Pedro Nunes

Pedro Nunes (latin, Petrus Nonius), (1502, Alcácer do Sal – August 11, 1578, Coimbra) was a Portuguese mathematician, born from a New Christian (of Jewish origin) family.

Work

Pedro Nunes lived in a transition period where science was changing from valuing theoretical knowledge (and thus where the main role of a scientist was commenting on previous authors), to providing experimental data, both as a source of information and as a method of confirming theories. Nunes was above all one of the last great commentators, as his shown by his first published work, but he also acknowledged the value of experimentation. For example, he saw the importance of the Portuguese navigators being able to sail south of the equator despite previous author's assurances that it was impossible, thereby demonstrating that the antipodes existed and that men lived there just as in Europe, something that even the saints deemed as impossible.

Related Topics:
Equator - Antipode

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Nunes believed that scientific knowledge should be shared. So his original printed works were written in three different languages, some in Portuguese, some in Latin, aiming for a broader audience of European scholars; and even one (Livro de algebra en arithmetica y geometria) in Spanish, which is considered as surprising by some historians, given that Spain was Portugal's main rival in a fight for world dominance of the seas.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Many of Nunes work related to navigation. He was the first to understand why a ship maintaining a steady course would not travel along a great circle, the shortest path between two points on Earth, but would instead follow a spiral course, called a loxodrome. The later invention of logarithms allowed Leibniz to establish algebraic equations for the loxodrome.

Related Topics:
Navigation - Course - Great circle - Spiral - Loxodrome - Logarithm - Leibniz - Algebraic equation

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In his Treaty defending the sea chart Nunes argued that a nautical chart should have its parallels and meridians shown as straight lines. Yet he was unsure how to solve all the problems this caused, a situation that lasted until Mercator developed Mercator projection, the system which is still used.

Related Topics:
Nautical chart - Parallels - Meridian - Mercator - Mercator projection

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

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, later known as vernier, to improve the astrolabe's accuracy. The nonius was used for a while by Tycho Brahe who, however, considered it too complex. Later it was perfected by Pierre Vernier to its present form.

Related Topics:
Nonius - Vernier - Astrolabe - Tycho Brahe - Pierre Vernier

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Pedro Nunes also worked on some mechanics problems, from a mathematical point of view.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

He was probably the last major mathematician to make relevant improvements to the ptolemaic system (a geocentric model), however this lost importance because Copernicus heliocentric system replaced it by then. Nunes knew Copernicus' work but he only made a short reference to it in his published works, stating that it was a mathematically correct model. In doing so he apparently wished to avoid givin an opinion on the question on whether the Earth or the Sun was the centre of the system. Some historians argue that he probably did so out of fear of the Portuguese Inquisition, because he was a convert Jew.

Related Topics:
Ptolemaic system - Geocentric model - Copernicus - Heliocentric system - Portuguese Inquisition - Convert Jew

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

He 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, independently, tackled by Johann and Jakob Bernoulli more than a century later with less success. They could find a solution to to the problem of the shortest day but failed to determine its duration, possibly because they got lost on details of differential calculus, still a recently developed tool (at that point in time). It also shows Nunes as a pioneer in solving maxima and minima problems, which only became common in the next century using differential calculus.

Related Topics:
Twilight - Johann - Jakob Bernoulli - Differential calculus

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Most of Nunes' achievements were possible because of his profound understanding of spherical trigonometry and his ability to transpose Ptolemy's adaptions of Euclidean geometry to it.

Related Topics:
Spherical trigonometry - Euclidean geometry

~ ~ ~ ~ ~ ~ ~ ~ ~ ~