But we need replication, replication is the way! Feynman wrote something about this, I recall. Someone proposes that the moon is made from Wensleydale, and NASA goes up and brings back some rocks. "It's made from rock", you say, but someone else says "it's actually made from Gouda, but some rock has fallen onto it". So the Russians go up and return more rock, and another proposes it's made out of Limburger. And so on.