The reason why some last hours and some last seconds? I'm not sure you noticed all the contrails that last a long time are at high altitude. This is because at cold enough temperatures the contrails are made of ice crystals. At those temperatures it is going to take a long time for them to thaw and dissipate.
I watched 90% of the video. Every plane was in high altitude, and every contrail started at the engines, so unless its injected into the exhaust.....The folks they used as voice overs had no credibility on the subject. Their obervations could have been done shortly after dropping acid, or after a 12 pack of coors light. Even if they are completely sober, they present no evidence to support their claims. As for the criss crossing, there are thousands of flights every day in the US. Combine that with living near several large airports and a humid day, and you'll have a ton of contrails in the sky. Starting and stopping contrails? Pockets of humidity or changing the altitude of the jet can do the same thing.
I'm sorry but I didn't see anything to sway my opinion yet. I need to see some science to back it all up.
so not all the planes were at a high altitude. theres planes at low altitude that cause your so called "normal" contrails. i have a video on my blackberry of a plane doing it at low altitude. my blackberry doesnt have the best camera, so its pretty hard to zoom into something that is super far away, and make it appear to be close. the turning on and off the spraying and your explanation of altitude doesnt make sense, cause if you go look at that part, how can you say a plane can drop altitude, and incline in altitude repeatedly in that short amount of time? pockets of humidity that small? at that altitude? that just doesnt sit right with me.
and you say how theres flights all over every day. so if thats the case, you should be able to see those lingering trails on a daily basis. what about the days that you see no trails at all? what, no planes fly that day?
and im sure you have noticed a plane that seemed to be super high in altitude without any sort of trail behind it, yet im sure you have seen a plane in the sky that to yourself didnt seem to be nearly high enough to cause a contrail, but still had a trail behind it, but didnt think anything of it.
so why do lower altitude planes have a trail behind it, while higher planes dont?
and its the "contrails" at lower altitudes that last for hours. every high flying contrail i have seen disapates within a minute or two. after hours of going by, the tiny ice crystals would have evaporated reguardless of temperature because of the suns rays. a contrails ice crystals arent thick enough per ice crystal. and the ice crystals that are formed arent thick enough amongst eachother to stick around, or seem to stick around. contrails dont expand and eventally cover the whole sky.
and any such arguement trying to explain that chemtrails dont exist is kinda stupid and pointless. as it is clear, that it was once denied by everyone imaginable that claimed to have the smarts to be able to determine that they werent real.
but now you have the doctors that were taking care of the pilots spraying the chemicals that are coming foward, and news stations are talking about it explaining how it works, and the people behind it, have 3 different reasons as to why theyre doing it, AFTER they denied it at first. and you now even have meteorologists that use to do it, talking about it and explaining it on the news. to me thats credible people.