At Gravity and Levity, a defense of teaching the Bohr model of the atom (at least as a prerequisite to teaching more modern models).
The Bohr model has been discredited, but it's still very useful.
A few years ago, at a big physics conference, I was party to an argument about whether we should be teaching the Bohr model of the atom in lower-level physics classes. The argument in favor was that the Bohr model is easy to teach and gives a simple way to think about the structure of atoms. The argument against was that the Bohr model is completely outdated, conceptually inaccurate, and has long been superseded by a more correct theory. The major statement of the opposition argument was that it doesn’t do anyone much good to learn an idea that’s wrong.
How strongly I disagree with that statement!
What follows is an explanation of the Bohr model and also an explanation of a similar problem in physics (Landau levels) that, in the blogger's opinion, itself justifies the teaching of the Bohr model. But he says -- and I agree -- that there are deeper reasons:
I can’t resist making a larger comment here about the idea that certain scientific ideas shouldn’t be taught because they are “not true.”
Science, as I see it, is not really a business of figuring out what’s true. As a scientist, it is best to take the perspective that no scientific theory, model, or idea is really “true.” A theory is just a collection of ideas that can stick in the human mind as a useful way of imagining the natural world.
Given enough time, every scientific theory will ultimately be replaced by a more correct one. And often, the more correct theory feels entirely different philosophically from the one it replaces. But the ultimate arbiter of what makes good science is not whether the idea an true, but only whether it is useful for predicting the outcome of some future event. (It is, of course, that predictive power that allows us to build things, fix things, discover things, and generally improve the quality of human life.)
It is undeniable at this point that the Bohr model is decidedly not true. But, as I hope I have shown, it is undoubtedly very useful for scientific thinking. And that alone justifies its presence in scientific curricula.
I would like to add that it's pretty impossible to understand what makes a revolutionary idea (like quantum physics) revolutionary, unless one has some concept of what came before.