This past October I had the pleasure of giving three talks at ITESO: The Jesuit University of Guadalajara (ITESO stands for “Instituto Tecnológico y de Estudios Superiores de Occidente”). They had invited me for their annual Semana de la Astronomía, that is Astronomy Week. This university has an astronomy week! Is that cool or what?
My main talk was on Jesuits and the Coriolis Effect, a subject Vatican Observatory Director Br. Guy Consolmagno and I discuss in a chapter of our book, When Science Goes Wrong — The Desire and Search for Truth, that had just come out a few weeks before I went to ITESO. The other two talks were related to the two brightest objects visible in the night sky during the Semana de la Astronomía, namely the moon and Jupiter. An observing session was part of the Semana, of course. And since this was a Jesuit university, I gave talks on (1) Jesuits and the moon, and (2) Jesuits and Jupiter.
Just before I was to give the Jupiter talk, I recalled something from my old college general astronomy textbook. This book was William J. Kaufmann’s 1985 Universe (W. H. Freeman and Company). It had a paragraph on Galileo and the Church, following three paragraphs discussing Galileo’s telescopic observations. It stated that “the Roman Catholic church attacked his ideas because they were not reconcilable with certain passages in the Bible or with the writings of Aristotle and Plato”. It also included a reproduction of one of Galileo’s drawings, labelled “Galileo’s observations of Jupiter’s moons”. It was this drawing:
Note the heading. See the word “Jesuit” there, in Galileo’s own hand? This drawing is a copy Galileo made of observations recorded by Jesuit astronomers. It is not Galileo’s observations. Galileo noted it as such, and this note, in Latin, is clearly visible in the Kaufmann book’s reproduction.
Galileo’s telescopic discoveries were not attacked by the Church but were rather confirmed by Jesuit astronomers. This is discussed by Jim Lattis in his 1994 book Between Copernicus and Galileo: Christoph Clavius and the Collapse of Ptolemaic Cosmology, published by the University of Chicago Press. Lattis includes Galileo’s drawings more fully:
And at the bottom of these drawings, Lattis indicates quite clearly that these drawings are Galileo’s copies of Jesuit observations:
I was thinking about including this in my ITESO talk, so I did an image search for “Galileo Jupiter moon drawings”. The Galileo copy of the Jesuit observations came up multiple times:
And so I clicked on one of the images, and it took me to a web page. On that page was discussion about Galileo seeing the moons, and about how this “shook the very foundations of the Catholic Church”, and about how Galileo’s findings were suppressed. And there, below all this junk, was Galileo’s drawing — his drawing of Jesuit observations of Jupiter’s moons.
How remarkable that a series of drawings of the Jovian moons by Galileo that he clearly labelled “Jesuit observations” could show up in a college textbook, under a discussion of how the Catholic Church attacked his ideas. Because, of course, the Jesuit astronomers were not attacking his ideas. They were confirming his ideas — very early on. The drawings start in 1610. Galileo published his Starry Messenger in 1610. The Jesuits were “early adopters”! In fact, the Jesuits were doing such a good job with their observations that Galileo wanted a copy of their data!
Galileo’s label should have given Kaufmann pause to think about what he was saying. But apparently the myth of the Catholic Church attacking Galileo for his discoveries is so widespread and so appealing that Kaufmann never considered what Galileo himself wrote on his drawings. And now, thirty years after Lattis’s scholarship (published by a top scholarly press, still in print, and widely available through Google books) we still see Galileo’s drawings used in support of that myth.
Faced with this, one has to ask: Does reality matter, even when it is staring us in the face? Does scholarship matter? Does history matter? Or are some junk stories just so adorable that we are going to repeat them, no matter what, and not even see what Galileo is telling us? We have eyes but we do not see.
I put this discussion into my ITESO talk. It was a great way to illustrate to students how true it is that we have eyes but do not see. Hopefully, Galileo’s drawing, and the way it has been used, helped them to understand that what they have heard everywhere about Jesuit astronomers and the Catholic Church at the dawn of telescopic astronomy is often completely bogus. Hopefully, they could see this for themselves, and not just have to take my word on it. Hopefully, the students were better able to understand the work of Jesuit astronomers like Fr. Christoph Scheiner and Fr. Giovanni Battista Riccioli, who observed Jupiter (and the moon) and on whom the rest of my talk was focused.
The observation session featured clear skies and lots of students turning out to look through telescopes. Through those telescopes, they saw the moons of Jupiter — just like those Jesuit astronomers did.
