Learn why Albert Einstein tops many people's lists of the greatest-ever scientific geniuses in this essay from the NOVA Web site. He established that the speed of light is constant, but that time and space are not as simple as had been thought. He found that energy and mass were intimately related, and that gravity resulted from the effect of energy and matter on space and time. He even conceptualized black holes—invisible stellar objects—long before they were proven to exist.
