Wikipedia: Galileo/Talk

Showing revision 31

When Galileo was defending the copernican model, it was not scientifically? superior? to the Ptolemaic system. Copernicus still tried to use circular orbits, and as they failed, had to use epicycles? and other resources of Ptolemaic kinematics. Only after Kepler's work (that was largely ignored by Galilei) was incorporated in the theory, and Newton's law of gravity gave a sound physical basis to the whole system, was the heliocentric model undoubtedly superior.

Also, despite what is said, the Church did not approve the Ptolemaic system as real. It simply stated that both were simply devices to predict positions. It was Galileo who tried to force an acceptance of the Copernican system as "real"

Wasn't the church in definite favor of a geocentric universe, though? At least, there were many [religious arguments]? put forth for it, and Copernicus undoubtedly published posthumously for some reason or another. Also the church had just finished some council or another where they decided there absolute and final stance on all sorts of issues, which I vaguely recall Galileo was opposing somehow...maybe the non-Aristotelian physics. In any case, I agree that the church was being fairly nice until Galileo got out of hand.

--Josh Grosse

I think you got some confusion with the terms philosopher and scientist Josh Grosse.

Not to mention superior?. Anyway I left your text there. I'm not AxelBoldt that likes deleting here and there.

--little guru

: The word "scientist" itself is probably recent. Newton called himself "natural philosopher".

Didn't mention superiority, and I'm not mixing philosophy and science up - the two fields split fairly recently, and much earlier material falls into both categories, in scope if not methodology.

Even in its early form, though, the Copernican system was clearly superior to Ptolemy in that the model of a tilted Earth rotating around the sun explained the oddly-inclined motion of sunspots in a simple way that Ptolemy could not, for example. Yes, Copernicus got a few things wrong like circular orbits, and Galileo himself was mistaken about his theory of tides being caused directly by the rotation of the Earth, but overall, his theories were still far superior to Ptolemy.

The church might not have accepted Ptolemy as "real" (and I don't think my text claims that), but at no point did Galileo ever claim that Copernicus' model was real either. The churuch's main concern was with scripture that claimed the Earth was stationary. The generally-accepted Ptolemaic system fit with that; the Copernican system (even in its early less-than perfect form) did not. Galileo pointed out that by _assuming_ a Copernican model, you could more easily calculate and predict certain things, but at no point in his life did he ever claim (at least publicly) that the system was "real"; he firmly backed away from such claims at every opportunity. De Revolutionibus itself is a masterpiece of weaseling and backpedaling.

Note: As I understand it, De Revolutionibus is no such thing, except in so far as there is an introduction that states the theory is intended for calculations and not as a description, which was not put in by the original author.

Did Galileo claim the universe was heliocentric, though? I can't imagine why he wouldn't have - after all, he defied the church to publish material on it (assuming the Dialogues mention the topic), and it seems more likely that he would do so if he though it was genuinely valid.

--- Actually the church claimed that in the book of Joshua when the text says that miraculously "the sun stood still" it implies that the sun rotates around the earth. This among other texts led the church to believe that be bible claimed that the Copernican theory was false, but it is now commonly understood that these texts were only intended to describe what the spectators saw, not to describe the natural processes behind the events, so the church now has no problem with the heliocentric position.

Does anyone besides me feel that Galileo should be credited, even more so than Newton, for founding [modern science]? by conducting experiments? rather than relying on mere conjecture (as Aristotle did). Or was there someone before Galileo who not only relied on experiment, but realized that it was the only way to really learn anything about the world?--

BlackGriffen

I think Francis Bacon came before Galileo in that regard.

--LDC

: Bacon? may have philosophized about the scientific method; Galileo actually practiced it.

: Bacon? did in fact perform some experiments, mostly in alchemy, but it is true that most of what he did was promoting the method in writing, speculating, and collecting other people's (Arab's) results.

--AxelBoldt

: By the way, is there any historical evidence of a person using a telescope to examine the night sky, prior to Galileo? In "Galileo's daughter" the author says Galileo first picked up a telescope ten years after its invention by Dutch spectacle makers. People used it to spot ships coming over the horizon. She claims Galileo first turned it towards the sky.

--Ed Poor

There is an account of Thomas Harriot observing the moon with a three-power scope in June of 1609, and no recorded account of Gallileo doing so before Obtober of that year. Galileo did have telescopes before then, so it is likely that he did so earlier, but it is just as likely that any number of people who had the first telescopes in 1608 did so but did not record it. Galileo should certainly be credited as the one who popularized the practice, but it is unlikely that he was in fact the first.

--LDC

: Okay, he's not the first. I've stirred up a lot of trouble today. Gotta start checking my sources and distinguishing between what I guess/hope and what I know (tucks in tail, slinks away).

--Ed Poor

It is commonly taught in science classes that Galileo was the first, so it is natural that that factoid would end up here. Here's a good rule of thumb: anything you ever learned about history in school is probably wrong. :-) Note, for example, [The Myth of the Lone Inventor]. Factoids of "X was the first to..." form are about as reliable as "X invented..."

--LDC

I think Bacon and Galileo should be mentioned in any article on the development of the scientific method. I don't know about "credit" in terms of "lone inventor", but it would nice to know what part each had in science's development. I make no claims for or against either. It's science I love, not dead white males (nothing against them, though).

--Ed Poor

I certainly agree that any article on the foundations of science ought to mention both men; but this isn't an article on that--it's an article on Galileo. If he, personally, was influenced by [Francesco Bacone]?, then that should be mentioned. But otherwise, I see no need to necessarily mention him, though I'm sure some description of Galileo's role in founding modern science might mention Bacon? in passing.

--LDC

The following passage seems a bit anti-church:

: he was forced to recant and put under life-long house arrest. The Church, and most everyone else, held to a Ptolemaic, or Aristotelian view, incorporating an Earth-centered theory of the universe. Recent scholarship has highlighted the fact that many of Galileo's problems with the Inquisition stemmed more from his lack of judgment than from any great desire by the Catholic Church to suppress his ideas.

: Nevertheless, Galileo remains a classic case of a scholar forced to recant some of his best work because it offended powerful forces in society.

What exactly was he "forced to recant"? The mobility of the earth?

What were the terms of the "life-long house arrest" and when did it start? Was he guarded, told not to leave his estate, or what?

In what way did Galileo's "lack of judgment" contribute to his problems with the Inquisition?

Note that I am not challenging, just asking for details. Ed Poor

The article as it stand is not NPOV, but the usual caricature of the case. --AN

Very much seconded.

If you have actual historical facts to add, feel free to do so. I object to any change of words as a gesture of "neutrality". I think the case is quite clear, but there is a lot of historical revisionism, understandably, given the continuing popularity of irrational mindsets.

I wonder about 'irrational' and 'antirational' in this entry Not that I accept Kuhn and paradigm shifts lock stock and barrel, but if you're in the midst of a paradigm shift and you yourself are perfectly adequately trained in the old paradigm how is it 'irrational' to not accept the new paradigm? The proof the opponents of Galileo relied upon was not purely scriptural (which is irrational in scientific inquiry, and to that extent should certainly be detailed and condemned in the entry), but older science. And don't believe that they stopped at Ptolemy - they were entirely aware of the centuries of further observation and refinement through the Muslim scientists; the model was wrong, but wasn't it as 'rational' as Newtonian physics was in the face of modern physics? So is opposition to new scientific theory on the basis of older theory inherently irrational, or cautious? --MichaelTinkler

I agree, the word "irrational" is too strong. Particularly since the Copernican model wasn't really that much better than the improved Ptolomeic model at predicting things (though it was a lot simpler and more elegant). Maybe "narrow-minded" fits better? --AxelBoldt

I think "conservative" is the correct word here, rather than "irrational" or "narrow-minded".

Also, the article says:

: Galileo is a classic case of a scholar forced to recant a scientific insight because it offended powerful, anti-rational forces in society

What are the other cases? -HWR

Petr Beckman's History of Pi (sounds boring as hell, doesn't it?) is a marvellous account of the history of political suppression of ideas. --LDC

I took out the "threat of torture and death" bit. Is there any evidence that he was threatened with that, beyond the generally known unfriendliness of the inquisition? He was never imprisoned, and lived at the villa of an archbishop after the trial. --AxelBoldt

Axel, yes, the threat of torture is generally well known (do a Google search: galileo torture), although apologists insist that it was only "formal" and has to be seen in light of the times, etc. I have inserted a source which summarizes the case.

Regarding conservative vs. irrational, I cannot call the use of physical force to prevent the publication of ideas which contradict your own anything but "irrational", because its underlying assumption is infalliblity. However, I agree that being conservative is equal to being irrational, so I think the substitution works just as well. -- Eloquence