Well, there are about as many scientists and laws as there are stars in the sky, so I shall narrow it down and speak of one in particular you asked about, Archimedes. Archimedes is considered one of the greatest mathematicians and scientists of known antiquity. He lived from 287 B.C. to 212 B.C., and was of Greek nationality. The resource I have attached delineates several of his more notable inventions and contributions. In science, one of the things he is remembered for is his Principle of Buoyancy, commonly known as Archimedes Principle. This principle basically states when we submerge an object in a volume of water, it displaces a volume of water equal to the volume of the object. It is said Archimedes was given a crown of gold that was suspected to be composed of gold mixed with cheaper metals, and asked to determine the composition of the crown without melting it down or damaging it. Archimedes, noticed his body displaced water when he got into the bathtub, and invented this method of volume determination by immersion in water. The story goes on, he was so excited by his discovery, he ran through the streets naked, exclaiming "Eureka!", which in Greek, means "I have found it".