Simon Stevin (1548 with Bruges - 1620) was a Engineer and a Flemish mathematician (Belgium).

Wonder in is gheen wonder was its currency.

Biographical elements

Made of a merchant with Antwerp of 1564 at the years 1570, Stevin was employed with finances of the wearing of Bruges in 1577. He did not manage to obtain the frankness from the rights on beer, and expatria the following year: he worked in Prussia, in Poland, with the Denmark, in Sweden and Norway. Of return to the Netherlands in 1581, at 33 years, it published a book on the calculation of the interests then was registered at the university of Leyde in 1583.

It is undoubtedly at the university that Stevin discovers the work of Archimedes in the translation of Maurolico entitled the Monumenta (Palermo). Stevin consequently makes its first research on the machines which he saw functioning in the various arsenals of the North Sea and the end of the year 1580 sees the publication, at the printer huguenot Christophe Plantin, of his principal works, in particular Statics or Art to weigh (1586) and hydrostatic the (1586).

This work attracts to him the favor of the prince Maurice de Nassau, who will often consult it from now on and the first intendant of the channels of the Republic of the Plain Provinces will make of it. In 1590, Stevin moves in Delft then in $the Hague. In front of the extent of work to carry out to defend the cities of the young republic, he pleads for a university education on Artillery and the Fortifications. In 1600, it founds with Leyde with the support of Maurice de Nassau a school of military engineers annexed to the university (but independent of this one): Descartes, Guez de Balzac and many other young French aristocrats will come to seek there the scientific and technical training which is lacking in their country, devastated by the Wars of religion and in prey with political instability.

One knows few things on private life of Stevin; it left a widow and two children. To Bruges, a place bears its name and one can see there a statue carried out by Eugen Simonis.

The engineer

Addressing itself to technicians and men of war, Stevin had an especially governmental recognition. Its contemporaries were primarily interested by his invention of a sand yacht whose model was preserved at Scheveningen until in 1802. We know that about the year 1600, Stevin with the prince of Orange and thirty-six other people used it between Scheveningen and Petten, and having only recourse to the force of the wind, they went more quickly than the horses.

Stevin seems to have been the first which took for base of the defense of the fortresses, the Heavy artillery. Previously it was based especially on the weapons of small gauge. He was the inventor of defense by a system of locks, which was moreover high importance for the Netherlands.

Philosophy of sciences

Stevin was convinced that an Age of Enlightenment had existed in the past (Hugo Grotius). Patriot, it endeavoured to make dialects low-German spoken in the Netherlands a language with whole share, and évertua in particular to be an equivalent Flemish/Dutch, for all the scientific and technical terms: thus the Dutch word for mathematical does not have a Greek but Germanic root: Wiskunde . Stevin saw the advantage of Dutch in the number of monosyllabic words and faculty to compose of the radicals.

Mathematics

The partly double Comptabilité can known by Stevin either when he was clerk in Antwerp, or through works of the Italian authors like Luca Pacioli and Gerolamo Cardano. However, it was the first to recommend the use of impersonal accounts in the national accounting. It practiced it for prince Maurice and recommended it to Sully.

Its greater success was a small treaty called De Thiende ( the dîme ), published like all its Dutch writings in 1586 and not exceeding seven pages in the translation in French.

The decimal fractions had been employed for the extraction of the square roots a few five centuries before its time but nobody before Stevin had shown the interest of his daily employment. Stevin was so conscious of the importance of this contribution which he declared that the universal use of the decimal system was inescapable. The notation which he proposes is rather difficult to handle: the decimals are affected of their power of ten, marked by a small circle around the exhibitor. Besides Stevin notes thus in the algebraic equations the high numbers with a power: encircled numbers indicate simple exhibitors. Stevin uses the fractional exhibitors, but never considers negative exhibitors.

The decimal notation of Stevin found an echo in erudite Europe. The decimal point was introduced by Bartholomäus Pitiscus into its trigonometrical tables (1612), and was taken again by John Napier in his two works on the tables of logarithms (1614 and 1619).

Stevin innovated finally little in geometry, but was the first to show how to build a Polyèdre by developing it on a plan.

Mechanics

The contribution of Stevin to Statics (1586) is considerable . Showing that any balance can bring back in last analysis to an abstract form of weighed , it gives to understand that behind the concept of weight is hiding place an abstracted concept, more general, that of force . By this method, it approaches the concept of Moment of a force by generalizing the principle of the lever with a greater boldness than all its predecessors (Cardan, Tartaglia). It thus reduces the law of balance on a level inclined to that of a balance of lever. Celebrate is the analysis of Pierre Duhem of the epistemology of its reflections (for Archimedes, against Aristote). It uses also the concept of virtual displacement , which will be taken again by Galileo. It releases finally the first the concepts of steady balance and unstable .

It showed, one century before Pierre Varignon the method of the parallelogram the force , which was known before only in particular cases (pushes equal in intensity and convergent to right angle, or 60°). The anecdote quoted previously of the sand yacht shows that it included/understood how to go back to the wind , which indicates a broad advance over its time.

He discovered the hydrostatic paradox : the pressure of a liquid on the bottom of a container is independent of its form, and also of the surface of the bottom; it depends only on the height of water in the container. It gave also the measurement of the pressure on any portion on the side of a container.

In 1606, it showed that two objects of different weights fall with same speed.

It finally tried to explain the Marée S by the attraction of the the Moon.

It thus precedes Galileo on many points; but its immense work remains largely ignored: the Flemish current will be translated only later, and one will know especially the Italian thought (Benedetti, etc), resulting from Leonardo, Cardan, Tartaglia. Wonder in is gheen wonder