I remember watching a documentary on flat earthers. I can't remember the scientists name, but he said he would be happy to engage them after they answer his question; "What if anything can I possibly say to change your mind", if they gave him a valid answer like show me x data, he would talk to them, if not he made his goodbyes.
So what would possibly change this cabal of intellects mind I wonder?
Best thing I've read in awhile, thanks for sharing that with us.