Friday, July 17, 2015
Shame he died so long ago. I'd have enjoyed hanging out with him. And since he's Tuscan, he probably had awesome culinary taste.
In chapter two, Finocchiaro gives excerpts from Galileo's Discourse on Bodies in Water. Galileo argues that some people are misinterpreting observations of surface tension to suggest that shape determines buoyant force. Galileo argues that shape is irrelevant to the buoyant force on an object that has pierced the surface of water, and that observations of dense but thin objects testing on the surface of water are in fact observations of resistance to piercing of the surface. Definitely a clear thinker, and broad in his interests.
Thursday, July 16, 2015
His next set of observations concerns mountains on the moon. Some popular accounts make it sound as though he simply looked up and saw things that look like Aspen, CO. In fact, his telescope was far too crude for that. Mostly he was looking at things sticking out on the edge of the moon, and seeing that the crescent moon is not a perfectly smooth crescent. There are peaks that stick out and catch light that would not have been caught at ground level. He deduced the presence of mountains from subtle inhomogeneities. This is very much of a piece with a great deal of experimental and observational science today. People rarely get to do a clean experiment where something stands out as clear as the "artist's depiction" in a newspaper article, or even the simple models in textbooks. The real signal is almost always too noise and complicated for that, and is influenced by many different factors. Instead, a great deal of indirect inference is used to go from a raw signal to something meaningful.
His lunar observations are followed by a short section describing how he was able to see stars in the constellations that were too faint to be seen by the naked eye. However, his longest section described two months of painstaking observations of Jupiter's four largest moons. He didn't simply look up and say "Hey, there are things going around Jupiter! It has moons just like earth! Clearly, the heavens and the earth are exactly the same!" Instead, he spent months observing again and again, seeing a pattern of objects in the sky that were always in the vicinity of Jupiter but changed their position relative to Jupiter. It was only from a couple months of observations that he had the data necessary to argue that Jupiter has satellites.
Interestingly, near the end, Galileo plays both sides on the heliocentric model. On the one hand, he describes the satellites of Jupiter as orbiting Jupiter every few days while simultaneously orbiting earth every 12 years. On the other hand, he also says that this observation helps to support the heliocentric model, by arguing that these observations make Jupiter more earth-like (in that it has satellites) and hence undermine the unique status of earth.
All in all, I recommend publication of this paper.
Tuesday, July 14, 2015
What bothers me is that the thrust of the sales pitch is not simply "These are great activities that make people think." Rather, the thrust is that students don't like books, don't like lots of text, and so we should adapt. It is one thing to believe that reading and activities are both important parts of a college-level science class. I believe that such a stance is referred to as "common sense" or even "consensus." It is quite another thing to disparage text and reading. It is a sign of just how deeply-rooted the anti-intellectualism really is.
What's funny about this is that the physics profession already tried replacing a "wall of text" with graphics and activities. Introductory textbooks don't have a whole lot of plain text. Instead, there are lots of sidebars with definitions and questions and color pictures and diagrams, and lots of section breaks and examples and checkpoints. This style is commonly mocked for its sensory overload, and few students seem enamored of it. Honestly, I can't blame them for not reading. I've had students tell me how much they like Moore's Six Ideas-Unit R (which I use to teach relativity) or Eisberg and Resnick's Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles (which I use to teach sophomore-level quantum physics). Both books have a certain amount of diagrams, and Moore definitely has more bells and whistles than Eisberg, but they have far more text than the standard freshman books (and I've never had a student praise the freshman books). My own experience is consistent with the student feedback: I can't say that my standard freshman books made much of an impression on me, but Feynman, Landau, and Purcell (all of which had far more text) certainly did.
The rot runs deep and the hour is late. Reading is openly disparaged in marketing to faculty. I know a person who has openly published articles bragging about how his general education class (ostensibly in a "science and society" category) requires no reading and is graded entirely on multiple-choice questions. (It is only the thinnest pretext of civility that keeps me from naming names.)
I don't know what will happen next, but I think I'll take a break and read a book.