House of Eratosthenes

[…] them to tar their political opponents as anti-science, on par with gap-toothed creationists and the guys who locked up Galileo. If they get called on their political bullshit, they simply retreat to their factual — or, […]
- D3: “Moonwalk” / “Moonwalking” | Rotten Chestnuts | 02/15/2013 @ 09:11
It’s probably a lot to expect someone from the 17th century to act like an ideal modern scientist, but Galileo didn’t do badly even so. I’m afraid these video clips are not facing up squarely to the Galileo lesson.

He was undoubtedly tactless. His “Dialogue Concerning to Two Chief World Systems” was disingenuous in that it purported to be an evenhanded weighing of two alternatives. In fact, the geocentric theory was mouthed by a character called “Simplicio,” who was given a somewhat ridiculous case to make, and who (worst of all) quoted Pope Urban almost verbatim. But tactless as this all was, the heliocentric view was obviously very good science even at the time, and even though it still had some wrinkles in it that had to be ironed out later. It was leaps and bounds ahead of the science of the geocentric version, which wasn’t science at all but an adherence to Psalms that spoke of the Earth as immovable. The Church had originally greeted the heliocentric theory with some equanimity, but began to get nervous about it by the time Galileo started needling the authorities. At this time, of course, not many people understood the math, even though Copernicus had nailed it down pretty thorough to a modern eye. Even scientists like Bacon were comfortable dismissing the heliocentric model as “against common sense” without any more convincing basis.

It’s true that the Church would have let Galileo get away with talking about heliocentrism as a mathematical fiction as long as he didn’t commit heresy by implying it was a physical truth, but frankly that’s pretty hard to do. He thought the religious climate was improving and that Urban would protect him if he pressed the point in his inimitable sarcastic style. He miscalculated. He was threatened with torture and sentenced to prison (immediately commuting to lifetime house arrest), but he never recanted.

No doubt Galileo made some errors. He followed Copernicus in positing circular orbits, whereas others were already beginning to understand that they must really be ellipses. Still, at the scale we’re talking about, the difference between a very-close-to-circular ellipse and a perfect circle is extremely subtle, almost beyond the power of observation of the day to detect. Galileo may also have muffed the mechanism that explains the tides. Nevertheless, Copernicus had worked out the basic theory of heliocentrism in a way that easily outperformed any Classical or traditional Catholic theory of geocentrism. In contrast, the geocentric theory couldn’t hold water in the tiniest way once you got beyond the concept that a man standing on the surface experiences the illusion that he is standing still and the Sun is going in a circle around him. It couldn’t account for a single other observation of the bodies in the solar system. The geocentric view supposedly commanded by Scripture was already chopped liver. The post-Galileo corrections to the heliocentric system were minor; the real advances came in the ability to associate the mathematical patterns with a physical theory (gravity) and with more general laws of motion based on the default position of straight-line movements altered only by accelerations induced by force.

So Galileo was something special in the way of scientists. In the 17th century, it was extremely rare to find a scientist who started with experimental observations rather than pre-conceived notions, but who also had a mind that was powerful and original enough to perceive mathematical patterns in the evidence. That combination is the essence of modern science.

The telescope had been around for a bit before Galileo seemingly became the first man to get the brainstorm of “Why not point it at the sky?” He didn’t come up with the notion that the planets orbited the Sun in ellipses; Copernicus started the idea and Kepler fleshed it out in the first decade of the 17th century. But Galileo added many new understandings on the basis of his telescopic observations. He figured out that “Kepler’s supernova” must be very distant, because it exhibited no parallax effect resulting from the distance an observer on Earth travels during the daily rotation of the planet. That’s good stuff, something he had to believe in the teeth of the classical world’s conviction that the heavens were unchanging, an idea the Church had latched onto as well and defended vigorously as a Scriptural truth. He figured out that three previously unobserved moons must be orbiting Jupiter.

The old Ptolemaic view of a geocentric system insisted that Venus could never be behind the Sun and that it therefore could only show new- and crescent-stages. Galileo’s new telescope allowed him to demonstrate that Venus went through the same phases as the Moon, from dark to new to full to crescent, and therefore that Venus must be orbiting the Sun, as Copernicus had predicted in the 16th century but could not confirm from observations.

Galileo was one of the first to gain a systematic understanding of the mathematical behavior of falling (i.e., accelerating) bodies, including the crucial notion that distance varied with the square of time. He also understood quite a lot about conic sections, the family of functions that are yielded by that crucial squared time factor. He figured out, for instance, that ballistic objects followed a parabola. He couldn’t quite wrap his mind around the notion that the Earth moved in a conic section (an ellipse), but he was getting there. His understanding of these mathematical patterns in movement, together with his observations of heavenly bodies, set the stage for Isaac Newton’s brilliant late 17th century and early 18th century statement of the mechanics of movement controlled by an inverse-square law of gravity, which we now understand to be the source of the conic-section formulas.

I’m a conservative Christian. I’d love to defend the Church of the 17th century as merely adopting a sensible reluctance to jump the gun. I just can’t make the case. They blew it. What they ought to have done is admit that the Scriptural references to the immoveable Earth should be understood metaphorically. Then they could concentrate on pointing out that no theory of the movement of planetary bodies has any power to alter a spiritual view of the role of God in the universe or the importance of man to God. Yes, Galileo was treated more kindly that the run-of-the-mill witch, but that’s not really the point, is it? The point is that the Church fell into the error of suppressing scientific research from fear that it was leading the faithful into error.
- Texan99 | 02/15/2013 @ 10:47
The point is that the Church fell into the error of suppressing scientific research from fear that it was leading the faithful into error.

I’m not so sure I agree with this.

If it’s legitimate to talk about “errors” being made by one side or the other, then the Church’s “error” was, at bottom, to defend an outmoded conception of the method by which Truth, capital-T, is established. To grossly oversimplify, their method was “Biblical literalism;” Galileo’s, “the scientific method.” In this case, paradigms really were incommensurate, which is why Kuhn spends so much time on it in The Structure of Scientific Revolutions.

In other words, I argue, the Church didn’t “blow it,” because the baseline from which the Church hierarchy evaluated truth-claims was so far from the scientific baseline that the decision makers in the hierarchy almost literally couldn’t understand what Galileo was saying.

Obviously that baseline changed rapidly after the Galileo affair, which makes it a justly famous incident in the history of science. But to cast this as a win for the Forces of Reason, full stop, as the Zachriel would have us do, is to miss the contingent and contextualized nature of scientific discovery. Which — their many, many protests to the contrary notwithstanding — is exactly what they’re trying to do in the various Threads that Won’t Die.
- Severian | 02/15/2013 @ 11:49
I guess I’m still not sure I agree. I don’t fault the Church at all for sticking to the geocentric model, or for considering it premature to adopt the heliocentric model. What I do fault the Church for is gagging Galileo and subjecting him to house arrest for publicizing views the Church considered dangerous. That’s always a bad idea even if the ideas are wrong, but in this case it’s even worse, because Galileo had by far the better part of the argument.

The Church was entitled to its views, but it discredited itself by censoring the views of developing science. It should have stuck to trying to counter them with its own position, and letting the public decide freely. It did start to do something like that quite soon after the Galileo house-arrest; it appears that the Church fathers were considerably calmer about the danger of heresy from astronomy both before and after this disquieting episode. But for the time it took to try and imprison Galileo, the Church was in error. I think you’re right that they literally couldn’t understand what Galileo was saying. That was not a good reason to gag him.

I would posit Galileo’s refusal to recant, and his eventual vindication on the substance of his scientific views, as a triumph of the Forces of Reason. It’s not that I think the Church was anti-Reason; far from it. But they were untutored in science, and they took for granted their right to suppress spiritually dangerous ideas, and they mistakenly concluded that Galileo’s ideas were spiritually dangerous, even if only temporarily.
- Texan99 | 02/15/2013 @ 13:12
Texan99: The point is that the Church fell into the error of suppressing scientific research from fear that it was leading the faithful into error.

Nice essay.

It’s not quite accurate to say Galileo didn’t recant. He did.
http://law2.umkc.edu/faculty/projects/ftrials/galileo/recantation.html
(Keep in mind that Giordano Bruno was burned for heresy when Galileo was 36 years old. Bruno had refused to recant, saying “Maiori forsan cum timore sententiam in me fertis quam ego accipiam.”)

Severian: If it’s legitimate to talk about “errors” being made by one side or the other, then the Church’s “error” was, at bottom, to defend an outmoded conception of the method by which Truth, capital-T, is established.

The Church sent the greatest scientist of the age before the Inquisition and forced him to sign an abjuration under threat of torture. Of course they were in error. Nor were they stupid. The political dynamic was the threat to the Church’s authority.
- Zachriel | 02/15/2013 @ 13:42
Fair enough. In any case, my argument rests on an assumption about Renaissance mentalities that I have very little business making.

(I do enjoy these kinds of philosophical arguments and look forward to having more of them).
- Severian | 02/15/2013 @ 13:43
We take it for granted today that there is freedom of speech and research and ideas. That was very far from the minds of society and the Church in the mid-17th century. Europeans were still enthusiastically killing each other over heresy. So I cut the ancient Church more slack that I do modern government-funded institutions.
- Texan99 | 02/15/2013 @ 14:06
I didn’t remember that Galileo recanted after all. Wiki says the “it still moves” remark may be a legend. I like the way he says “I wrote and printed a book in which I discuss this new doctrine already condemned, and adduce arguments of great cogency in its favor, without presenting any solution of these” — in other words, you got me fair and square: I made such a cogent argument, and so thoroughly failed to present a convincing counterargument, that I exposed myself to a charge of believing my cogent argument, which was no doubt very evil of me. Did his audience understand the insult, I wonder?
- Texan99 | 02/15/2013 @ 14:19

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The Galileo AffairFriday, February 15th, 2013

The Galileo Affair
Friday, February 15th, 2013