Which two isotopes are compared in radiocarbon dating
Heraclitus - Greek philosopher; first of the Greeks to develop a theory of the human soul; he praised its creative resources and spoke of the importance of self-exploration; he spoke of the logos that is common to all and said that the universe is ruled by logos; he always urged that close attention be given to the polarites and concealed structures emodied in language.
His famous claim that an idividual can and cannot step into the same river twice reveals an interest in criteria of unity and identity; even though all material constituents have undergone change, it is still, in a sence, the same river.
Preoccupied with change, he declared that fire is the central element of the universe, and he postulated a world with no beginning and no end...
Pythagoras - Greek philosopher and mathematician; held that numbers were basic to matter; the Pythagorean Theorem is named for his geometric formulation; developed atomic theory; students of his philosophy emphasized geometrical form as a basic property of atoms; developed mathematical relationships which led to musical harmony.
Empedocles - Some suggest (c.484-c.424) - Greek doctor, poet and philosopher.
To account for real change, he assumed that there must be more than one kind of matter, and he postulated four roots as elements; earth, air, fire, and water.
He cured a plague at the Sicilian city of Selinus and claimed he was a god.
One legend, which forms the basis of Matthew Arnold's poem Empedocles on Etna, held the Empedocles, tired of life and wanting people to believe that the gods had taken him with them, committed suicide by leaping into the crater of Mt. Socrates - Greek philosopher; emphasized the study of human nature in relationship to society; influence the growth of science through standards for clear definitions and classifications, for logic and order, and for prudent skepticism.
Democritus of Abdera - Greek philosopher; pupil of Leucippus; developed atomic theory; elaborated idea that matter consisted of atoms having physical size and shape which constantly moved in a void and interacted in different ways; Greek word atoma means indivisible.
Plato - Greek philosopher; pupil of Socrates; dealt with the nature of the universe; developed atomic theory of chemical change; ascribed geometric forms composed of bounding planes to the elements of earth, fire, air and water based upon their physical properties; held that elements could convert into one another through rearrangement of bounding planes; used deductive reasoning as a learning method.
Aristotle - updated engraving; Greek philosopher, educator and scientist; undertook a large-scale classification of plants and animals; introduced a method of scientific thinking that still plays a role today.
Epicurus - Greek philosopher; founded the system known as Epicureanism.