Current Reading

This blog is primarily for me to blog my responses to books that I'm reading. Sometimes I blog about other stuff too, though.

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Friday, July 17, 2015

Some heroes look better in close view rather than worse

Many of our heroes turn out to look worse when examined close-up, because they are flawed humans.  However, Galileo is starting to look better and better.  What do we really learn about him in science classes?  We learn that he got in trouble for saying that the earth goes around the sun, that he discovered some satellites of Jupiter, dropped balls from the Leaning Tower of Pisa (except he probably didn't), and then in more advanced classes we learn that he enunciated a principle of relativity that was simpler than Einstein's (and eventually supplanted by Einstein).  We also learn, as we go on, that the politics surrounding his trial were a bit more subtle than the popular accounts, that he didn't actually invent the telescope (just made really good use of it), and that he didn't drop balls from a tower.

So what's left?  Mostly just the principle that x'=x-vt.  Which seems...trivial.

Of course, when you start reading his work you find out that making and properly using a good telescope was no easier then than it is now, and that interpreting the images required very subtle reasoning.  You learn that elucidating principles of relativity that we brush past in a page or two took a great deal of careful thought to cut through the conceptual fog of his time.  You learn that besides the handful of things for which he was most famous he also worked on many other questions, and had to do careful work and cut through a great deal of conceptual fog and rule out a great many competing theories, not living in an era where the right answers are known and taken for granted.

In other words, you learn that he was pretty smart.

All too often we take a principle or discovery that required years of careful work by some of the greatest thinkers in human history, and we reduce them to a few pages.  In more traditional lecture classes, you might spend half a class session on somebody's most important discovery before moving to the next topic.  In the more reformed, interactive classes, you might spend A WHOLE CLASS!!! on somebody's most famous discovery.  This means that you spend an entire 50 minutes on something that took a genius and his/her collaborators several years to work out.  50 minutes!  (Even worse, in the reformed, interactive classes you spend 30 of those minutes discussing a hero's life's work with a semi-literate 18 year-old who graduated from the same lousy education system that miseducated you.  That seems like an underwhelming way to encounter the fruit of years of intellectual effort.

I have no easy answer for what to do about this, but it just feels wrong to reduce this work to "Here's two  pages and an apocryphal tale about some eccentricity of this scientist."  I know that if we spent weeks reading Galileo and then several more weeks reading Newton and so forth we would never get anywhere in freshman physics.  Still, I wish we could do our heroes more justice than quick treatment and urban legends.

Galileo! Galileo! Galileo Figaro! Magnifico!

Well, I've now read a selection on sunspots, and also his letter to Castelli (a monk and mathematics professor). I'm in the middle of his letter to the Grand Duchess Christina.  The man clearly likes to argue, he clearly knows when he's right, he clearly knows just how wrong his enemies are, and he has an incisive intellect and wit.

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.

Galileo and fluids

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

The Sidereal Messenger by Galileo

The Sidereal Messenger is an essay describing Galileo's first telescope observations.  Galileo is sometimes lionized as a hero of unconventional thought.  While his thoughts may have rubbed some people the wrong way on religious or political grounds, his writings would fit right into the mainstream of todady's scientific community, and not just because his theories happen to be right.  Galileo opens his essay with profuse gratitude to the Duke of Tuscany; the modern equivalent would be a Powerpoint slide thanking the funding agency.  He then describes his method of calibration for determining his telescope's magnification.  Were I reviewing his paper for a journal I would probably ask for more details of his equipment, seeing as how he was using the world's second telescope and hence the methodological details were not yet widely known in the scientific community.  However, we'll cut him some slack, given that these professional conventions were still being worked out by scientists.

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

Next book: The Essential Galileo

A while ago I read snippets of Galileo.  I liked his style, but because I just read it without journaling or discussing I retained far too little.  (See, I can admit the  problems of a "wall of text": Those problems come when you don't follow it up with something to sear it into your memory.)  Now I'm reading an anthology of his writings, edited and translated by Maurice Finocchiaro.  More details to follow.

The hour is very, very late

I'll step away from blogging about books that I'm reading, and instead blog about an article.  Today in the Chronicle they published a press release (dolled up to look like journalism) about a company called zyBooks.  They apparently produce interactive online activities and presentations.  I think that such things are fine in many contexts, and can be a useful component of many sorts of classes.  So far, so good.

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.