20 abr 400 ano antes da era comum - Democritus - 400 B.C.
Descrição:
 Came up with atomic theory which stated that the universe is composed of two elements: the atoms and the void in which they exist and move. According to Democritus atoms were miniscule quantities of matter. 
Adicionado na linha do tempo:
Data:
20 abr 400 ano antes da era comum
Agora
 ~ 2427 years ago