Uuummm... I hate to break this to these brilliant scientist but a Mr. Nicoli Tesla did this back in 1890. Maybe they haven't thought about going to the library and reading something about the history of their trade.

Hey! Maybe next they'll devise some sort of round things that can be attached to an axle to allow man to move heavy things more easily. They could call it... Oh... Let's say a "Wheel?" Duh!