Thread dredge! I've been getting flat earthers on my FB feed, wtf. WTF is this "firmament" that they talk about lol. Anyway, I've never laughed so hard at some of the comments in my life. I need to drink more and think less.
Firmament sounds like religious text. Its been awhile since I kept up with the current conspiracy theory/religious insanity, but doesn't surprise me if that's the route many are taking to get there.
There were a couple of flat-earth documentaries several years back that gave some insight. Many of the people ended up there by first getting started with one small conspiracy theory or even just one moment where they realize how much of the world is built on bullshit, finding out something they learned as a child turned out to be false, etc. And then they get to another one, and so on, until they end up where they go "well they lied to me about this, why wouldn't they lie about the Earth being round?".
The mix of the political movements post 2015 and COVID has really pushed people to that type of thinking.