Introducing Students to Nuclear Physics

In this section, Professor Michael Short describes his approach to introducing students to nuclear physics.

The students who take this class are mainly sophomores who are majoring in nuclear engineering. But about a quarter or a third are people majoring in other things like Computer Science or Mechanical Engineering, who want to get a flavor of nuclear science. In fact, it's the first modern physics class these folks will take at MIT, because GIRs taken by all freshmen are classical mechanics and classical electricity and magnetism. So you come here to the center of high learning, and you learn stuff that's 150 years old! 22.01 Introduction to Nuclear Engineering and Ionizing Radiation is their first experience with things that are two digits years old, and still evolving now. We're still discovering heavier elements. We're still unraveling the subatomic nature of things. And this is where the students get hit in the face with it—in a gentle way!

We don’t give them an insane amount of math and derivation because wrapping your head around the concepts is more difficult than intuitive mechanics and semi-intuitive electricity and magnetism. For example, you see a lot of MIT students with “E = mc²” on their T-shirts. Many of them get to this class and realize they don't really know what that means. They have trouble reconciling the fact that matter is energy and vice versa, and that you can convert from one to the other, and that's the whole idea behind radioactive decay and transmutation. So that process takes three or four weeks—to really hammer in with enough examples for them to understand.

Then they do get the equivalency between matter and energy, and they're able to understand not just that things undergo alpha or beta decay, but why. Why some elements do, and some don't, has to do with the amount of excess energy or the binding energy of the nucleus, and what the origin of those decays comes from.  They can start to really understand, well, why does this element have a short half-life? Oh, because it's fairly unstable. So it's got a lot of excess energy, and it really wants to decay to something more stable, so it will do it faster.