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Galileo di Vincenzo Bonaiuti de’ Galilei (1564-1642) was an Italian intellectual and polymath known as the father of, among other things, physics, astronomy, and the scientific method.

In his time, the world believed what Aristotle had decreed 1500 years earlier: that Earth stood at the center of the universe, and all other celestial bodies rotated around it. This was the geocentric model.

Science was a fledgling thing in the 1500s, but slowly, it was examining the old beliefs and often calling baloney on them. This did not please the Catholic Church, which saw a threat to its influence. To the church and many common folk, questioning the traditional teachings was blasphemous.

To be clear, Galileo and others who rejected geocentrism didn’t get it right, either. They believed in heliocentrism, which said the sun is at the center of the universe. Not until the 1700s did we figure out that the sun is just an ordinary, unregarded star.

That error aside, Galileo’s achievements were many and impressive. And his ideas were so radical and disruptive that the Catholic Church eventually locked him up for them.

Galileo was born in Pisa, and both of his parents were from prominent families. His father wanted him to pursue the lucrative profession of medicine, but young Galileo was drawn to mathematics and various sciences.

His studies led him to teaching positions in Pisa and Florence and the beginning of a long series of scientific breakthroughs.

As a young man, he invented the thermoscope, a device that measured temperature changes and evolved into the thermometer.

He dropped items of different weights from the top of the Leaning Tower of Pisa, demonstrating that the speed of fall is not proportional to weight, the prevailing wisdom at the time.

He also built a series of refracting telescopes, first of 3x magnification, then 9x, then 30x. The devices immediately became a sensation in the nautical world and gave Galileo a profitable side business.

Observations with his telescopes led him to deduce that the supernovae of 1572, 1691, and 1694 involved distant stars. The Catholic Church was not amused.

Observing the Moon through a telescope, he concluded that the mottled lighting and uneven appearance is caused by craters and mountains. At the time, the surface of the Moon was believed to be smooth.

His telescopes also located four “fixed stars” close to Jupiter. After studying their motion, he correctly declared them to be moons orbiting Jupiter.

The idea of moons orbiting another planet directly contradicted geocentrism. The church fumed.

Galileo concluded that all stars and planets are round. He also said that the Milky Way consisted of so many stars that, as viewed from Earth, they have the appearance of a cloud.

By his 50s and 60s, Galileo had become famous, wealthy, influential, and probably somewhat cocky. But the church and a host of enemies opposed him, and finally, his activism went too far.

In 1616, he was hauled before the church’s dreaded Roman Inquisition — which had been pursuing witches and blasphemers since the 5th Century — to answer for his sacrilegious views. There, he was told he could write about heliocentrism or anything else as personal opinion, but he was ordered to stop teaching heliocentrism as scientific fact.

Galileo agreed, and for a time stayed out of trouble. But only for a time.

Eventually, he wrote a book that featured the account of a fictional geocentrist and heliocentrist making their respective arguments. No surprise, the heliocentrist won easily — and proceeded to refer to the geocentrist as a “simpleton.”

His enemies pounced, claiming the comment was directed at Pope Urban VIII. Galileo vehemently denied it, but the Pope could not allow himself to be subjected to public ridicule. Accordingly, in 1633, the 70-year-old Galileo faced the Inquisition in Rome for a second time.

This time, he was found “suspect of heresy.” His writings, past and future, were banned from publication, and he was placed under house arrest, where he remained for the rest of his life.

Historians point out that the Inquisition generously did not convict Galileo of heresy per se, for which he would have been executed.

During his years under house arrest, Galileo wrote at length, refining and organizing his works of the previous 40 years. But his health steadily declined, and in 1642, he died of heart failure at age 77.

In 1718, the church announced that Galileo’s works could be published, if they were edited to remove the offending heliocentric references.

In 1758, the church modified its Index of Prohibited Books to allow authors, including Galileo, to assert that Earth is not the center of the universe.

Finally, in 1992, 360 years after the fact, Pope John Paul II formally declared that the church was wrong to condemn Galileo and lock him up.

A truly magnanimous gesture. Who says the Catholic Church invented science denial?