Monday, November 20, 2006

Who Refused to Look through Galileo's Telescope?

According to popular legend, when Galileo presented his telescope to senior cardinals/Jesuits/Aristotelian philosophers/the Inquisition (delete as applicable) they refused to even look through it. This tale has become a standard trope for when we want to attack anyone who won't accept 'obvious' evidence. As the last chapter of my book will be on Galileo, I thought I should try to nail down the primary sources for the legend. So I asked the internet's resident Galileo expert, Paul Newall of the Galilean Library to chase them down for me. His reply was extremely interesting.

There are three peices of evidence that have gone into the construction of the legend, as far as we can tell. The first concerns Cesare Cremonini, a good friend of Galileo and a Professor of Aristotelian Philosophy at the University of Padua. Quoted in a letter from a mutual friend to Galileo, Cremonini says of the telescope "I do not wish to approve of claims about which I do not have any knowledge, and about things which I have not seen .. and then to observe through those glasses gives me a headache. Enough! I do not want to hear anything more about this." It's clear that Cremonini did look through the telescope long enough to give himself a headache but could not see what Galileo could. Frankly, it was more than Cremonini's job was worth to endorse Galileo because it would have refuted Aristotle.

The second case is Guilio Libri, Professor of Aristotelian Philosophy at Pisa and no friend of Galileo's. He died very shortly after the telescopic discoveries were made public. Galileo was viciously biting when he heard the news, writing to a friend to ask if Libri, "never having wanted to see [the moons of Jupiter] on Earth, perhaps he'll see them on the way to heaven?" Did Libri refuse to look through the telescope or look and not see the moons (which was not easy at all, especially if you were old and without the keenest of eyesight)?

Finally, the senior Jesuit astronomer Christopher Clavius said of the moons of Jupiter "One would first have to built a spyglass that creates them and only then would it show them." However, the fault was with the Jesuits' first effort to built a telescope. Once they had built themselves a better one, Clavius confirmed that he could see the moons.

So who refused to look through Galileo's telescope? According to the historical record, no one did for certain. The argument was over what they could see once they once they did look.

Comments or questions? Post them at Bede's dedicated yahoo group.

3 comments:

- said...

You are correct - Refusal-To-Look - is used today as a figure of speech - and you did hit the nail on the head when you said that obvious evidences are often refused to be seen.

This is especially true when it comes to the vast distances as measured across our universe and the accompanying modern data gathered for a very old universe. Over the past decade using modern technologies (not even imagined in Galileo's day), we see stars in various burning stages - some being born, some (like our sun) in a very stable mid-life, others dying, some dead, etc. We see background radiation, an expanded and still expanding universe, galactic collisions, red-shifted light and a mountain of other data for which limited space here restricts, all pointing to an old universe.

Yet, is not the vehement denial of such data by many fine Christian brothers akin to a refusal to look because of an adopted orthodox view of creation superimposed upon God's handiwork of which we are directed to consider.

As so, are we not today still refusing to look - - ?

Anonymous said...

The point is that Galileo was willing to look further -- beyond what was commonly accepted. His insight was based on observation which is the fundamental basis of all science and knowledge to this day.

Cremonini(sp) insisted that all of the orbs must be perfectly round and smooth. Galileo saw through his invention -- the telescope, that the moon had peaks and valleys.

Legend says that Cremonini then said that "thats fine, but there is certainly a layer of ice taller than those mountains that make it perfectly smooth as Aristotle says"

The point is -- who was right? History will always tell who was correct.

Ever heard of Galileo?
Ever heard of Cremonini?

That's what I thought

Frankie said...

"The point is that Galileo was willing to look further -- beyond what was commonly accepted. "

True. Too bad his argumentation was poor. So poor in fact, that he didn't even follow his own data.

http://www.nature.com/news/2010/100305/full/news.2010.105.html


"The point is -- who was right? History will always tell who was correct.

Ever heard of Galileo?
Ever heard of Cremonini?"

Ever heard of Kepler? You know, the man who actually proved Heliocentrism? The man whose brass was actually backed up by solid data?