Who is pedro nunes

Nunes also solved the problem of finding the day with the shortest twilight duration, for any given position, and its duration.

This problem per se is not greatly important, yet it shows the geometric genius of Nunes as it was a problem which was independently tackled by Johann and Jakob Bernoulli more than a century later with less success. They could find a solution to the problem of the shortest day, but failed to determine its duration, possibly because they got lost in the details of differential calculus which, at that time, had only recently been developed.

The achievement also shows that Nunes was a pioneer in solving maxima and minima problems, which became a common requirement only in the next century using differential calculus.

He was probably the last major mathematician to make relevant improvements to the ptolemaic system a geocentric model describing the relative motion of the Earth and Sun. However, this lost importance because Copernicus introduced his heliocentric system theory around the same time. Nunes knew Copernicus' work but referred only briefly to it in his published works, with the purpose of correcting some mathematical errors.

Most of Nunes' achievements were possible because of his profound understanding of spherical trigonometry and his ability to transpose Ptolemy 's adaptations of Euclidean geometry to it. Nunes worked on several practical nautical problems concerning course correction as well as attempting to develop more accurate devices to determine a ship's position.

He created the nonius to improve the astrolabe's accuracy. This consisted of a number of concentric circles traced on the astrolabe and dividing each successive one with one fewer divisions than the adjacent outer circle. When an angle was measured, the circle and the division on which the alidade fell was noted. A table was then consulted to provide the exact measure.

The nonius was used by Tycho Brahe , who considered it too complex. The method inspired improved systems by Christopher Clavius and Jacob Curtius.

These were eventually improved further by Pierre Vernier in , which reduced the nonius to the Vernier scale that includes two scales, one of them fixed and the other movable. In some languages, the Vernier scale is still named after Nunes, for example nonieskala in Swedish.

Nunes was very influential internationally e. In his Treatise in Defense of the Marine Chart Tratado em defensam da carta de marear published in , Nunes was the first mathematician to discuss the rhumb line or loxodrome - a spiral course when a ship maintains a steady course at sea.

His work on navigation also included inventing the Nonius - named in his honor - which is an improvement to the astrolabe. His research in this field was to lead to greater advances in navigation as other mathematicians carried on his experiments. His writings on the subject were published in De crepusculis Pedro Nunes was part of a network of European intellectuals and maintained a correspondence with the English scholar John Dee Nunes returned to Portugal in On November 16th , he was appointed cosmographer.

In January 15th , Nunes was appointed to teach Logics. In he was still teaching Logics at the University but it seems that his classes were not very popular so, in April 4th, started to teach Metaphysics. These classes would last until In the following year he took the Licentia exame at Lisbon's Cathedral February 17th. Less than a week later February 23rd became doctor PhD equivalent and abandoned public teaching.

When, in , the Portuguese University then located in Lisbon returned to Coimbra, he moved to the re-founded University of Coimbra to teach mathematics. He was appointed Mathematics Professor on October 16th, In was elected to take part in Coimbra University's statutes reformation. In he took a leave from the university and moved to Lisbon for a period of 4 years.

He then retired from the University in