One for the science and metaphor files? From “The Thermodynamics of Glass“:
A liquid has viscosity, a measure of its resistance to flow. The viscosity of water at room temperature is about 0.01 poises. A thick oil might have a viscosity of about 1.0 poise.
Now, OED lets us know that “poise, n.1” is originally “The quality of being heavy; heaviness, weight” (ultimately from pendere, to weigh, through Old French pois, now poids), but has by metaphorical processes also come to mean “composure and dignity of manner, self-possession.” So, the more poises a liquid has, the more poise it has. The more weighty, the less runny. The more self-possessed, the better it keeps itself together. Poised liquids don’t dribble, and dribbling liquids lack poise(s). It’s a metaphor connecting viscosity and dignity in “poise,” which can connote both physical and metaphysical properties (as can “weight”).
But it isn’t. Or at least, it only is in my initial analysis of “poise.” What I didn’t know then is that the “poise” we’re talking about is “poise, n.2” which is not the result of a metaphorical extension at all, but just a regular old scientific unit named after the guy who came up with the equation describing the flow of liquids. It’s a shortening of the Poiseuille, named for Jean Leonard Marie Poiseuille (b. 1799). I’m disappointed by this fact, because it seems to affect somehow the authenticity of my metaphor, which I thought was rather effective at getting me to think about a physical property in a new and imaginative way. Yet I think I can hold on to a (perhaps reduced) version of it, by appealing to synchronicity and homophony.
Here are some other scientific terms which may or may not provoke spontaneous metaphors: