Leucippus

Leucippus or Leukippos (, first half of 5th century BC) was a Greek philosopher. He was an early philosopher of atomism, the idea that everything is made up of many tiny things which always continue to exist.
Leucippus was born at Miletus or Abdera, although apparently Epicurus said he never existed. There has long been a controversy about this.
Leucippus may have been the first person to suggest the idea of empty space (a vacuum). It is difficult to know which ideas come from him, and which come from Democritus.