Marin Mersenne | |
|---|---|
 | |
| Born | (1588-09-08)8 September 1588 |
| Died | 1 September 1648(1648-09-01) (aged 59) Paris, Kingdom of France |
| Other names | Marinus Mersennus |
| Known for | Mersenne primes Mersenne's conjecture Mersenne's laws Acoustics |
| Scientific career | |
| Fields | Mathematics,physics |
Marin Mersenne,OM (also known asMarinus Mersennus orle Père Mersenne;French:[maʁɛ̃mɛʁsɛn]; 8 September 1588 – 1 September 1648) was a Frenchpolymath whose works touched a wide variety of fields. He is perhaps best known today among mathematicians forMersenne prime numbers, those written in the formMn = 2n − 1 for someintegern. He also developedMersenne's laws, which describe the harmonics of a vibrating string (such as may be found onguitars andpianos), and his seminal work onmusic theory,Harmonie universelle, for which he is referred to as the "father ofacoustics".[1][2]
Mersenne, an ordainedCatholic priest, had many contacts in the scientific world and has been called "the center of the world of science and mathematics during the first half of the 1600s"[3] and, because of his ability to make connections between people and ideas, "the post-box of Europe".[4] He was also a member of the asceticalMinim religious order and wrote and lectured ontheology andphilosophy.
Mersenne was born of Jeanne Moulière, wife of Julien Mersenne, peasants who lived nearOizé,County of Maine (present-daySarthe, France).[5] He was educated atLe Mans and at theJesuit College of La Flèche. On 17 July 1611, he joined theMinim Friars and, after studying theology andHebrew in Paris, was ordained a priest in 1613.
Between 1614 and 1618, he taught theology and philosophy atNevers, but he returned to Paris and settled at the convent ofL'Annonciade in 1620. There he studied mathematics and music and met with other kindred spirits such asRené Descartes,Étienne Pascal,Pierre Petit,Gilles de Roberval,Thomas Hobbes, andNicolas-Claude Fabri de Peiresc. He corresponded withGiovanni Doni,Jacques Alexandre Le Tenneur,Constantijn Huygens,Galileo Galilei, and other scholars in Italy, England and theDutch Republic. He was a staunch defender of Galileo, assisting him in translations of some of his mechanical works.
For four years, Mersenne devoted himself entirely to philosophic and theological writing, and publishedQuaestiones celeberrimae in Genesim (Celebrated Questions on the Book of Genesis) (1623);L'Impieté des déistes (The Impiety of theDeists) (1624);La Vérité des sciences (Truth of the Sciences Against the Sceptics, 1624).[6] It is sometimes incorrectly stated that he was aJesuit. He was educated by Jesuits, but he never joined theSociety of Jesus. He taught theology and philosophy at Nevers and Paris.
In 1635 he set up the informalAcadémie Parisienne (Academia Parisiensis), which had nearly 140 correspondents, including astronomers and philosophers as well as mathematicians, and was the precursor of theAcadémie des sciences established byJean-Baptiste Colbert in 1666.[a] He was not afraid to cause disputes among his learned friends in order to compare their views, notable among which were disputes between Descartes,Pierre de Fermat, andJean de Beaugrand.[7]Peter L. Bernstein, in his bookAgainst the Gods: The Remarkable Story of Risk, wrote, "The Académie des Sciences in Paris and the Royal Society in London, which were founded about twenty years after Mersenne's death, were direct descendants of Mersenne's activities."[8]
In 1635 Mersenne met withTommaso Campanella but concluded that he could "teach nothing in the sciences ... but still he has a good memory and a fertile imagination." Mersenne asked if Descartes wanted Campanella to come to Holland to meet him, but Descartes declined. He visited Italy fifteen times, in 1640, 1641 and 1645. In 1643–1644 Mersenne also corresponded with the German SocinianMarcin Ruar concerning the Copernican ideas ofPierre Gassendi, finding Ruar already a supporter of Gassendi's position.[9] Among his correspondents were Descartes, Galileo, Roberval,Pascal,Beeckman and other scientists.
He died on 1 September 1648 of complications arising from alung abscess.
Quaestiones celeberrimae in Genesim was written as a commentary on theBook of Genesis and comprises uneven sections headed by verses from the first three chapters of that book. At first sight the book appears to be a collection of treatises on various miscellaneous topics. However Robert Lenoble has shown[10] that the principle of unity in the work is a polemic againstmagical anddivinatory arts,cabalism, andanimistic andpantheistic philosophies.
Mersenne was concerned with the teachings of some Italiannaturalists that all things happened naturally and determined astrologically; for example, thenomological determinism ofLucilio Vanini ("God acts on sublunary beings (humans) using the sky as a tool"), andGerolamo Cardano's idea that martyrs and heretic were compelled to self-harm by the stars;[11] Historian of science William Ashworth[12] explains "Miracles, for example, were endangered by the naturalists, because in a world filled with sympathies and occult forces—with what Lenoble calls a "spontanéité indéfinie"—anything could happen naturally".[13]
Mersenne mentionsMartin Del Rio'sInvestigations into Magic and criticisesMarsilio Ficino for claiming power for images and characters. He condemns astral magic andastrology and theanima mundi, a concept popular amongstRenaissanceneo-platonists. Whilst allowing for a mystical interpretation of the Cabala, he wholeheartedly condemned its magical application, particularlyangelology. He also criticisesPico della Mirandola,Cornelius Agrippa,Francesco Giorgio andRobert Fludd, his main target.
Harmonie universelle is perhaps Mersenne's most influential work. It is one of the earliest comprehensive works on music theory, touching on a wide range of musical concepts, and especially the mathematical relationships involved in music. The work contains the earliest formulation of what has become known asMersenne's laws, which describe the frequency of oscillation of a stretched string. This frequency is:
The formula for the lowest frequency is
wheref is the frequency [Hz],L is the length [m],F is the force [N] and μ is the mass per unit length [kg/m].
In this book, Mersenne also introduced several innovative concepts that can be considered the basis of modern reflecting telescopes:
Because of criticism that he encountered, especially from Descartes, Mersenne made no attempt to build a telescope of his own.
Mersenne is also remembered today thanks to his association with theMersenne primes. TheMersenne Twister, named for Mersenne primes, is frequently used in computer engineering and in related fields such as cryptography.
However, Mersenne was not primarily a mathematician; he wrote aboutmusic theory and other subjects. He edited works ofEuclid,Apollonius,Archimedes, and otherGreek mathematicians. But perhaps his most important contribution to the advance of learning was his extensive correspondence (inLatin) with mathematicians and other scientists in many countries. At a time when thescientific journal had not yet come into being, Mersenne was the centre of a network for exchange of information.
It has been argued that Mersenne used his lack of mathematical specialty, his ties to the print world, his legal acumen, and his friendship with the French mathematician and philosopher René Descartes (1596–1650) to manifest his international network of mathematicians.[16]
Mersenne's philosophical works are characterized by wide scholarship and the narrowest theological orthodoxy. His greatest service to philosophy was his enthusiastic defence of Descartes, whose agent he was in Paris and whom he visited in exile in theNetherlands. He submitted to various eminent Parisian thinkers a manuscript copy of theMeditations on First Philosophy, and defended its orthodoxy against numerous clerical critics.[6]
In later life, he gave up speculative thought and turned to scientific research, especially in mathematics, physics and astronomy. In this connection, his best known work isHarmonie universelle of 1636, dealing with thetheory of music andmusical instruments.[6] It is regarded as a source of information on 17th-century music, especially French music and musicians, to rival even the works ofPietro Cerone.
One of his many contributions tomusical tuning theory was the suggestion of
as theratio for anequally-temperedsemitone (). It was more accurate (0.44cents sharp) thanVincenzo Galilei's 18/17 (1.05 cents flat), and could be constructed usingstraightedge and compass. Mersenne's description in the 1636Harmonie universelle of the first absolute determination of the frequency of an audible tone (at 84 Hz) implies that he had already demonstrated that the absolute-frequency ratio of two vibrating strings, radiating a musical tone and itsoctave, is 1 : 2. The perceived harmony (consonance) of two such notes would be explained if the ratio of the air oscillation frequencies is also 1 : 2, which in turn is consistent with the source-air-motion-frequency-equivalence hypothesis.
He also performed extensive experiments to determine the acceleration of falling objects by comparing them with the swing ofpendulums, reported in hisCogitata Physico-Mathematica in 1644. He was the first to measure the length of theseconds pendulum, that is a pendulum whose swing takes one second, and the first to observe that a pendulum's swings are notisochronous as Galileo thought, but that large swings take longer than small swings.[17]
Two German pamphlets that circulated around Europe in 1614–15,Fama fraternitatis andConfessio Fraternitatis, claimed to be manifestos of a highly select, secret society of alchemists and sages called the Brotherhood ofRosicrucians. The books were allegories, but were obviously written by a small group who were reasonably knowledgeable about the sciences of the day,[citation needed] and their main theme was to promote educational reform (they were anti-Aristotelian). These pamphlets also promoted an occult view of science[citation needed] containing elements ofParacelsian philosophy,neo-Platonism,Christian Cabala andHermeticism. In effect, they sought to establish a new form of scientific religion with some pre-Christian elements.[citation needed]
Mersenne led the fight against acceptance of these ideas, particularly those of Rosicrucian promoterRobert Fludd, who had a lifelong battle of words withJohannes Kepler. Fludd responded withSophia cum moria certamen (1626), wherein he discusses his involvement with theRosicrucians. The anonymousSummum bonum (1629), another critique of Mersenne, is a Rosicrucian-themed text. The cabalistJacques Gaffarel joined Fludd's side, whilePierre Gassendi defended Mersenne.
The Rosicrucian ideas were defended by many prominent men of learning, and some members of the European scholarly community boosted their own prestige by claiming to be among the selected members of the Brotherhood.[citation needed] However, it is now generally agreed among historians that there is no evidence that an order of Rosicrucians existed at the time, with later Rosicrucian Orders drawing on the name, with no relation to the writers of the Rosicrucian Manifestoes.[18]
During the mid-1630s Mersenne gave up the search for physical causes in theAristotelian sense (rejecting the idea ofessences, which were still favoured by thescholastic philosophers) and taught that true physics could be only a descriptive science of motions (Mécanisme), which was the direction set byGalileo Galilei. Mersenne had been a regular correspondent with Galileo and had extended the work on vibrating strings originally developed by his father,Vincenzo Galilei.[19]
Anair attributed to Mersenne was used byOttorino Respighi in his second suite ofAncient Airs and Dances
{{cite book}}:Check|isbn= value: invalid character (help)Italian naturalism was considered dangerous to religion because it confused the natural with the supernatural and physics with metaphysics; essentially, it eliminated the boundaries between science and faith.p. 138.
This article incorporates text from a publication now in thepublic domain: Chisholm, Hugh, ed. (1911). "Mersenne, Marin".Encyclopædia Britannica (11th ed.). Cambridge University Press.
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