» Galileo Was No Scientist
I recently heard about philosopher of science Paul Feyerabend’s criticism of Galileo (and by inference all science): Galileo did not have sufficient evidence to make a logical case for heliocentrism. Instead, he used “rhetoric, propaganda, and various epistemological tricks”.
At the time, optical theory was not advanced enough to explain how telescopes worked. So Galileo had to trust on faith that his instruments were measuring what he thought they were measuring. It’s not scientific, but Galileo was supported by a consensus of astronomers, including Jesuits.
Observations of planets do not distinguish between the Tychonic system, where the sun orbits the earth and all other planets orbit the sun, and the heliocentric system. The only way to determine if the earth is moving is by stellar parallax: the triangulation of stars from opposite ends of the earth’s orbit. Galileo predicted stellar parallax but it was not observed for 115 years*, so his theory was falsified until then.
In fact, under relativity it is impossible to determine whether the universe has a centre, so it is a theological rather than scientific statement.
The proper way to consider Galileo’s work is not as a scientific result, but a shift to a new paradigm: astronomy based on telescope evidence with no reference to scripture. You might find this more elegant, it might be better at landing people on the moon, but there’s no basis for saying it’s more truthful.
* And even then it wasn’t stellar parallax, it was the unpredicted steller aberration. Parallax wasn’t observed until 228 years after Galileo’s prediction.
When you look through a telescope at terrestrial objects and see them, only larger, it seems a straightforward and safe assumption to assume that when you look at celestial objects the same principal will apply. Yes, they didn’t have the detailed model of optics to fully explain why that is the case, but it seems unfair to label the whole structure that Galileo built upon the telescopes-enlarge-and-resolve-things assumption as unscientific.
Nonetheless, I’m sure that many of Galileo’s methods and his rigour wouldn’t meet the modern standard of science, and so it may be fair to say he was not a scientist because he preceded and spearheaded modern science. Surely he is the giant upon which Newton et al stood and stand. His main importance, I think, was not merely his role in the heliocentrism debate, but that he actually bothered to measure and observe things, and that he engaged in real thought experiments. Unlike Aristotle who claimed things like “flies have six wings and I won’t bother actually looking at a fly to check”, Galileo checked things. So no wonder Feyerabend didn’t like that; here is Wikipedia quoting Feyerabend, with emphasis added by me:
That is what I’ve long considered the essence of religious thinking, the idea that how much you want something to be true has any relationship to how true it actually is.
I could generalize the new paradigm that you suggest “astronomy based on telescope evidence with no reference to scripture” to “understanding the universe by observing the universe.” And, unfortunately, that paradigm wasn’t fixed in place by Galileo – centuries later, Freud invented psychiatry by saying “here’s how I think the human mind works, therefore it does.” And that’s the major problem I have with philosophy, when philosophical systems protrude into areas that involve how the universe actually works. It seems to me that almost every philosophical system includes a description of how people develop and learn language. They will say, “humans learn language by breaking down concepts and words like this and that, and they correlate words to concepts to objects like this“. This always struck me as bizarre – why would it occur to anyone to say that “this is how things work in the real world because of philosophy” instead of saying “if my philosophy is true then it follows that people learn and use language like this and here are scenarios X and Y that could, in principal, empirically test that”?
Within the realm of discussing which co-ordinate systems and frames of reference allow for a valid model of the universe, then that statement is certainly valid. But that seems like a narrow realm, but in the larger realm there seems to be a significant difference in the truthfulness of the heliocentric and geocentric models. As Judge Holden said in Blood Meridian: “Words are things. The words he is in possession of he cannot be deprived of. Their authority transcends his ignorance of their meaning.”
Don
4 Dec 09 at 2:54 pm
I don’t think that “falsified” is the right word for that. I think his theory was effectively untested until then.
Don
4 Dec 09 at 2:56 pm
Yeah, that’s the claim I’m trying to make: Galileo presented a model for how to do science. Heliocentrism is often given as an example of that model. But heliocentrism is a very imperfect implementation of that model. And in fact no science ever follows the model perfectly.
My understanding is that the astronomers of the time didn’t realise how hard parallax was to detect (because they underestimated the distance to the stars), so they were quite concerned that they couldn’t detect it. Parallax was, in fact, the only unique prediction made by heliocentrism (over the Tychonic system). By the standards of science, heliocentrism was less true than Tychonism for 115 years. But heliocentrism was adopted by astronomers for non-scientific reasons…
Jared
6 Dec 09 at 10:44 pm