The earth isn't flat

[Nebulous]

There are people who believe the world is really flat.

How would you convince them it isn’t?

[Maniakkid25]

Very simple: you don't. And you can blame human psychology for that. See, it's been shown over and over that the more you try to prove someone wrong, the harder they dig in. This is known as the "Backfire Effect". The fact is, once someone is committed to believing a "truth", it is almost impossible to dissuade them, no matter how irrefutable your evidence may be.

There are three effects that you are fighting when you try to prove someone wrong: pattern recognition, confirmation bias, and the Dunning-Kruger Effect. Humans are hardwired to see patterns. Anyone who's looked at clouds and saw things in them can tell you this. As such, when people are looking for answers in something that has a much more chaotic explanation, they will see things that aren't there. Take, for example, the JFK second shooter conspiracy. The official explanation is Lee Harvey Oswald acted alone. But, for decades, there has been the idea that there was a second shooter in "the grassy knoll" because the trajectory for the bullet that killed JFK also injured Govenor Connally. If they had been in a normal car, this means that the trajectory of the bullet would have to turn in mid-air to cause the injury. What those people forget is that the car had been modified, and the occupants were at weird angles at the time of the shot, making a straight line trajectory easily plausible.

Confirmation bias is one of the many, many biases that humans often unintentionally have. Confirmation bias is the tendency to remember information that confirms previous beliefs. Simply put, we remember things we want to remember, and forget things we don't. The Anti-vaccine movement can help me out here. In the original paper that kick-started the modern Anti-Vax movement, most of the explanations that said that MMR caused the kids autism was made by the parents themselves SAYING the MMR vaccine caused their kids autism. As such, when the paper was announced to the world, suddenly there was a scientific paper that confirmed their original hypothesis, and they remembered that part, and not the part where it was eventually retracted and Andrew Wakefield became disgraced (the utter c*** deserves it, though).

Finally, if you've been around the debunk space, the Dunning-Kruger Effect is not a new phenomenon. In essence, the Dunning-Kruger Effect shows a weird psychological phenomenon, in that it shows that untrained people are likely to think they are far more competent at a task than they actually are. This quickly falls off with a little bit of training, and slowly falls to a deep low before rising back up. The graph is very illustrative.



Or, to put it in words, its not that the people on the extreme left are incompetent and cannot give a correct answer to a question, but that they are SO incompetent that they don't understand what a correct answer looks like in the first place, so therefore they think they have the correct one. And to round out my trilogy, let's talk about Creationism. There are many PRATTs (Point Refuted A Thousand Times) in Creationism, but they all stem from a similar problem: they don't understand what Evolution actually is (granted, they often lack understanding of A LOT of science, but that's not my point). As such, they are so incompetent, they think their interpretation of it is the correct answer, when it's often not.

Relatedly, I'd recommend the video In Search Of A Flat Earth by Dan Olsen. It's a great dissection of what the movement really wants out of the world, and how disturbing their ideas can truly be.