Instructor Insights

Opening Knowledge Gaps in Nuclear Science

In this section, Professor Short explains his sense of the educator’s role in helping students to attain fluency in a subject.

OCW: What does it mean to you for students to develop fluency in this field?

PROFESSOR SHORT: A cursory knowledge of radiation science is not enough. There are a lot of self-proclaimed experts who have learned a bit of genuine knowledge, but then extrapolate it too far. And there are celebrities and other role models spouting falsehoods about radiation, or vaccines, or other things that they don’t understand. It’s important to be fluent and well grounded in the fundamentals so that you can sort out fact from fiction. I want every student that leaves my class to be able to tell whether a claim is plausible or not, and to verify if the source is genuine.

OCW: How do you help students develop this fluency?

PROFESSOR SHORT: It starts off with the fundamentals of radiation science. As in any class, we teach all the fundamentals from well-established theory, but along the way, every week, we have labs and personalization. For example, on the first day of class I ask students to bring in their toenail clippings. And they usually say, “That’s disgusting! What are we doing?” And I say to them, “You’ll see.” We put their toenail clippings in the reactor and we irradiate them. And because, to some degree, you are what you eat, some of the elements that we eat get incorporated into our toenails. So we activate those toenails by putting them in the reactor.

"Not too many people learn well by being lectured at, but everyone learns well by opening knowledge gaps."
— Michael Short

They absorb neutrons and give off characteristic gamma rays, revealing with striking precision how many atoms of arsenic, and selenium, and such are incorporated into the toenails. And we’re even able to tell where students come from based on analysis of their toenails. We had one student whose toenails contained a lot of gold. And I said, “I thought I asked you guys to clean these off, to remove any polish.” And the student said, “Yeah, I did, but I live near a gold mining town.” I was wondering why that one student had far more gold than all the others, and it turns out it’s where the student lived: it was in the water. In the problem sets, instead of saying, “Analyze this theoretical problem,” I say, “Analyze your toenails. Tell me how much arsenic and gold you’ve got in your body.” That’s what I mean by personalization: students discover things about themselves through nuclear science.

As an instructor, I like to start by opening knowledge gaps rather than spouting theory at someone. It doesn’t usually stick if I just say, “Here are some facts. Learn them.” It usually goes in one ear, out the other. But when you show someone something surprising, they’re fully engaged—they’re multi-sensorily engaged. They’re listening, in a lot of cases they’re touching or even smelling. Taste is the one sense that we don’t tend to engage in nuclear science—with good reason!—but you can see, and feel, and hear a lot of things in nuclear science. Yesterday, for example, I was with one of my graduate students. We were looking at some highly irradiated materials from a reactor in Idaho, and we heard a little, faint buzzing noise in the Geiger counter. And if you put your ear up to the Geiger counter near the radiation source, you can hear tiny electrical discharges. You can hear the detector working.

I want the student to hear that sound and ask, “Why is that? Why do I hear this fuzzy noise near the detector when it’s working?” Then, when you explain why, students tend to remember. Not too many people learn well by being lectured at, but everyone learns well by opening knowledge gaps. And you’re effectively letting the student pull the information in rather than trying to push it into them.

Something I learned from a mentor here is you can’t push a string. If you want knowledge to go into a student’s brain, they’ve got to pull it. You can’t push it.

Course Info
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As Taught In
Fall 2016
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