<P> Hippasus of Metapontum (/ ˈhɪpəsəs /; Greek: Ἵππασος ὁ Μεταποντῖνος, 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 . </P> <P> Little is known about the life of Hippasus . He may have lived in the late 5th century BC, about a century after the time of Pythagoras . Metapontum in Italy (Magna Graecia) is usually referred to as his birthplace, although according to Iamblichus some claim Metapontum to be his birthplace, while others the nearby city of Croton . Hippasus is recorded under the city of Sybaris in Iamblichus list of each city's Pythagoreans . He also states that Hippasus was the founder of a sect of the Pythagoreans called the Mathematici (μαθηματικοί) in opposition to the Acusmatici (ἀκουσματικοί); but elsewhere he makes him the founder of the Acusmatici in opposition to the Mathematici . </P>

The pythagoreans discovered irrationals in about the ____th century bc
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