- Simon Stevin
**Simon Stevin**(1548/49 – 1620) was a Flemishmathematician andengineer . He was active in a great many areas of science and engineering, both theoretical and practical. He also translated various mathematical terms into Dutch, making it one of the few European languages in which the word formathematics , "wiskunde", was not derived from Greek (viaLatin ).**Biography**Stevin was born in

Bruges , Flanders (nowBelgium ) in the year 1548 by Antheunis Stevin and Cathelyne van der Poort. Very little has been recorded about his life. Even the exact date of birth and the date and place of his death (The Hague orLeiden ) are uncertain. It is known that he left a widow with two children; and one or two hints scattered throughout his works inform us that he began life as a merchant's clerk inAntwerp , that he travelled inPoland ,Denmark and other parts of northern Europe. After his travels, he became advisor and teacher of PrinceMaurice of Nassau , who asked his advice on many occasions, and made him a public officer—at first director of the so-called "waterstaet" (the government authority for public works), and later quartermaster-general.In Bruges there is a Simon Stevin Square which contains his statue by

Eugen Simonis , which includes his inclined plane diagram.**Discoveries and inventions**His claims to fame are varied. His contemporaries were most struck by his invention of a so-called land yacht, a carriage with sails, of which a little model had been preserved in

Scheveningen until 1802. The carriage itself had been lost long before. Around the year 1600 Stevin, with Prince Maurice of Orange and twenty-six others, made use of it on the beach between Scheveningen and Petten. The carriage was propelled solely by the force of wind, and acquired a speed which exceeded that of horses.**Philosophy of science**Stevin had developed a theory about a bygone age of wisdom, for which even

Hugo Grotius gave him great credit. Stevin's goal was to bring about a second age of wisdom, in which mankind would have recovered all of its earlier knowledge. He had deduced that the language spoken in this age would have had to be Dutch, because, as he had showed empirically, in that language, more concepts could be indicated with monosyllabic words than in any of the (European) languages he had compared it with. This was one of the reasons why he wrote all of his works in Dutch and left translations to others. The other reason was that he wanted his works to be practically useful to people who had not mastered the common scientific language of the time, Latin.Geometry andphysics Stevin was the first to show how to model regular and semiregular

polyhedra by delineating their frames in a plane. Stevin also distinguished stable from unstable equilibria. He proved the law of the equilibrium on an inclined plane, using an ingenious and intuitive diagram showing a rope containing evenly spaced beads draped over an inclined plane (see the illustration on the side). The diagram is said to have been inscribed on his tombstone, leading the physicistRichard Feynman to remark to his students, "If you get an inscription like that on your tombstone, you are doing fine!"He demonstrated the resolution of forces before

Pierre Varignon , which had not been remarked previously, even though it is a simple consequence of the law of their composition.Stevin discovered the

hydrostatic paradox , which states that the downward pressure of a liquid is independent of the shape of the vessel, and depends only on its height and base.He also gave the measure for the pressure on any given portion of the side of a vessel.

He was the first to explain the tides using the attraction of the moon.

In 1586, he demonstrated that two objects of different weight fall down with exactly the same acceleration.

**Music theory**Stevin was the first author in the West (1585, simultaneously with, and independently of,

Zhu Zaiyu in China) to give a mathematically accurate specification forequal temperament . He appears to have been inspired by the writings of the Italian lutenist and musical theoristVincenzo Galilei (father ofGalileo Galilei ), a onetime pupil ofGioseffo Zarlino .**Bookkeeping**Bookkeeping by double entry may have been known to Stevin, as he was a clerk in

Antwerp in his younger years, either practically or through the medium of the works of Italian authors such asLuca Pacioli andGerolamo Cardano . However, Stevin was the first to recommend the use of impersonal accounts in the national household. He brought it into practice for Prince Maurice, and recommended it to the French statesman Sully.**Decimal fractions**Stevin wrote a 36 page

booklet called "De Thiende" ('the tenth'), first published in Dutch in 1585, though the French translation "Disme" The sub-title: teaching how all computations that are made in business may be performed by integers without the aid of fractions doesn't exceed seven pages was referencingunit fractions orEgyptian fractions .Decimal fractions had been employed for the extraction of square roots some five centuries before his time, but nobody established their daily use before Stevin. He felt that this innovation was so significant, that he declared the universal introduction of decimal coinage, measures and weights to be merely a question of time.

His notation is rather unwieldy. The point separating the integers from the decimal fractions seems to be the invention of

Bartholomaeus Pitiscus , in whose trigonometrical tables (1612) it occurs and it was accepted byJohn Napier in his logarithmic papers (1614 and 1619).Stevin printed little circles around the exponents of the different powers of one-tenth. That Stevin intended these encircled numerals to denote mere exponents is clear from the fact that he employed the very same symbol for powers of algebraic quantities. He didn't avoid fractional exponents; only negative exponents don't appear in his work.

Stevin wrote on other scientific subjects—for instance optics, geography, astronomy—and a number of his writings were translated into Latin by W. Snellius (

Willebrord Snell ). There are two complete editions in French of his works, both printed in Leiden, one in 1608, the other in 1634.**Neologisms**Stevin thought the

Dutch language to be excellent for scientific writing, and he translated a lot of the mathematical terms to Dutch. As a result, Dutch is one of the few Western European languages that have a lot of mathematical terms that do not stem from Latin. This includes the very name "Wiskunde" (Mathematics).His eye for the importance of having the scientific language be the same as the language of the craftsmen may show from the dedication of his book De Thiende ('The Disme' or 'The Tenth'): 'Simon Stevin wishes the stargazers, surveyors, carpet measurers, body measurers in general, coin measurers and tradespeople good luck.' Further on in the same pamphlet, he writes: " [this text] teaches us all calculations that are needed by the people without using fractions. One can reduce all operations to adding, subtracting, multiplying and dividing with integers."

Some of the words he invented evolved: 'aftrekken' ("subtract") and 'delen' ("divide") stayed the same, but over time 'menigvuldigen' became 'vermenigvuldigen' ("multiply", the added 'ver' has no meaning). 'Vergaderen' became 'optellen' ("add").

Another example is the Dutch word for diameter: 'middellijn', lit.: line through the middle.

The word 'zomenigmaal' ("quotient" lit. 'that many times') has become the perhaps less poetic 'quotiënt' in modern day Dutch.

Other terms did not make it into modern day mathematical Dutch, like 'teerling' ("die", although still being used in the meaning as die), instead of cube.His books were bestsellers.

**Publications**Amongst others, he published:

* "Tafelen van Interest" (Tables of interest) in 1582;

* "Problemata geometrica" in 1583;

* "De Thiende" (La Theinde, The tenth) in 1585 in which decimals were introduced in Europe;

* "La pratique d'arithmétique" in 1585;

* "L'arithmétique" in 1585 in which he presented a uniform treatment for solving algebraic equations;

* "De Beghinselen der Weeghconst" in 1586, accompanied by "De Weeghdaet";

* "De Beghinselen des Waterwichts" (Principles on the weight of water) in 1586 on the subject ofhydrostatics ;

* "Vita Politica". Named "Burgherlick leven" (Civil life) in 1590;

* "De Stercktenbouwing" (The construction offortifications ) published in 1594;

* "De Havenvinding" (Position finding) published in 1599;

* "De Hemelloop" in 1608;

* "Wiskonstighe Ghedachtenissen" (Mathematical Memoirs). This included earlier works like "De Driehouckhandel" (Trigonometry ), "De Meetdaet" (Practice of measuring), and De Deursichtighe (Perspective);

* "Castrametatio, dat is legermeting and Nieuwe Maniere van Stercktebou door Spilsluysen" (New ways of building ofsluice s) published in 1617;

* "De Spiegheling der Singconst" (Theory of the art of singing).**External links***

*

* [*http://home.planet.nl/~hopfam/ThiendeMenu.html*] contains an HTML version (including hyperlinks to explanations) of "De Thiende" and its translations into English, French and Swedish, and scans of these books

* [*http://home.planet.nl/~hopfam/Stevin.html*] contains a lot more information about Simon Stevin

* [*http://www.newadvent.org/cathen/14293b.htm*] is the text of the Catholic Encyclopedia about Stevin. The author can hardly conceal his admiration, and for the rest the article is mostly a bibliography of Stevin's work.

* [*http://3quarksdaily.blogs.com/3quarksdaily/2005/05/monday_musing_s.html*] is a short essay on Simon Stevin by S. Abbas Raza at [*http://3quarksdaily.com "3 Quarks Daily"*]

* [*http://www.simonstevin.be*] is an Internet bibliography regarding Simon Stevin.

* [*http://mathdl.maa.org/convergence/1/?pa=content&sa=viewDocument&nodeId=1034&bodyId=1228*] treats Stevin's use of the rule of false position.

* http://www.newadvent.org/cathen/14293b.htm

* [*http://www.mathpages.com/home/kmath548/kmath548.htm MathPages - "Wonder En Is Gheen Wonder"*]**References***1911

**Further reading*** Virtually all of Stevin's writings have been published in five volumes with introduction and analysis in: cite book | editor=

E. J. Dijksterhuis , et al. | title=The Principal Works of Simon Stevin | location=Lisse | publisher=Swets & Zeitlinger | year=1955-1966 The Principal Works are available online at [*http://www.library.tudelft.nl/ws/a/resources_guide/treacutesor/digital_works/principal_works_stevin/index.htm the website of the Delft University of Technology library*] .

* Another good source about Stevin is the French-language bundle: cite book | editor=Bibliothèque royale de Belgique | title=Simon Stevin (1548-1620): L'émergence de la nouvelle science | location=Turnhout | publisher=Brepols | year=2004

* A recent work on Simon Stevin in Dutch is: cite book | author=Devreese, J. T. en Vanden Berghe, G. | title=Wonder en is gheen wonder. De geniale wereld van Simon Stevin 1548-1620 | location=Leuven | publisher=Davidsfonds | year=2003**Trivia**The study association of mechanical engineering at the Technische Universiteit Eindhoven, [

*http://www.simonstevin.tue.nl W.S.V. Simon Stevin*] is named after Simon Stevin. In Stevin's memory, the association has called its bar "De Weeghconst" and owns a self-built fleet ofland yacht s.

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