Really? Do you have more info on this? I’ve gotten plenty bitten by mosquitos in Chicago, they must not be hitting the Midway area very well.
edit: Ah, are you talking about the West Nile spraying they do? They do that with trucks (not from overhead), and they’ve only done two or three of those in my lifetime (since 1975).
There is no way that you can tell how high a piece of cloud is except that we assume fine whispy stuff is high and thick cloudy stuff is low. Also if it obscures the top of a small horse, we know it is very low :). In general, though, it is very difficult to judge altitude as there is no reference.
Contrails sometimes spread out quite wide, they also can stop and start relatively neatly. Just as neatly as if a chemical spray had been turned on and off. This is simply caused by the aircraft flying in and out of areas that are conducive to forming contrails.
Another possibility is a sky writer testing their smoke system.
It is also possible that it was a chemical of some kind, although when I’ve seen aircraft dropping chemicals over cities (such as for mosquitoes or other pests) they fly quite low and the spray looks nothing like cloud.
My point is just that, whatever the method, the fact that “they” spray toxic, cancer causing chemicals all around major urban areas is not exactly a well-kept secret, or great fodder for conspiracy theorists. It ain’t paranoia if everyone really is out to get you. If aerial spraying is the best way to do that, then they’ll do it. Then again, if I had a dollar for every hippie friend of mine shrieking about carcinogenic pesticides while sucking down a cigarette, I’d be a happy girl. Tends to make one cynical rather quickly.
But, again, I didn’t see the show, so I’m not sure exactly what the theorists were theorizing. It may have nothing to do with pesticides, I don’t know.
Continuing with the flimsy science of the Discovery channel theme, just last week I saw something about experimental automobile designs. It was mainly the fringe stuff that people are toying with but will probably never be commercially viable, though that didn’t stop the narrator from breathlessly declaring that each thing they showed us would be what we’d drive in the future even when it directly contradicted earlier statements. That’s mildly annoying but it’s the kind of tech fetish you see in Popular Mechanics and the like all the time so it didn’t bother me that much. What killed me was the one that ran on compressed air and the person developing it stated that they wanted to use the same compressed air driving the car to compress more air. The narrator actually described it as “perpetual motion”! When the developer of a propulsion system doesn’t understand the laws of thermodynamics then they’re probably right off the fringe and into the crackpot territory…
Ferchrissakes people, I thought everyone knew what chem trails were for. I’m only going to say this once: Chem trails are the brainchild of the United Nations. The chemicals are used to pacify the US populace, so that the UN and her commie/liberal allies can disarm the law abiding, but armed, citizen militias. This is obviously done with full cooperation of the Federal Government.