For our forebears from the Stone Age to the Middle Ages, the celestial bodies were mainly of religious significance. In Christianity, there was a belief that rotating crystalline spheres were behind the sun, moon, and planets, within which the stars could be found. And behind this as the outermost sphere was the primum mobile, which rotated with God’s touch. All of this consisted of ether – or so people believed – and they didn’t mean the anesthetic, but a flawless fifth element postulated by Aristotle.
Enter Galileo Galilei: The mathematician had been teaching at the University of Padua since 1592 and also sold scientific instruments. That’s because Galileo may have been a scientist, but he was also not totally averse to life’s profane pleasures: He needed the money, among other things, to financially support the three children he had fathered with his mistress. At the same time, he regularly caused a stir in the academic community – and the Catholic Church – with his experiments on pendulum motion, the law of falling bodies, and acceleration.
In 1609, a new telescope for enlarging objects was developed in the Netherlands. The invention was known as the spyglass. You don’t have to be a genius like Galileo to deduce that the original purpose of the apparatus was not to observe the night skies. The scientist, however, had another use in mind and built his own, much more powerful model – without having seen the original plans – and pointed it toward the sky. And what he saw was not at all compatible with the dogmas of the church at the time – and thus with society in general.
Galileo pointed his telescope toward one of the celestial bodies created by God, which was by definition perfect: the moon. What he saw and recorded in his drawings didn’t at all fit in with the theory of the divine origin of the Earth’s moon: The surface was not smoothly polished and flawless, but pockmarked and dotted with hills, boulders, and craters – not dissimilar to the earth in terms of structure. Yet that wasn’t all. He established that Jupiter also had moons, making the earth not at all as unique as the church claimed.
In short, all of his findings suggested that Copernicus’ assumption that the earth and all other planets in the solar system revolved around the sun was correct. The publication of these discoveries in Sidereus Nuncius (Sidereal Messenger) in 1610 made him an overnight star. It didn’t immediately lead to an open conflict with the church, because Galileo hadn’t yet publically taken an opposing view to the dogmatic beliefs of the time. He declared that a biblical exegesis may be compatible with Copernicus’ system – thereby averting the risk of persecution by the Inquisition.In 1632, Galileo was eventually charged by the Inquisition for his closing remarks in his work Dialogo – and he had to renounce his “errors.” He was sentenced to life imprisonment, although this was controversial among the cardinals: Three out of ten didn’t sign the judgement. The defiant words “… and yet it moves!” that Galileo is reported to have mumbled upon leaving the courtroom are now mostly doubted. And for good reason: If a senior church figure had overheard this hissed disobedience, instead of going to prison he would have probably ended up on the funeral pyre as feared at the beginning of the trial.
All the same, the scholar didn’t stay in prison and spent the rest of his life under house arrest. This allowed him to conduct further research and complete his scientific masterpiece Discorsi e Dimostrazioni Matematiche intorno a due nuove scienze. Galileo died in Arcetri in 1642. A ceremonial burial was initially prohibited and it wasn’t until 1737 that he was reburied in the pantheon of Florence, the Basilica Santa Croce. Galileo is in the best company, because this is where Niccolò Machiavelli, Michaelangelo, Gioachino Rossini, and other great Florentines have been laid to rest.
In the process, however, he was probably separated from some of his body parts: In 2009, researchers from the Institute and Museum of the History of Science presented the skeletal remains of a middle finger, a thumb, and a tooth that are said to have come from Galileo, according to DNA tests. It remains the subject of speculation as to whether the middle finger in particular was removed at the time with the ulterior motive of pointing it toward the church.
Yet if there is a heaven in the Christian sense, Galileo probably looked on with a great deal of satisfaction as he saw the Enlightenment triumph despite all the efforts of the church. It was ultimately even a comprehensive victory: In 1992, 350 years after his death, the Catholic Church lifted its condemnation of Galileo – while ‘Stars’ by Simply Red provided a fitting hit in the charts.