Hexbyte – Tech News – Ars Technica | Newly discovered letter by Galileo resolves puzzling historical mystery

Hexbyte – Tech News – Ars Technica |

And yet it moves —

Letter shows Galileo lightly edited his original words to appease Catholic Church

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The original letter in which Galileo argued against the doctrine of the Roman Catholic Church.

Royal Society

Renowned astronomer Galileo has been lauded for centuries for his courageous principled stance against the Catholic Church. He argued in favor of the Earth moving around the Sun, rather than vice versa, in direct contradiction to church teachings at the time. But a long-lost letter has been discovered at the Royal Society in London indicating that Galileo tried to soften his initial claims to avoid the church’s wrath.

In August, Salvatore Ricciardo, a postdoc in science history at the University of Bergamon in Italy, visited London, searching various British libraries for any handwritten comments on Galileo’s works. He was idly flipping through a catalogue at the Royal Society when he came across the letter Galileo wrote to a friend in 1613, outlining his arguments. According to Nature, which first reported the unexpected find, the letter “provides the strongest evidence yet that, at the start of his battle with the religious authorities, Galileo actively engaged in damage control and tried to spread a toned-down version of his claims.”

“I thought, ‘I can’t believe that I have discovered the letter that virtually all Galileo scholars thought to be hopelessly lost,’” Ricciardo told Nature. “It seemed even more incredible because the letter was not in an obscure library, but in the Royal Society library.”

Hexbyte – Tech News – Ars Technica | Oh more than moon

To  fully understand the significance of this discovery, one has to go back to Claudius Ptolemy around 150 AD, who was the first to synthesize the work of Greek astronomers into a theoretical model for the motions of the sun, moon and planets—all that made up the observable universe at the time. In his Almagest treatise, Ptolemy suggested the Earth was fixed, positioned at the very center of closed, spherical space, with nothing beyond it. A set of nested spheres (called “epicycles”) surrounded the Earth, each an orbit for a planet, the Sun, the moon, or the stars.

“The aesthetics [of the Ptolemaic model] meshed nicely with the prevailing Christian theology of that era.

Everyone loved the Ptolemaic model, even if it proved an imperfect calendar. It was so clean and symmetrical—positively divine. That’s why it was the dominant model for fourteen centuries. The aesthetics meshed nicely with the prevailing Christian theology of that era. Everything on Earth below the moon was tainted by original sin, while the celestial epicycles above the moon were pure and holy, filled with a divine “music of the spheres.”  It became the fashion for courtier poets, like John Donne (a personal favorite), to praise their mistresses as being “more than moon,” and dismiss “dull sublunary lovers’ love” as inferior and base. And it provided a rationale for maintaining the social hierarchy. Upset the order of this “Great Chain of Being,” and the result would be unfettered chaos.

Everything changed in the mid-16th century, when Nicolaus Copernicus published De Revolutionibus, calling for a radical new cosmological model that placed the Sun at the center of the universe, with the other planets orbiting around it. His calculations nailed the order of the six known planets at the time, and he correctly concluded that it was the Earth’s rotation that accounted for the changing positions of the stars at night. As for planets moving in apparent retrograde motion, he concluded this was because we observe them from a moving Earth.

Frankly, the book didn’t immediately cause much of a stir outside rarefied astronomical circles, perhaps because it was a massive tome filled with lots of tiresome mathematics. It didn’t make the list of the church’s banned books until 1616. That’s when it was pulled from circulation pending “correction” to reflect that its audacious claims were “just a theory”—an argument all too familiar today with regard to evolution and creationism.

Hexbyte - Tech News - Ars Technica | Frontispiece and title page of the Galileo's
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Frontispiece and title page of the Galileo’s “Dialogue Concerning Two World Systems,” 1632

Public domain

Then Galileo came along with his handy telescope (a recent invention) and his observations clearly supported the Copernican worldview. The church started taking notice, because Galileo openly espoused the Copernican system, in his papers

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