What is "hippasus"

Hippasus of Metapontum (; , Híppasos; fl. 5th century BC), was a Pythagorean philosopher. Little is known about his life or his beliefs, but he is sometimes credited with the discovery of the existence of irrational numbers. The discovery of irrational numbers is said to have been shocking to the Pythagoreans, and Hippasus is supposed to have drowned at sea, apparently as a punishment from the gods for divulging this. However, the few ancient sources which describe this story either do not mention Hippasus by name (e.g. Pappus) or alternatively tell that Hippasus drowned because he revealed how to construct a dodecahedron inside a sphere. The discovery of irrationality is not specifically ascribed to Hippasus by any ancient writer. Some modern scholars though have suggested that he discovered the irrationality of √2, which is believed to have been discovered around the time that he lived.

In Greek mythology, Hippasus (Ἴππασος) is the name of fourteen characters.

• Hippasus, name shared by fathers of several heroes of the Trojan War:
  • of Hippomedon by the nymph Ocyrrhoe
  • of Charops and Socus
  • of Agelaus the Milesian
  • of Coeranus the Lycian
  • of Hypsenor
  • of Demoleon the Lacedaemonian
  • of Apisaon the Paeonian
  • of two nameless - only known by the patronymic Hippasides - charioteers:
    • the charioteer of Pammon (the son of Priam)
    • a Greek charioteer killed by Deiphobus.
• Hippasus, son of Eurytus. He was one of the hunters of the Calydonian Boar.
• Hippasus from the Pellene district of the Peloponnese, father of Actor, Iphitus, Asterion, Amphion, and Naubolus. The latter four are otherwise ascribed different parentage.
• Hippasus, a Centaur. Killed by Theseus at the wedding of Pirithous and Hippodamia.
• Hippasus, one of the sons of Priam.
• Hippasus, a Thessalian killed by Agenor in the Trojan War.
• Hippasus, son of Ceyx, killed in battle whilst fighting alongside Heracles against Eurytus.
• Hippasus, son of Leucippe. He was killed by her and her fellow Minyades.
• Hippasus from Phlius opposed his fellow citizens, who wished to accede to the wishes of the Dorian Rhegnidas and make him their king. He and his fellow supporters fled to Samos. Hippasus is the ancestor of the philosopher Pythagoras, Pythagoras being the son of Mnesarchus, the son of Euphranor, the son of Hippasus.