Yes, our great-grandfathers really remember the sky clean, unspoiled by suspicious white stripes. Conjunction lines began to appear in the heavens only after the aircraft had been able to effectively climb to the appropriate heights. Hence, to a standard flight height of seven to twelve kilometers, with somewhat different climatic conditions. Specifically relatively sparse air and a very low temperature, around minus fifty degrees Celsius.
Running aircraft engines (piston, jet, turboprop) are leaking as well as off engine engines on the ground. And you've already noticed that the gray-foggy "smoke from the smuggling cars" is better to see when it's cold. As? Because the hot gas escaping from the car engine mixes with cool air outdoors. Condensation, precipitation and liquefaction of water vapor occur. And the same is happening at a height of ten kilometers above the ground, where there is only really cold winter. Where do you get the "water vapor"?
Most known fuels and aviation fuels are based on hydrocarbons. And just disrupting the rigid bonds of these hydrocarbons during combustion under the air, the energy that rotates the engine is released. The result of the reaction is that of visible "smoke", or carbon dioxide and water, respectively. Mostly because the fuels are not "clean". Simplified: Lead-enriched gasoline burned on the ground gives us exhaust gas with lead. And aviation fuels, depending on their prescription, save carbon dioxide and water molecules, release some sulfur, mercury and nitrogen. It depends on aditives.
However, water vapor still plays in the prim composition, but it is unlucky for the aircraft to appear in a rather "frozen" environment. Very little water droplets or ice crystals become very fast. And that long white line is made of them. How long it lasts in the sky is dependent on air temperature, atmospheric humidity, atmospheric pressure, and air flow at the point of origin. Other mysteries are not there. Airplanes do not leave "chemtrails", but more precisely "contrails". Condensing lines.
Source: Ekolist.cz
Author: Radomír Dohnal, Associate Ekolist