PHYSICIST, ENGINEER, PHYSICIAN, INVENTOR

Life
Son of the Olympic champion Meton, student of Xenophanes of Colophon, Anaxagoras of Clazomenae and Parmenides of Elea, Empedocles was a great naturalist who sought to construct a coherent theory of the physical world. He is cited by Diogenes Laertius, Plutarch, John Tsetses, Iamblichus and Vitruvius.


Work
Empedocles did not accept "coming-into-being" and "passing-away" in the strict sense of the words. Rather, in order to explain changes in matter he posited a cohesive elemental matter of which the entire world is composed, based on the four fundamental elements of fire, water, earth and air. In his theory, change was brought about by the action and interaction of two forces: "Love" (or attraction) and "Strife" (or repulsion). In the beginning, matter was "held together by Love in the form of a sphere". Then "Strife intervened to dissociate the elements, and whirlwinds and vortexes were produced". Empedocles, in other words, foreshadowed modern theories of nebulae, atoms and nuclei; he was also the first to formulate a corpuscular theory of matter.

He invented a clepsydra based on water pressure and the difference in pressure in a void.

He formulated an optical "theory of the emanation of light particles" (radiation), and a similar theory - the "repulsion" and "attraction" of magnets - to explain magnetic phenomena: that is, his acceptance of the entry and exit of magnetic lines was in fact an intuition of magnetic flow.

With regard to colours, Empedocles said that "colour is the sense produced by the entry into the eye of the appropriate rays".

Sound, he thought, came from the pulsation of solid bodies.

Empedocles was the first to formulate the theory of the imperishability of matter.

He investigated chemical, biological and anatomical matters.

According to Plutarch, he raised a wall to seal off a canyon which funnelled the southerly gales directly against the city of Selinus.

Finally, in order to improve the climate of the city of Selinus he undertook to drain a marshy area where fevers bred. He designed a series of canals to connect two rivers, in order to produce a stronger flow that would flush out the marsh and drain the waters into the sea.

TREATISES

"De natura": Didactic poem in 3 books. Only 450 of its 2000 lines are extant.

Explores the gnostic of human force - Moon, earth, eclipses, air, ether - Composition of the universe - Theory of absorption and emanation - Explanation of magnetism - Explanation of the phenomenon of breathing through the experiment with the clepsydra. Explanation of the phenomenon of vision. Drugs against the ailments of old age.

"Epigrams"

"Katharmoi" (Purifications): All but 100 of its 1000 lines have been lost.

"On Persia": Lost. Cited by Diogenes Laertius.