Columbus wasn't ridiculed for saying the Earth was round and that he could get to Asia by sailing across the ocean. They already knew that. He was ridiculed because their calculations indicated that there would be no way to get there without running out of supplies and dying because Asia was too far away in that direction.
Good point IMAPHB,although he was ridiculed you have the point of him also being the only one of several trying to do the same thing to get permission from the Queen.
Well they said of Columbus that 'he left not knowing where he was going, when he got there he didn't know where he was, and when he returned he didn't know where he'd been.'