hottish coolish? hot. okay. now, that there didn't expand very much. now, do it again, and this time, make your lips down small so the air has to expand when it comes out. try it. hey, hey. what happened to the expanding air, gang? what did it do? begin with a c or h? c. c, it cooled. how come the air cooled? that's chapter 17, okay? [laughter] you know how we answer a question like that? by thinking small, really, really small. we think down to the little atom. you guys know you're made out of atoms, don't you? i mean, not all of us, but most of us, right, okay? those who have the citizenship are made of atoms. no, no, i'm kidding. we're all made of little atoms, you guys know that? a lot of atoms or a little atoms? begin with a l. try it. lot, a lot of atoms. a lot or a lot lot? a lot lot. a lot lot. a lot lot. when you breathe in some air, atoms go in your lungs? right? now when you breathe out, same atoms come out? well, if that's the case, then why would you use clorets, right? now, can a dog tell who you are by-- dog can tell even in the dark, ye