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!