These people are sub-atomic particle physicists. They study things you can't even see and have a vocabulary that consists of words like 'gluon' and 'lepton' and 'gauge boson'. The odds of them ever having seen a member of the opposite sex naked, let alone getting a chance to reproduce, is next to nil. (Heh, heh, heh. Just trying to bring a little levity to the end of the world! )