Archimedes

Archimedes prepared the way for integral calculus and approximated the number Pi. He discovered the law of leverage and invented new formulas to calculate the properties of cylinders and spheres. He once yelled "Eureka" while bathing, after having dreamed up the concept of specific weight while splashing around. He even specified the number of grains of sand that could fit into the universe: 1063. Until then the Greeks had merely left it at a "myriad" (or 10,000).