Yesterday in Physics 100 we started a discussion of the structure of matter. This inevitably brings up the early ideas from 400 BC about atoms, from Democritus (and others) at least in the Greek line of thought. These ideas were later brushed aside by Aristotle who declared that the elements from which everything can be constructed were Earth, Air, Fire, and Water.
Of course, one is obliged to show a slide at this point. I could not resist this one:
There were some giggles, some of which were probably appreciative. I do wonder what my young audience thought…