One of the interesting things to come out of the switch to Matter & Interactions for our intro classes has been some discussion among my colleagues of how the books treat specific topics. A couple of people have raised concerns that the coverage of certain topics is different from the traditional presentation, in a way that isn’t entirely accurate.
This is interesting to me not because it calls the books into question, but because the standard treatments of these things aren’t entirely accurate, either. Both the new book and the older book are full of lies-to-children.
“Lies-to-children” is a term that I attribute to Terry Pratchett (via one of the Science of Discworld books), and it’s distinct from an ordinary lie. A lie-to-children is a simplified story you tell to people who aren’t ready for the full picture.
An ordinary lie, as I said in class the other day, is “I did the homework, I just don’t have it with me.” A lie-to-children is, for example, the story we tell elementary school kids about how a bill becomes a law:
“Somebody proposes a law, it’s debated in Congress, both houses vote, then the President signs it, and it becomes a law.” It’s a wonderful, comprehensible story, but it’s also a lie-to-children. There’s nothing in there about subcommittee hearings, or lobbyists, or earmarks, or filibusters, or signing statements, or judicial review, or…
The reality of our legislative process is much more complex, and much more sordid. But kids watching cartoons aren’t ready to hear that sort of thing– many adults can barely get their heads around it– so they get the simple version first. It gives them enough information to understand the broad outlines of the world, and start to function as citizens, and when they’re ready to know more, they can learn more.
Physics is full of lies-to-children. Newton’s Laws are a lie-to-children– they’re a wonderful description of the motion of macroscopic objects at low speeds, but they fail utterly when dealing with very small objects, or objects moving at speeds close to that of light. We teach first-year college students about classical mechanics alone, because that’s enough to get the basic idea, and if they want to know more, then we let them in on Special Relativity and the Schroedinger Equation. Which are themselves lies-to-children, standing in for General Relativity and the Dirac Equation, and so on.
What’s interesting about the Matter & Interactions books is not that they’re full of lies-to-children, but that they use a different set of lies-to-children than the standard texts we all grew up with. And people’s reaction to this is really interesting– some of the concerns people have expressed are really fine technical points, having to do with things that M&I covers that more traditional books skip completely– a microscopic picture of the flow of current, for example.
I’m not trying to run down my colleagues, here– they’re not raising objections just to be difficult. They’re sincerely concerned that the inaccurate points in the new book might create some student confusion later on these points. They may even be right (though I’m not convinced it would matter, for some of the points raised).
What’s fascinating to me, though, is that I don’t think that the conventional treatment is really all that much better at avoiding things that are technically untrue, particularly on the sort of technical points that people have raised in discussion. It’s just that we all took classes under a traditional curriculum, and we’ve all taught classes in a traditional curriculum, so the lies-to-children that we tell when teaching from those books are familiar and comfortable, while the lies-to-children we tell in the new curriculum are unfamiliar, and thus unsettling.
There might be some insight here into the unending debate about communication strategies here in blogdom. Lots of the objections to “framing” and the like are phrased as objections to “lying” about science. But really, the “lies” in question are lies-to-children, and scientific education is all about lies-to-children. It’s just that the lies-to-children suggested by advocates of alternate communication strategies are different than the lies we’re used to telling, and that makes some people uncomfortable.
(I don’t think that’s the whole story– I think it’s really a question of differing goals– but that could be a part of it.)