Particle physics

The twenty-seventh entry is il calorimetro, and a reader who takes the name apart is handed a promise the physics does not keep. The first half is Latin calor, heat, from the verb calere, to be warm; the second is Greek metron, a measure. On that reading a « calorimeter » is a heat-measurer, and in a chemistry laboratory it is exactly that. Here it is not. What sits at the end of a beam line is a block dense enough to stop a particle outright, and what it reports is the energy the particle was carrying — no temperature anywhere in the account. The root is worth following, though, because English keeps it in two places where nobody looks for it. « Calorie » is that same calor with a small ending on it, and « calorific » is its adjective. And « nonchalant » came in through French chaloir, the worn-down descendant of calere: to be nonchalant is, quite literally, not to warm to something. Il calorimetro keeps the word and drops the heat.