All I can say is that jet vapour trails look pretty much the same as they did when I was a kid. There's just a lot more of them and they come from bigger jets. Chemtrails are just contrails. They are usually just frozen water, not mysterious chemicals dropped by the government.

...And then you say you "remember when trashing science was unpatriotic and injurious to our national progress".

Mixing conspiracy theory woo in with real problems causes people to think maybe the real problems aren't real either - counterproductive, IMO.

Donuel, this thread I'm linking to is several years old. Some of the participants are or were pilots and meteorologists. Here and there through the posts, they explain why some contrails look different, what atmospheric conditions cause these things, how different planes operate to produce different looking contrails.

a href="http://www.bautforum.com/conspiracy-theories/17557-help-me-debunk-chemtrails-belivers-3.html">http://www.bautforum.com/conspiracy-theories/17557-help-me-debunk-chemtrails-belivers-3.html