Pedro Nunes

Pedro Nunes ( Latinized Petrus Nonius; * 1502 in Alcácer do Sal, † August 11 1578 in Coimbra ) (Latin: Petrus Nonius Salaciensis ) was the most famous mathematician and astronomer of Portugal. Since one of the main applications of astronomy was the navigation at sea, especially here showed Nunes ' skills. So he dealt with the problems of the then in use so-called flat maps (distortion due to constant longitudes) and the first to describe in 1550 the properties of the rhumb line, which is based on the simple price determination rule, always maintain the same angle to the meridian, in the Mercator projection appears as a straight line, but, as recognized Nunes, not the shortest distance between two points on the earth corresponds.

Nunes had Jewish ancestors and studied from about 1517 at the University of Salamanca, where he took his degree in 1523 (bachelor ) in medicine. In the same year he married a Spanish woman, with whom he had six children. 1527 he returned to Portugal, where he remained until 1531, the brother of King John III. , Louis of Portugal ( Luis ) taught. Also starting in 1527, he taught Martim Afonso de Sousa in navigation and as João de Castro. 1529 he was appointed royal cosmographers and 1547 the First cosmographers of the kingdom and in this function especially teacher of navigation. In the same year he began to lecture on philosophy at the University of Lisbon, where he in 1530 was appointed Professor of Logic. 1532 he moved to the chair of metaphysics and acquired in the same year his doctorate in medicine. He was also the teacher of Henry I, before this Bishop of Braga was. 1544 to 1561 he was professor of mathematics at the University of Coimbra, where, among other things, Christopher Clavius ​​was his pupil. In between, he lived from 1557 to 1561 in Lisbon.

In 1548 he received from the king the title Cavaleiro do Habito de Cristo.

He led the vernier to improve the astrolabe a ( concentric circles as a system that would make the angle reading in more detail ), which was used in his time of Tycho Brahe and Christoph Clavius ​​and was introduced in a modified form by Pierre Vernier 1631. Nunes was at the time a Europe-wide reputation and influence among others John Dee.

The lunar crater is named after the vernier.

Writings

• Tratado da sphera com a Theorica do Sol e da Lua. Lisbon 1537. The book is based on translation of works of Sacrobosco, Georg von Peuerbach and the Geography of Claudius Ptolemy.
• De Crepusculis. Lisbon 1542nd 2nd edition Coimbra 1571st The book deals with the length of the dawn.
• De erratis Orontii Finaei. Coimbra 1546. 2nd edition 1571st refute the purported solution of the three classical geometric problems of angle trisection, duplication of the cube and squaring the circle by Oronce Fine.
• Petri Nonii Salaciensis Opera. 1566. Collected Works, an expanded edition was published in 1573 as De arte atque ratione navigandi.
• Libro de Álgebra s Arithmetica y geometría. Antwerp 1567. His algebra, in which he wrote since 1534.