ABSTRACT
In ancient Greek philosophy the term atom (the indivisible) was used to
describe the small indivisible pieces of which matter consists. Father of
the so-called Atomism theory was the philosopher Leucippus (450-370 B.C.)
and his student Democritus (460-370 B.C.). According to them, matter is
built of identical, invisible, and indivisible particles, the atoms. Atoms are
continuously moving in the infinite empty space. This infinite empty space
exists without itself being made of atoms. Atoms show variations in their
form and size and they tend to be bound with other atoms. This behavior
of the atoms results in the building of the material world. According to
Democritus, the origin of the universe was the result of the incessant
movement of atoms in space. In this sense atoms were the elementary
particles of nature.