as a non-nerd I gotta ask ( I don't really want to know ) what does Thrust have to do with anything? is till think the easiest way to explain it, at least for people in cold climes, is car exhaust on cold mornings. everyone knows about that.Agreed. How hard is it to spell out the simple fact that when you burn jet fuel in an engine you get thrust and lots of water vapor? If they start questioning the details, then explain further. The believers already THINK they are being scientific about it all. I don't see any alternative to blowing their minds by showing them just how shallow and flawed their "science" has been.
and the colder it is the longer the frozen stuff persists (see at 5:30mins)