The devil of false precision

Eating lunch today I noticed on my bottle of soy sauce the words expiration date on label and, an inch away, a dot matrix stamp: 2019.03.28 14:48.

I expect that the stuff was bottled on March 28, 2016 at 2:48 pm and that it’s supposed to be good for three years from the date of bottling. But that’s not the same thing as saying it’s good until March 28, 2019 at 2:48 pm. Certainly a machine can record the exact time of bottling, but the idea that the soy sauce is good for exactly three years, for three years down to the minute, is absurd — as if, at twelve minutes to three on a particular March afternoon two years from now, the contents of the bottle will instantly develop a fuzzy blue mold and smell distinctly of gasoline. Obviously that’s absurd.

For one thing, it was bottled in Taiwan, so it would actually expire at 1:48 am EST and not in the middle of the afternoon.

“Three years from date of bottling” means three years, give or take. Give or take what? That’s the question. Six months, maybe? I would assume that they kept a bottle around for three years and it seemed to be okay. I doubt it’s very scientific at all. But it’s so easy just to take the present time, add three years, and stamp it on the bottle.

The expiration date on my soy sauce is not in itself a big deal. (I’ll use it within a few months anyway.) But this kind of arbitrary precision is everywhere — the practice of assigning a number to something, giving it as many decimal places as we can, and then slapping it on a label, noting it in a chart, entering it into a database — where it takes on a kind of magical invincibility, a rightness that can no longer be questioned or challenged. There are cases where this might have disastrous consequences, but more important is the impression of invincibility. Knowledge is power; false precision is an implication of knowledge; therefore false precision is an assumption of power. False precision is one way that science and industry and government claim power over us. But wallpapering the world with false precision builds false confidence in our own abilities, individually and collectively.

Every measurement is an estimate. If I were king of the world, I’d decree that every published measurement must be accompanied by a margin of error, e.g. “Expires on 2019.03.28 14:48 ± 6 mos.” It would be honest, it would be accurate, and it would remind everyone many times a day of the limits of human knowledge.

(And no, since you ask, I cannot think of anything better for a king to do than to demand accountability and humility from the powers of the world. Can you?)