MATHEMATICIAN

Life
Mathematician from Metapontum in Magna Graecia (south Italy) and disciple of Pythagoras, Hippasus established the "mathematical section" of the Pythagorean school. He is cited by Diogenes Laertius, Iamblichus and Suidas. Fragments of his work survive.


Work
Hippasus discovered that the ratio of the side to the diameter of a regular pentagon is an incommensurable number (The pentagon was a sign of recognition among the Pythagoreans.) His teaching differed from that of the orthodox Pythagoreans, in that he believed that the origin of the world was material (fire), whereas the Pythagoreans held it to be immaterial (numbers).

"Mysteries": Treatise published (according to Diogenes Laertius) under the name of Pythagoras.

Hippasus constructed vessels with different quantities of water and metal discs of different thicknesses and performed experiments in acoustics. His experiment with copper discs confirmed the proportionals of acoustic resonance.

Iamblichus tells us that Hippasus established a circle of "acousmatists", a group that studied the science of acoustics and its applications.