RE: Chemtrails - Look to the Skies
Its called "Cloud Seeding" - which is hard to refute based on the fact that A: The UN has admitted its 'real'.. and B: China openly admits to doing it everyday.
Also - the map is not the territory - meaning that just because you worked in "Aviation all over the place" doesn't mean you definitively know everything about every aeronautical program in existence. (i.e. Classified Military Facilities)
But don't take my word for it! Save some of your energy and keep an open mind, as its important to remember that you (or I) NEVER have ALL the answers. "In knowing nothing - you will be aware of everything". - (Tao Te Ching)
Sources if you're actually interested in learning something new outside your choosen belief system:
A: The UN:
B: China: Hundreds of articles via a google search. (take your pick)