“Half life” is a scientific concept. I’ve seen it used for medicine and nuclear physics. A radioactive element decays in a weird way, with the decay time measured in half-lives. If the half-life of a radioactive element is ten years, after ten years half of the atoms in that sample will have decayed.

Ten years later it’s all gone, right? Nope. In another ten years, half of the *remaining* atoms have decayed. Ten years later, half of those remaining atoms. And this dribbles on and on. This isn’t a strictly scientifically accurate explanation, and probability raises its ugly head (or maybe it doesn’t), but it’s close enough.

Typos and other mistakes in a manuscript seem to be like that. In my latest manuscript my readers found a bunch of them to start with, and after the corrections I declared my manuscript “clean.” Then there was another read a while later, and lo! There were a few more mistakes. Not as many, of course. Maybe half. I made the corrections. A few weeks later, someone read it again. More mistakes. Fewer this time.

It’s just been through another read, and a few *more* mistakes trickled in. This is no big deal, since I haven’t submitted a full to anyone yet, but cripes!

So the way I see it, mistakes in a manuscript have a half-life. No matter how careful the first edit, the next one will find a smaller number of mistakes. And the next one, an even smaller number. I’m not sure yet there’s an end to this process. Plenty of best-selling novels come out from great corporate publishers with a few mistakes still lurking in them.

Eventually, after times ranging from seconds to centuries, all radioactive materials decay to where they’re no more radioactive than something you’d pick up off the ground at the park, at levels only detectable by instruments. Safe enough.

I imagine there’s an acceptable level, even for professional editors, where they decide they’ve run through enough editing half-lives and there’s no more they can do with a manuscript, so off it goes to the printer with no regrets.