Jacques de Billy
Encyclopedia
Jacques de Billy was a French
Jesuit mathematician
. Born in Compiègne
, he subsequently entered the Society of Jesus
. From 1629 to 1630, Billy taught mathematics at the Jesuit College at Pontà Mousson. He was still studying theology
at this time. From 1631 to 1633, Billy taught mathematics at the Jesuit college at Rheims. From 1665 to 1668 he was professor of mathematics at the Jesuit college at Dijon
. One of his pupils there was Jacques Ozanam
. Billy also taught in Grenoble
. He also served as rector
of a number of Jesuit Colleges in Châlons
, Langres
and in Sens
.
The mathematician Claude Gaspard Bachet de Méziriac
, who had been a pupil of Billy's at Rheims, became a close friend. Billy maintained a correspondence with the mathematician Pierre de Fermat
.
which have been named after him. Bachet introduced Billy to indeterminate analysis. Billy's mathematical works include Diophantus
Redivivus.
In the field of astronomy
, he published several astronomical tables. First published in Dijon
by Pierre Palliot in 1656, Billy's tables of eclipse
s is called Tabulae Lodoicaeae seu universa eclipseon doctrina tabulis, praeceptis ac demonstrationibus explicata. Adiectus est calculus, aliquot eclipseon solis & lunae, quae proxime per totam Europam videbuntur. The tables were calculated for the years 1656 to 1693. This work also contains solar and lunar tables based on the Paris meridian
. It also includes a detailed examination of problems involved in astronomical calculations.
Billy was one of the first scientists to reject the role of astrology
in science. He also rejected old notions about the malevolent influence of comet
s.
He died at Dijon
.
The crater Billy
on the Moon
is named after him.
French people
The French are a nation that share a common French culture and speak the French language as a mother tongue. Historically, the French population are descended from peoples of Celtic, Latin and Germanic origin, and are today a mixture of several ethnic groups...
Jesuit mathematician
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
. Born in Compiègne
Compiègne
Compiègne is a city in northern France. It is designated municipally as a commune within the département of Oise.The city is located along the Oise River...
, he subsequently entered the Society of Jesus
Society of Jesus
The Society of Jesus is a Catholic male religious order that follows the teachings of the Catholic Church. The members are called Jesuits, and are also known colloquially as "God's Army" and as "The Company," these being references to founder Ignatius of Loyola's military background and a...
. From 1629 to 1630, Billy taught mathematics at the Jesuit College at Pontà Mousson. He was still studying theology
Theology
Theology is the systematic and rational study of religion and its influences and of the nature of religious truths, or the learned profession acquired by completing specialized training in religious studies, usually at a university or school of divinity or seminary.-Definition:Augustine of Hippo...
at this time. From 1631 to 1633, Billy taught mathematics at the Jesuit college at Rheims. From 1665 to 1668 he was professor of mathematics at the Jesuit college at Dijon
Dijon
Dijon is a city in eastern France, the capital of the Côte-d'Or département and of the Burgundy region.Dijon is the historical capital of the region of Burgundy. Population : 151,576 within the city limits; 250,516 for the greater Dijon area....
. One of his pupils there was Jacques Ozanam
Jacques Ozanam
Jacques Ozanam was a French mathematician.-Biography:Jacques Ozanam was born in Sainte-Olive, Ain, France....
. Billy also taught in Grenoble
Grenoble
Grenoble is a city in southeastern France, at the foot of the French Alps where the river Drac joins the Isère. Located in the Rhône-Alpes region, Grenoble is the capital of the department of Isère...
. He also served as rector
Rector
The word rector has a number of different meanings; it is widely used to refer to an academic, religious or political administrator...
of a number of Jesuit Colleges in Châlons
Chalons
Chalons may refer to:Places* Châlons, in France's Isère département* Châlons-en-Champagne, formerly Châlons-sur-Marne, in the Marne département* Chalon-sur-Saône, in the Saône-et-Loire département* Roman Catholic Diocese of Châlons...
, Langres
Langres
Langres is a commune in north-eastern France. It is a subprefecture of the Haute-Marne département in the Champagne-Ardenne region.-History:As the capital of the Romanized Gallic tribe the Lingones, it was called Andematunnum, then Lingones, and now Langres.The town is built on a limestone...
and in Sens
Sens
Sens is a commune in the Yonne department in Burgundy in north-central France.Sens is a sub-prefecture of the department. It is crossed by the Yonne and the Vanne, which empties into the Yonne here.-History:...
.
The mathematician Claude Gaspard Bachet de Méziriac
Claude Gaspard Bachet de Méziriac
Claude Gaspard Bachet de Méziriac was a French mathematician, linguist, poet and classics scholar born in Bourg-en-Bresse.Bachet was a pupil of the Jesuit mathematician Jacques de Billy at the Jesuit College in Rheims...
, who had been a pupil of Billy's at Rheims, became a close friend. Billy maintained a correspondence with the mathematician Pierre de Fermat
Pierre de Fermat
Pierre de Fermat was a French lawyer at the Parlement of Toulouse, France, and an amateur mathematician who is given credit for early developments that led to infinitesimal calculus, including his adequality...
.
Work and legacy
Billy produced a number of results in number theoryNumber theory
Number theory is a branch of pure mathematics devoted primarily to the study of the integers. Number theorists study prime numbers as well...
which have been named after him. Bachet introduced Billy to indeterminate analysis. Billy's mathematical works include Diophantus
Diophantus
Diophantus of Alexandria , sometimes called "the father of algebra", was an Alexandrian Greek mathematician and the author of a series of books called Arithmetica. These texts deal with solving algebraic equations, many of which are now lost...
Redivivus.
In the field of astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
, he published several astronomical tables. First published in Dijon
Dijon
Dijon is a city in eastern France, the capital of the Côte-d'Or département and of the Burgundy region.Dijon is the historical capital of the region of Burgundy. Population : 151,576 within the city limits; 250,516 for the greater Dijon area....
by Pierre Palliot in 1656, Billy's tables of eclipse
Eclipse
An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer...
s is called Tabulae Lodoicaeae seu universa eclipseon doctrina tabulis, praeceptis ac demonstrationibus explicata. Adiectus est calculus, aliquot eclipseon solis & lunae, quae proxime per totam Europam videbuntur. The tables were calculated for the years 1656 to 1693. This work also contains solar and lunar tables based on the Paris meridian
Paris Meridian
The Paris Meridian is a meridian line running through the Paris Observatory in Paris, France—now longitude 2°20′14.025″ east. It was a long-standing rival to Greenwich as the prime meridian of the world, as was the Meridian of Antwerp in Antwerp, Belgium....
. It also includes a detailed examination of problems involved in astronomical calculations.
Billy was one of the first scientists to reject the role of astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...
in science. He also rejected old notions about the malevolent influence of comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s.
He died at Dijon
Dijon
Dijon is a city in eastern France, the capital of the Côte-d'Or département and of the Burgundy region.Dijon is the historical capital of the region of Burgundy. Population : 151,576 within the city limits; 250,516 for the greater Dijon area....
.
The crater Billy
Billy (crater)
Billy is a lunar crater that is located at the southern fringes of the Oceanus Procellarum, in the western hemisphere of the Moon. It lies to the southeast of the similar-sized crater Hansteen, and west-southwest of the flooded Letronne....
on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named after him.