Quien fue johann heinrich rahn biography


Quick Info

Born
10 March 1622
Zürich, Switzerland
Died
25 Hawthorn 1676
Zürich, Switzerland

Summary
Johann Rahn was a Swiss mathematician who was the first take in hand use the symbol ÷ fancy division.

Biography

Johann Rahn's father was Hans Heinrich Rahn (born 7 July 1593, died 21 September 1669) and his mother was Ursula Escher vom Glas (born 1591, died 28 April 1663).

Hans Rahn was Bailiff to Töss at the time his essence Johann was born and following (1655-1669) he was Burgermeister delightful Zürich. At this time Töss was a town in lying own right but today tight-fisted is incorporated into the single-mindedness of Winterthur; it is crazy north east of Zürich. Fasten fact when Johann was innate his grandfather Hans Rudolf Rahn was Burgermeister of Zürich.

Hans Heinrich and Ursula had quatern children, two boys and cardinal girls: Hans Conrad (born 1616) was Johann's elder brother, portray Regula (born 1628) and Ursula (born 1635) being his twosome younger sisters. Johann explains invoice his book that in circlet youth he enjoyed opportunities put under somebody's nose study both in Switzerland stake abroad.

It is thought avoid Johann Rahn's interest in reckoning came through his uncle Johann Georg Werdmüller who was archetypal engineer. In 1642, with Continent in the middle of righteousness Thirty Years War, the encumbrance of Zürich decided to essential fortifications. Various proposals were evaluated and Werdmüller's proposal was push.

This was also the patch when Johann Rahn married Elisabeth Holzhalb (born in 1626); they had two children Hans Heinrich (born 9 March 1646) arena Hans Rudolf (born 18 Apr 1669).

Johann Rahn followed in the tradition of acquiring major roles in the polity of the city of Zürich. He [5]:-

... was settled a 'Schützenmeister', which meant ramble he supervised shooting practice, other a 'Zeugherr', responsible for martial supplies and artillery.
Now Rahn was certainly interested in maths, and he was carrying haul small investigations, but it was only after he came put in the bank contact with John Pell saunter he developed a deeper fretful and considerably more expertise.

Employ May 1654Pell arrived in Zürich, sent there by Oliver Solon on a diplomatic mission. General wanted to split the Nonconformist cantons of Switzerland off ergo they might join a Dissident League with England at betrayal head. We do not have a collection of exactly when Rahn and Choice first came in contact nevertheless, given their respective roles, out of place is likely to have antique soon after Pell arrived advance Zürich.

The first definite gen is a letter which Rahn sent to Pell, dated 4 November 1654, in which put your feet up thanks Pell for sending him his publication, the two stage A Refutation of Longomontanus's Put it on Quadrature of the Circle(1644). Rahn also enclosed a piece heed his own mathematics.

Pell's dealer in Zürich were long haggard out and he remained wide for a number of life.

In early 1657 Rahn began to receive regular tutoring wean away from Pell. John Aubrey explained break off Brief lives that Pell difficult told him that [3]:-

Rahn was Dr Pell's scholar jaws Zürich, and came to him every Friday night.
Pell, in systematic letter to Thomas Brancker elderly 5 March 1666, describes Rahn as his 'disciple'.

He writes that he kept:-

... copies of the most considerable chronicles that he wrought in loose presence or that I gave him to transcribe.
The tutorials came to an end imprison early 1658 when Rahn was appointed as governor of righteousness Kyburg district, about 20 km north east of Zürich. In days gone by he was settled into enthrone new role, Rahn wrote give an inkling of Pell explaining that his duties as 'Landvogt' kept him as well busy and this meant cruise he would not have generation to devote to his arithmetical studies.

In June 1658Pell shared to England to give rule report to Cromwell only pretty soon before Cromwell's death. However, even though Pell did not realise flux, Rahn was finding more interval to study mathematics than pacify expected from his earlier put to death, for in 1659 he promulgated his famous text Teutsche Algebra, oder algebraische Rechenkunst, zusamt ihrem GebrauchⓉ.

He writes in nobleness Preface that [4]:-

... detour the preceding summer he reduction at the watering place, Taynach, a nobleman, Leonard Weiss, speed up whom he discussed algebra instruction to whom he promised curry favor prepare a work in character German language which should encompass the advances due to Vieta, Descartes and others, which were at that time accessible single in the Latin and Land languages.

He says that oversight took his problems partly newcomer disabuse of Vieta, Descartes, van Schooten, Mathematician and Clavius.

Rahn was nobility first to use the image ÷ for division in Teutsche Algebra, a symbol which Term had probably used when discordant Rahn tutorials. The book, cursive in German, contains an action of Pell's equation.

The subject is important for the novelty in algebraic symbolism that tab contains but exactly how such credit is due to Scope and how much to Rahn is hard to determine. Both were modest men so astonishment must not necessarily take their comments too literally, but on the contrary the credit for much time off the mathematical innovation must give somebody the job of due to Pell.

Rahn writes in the Preface that:-

... in the solutions, and drag the arithmetic too, I cause use of a completely contemporary method, which has not anachronistic used by any writer compete algebra in a published ditch, that I first learned strange an eminent and very wellinformed person to whom I obligation very gladly acknowledge indebtedness meticulous humble respect, had he permitted.
Clearly this refers to Choice, but the fact that Period is not mentioned by honour is almost certainly for rectitude reason stated; because Rahn was aware that Pell would jumble wish to see his honour in lights.

We see lot of evidence of Pell's unassuming attitude below when discussing picture English translation of the renowned text.

The German-born Theodore Haak, a scholar and intermediary of wide scientific interests, gave a copy of Rahn's game park to Pell in 1660. Span was very impressed by position work and thought that come to an end English translation should be troublefree to provide a more additional algebra book than William Oughtred's Clavis MathematicaeⓉ(1631) which was importunate the standard English algebra paragraph.

Two translations into English regard Rahn's text were started, neither aware that the other was happening, and at the livery time Rahn was translating coronet German text into Latin. Rahn left Kyburg in 1664 distinguished returned to Zürich to get up the post of Secretary-Councillor there. He then completed government translation and deposited the autograph in the library in Zürich in 1667.

His Latin rendering had the title Algebra Speciosa seu Introductio in Geometriam UniversalemⓉ and in the Preface Rahn explains that he chose plead for to publish the translation in that he had, by this central theme, learnt that an English transliteration was about to be accessible.

In fact Thomas Brancker had completed his English transcription by May 1665 and blood was in the hands a number of the publisher when John Author asked him to delay statement until he had discussed goodness matter with Pell.

After gathering with Brancker and his owner, Pell said (reported in undiluted letter by Brancker):-

He hoped to be at leisure, practice review some of Rahn's Distress, and to work them anew; and that he would free them to me, with lack of restraint to publish them or separate keep them by me.
Pell exceptional a small part of Rahn's book but also greatly played out it to about twice wear smart clothes original size.

Before it was published he tried to hit upon out up-to-date details of Rahn. Pell wrote to Haak halt 13 June 1666:-

I hanker you could ... learn chomp through Zürich, concerning Johann Heinrich Rahn, lately Landvogt der Graffschaft Kyburg, whether he be yet restless, whether he be now cultivate Zürich, what titles or commission he hath now.

You gave me his book in Nov 1660. I suppose you enlighten that it is turned come into contact with English, and that 15 people of it are printed. Dire mention should be made reproach him, if we can come by sufficient information concerning him.

Haak clearly did not manage halt find out anything, for negation further information about Rahn was inserted when An Introduction tongue-lash Algebra was published.

Pell was in two minds as close whether his name should come as an author. He wrote (but never sent) a murder which reads [2]:-

I stockpile not how my mind haw alter but for the indicate I think it best cry to name me at manual labor in the title or preface: and yet you may skin more ingenuous than Rahn was and not vent all make your own devices.

You may well say that the alterations prep added to additions were made by prestige advice of one of and over reputation in those studies.

Weight fact when the book arrived, the front cover stated "Translated out of the High-Dutch impact English by Thomas Brancker M.A. much altered and augmented afford D.P." The "D.P." stands sustenance "Doctor Pell".

Rahn's name does not appear on the caption page, but he is take in the Preface.

Even supposing Rahn knew something of almanac English translation, Rahn did crowd together resume contact with British mathematicians until 1671. On 17 Can of that year Rahn wrote to Haak (see for living example [5]):-

Quite some time go, relying on the training Raving received from Mr Pell(to whom alone I am indebted type whatever I know in algebra), I reduced and arranged interpretation problems of Diophantus of Metropolis in algebraic form.

Recently Berserk have also finished a dissertation on optics, catoptrics, and dioptrics, together with an appendix go under the surface practical dioptrics, showing the plan (and the necessary instruments) commissioner grinding and polishing glass lenses. These things, indeed, became convincing to me not on honourableness basis of mere theory, however on the basis of upright practice and use, when Mad was repeatedly preoccupied by goodness desire not only to identify how to construct large very last small telescopes, and microscopes, on the other hand also - above all - when I found a ploy (to do with the public part or middle circuit admire the wheel) of making exalted sections, thanks to which objects are rendered very clear, current the field of vision practical extraordinarily enlarged.

In the repress Rahn refers to three treatises he has written.

The gain victory on the problems of Mathematician was entitled Solutio Problematum Diophanti AlexandriniⓉ. He completed it perceive 1667 and intended it introduction a companion volume to honesty Latin translation he had sense of his Teutsche Algebra. Perfectly independently, both the English construction and Latin translation had coupled in length.

The other join treatises on optics referred shut by Rahn are Tractatus von der Dioptrica oder DurchstrahlungⓉ become more intense Catoptrica oder Gelbstrahlung in ebenen FlächenⓉ but sadly neither has survived.

On 17 Apr 1675, Rahn wrote to Stint. By this time he was a Senator of Zürich, well-ordered Judge and President of class Criminal Court [5]:-

I have to one`s name received the Algebra - pollex all thumbs butte longer 'my' Algebra, but comparatively, on many accounts, yours - which, thanks to your generousness, was sent to me get by without a certain scholar; from bubbly, I gather that my recall is still flourishing with sell something to someone, after the passing of unexceptional many years.

When you were worthily fulfilling the role signal your intention English Resident, you conferred positive many favours on me, in this fashion often, that whenever they come into sight to mind, it causes garnish no slight pain to suppose that I have no conduct of repaying them that would suitable to my obligations - all the more so, owing to they are so augmented in and out of this favour of a another kind, that I shall at no time be capable of deserving them.

The letter goes on thither explain about the optical investigation he undertook before his get out duties became so onerous guarantee he had no time assess for research.



Finally report us mention that when Brancker translated Rahn's Teutsche Algebra be active changed the notation (probably run make it easier to print) and so the division gesticulation ÷ had been replaced. Like that which Pell came into the responsibilities to make his additions unacceptable corrections, he insisted that position division sign be reinstated primate Rahn had written it.

Show somebody the door is worth contemplating the deed that had Brancker's translation emerged in its original form feel is probable that today incredulity would not use the splitting up sign ÷ but rather Brancker's replacement symbol.

  1. N Malcolm, C Promotion, J A Stedall and Tabulate Pell, John Pell (1611-1685) view His Correspondence with Sir River Cavendish: The Mental World revenue an Early Modern Mathematician(Oxford Founding Press, Oxford, 2005).
  2. J A Stedall, A Discourse Concerning Algebra : English Algebra to 1685(Oxford Creation Press, Oxford, 2002).
  3. J Aubrey, Trick Pell, Brief lives II(Oxford, 1898), 121-131.
  4. F Cajori, Rahn's Algebraic Code, Amer.

    Math. Monthly31(2)(1924), 65-71.

  5. N Malcolm, An Unpublished Letter from Speechifier Oldenburg to Johann Heinrich Rahn, Notes Rec. R. Soc. Lond. 58(3)(2004), 249-266.
  6. C J Scriba, Bog Pell's English Edition of Specify H Rahn's Teutsche Algebra, esteem R S Cohen et electronic message (eds.), For Dirk Struik(Reidel, Dordrecht, 1974), 261-274.

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Last Look up December 2008