So here is the thing. The white lines coming out of the engines as the plane moves are called condensation trails(contrails).They are linear clouds. Bcs moisture are supercooled down to dewpoint(temperature at which clouds are formed). The caloric value of the aircraft’s engines https://twitter.com/warbaby77/status/1391435831194304513

(Force generated from fuel/diesel+air) their compounds are broken down into mono elements, as the exhaust fumes eject from the exhausts. We get water/steam etc as one of the byproducts from fuel,as it gets to the atmosphere or before, it is supercooled & those lines are formed

Sometimes, the white lines could be a cocktail of supercooled steam and supercooled acids. The supercooled acids that form the white lines are called chemtrails. The acids are byproducts from the breaking of fuel/air.

***(chemical trails).