So a common theory around these parts, that happens to coincide with the flat earth is Chemtrails and Geo-engineering.
The governments are seeding the skies with mind-warping chemicals that trick us into believing things, and they're polluting the water with them too.
Yeah, no.
I've heard cases for flouride, flourine, and flourite, though that could easily be some unfortunate typos.
They have a point, the governments are tainting our water supply with flouride in a dastardly plot to
reduce tooth decay.
That's what it does. It's a teeth cleaner.
Also, in the actual conspiracy theory, if they did poison the air with this, don't they breathe the same air as us? If anything they'd be poisoning themselves too.
And how does a chemical make you brainwashed? Oxygen isn't whispering dark secrets in your ear. You aren't going to go mad from the Silicon in your computers, and whatever flourine/flourite/baking flour they're putting in the skies doesn't make the earth any flatter.
As for the cloud lines, you're thinking of
contrails. It's water condensing behind the wings as the air on top of them collides with the air below.
Clouds form around them, since water droplets in the air want to come together into clouds, and there's already a perfectly good cloud nearby to join.
If you've owned a plane you would know this. It happens to all of them, given the right humidity. Your backyard puddle jumper isn't warping the minds of the misled masses, it's just flying.
Of course, if I'm mistaken, there's a perfectly good reply button to tell me how wrong and stupid I am.