They are lunatics! And I also feel sorry for them... I mean it's one thing to completely reject 500 yrs of hard science and much more in terms of rational observation, but it's completely different when you start building theories that are COMPLETELY MAD and can be cut short by 15 minutes of googling things up!
Did you know that flat earthers believe we are surrounded by blocks of ice from all sides and if we break them then we fall into outer space?
It's beyond comprehension, but the worst thing is that you can't even debate with sth like that, cause it's like fuckin' dogma, thus completely immune to argumentation!
And this is the problem! There's no way we can find a common space here! It's total detachment from reality as we know it! It's like a rabbit hole! Different dimension!
That's the bit that gets me, denial in the face of overwhelming evidence to the contrary. I read an interesting article the other day, in a nut shell "social pain" or being told you're wrong hurts just the same as physical pain: https://www.theguardian.com/lifeandstyle/2016/feb/28/why-being-wrong-really-hurts
Ha, yes I've heard that one, the flatearthers I find particularly amusing. There's a million different ways to prove that they are wrong, but I think even Neil Degrasse Tyson has given up on that one. I read that they accept that Mars and the others planets are round, but it's just Earth for some reason...
Sadly you're right about debating it, I stupidly tried once. If you have a spare few hours and don't mind losing some of your sanity, you can see the results of that encounter here: https://steemit.com/vaccines/@truthtrain/people-want-proof
It's a shame because this backwards thinking needs to be abandoned before we can really start moving forward. They've rejected both the red and blue pills in favour of the black pill!