Flashing, nibbling, and the Poisson distribution

The Poisson distribution rears its ugly head in a discussion of flashing lights.

If you’ve been reading this blog for a while–or just have a degree in something quantitative–you know about Zipf’s Law.  This formula describes the distribution of word frequencies, and captures the fact that our daily language is filled with a small number of words that occur extremely frequently (in English, the, a, me, and the like; in French, le, un, moi), and a very large number of words that almost never occur–and yet, they do occur, thus damning second language learners to a hell of constant dictionary consultation for the rest of their lives.

We’ve talked far less often about the Poisson distribution.  The related formula has the consequence that even rare events will sometimes occur in clusters.  Maybe three rock stars die in the same month, or the same tree gets hit with lightning twice in a week.  Similarly, it’s not that unusual to see unusual words in clusters.

I was reminded of that last night, when I ran into the verb clignoter, which is used in reference to lights and means to flicker or to blink.  I don’t think I’d ever run across it before, but I saw it not once, but twice yesterday: once in the elevator, related to the light that lets you know if your emergency call to whoever it is that answers emergency calls from elevators has succeeded, and once on a big sign at an intersection with a bunch of construction going on.  (Yes, I’m such a geek that I am basically constantly looking up new words.  That’s what smart phones were made for, right?)

Now that we know this rare-but-it-happens word, we need to cover another word to go with it.  For reasons that will be obvious to the phonologists in the audience, it looks almost identical to the word clignoter to a linguist, and I know that I’m going to confuse these two constantly, so let’s memorize them:

• clignoter: [of a light] to blink or flash.
• grignoter: to snack or nibble; to edge forward, to gain on.