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Nov 3, 1111
Aristotle
Aristotle did not believe in the atomic theory and he taught so otherwise. He thought that all materials on Earth were not made of atoms, but of the four elements, Earth, Fire, Water, and Air. He believed all substances were made of small amounts of these four elements of matter. -
Nov 3, 1122
Democritus
His speculation on atoms, taken from Leucippus, bears a passing and partial resemblance to the 19th-century understanding of atomic structure that has led some to regard Democritus as more of a scientist than other Greek philosophers; of "atoms", which are physically, but not geometrically, indivisible; that between atoms, there lies however, their ideas rested on very different bases. -
John Dalton
English Chemist
The most important of all Dalton's investigations are those concerned with the atomic theory in chemistry. While his name is inseparably associated with this theory, the origin of Dalton's atomic theory is not fully understood. It has been proposed that this theory was suggested to him either by researches on ethylene (olefiant gas) and methane (carburetted hydrogen) or by analysis of nitrous oxide (protoxide of azote) and nitrogen dioxide (deutoxide of azote). -
Robert Brown
Scottish scientist
He observed that some dead pollen grains suspended in water were constantly moving about randomly in all directions. This is know as the Brownian motion. His contributions include one of the earliest detailed descriptions of the cell nucleus and cytoplasmic streaming -
Albert Einstien
German-born American physicist
He explained that the dead pollen grains were moving because they were being bombarded by the moving water particles.
. This led to the development of his special theory of relativity. He realized, however, that the principle of relativity could also be extended to gravitational fields, and with his subsequent theory of gravitation in 1916, he published a paper on general relativity.
