Two planes fly by with chemtrails on a perfectly beautiful fall day in Chicago and then a third flies by with nothing. Do I have to be a physicist or an expert to know this is total BS?
Discussion
Yes
Could be different engine or even altitude. Cooler air is the easiest time to see them depending on how clean the burn is. As an experiment next time it is 40° or below outside, stand by the road. It's easier to see your breath in the air when a car passes. The reason for this is because the water vapor in your breath becomes more visible because it sticks to the carbon molecules in the air from the car exhaust. I believe jets do the same as the car but look prominent when they fly through more humidity pockets.