Oh dear, are you kidding me?
I have done meteorological aviation courses at the Met Office HQ in Exeter, and I can answer everything they are bleating on about. Its utter toss!
The fact that a lot of these trails they are on about are at the end of the day or early in the morning when the sun is coming up and going down so the temperature is fluctuation a huge amount is why they are different per plane minute apart. The dark trails are actually the shadows of trails up higher being cast on lower clouds.
That woman at 14mins lives in NEW YORK. Thats a major joining point for all the European traffic not landing on the east coast of the states. High aircraft going from transatlantic cold air to over land warm air, thats why there are more trails than normal.
Think I am wrong?! Look at
this link and tell me they were spraying stuff back then.
As for the images at around 16:50 and 17:00. Those are taken from new aircraft in development and they are ballast tanks.
http://www.airliners.net/photo/Emira...50002dc96a365c
I have provide many many more photos from planes like that one, it even explains it in the details below the picture what they are for!
Its easy to twist peoples though process when they dont know anything. I however have a considerable background knowledge and just sadly wasted 30min of my life in order to **** all over that video.
If you believe this drivel you seriously need to get out more mate. Its water vapour, no different to that which comes out the back of your car or bike.