Bullship

If I'm reading pages 228-229 correctly, Galileo never actually dropped a rock from the top of the mast of a ship, and is just asserting what the outcome of the experiment must be.  That is...not what I was expecting from Galileo.

The words of the prophets are written on...?

I'm on chapter 8 of The Essential Galileo now.  Chapter 5 was letters from Galileo to supporters, largely arguing that a figurative interpretation of Biblical verses on natural phenomena need not be a threat to faith.  Countless scientists throughout the ages have been followers of religious faiths and would agree with him.  I find it interestingly that Galileo did not mention the Gospels, which are full of parables, as evidence that the Bible is awash in figurative language.  Also, in two of his letters he says (paraphrase) that if God only wanted us to learn about the natural world from the Bible then He would not have given us the ability to observe and reason.  Countless scientists who are also religious agree whole-heartedly with our illustrious predecessor on this point.

Chapter 6 is largely documents and testimony from Galileo's first trial, in 1615.  These documents are consistent with a distinction that a historian friend of mine drew:  Galileo didn't get in trouble for heliocentric theory so much as for public statements concerning the Church's authority on astronomical questions.  The testimony of the witnesses is less about heliocentrism vs. geocentrism and more about Galileo proclaiming that his heliocentric-compatible interpretation of Scripture is superior to the Church's.  Also, the witnesses refer ominously to "disciples" of Galileo.  They feared his theory less than his ability to persuade people to favor his teachings over those of the Church.

Chapter 6 ends with a 1616 edict adding several books to the Index of forbidden books.  Nothing by Galileo was on the list, but Copernicus' work made the list.  What else got banned in that year?  Well, it will be no surprise that a book on Calvinism made the list (poor Puritans :( ), nor that some books on law and politics got banned.  But it is amusing that a book called Scotanus Redivivus, or Erotic Commentary in Three Parts, was banned alongside Kepler.  A quick Google search mostly returns pages about Galileo and Copernicus, which is rather disappointing.  (Though there is a link to Fark!)  I could get my freshmen more interested in physics if I did a comparative study of Copernicus' writings and those of his contemporaries.

Chapter 7 was boring, so I skipped it.  Something about comets and disputes with contemporaries.

Chapter 8 is a series of excerpts from Dialogue on the Two Chief World Systems.  I haven't gotten very far in that chapter, but I like this quote from his preface:

Many years ago I had occasion to say that the unsolved problem of the tides could receive some light if the earth's motion were granted.  Flying from mouth to mouth, this assertion of mind has found charitable people who adopt it as a child of their own intellect.

Yeah, that burns.

Galileo, Chapter 5

Chapter 5 is mainly documents written by Galileo in 1615, answering his critics at trial.  Much of it concerns interpretation of Scripture, and how a robust, honest, and defensible Catholicism will require a figurative interpretation of passages whose literal meaning would contradict observations.  However, in the midst of that, he also challenges the argument that there's no point in believing Copernicus if even Copernicus regarded his model as only a tool for calculation.  Galileo elides questions of what Copernicus "really" thought (as high as his self-esteem was, Galileo did not consider himself capable of performing necromancy and consulting the dead Copernicus).  Instead, he noted that in many ways it's the geocentric model that is a calculational tool.  The heliocentric model enables fairly simple calculations, but if one wishes to put those results into a form that can be compared with observation, one must switch to a geocentric frame.  This blurs the distinction between steps taken for convenience and steps taken to reflect reality.  (Einstein finally shattered that distinction altogether.)

I like this argument.  I'm not, however, quite so favorable towards another argument.  He also tries the argument that everyone who favors the heliocentric model started off favoring the geocentric model, so they must have had a good reason to change their minds.  Furthermore, only smart and informed people will even think of adopting the heliocentric model, because they will understand the subtle observational and theoretical arguments for it, whereas less informed people (and well-informed but cautious people) will reject it.

I don't like that argument.  I've met smart people who believed all sorts of dumb things for all sorts of dumb reasons, and I've met ignorant people who embraced alternative viewpoints simply because they wanted to be in the opposition, not because they actually understood the merits of the idea.  I get that Galileo was on trial and trying to persuade people rather than trying to carefully strike at deep truths of human psychology.  However, I am nonetheless unimpressed by the argument.  Surely he must have known that fools were, are, and always will be everywhere.