I have a friend who really believes in this chemtrail shit. Acting like I'd never heard of it, I said "well that sounds pretty crazy to me. Are you sure about this?" And he went into this whole five-minute discussion of the research that he's done etc ... So, again acting innocent, I said "this seems hard to believe. Has anybody just taken a plane up to one of these chemtrails, collected some of it, and had it analyzed? Because that seems like it wouldn't be too hard to do and it would put the whole thing to rest." About five seconds of silence, followed by "I don't know. I don't think so. I'll check." About a month later I asked and he said he'd researched it and couldn't find anybody who'd ever done that. I just said "Well, being as it couldn't be too hard to do, I reckon I'd want somebody to do that before I started to believe it." I'm not sure, but I may have actually planted seeds of doubt in his mind. The thing is, you can't argue with a conspiracy theorist. You just have to ask the simplest question you can in plain spoken, uncombative language that makes it sound like you have never heard of the conspiracy but ... Then you ask the question and let it simmer for a while.