Discuss the origin and evolution of the Flat Earth Society.
Someone should probably tell him that the "Flat Earth Society" (the one from my youth) was formed on a basis of challenging science for "the unexplained". Nobody in that infant organisation feel the earth was actually flat - it was a allegory for refuting science as a reason for everything. Silly in itself but it had its own raison d'être. Now its been taken over by not just skeptical anti-science people, but wilful idiocy. Ah well..