Democritus lived in Abdera, Greece. He was responsible for the understanding that matter was made up of particles called "atamos." He also theorized about atoms being infinite in number. One experiment Democritus conducted was simply breaking a seashell. First in half, then in half again over and over until it was just powder. once he couldn't break it into any smaller pieces, he came to the conclusion that it was indivisible. His theory was not initially accepted however, because Aristotle, a well known (and more influential) philosopher did not believe it.