Thursday, August 10, 2017

Aaronson on Galileo, Civil War, and Hitler

Scott Aaronson posts some excuses for not commenting on the controversies of the day, such as the Google Diversity Memo, but cannot resist trashing Pres. Trump:
I think it’s clear that Trump is not Hitler (equating the two is even offensive), but equally clear that Trump has taken the US down the first steps of the long path that historically leads to totalitarianism. Trump probably has the closest resemblance to tinpot autocrats ...

Just like the capitalists and communists temporarily set aside their differences to defeat Hitler, ever since before the election I’ve maintained the fantasy that countless segments of American society normally considered diametrically opposed to each other—for example, libertarians and socialists, Silicon Valley nerds and social-justice warriors, New-Age hippies and business leaders, pacifists and national-security hawks, atheists and principled religious believers, etc. etc. — would bury their hatchets for awhile and come together for the shared goal of stopping Trump. It remains a beautiful vision to me, and one that I still hope comes to fruition.
This is obviously just an emotional reaction, and this blog is more concerned with scientific opinions.
When I see social media ablaze with this or that popular falsehood, I sometimes feel the “Galileo urge” washing over me. I think: I’m a tenured professor with a semi-popular blog. How can I look myself in the mirror, if I won’t use my platform and relative job safety to declare to the world, “and yet it moves”?

But then I remember that even Galileo weighed his options and tried hard to be prudent. In his mind, the Dialogue Concerning the Two Chief World Systems actually represented a compromise (!). Galileo never declared outright that the earth orbits the sun. Instead, he put the Copernican doctrine, as a “possible view,” into the mouth of his character Salviati — only to have Simplicio “refute” Salviati, by the final dialogue, with the argument that faith always trumps reason, and that human beings are pathetically unequipped to deduce the plan of God from mere surface appearances.
And thus he was mocking his sponsors.

The Pope invited him to write a book that fairly presents the scientific arguments. Galileo gave some stupid arguments about the tides, and called the Pope "Simplicio".
In fact, my understanding from Weinberg’s book To Explain the World is that, when you try hard to make the Ptolemaic model work, it basically becomes the Copernican model in all but name! More precisely, the epicycles that arise in calculating the orbits of Mercury, Venus, etc. are just precisely the corrections you would make if you knew from the beginning that they, along with the earth, were all orbiting the sun. So at that point all that remains is a final slice of Occam’s Razor, which Copernicus provided tepidly and Galileo later provided with gusto.

In summary, I view “the Church was right in its dispute with Galileo” as analogous to “the American Civil War had nothing to do with slavery”: a perfect example of a belief people utter when they’ve learned just enough to be wrong, but not yet enough to be unwrong.
I don't know whether Weinberg explains this correctly, but the Ptolemaic model has very little to do with whether the Earth goes around the Sun or the Sun goes around the Earth. Ptolemy has a page or two discussing the matter, but the rest of the model models the appearance of the sky from Earth. More accurate data could have improved the model where at some point it would have been obvious that an Earth orbit could explain epicycles. Likewise the Copernican model could have also been improved to the point where it might have been obvious that elliptical orbits could reduce the epicycles.

The view since relativity is that motion is relative, and one can use either the Earth or the Sun as a frame of reference.

Notice how Aaronson and lot of others keep returning to the same examples for their moral righteousness: Galileo, Civil War, slavery, Hitler. The more I learn about these examples, the more I think they fail to show any of the points that the examples are commonly used for.

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