And Yet it Moves! Part IV

Galileo before the Inquisition

The whole affair has an air of tragedy about it, with the protagonists cursed by their own abilities and destroyed by their own inherent faults. The Church was initially agreeable to helio-centrism (which is true, just in case people were wondering) but the thought of being questioned on theology terrified them and to be faced with a layman who told them what to believe caused the clerics to strike back to protect the status quo. Galileo was a victim of his own ego. He repeatedly alienated potential allies because they showed signs of ability and he refused to admit the possibility that he was wrong to champion Copernicus' theory.

What turns the tragedy into farce is that, while both sides were wrong, the answer had already been discovered if either side in the trial had bothered to read it. Johannes Kepler, whom we came across earlier, had been obsessing about perfect shapes affecting the planets which had by a convoluted process, allowed him to discover the laws of planetary motion. The flaw in Copernicus' theory was that Copernicus, like the medieval philosophers, had simply assumed that all planetary motions were circular. By introducing elliptical orbits Kepler had saved the day and completed the revolution (if you'll pardon the pun) that Copernicus had started. Kepler had helped Galileo with his work but when he sent a copy of his own book to Galileo, hoping for an endorsement from the great astronomer, Galileo ignored it. Kepler died in 1630 but his theories were already receiving tentative confirmation by 1631.The great showdown between Galileo and the Inquisition was not until 1633 and news travelled fast between scientists.

Johannes Kepler

The church astronomers and Galileo should have been aware of Kepler's ideas and discoveries (Galileo had actually had the book sent to him by the author). Another damning mark against Galileo is that Kepler had also published a theory of the tides, which Galileo viewed as being pivotal to helio-centrism. Kepler had an alternative idea, albeit a crazy one, that the tides were caused by the Moon's movement acting at a distance. Galileo laughed at it as a "useless fiction." Kepler was right. Galileo was wrong.

The Galileo Affair was a clash of science against religion. It was also a clash of bad science against well, bad science. But it was mainly a clash of egos. Galileo was a great man. His work on falling bodies paved the way for Newton and was perhaps his greatest achievement, but he was active in making discoveries in many branches of science. But, by refusing to admit that he could be wrong he drew the anger of the authorities on himself. The Catholic Church behaved poorly as well, and its dogged insistence on treating anything associated with opposition as heresy hurled it from being at the cutting edge of science to being (from a scientific perspective) hundreds of years behind the rest of Europe.

And who was the real hero of the affair? Galileo was not the infallible man of science. There's no real evidence that he ever muttered "Eppur si muove!" (And Yet It Moves!) and his conduct betrayed all too human failings. He was a genius and we can forgive genius a lot. But for a truly extraordinary man of science, one whom we should take as a role model, I believe that Kepler is the real hero of the tale.

The Old Geocentric Model: What we have left behind

Postscript: It should be noted that some people have told this tale with slight variations, some favouring Galileo more, others favouring the Church. I am roughly retelling, in a far inferior form, the historical narrative laid out by Arthur Koestler in his excellent book Sleepwalkers. If you want to read more about the events, times and people involved in the birth of the scientific revolution I would highly recommend it.

And Yet It Moves: Part I
And Yet It Moves: Part II
And Yet It Moves: Part III
And Yet It Moves: Part IV

And Yet it Moves! Part III

Page from Galileo's Book "The Starry Messenger"

Galileo continued to make discoveries about the planets but his writings about heliocentricity were beginning to attract unwanted attention. There are certain verses in the Bible that speak of the Earth remaining still. Galileo, anxious that the Church should endorse his ideas, began to interpret these as speaking in a strictly poetic sense (the verses are taken from books of what are essentially, poems) effectively saying that these verses were merely figures of speech, rather like the way that we continue to speak of sunrises, despite knowing that the sun does not actually rise. St Augustine, the great 5th century theologian of the West had made similar claims about these books so it was a valid interpretation. If Galileo had made these claims in the Middle Ages he would have probably have gotten away with it. But when Galileo wrote, the Counter-Reformation was gaining strength. The Counter-Reformation was the response of the Church to Protestantism and the one thing that they were determined to prevent was individual scriptural interpretation. Even if this had not been ongoing, Galileo was not a theologian and he was told to stick to what he did best and not write about theology when he was unschooled in it.

Cardinal Bellarmine

At this stage Galileo had had an earlier run in with the Inquisition in 1616 but was released after questioning with no ill effects or stain upon his character. The question then had been about the Copernicus himself, who was now long dead. Copernican theory was deemed technically heretical but it was done in such a way that neither the works of Copernicus or Galileo were banned. This was a warning but by 1630 Galileo was on terms of reasonable friendship with the new Pope. The Pope was interested in the heliocentric theory but, with the Church under attack by the Protestants, he was concerned that the Church should only commit to the theory when it was a certainty. The Pope urged Galileo to write a book dealing with the strengths and weaknesses of the different theories and the Pope even put forward some ideas of his own that he thought could contribute to the discussion. Galileo wrote the book.

The book was a great success in terms of publishing but was not well received by the authorities. Galileo had ignored the Tychonic system and completely favoured the Copernican system over the Ptolemaic one. He had also put the ideas of the Pope into the mouth of a character (the book is a fictional conversation between three characters) called Simplicio, who as the name suggests, is consistently portrayed as an idiot. The Pope was furious and turned against Galileo. Now Galileo had to prove his case once and for all and he had to do it before the Inquisition.

Pope Urban VIII

What about the astronomers of Europe? Intellectuals were given quite a bit of free rein in this age of intolerance. If there was a concerted plea from the learned, possibly Galileo would be spared. But Galileo’s skill at making friends had worked here as well. He would make demands for data from other scientists who by and large would share. But Galileo not only did not share his research, but also would often not even answer his letters. He would also occasionally write nasty papers about other people’s work. This was not uncommon unfortunately, but it didn’t help him make friends. Worst of all he had made a declaration to the effect that only he could discover things using a telescope. So when any astronomer made a discovery Galileo would publish a subsequent paper saying that he had seen it first. This was downright intellectual theft and so when Galileo needed friends he found he had none.

In 1633 Galileo was summoned before the Inquisition and he had to prove his case; firstly that he was in no way involved in independent theological reasoning and secondly that there was good proof for the Copernican theory. Galileo had what he believed to be a perfect proof; that the tides were caused by the motion of the earth as it orbited the sun.

Sketches of Imperfections on the Moon

Thus armed, Galileo faced his accusers. What destroyed Galileo was the fact that some of his adversaries were scientists as well. As you may have guessed, Galileo’s theory of the tides was completely incorrect and his accusers were able to point to glaring inconsistencies. The worst by far was that Galileo’s theory predicted the wrong number of tides. With no explanation for the planetary orbits and his theory of tides and motion in tatters, Galileo (who was now an old man) was hemmed in by the power of the Church, abandoned by his friends and scientists and lacking the crucial theories and proofs that would have cleared his name. Facing uncertain consequences he signed a document abandoning Copernicanism and helio-centrism. Galileo spent the rest of his life under house arrest, in relative comfort it is true, but he was nevertheless confined. His works were banned and helio-centrism was confirmed as heretical. The Catholic Church wavered no longer and judged helio-centrism to be contrary to Scripture and as a consequence was left behind by further progress of science. Galileo died in disgrace some years after.

Galileo Galilei

And Yet It Moves: Part I
And Yet It Moves: Part II
And Yet It Moves: Part III
And Yet It Moves: Part IV