The way your significant other chews. Your co-worker's ringtone. People who spell "definitely" "definately." Videos that won't stop "buffering." Traffic. "Halfalogues."Farmville.

You know what bugs you. But do you know why? In the new book "Annoying: The Science of What Bugs Us," two science journalists attempt to answer exactly that. 

 One of the key things about what's annoying is what it's not: It's not deadly, it's not lethal -- it's minor. There are three characteristics: Unpredictable, in the sense that you get on the subway and you can't know or even control that the guy next to you is going to pull out a nail clipper. The second thing is it's unpleasant. I can't tell you what's going to be unpleasant to you, but as long as it's unpleasant to you, it's potentially annoying. The third is an uncertain duration. There's this optimism of, it's gotta stop sometime, but it's the uncertainty of when. And then there's "terminal annoyance" -- you become annoyed with yourself for being annoyed. There are unconfirmed reports of heads exploding. -