Some crazy thing about a neutron turning into a proton or something
Keith S. Taber
Amy was a participant in the Understanding Science Project. I talked to her after she had just started studying radioactivity in her Y11 physics class. She had been introduced to alpha, beta and gamma radiation, and the teacher had been telling the class crazy things: "he told us some crazy thing about a neutron turning into a proton or something, and losing, two electrons or some crazy thing like that."
This was crazy because "it doesn't make any sense". Amy had only just started the topic, and had not yet sorted out all the details in her own mind, but the teacher had "showed us this little equation thing they [sic] have, and when – is it the electrons that are released or something – the atom, it changes, it changes into something else". This was not something else other than an atom, but "an element will become a different element or some stupid thing like that". Amy concluded that "all of it sounds crazy, physics is crazy. I don't understand it." This seemed a rather harsh judgement.
Amy was generous enough to talk to me regularly about her understanding of the science she was taught in school. She, regularly, told me she knew or understood little about the topics she was taught, although a little probing often revealed considerable learning. However, on this occasion, Amy genuinely seemed to be genuinely mystified by what she was being told.
I spent a little time talking to Amy about radioactivity. I discussed beta decay with Amy, concluding with "an electron comes shooting out of the atom, and that's your beta radiation". Amy maintained "it's crazy". We discussed the different types of radioactivity she would study: "it's crazy". I think Amy believed what I was telling her, but she made it clear what she thought of these nuclear changes and the accompanying transmutation of elements: "it's mad"!
What I find especially interesting here, is that Amy seemed to have strong intuitive views of the way the world should work, even when the focus was something so far from our everyday experience. Atoms, nuclei, electrons, neutrons, protons, are all theoretical constructs we introduce to students that have no obvious and clear link with anything in everyday experience. They also behave in ways unlike objects of common experience. It can only have been a couple of years since Amy was taught that atoms had structure and comprised of protons, neutrons and electrons. But now she readily accepted that neutrons existed. Indeed they had become so 'real' to her, that the idea one must spontaneously change into a proton and an electron seemed quite mad. So Amy had relatively quickly applied her intuitive ideas about the way the world is to form a mental model of a neutron as a discrete, stable entity: not something that could suddenly reveal itself as potentially two other things that were supposed to be quite different. When Amy was introduced to a model of the sub-atomic components of the atom she 'assigned' (i.e., pre-consciously interpreted them to have) them certain ontological qualities (such as stability, permanence) which made sense to her at the time, but which did not capture the way scientists understand these entities. This assumption of the nature of the neutron acted as a grounded learning impediment, because when she was later taught about radioactivity it did not make sense in terms of her prior learning.
Too crazy to remember?
In a later interview, Amy was able to tell me that the neutron is made up of other stuff, and it decays to give an electron and, she thought, a proton – although (she told me) that was only a guess.
