Why Galileos use of the Telescope got him in Trouble with the Inquisition

In Venice, in 1609, Italian astronomer and mathematician, Galileo Galilei heard rumors that a Dutch spectacle maker had invented a spyglass. Later renamed telescope, this device was believed to make distant objects appear nearer. A patent had been requested, but was yet to be granted, and the methods were being kept secret as this device was obviously of tremendous military value to Holland.

Acting only on instinct and hearsay, Galileo made a frantic 24 hours experiment, and eventually built a 3-power telescope. Given his determination, this telescope only improved with time: he later constructed a 10-power telescope which he presented to senate. The senate was highly impressed with his invention, and, at last, he got what he was looking for—a salary raise, and honorary proclamations. With his new status, he became a man of wealth and honor, but he would not stop here.

Trouble started when, one evening, he focused his telescope on an object in the sky that all people, at that time, believed was a perfect, smooth, polished heavenly body—The Moon. To his amazement, he observed that the moon’s surface was rough, uneven, and full of cavities. Of course, many insisted that he was wrong, and their arguments, indeed, seemed reasonable:

“Even if the moon’s surface is rough,” reasoned one mathematician, “it has to be covered in invisible, transparent, smooth crystal.” Or so he thought; but Galileo kept working on his observations.

As expected, his telescopes only improved with time. On 7 Jan. 1610, he focused his 30-power telescope on Jupiter and discovered three small bright stars near the planet. One was off to the west, the other two were to the east, but all three were in straight line. The next day, in the evening, he took yet another look at Jupiter, and found that all three of the stars were now west of the planet, and still in straight line. He concluded that these small “stars” were, in fact, satellites which were rotating about Jupiter: and that if there were satellites that did not rotate around Earth; then the Earth is not at the center of the universe as assumed. The Copernican idea of the sun at the center of the universe could as well be valid.

In March, 1610, he published his findings as a small book titled: “The Starry Messenger,” which postulated that the Earth went around the sun. The public seemed impressed with his publication, but the church was not, neither was the Vatican; for he was beginning to contradict the teachings of the church. Nevertheless, some of the church’s mathematicians wrote that his observations were accurate, but others disagreed.

In December, 1613, one of his friends recounted how a powerful member of the nobility said that she could not see how his observations could be valid as they dissented with the Biblical view of astronomy. The lady had quoted a passage in Joshua (Joshua 10:10-15) where God caused the sun to stand still, and, thus, lengthened the day. This only meant that the sun went round the Earth.

Although Galileo was a religious man, and agreed that the Bible could never be in error, he, however, said that its interpreters could make mistakes; one of which was to take the Bible literally. (At that time, only church priests had the right to interpret scriptures, or to define God’s intentions.)

Consequently, he was formally accused of heresy, and was dragged to the inquisition. (The papal Inquisition, which began in 1232 under the leadership of Pope Gregory IX, was a church court that addressed issues of heresies and other damnable doctrines that threatened to break up the unity of the church.) Luckily, he was not found guilty, but was, however, cautioned to refrain from teaching the Copernican system.

Sixteen years had passed, and the church had moved on. So did Galileo; but his interests only broadened with time. Fascinated with ocean tides, he wrote a great deal about the subject except that he did not present his arguments as a scientific paper. He thought it was much more interesting to have an imaginary conversation between three fictitious characters. One character that would support his own side of the argument was brilliant. Another character would be open to either side of the arguments, and the final character, named Simplicio, was dogmatic and foolish—he represented the church and the Vatican. Or so it appears.

Following the success of this publication, he published a similar dialogue titled: “Dialogue of the Two Great Systems of the World.” The book, which talked about the Copernican theory, was an immediate hit with the public, but the Vatican was greatly infuriated. More so, the Pope, suspecting that he was the model for Simplicio, ordered the book to be banned and summoned its recalcitrant writer to appear before the Inquisition, in Rome, for the crime of teaching the Copernican theory.

Usually, heretics were burnt at the stake, and Galileo, aware of his awaited torture and death, publicly confessed that he was wrong to have said that the Earth revolved around the sun. At this time, he was 68, and his state of health was rapidly deteriorating—he could not withstand any torture from the Inquisition. Ultimately, he was let off the hook, but was placed under house arrest. Until his death in 1642, he lived near one of his daughters, a nun, and continued to explore other areas of science.

In 1822, by that time it was common knowledge that the Earth was not at the center of the Universe, the church lifted the ban on Galileo’s Dialogue, and finally in 1983, he was formally cleared of any wrongdoing.