, new pope Urban VIII, friendly to Galileo’s views, gave him permission to write a book discussing both ideas. Despite that, after Galileo’s “Dialogue” appeared in 1632, he was called in front of the Inquisition in Rome, and in June of 1633 condemned to life in prison for “vehement suspicion of heresy.” Supposedly, after being convicted, he muttered, “But yet it moves,” referring to the Earth.
Nobody in Italy could print Galileo’s “Dialogue” or publish anything else he had written, but outside Italy the book was read by scholars all over Europe.
“Life in prison” became “house arrest,” at first in Siena and then in Galileo’s own villa near Florence, where he continued his research into motion and the strength of materials. In 1638 he published one more book on both topics, “Discourses and Mathematical Demonstrations Concerning Two New Sciences.” He died on January 8, 1642.
Galileo’s true importance to the history of science isn’t so much in his research as in the way he symbolizes the necessity of allowing scientists to pursue knowledge without fear of being censured because their discoveries run counter to some cherished dogma, whether religious or “politically correct.”
These days, Galileo might not have to fear the Church (which, a couple of years ago, finally admitted it was wrong in condemning him), and his views on the relative positions of the Earth and sun might no longer be controversial, but he could certainly find other scientific positions that would squash other sensitive toes. Instead of an Inquisition, though, he’d probably face shouting mobs in university classrooms that would refuse to let him even state his views, much less defend them.
Galileo taught us that science can only advance with free and open debate. Falsehood will eventually fall to the unrelenting pressure of the further accumulation of knowledge–and truth, however unpleasant it may sound to certain ears, cannot be buried forever, no matter how much condemnation and scorn is heaped upon it.
Those who today are shouting down people giving academic presentations of positions the shouters find unpalatable should be careful: they could be the ones being shouted down tomorrow.
