Well, Bill Gates seems to want to fight humanity's problems of today - AIDS, Malaria, Poverty. Elon/Larry want to go to Mars and build vacuum-tube trains from S

Well, Bill Gates seems to want to fight humanity's problems of today - AIDS, Malaria, Poverty. Elon/Larry want to go to Mars and build vacuum-tube trains from SF to LA. One is a real need, one is Science-Fiction. Obviously the latter is more 'fun'/nerdy.