You know what's the single most ridiculous detail in Flat-Earth-theory? [View all]
I have been in two FE-forums and have watched several FE-videos and I can say from my own experience, the most ludicrous part of Flat-Earth-theory is... Flat-Earthers.
Flat-Earthers regard themselves as free-thinkers. As true researchers. As heroes fighting a corrupt system that suppresses the truth.
To quote a Youtube Flat-Earther: "Knowing that Earth is flat already makes you one of the smartest people in the world."
All the while these free-thinkers go to insane mental gymnastics to protect the idea that Earth is flat from scrutiny.
* They invent conspiracy-theories to declare uncomfortable evidence to be fake.
(There are actually two rivalling FE-factions with two rivalling conspiracy-theories. One side believes that there is a conspiracy to cover up the fact that Earth is flat. The other side believes that this is ridiculous: The conspiracy is really about faking travel to space.)
* They lie about what can and cannot be seen in a photo.
Seriously: Their best evidence is hazy, foggy photos of skyscrapers or mountains on the horizon, which are so blurred that it's impossible to make any conclusive statement.
* They don't understand or deliberately refuse to understand what they are talking about, just so they can score points.
Flat-Earthers who think that buoyancy disproves the concept of gravity.
Or Flat-Earthers who don't understand how optical perspective works.
Or Flat-Earthers who don't understand that Earth's axis is tilted.
Or Flat-Earthers who create assumptions from gut-feeling and then declare evidence fake because it doesn't match their assumptions. ("These photos of other planets look fake. How come other planets don't have climate-zones?" - How about, because they don't have atmosphere and seas?)
* If all else fails, use a method of research where disproving Flat-Earth is impossible.
What Flat-Earthers love to do is to shift the goalposts: They claim that they are not out to prove that Earth is flat. They claim, they merely want to do a measurement on the shape of the surface of Earth and from that deduce the shape of Earth. (And guess what their single measurement shows...)
Please ignore that it is impossible to make a statement with 100% certainty when using only a subset of all of the available information. (Basic statistical math.)
What's more important here is that Flat-Earthers are deliberately not using the scientific method, because the scientific method discards theories that don't match reality. This must never happen. Flat-Earthers don't want to investigate Flat-Earth-theory in a way where there even is a possibility that it could be proven wrong.
You are a free-thinker only if you think like all the other free-thinkers.