#8 The Sky Doesn’t Exist
This theory is a little out there even for the most flat-Earthers, so just a handful of them actually believes in this (probably the ones that read Stephen King’s novel ‘Under the Dome’). According to this, the sky and all the other things in it are fake. Instead, it is a big dome placed by someone to keep you from knowing what’s up there.
This theory origin is in religion, which claims that God put a ‘firmament’ above the Earth, stopping us from knowing true nature of the heavens. Or perhaps it was the aliens who wanted to observe us but didn’t want us to know they are watching. Oh, and if you’ve been wondering how this theory explained night showing up, it’s actually a hologram projected on the surface of the dome.