Auguste Bravais (; 23 August 1811,

Annonay Annonay (; ) is a Communes of France, commune and largest city in the north of the Ardèche department in the Auvergne-Rhône-Alpes region of southeastern France. It is the most populous commune in the Ardèche department although it is not the ...

, Ardèche – 30 March 1863, Le Chesnay, France) was a French physicist known for his work in

crystallography Crystallography is the branch of science devoted to the study of molecular and crystalline structure and properties. The word ''crystallography'' is derived from the Ancient Greek word (; "clear ice, rock-crystal"), and (; "to write"). In J ...

, the conception of Bravais lattices, and the formulation of Bravais law. Bravais also studied

magnetism Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, ...

, the northern lights,

meteorology Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agricultur ...

geobotany Phytogeography (from Greek φυτόν, ''phytón'' = "plant" and γεωγραφία, ''geographía'' = "geography" meaning also distribution) or botanical geography is the branch of biogeography that is concerned with the geographic distribution o ...

phyllotaxis In botany, phyllotaxis () or phyllotaxy is the arrangement of leaf, leaves on a plant stem. Phyllotactic spirals form a distinctive class of patterns in nature. Leaf arrangement The basic leaf#Arrangement on the stem, arrangements of leaves ...

astronomy Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest includ ...

statistics Statistics (from German language, German: ', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a s ...

and

hydrography Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, seas, coastal areas, lakes and rivers, as well as with the prediction of their change over time, for the primary ...

. He studied at the Collège Stanislas in Paris before joining the

École Polytechnique (, ; also known as Polytechnique or l'X ) is a ''grande école'' located in Palaiseau, France. It specializes in science and engineering and is a founding member of the Polytechnic Institute of Paris. The school was founded in 1794 by mat ...

in 1829, where he was a classmate of groundbreaking mathematician

Évariste Galois Évariste Galois (; ; 25 October 1811 – 31 May 1832) was a French mathematician and political activist. While still in his teens, he was able to determine a necessary and sufficient condition for a polynomial to be solvable by Nth root, ...

, whom Bravais actually beat in a scholastic mathematics competition. Towards the end of his studies he became a naval officer, and sailed on the ''Finistere'' in 1832 as well as the ''Loiret'' afterwards. He took part in hydrographic work along the

Algeria Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. It is bordered to Algeria–Tunisia border, the northeast by Tunisia; to Algeria–Libya border, the east by Libya; to Alger ...

n Coast. He participated in the ''Recherche'' expedition and helped the ''Lilloise'' in

Spitzbergen Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. North of mainland Europe, it lies about midway between the northern coast o ...

and Lapland. Bravais taught a course in applied mathematics for astronomy in the Faculty of Sciences in

Lyon Lyon (Franco-Provençal: ''Liyon'') is a city in France. It is located at the confluence of the rivers Rhône and Saône, to the northwest of the French Alps, southeast of Paris, north of Marseille, southwest of Geneva, Switzerland, north ...

, starting in 1840. He succeeded Victor Le Chevalier in the Chair of Physics at the Ecole Polytechnique from 1845 until 1856 when he was replaced by

Henri Hureau de Sénarmont Henri Hureau de Sénarmont () (6 September 1808 – 30 June 1862) was a French mineralogist and physicist. He was born in Broué, Eure-et-Loir. From 1822 to 1826, he studied at the École Polytechnique in Paris, then furthered his education at t ...

. In 1844 he published a paper on the statistical concept of

correlation In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistics ...

, and arrived at a definition of the

correlation coefficient A correlation coefficient is a numerical measure of some type of linear correlation, meaning a statistical relationship between two variables. The variables may be two columns of a given data set of observations, often called a sample, or two c ...

before

Karl Pearson Karl Pearson (; born Carl Pearson; 27 March 1857 – 27 April 1936) was an English biostatistician and mathematician. He has been credited with establishing the discipline of mathematical statistics. He founded the world's first university ...

. He is, however, best remembered for his work on Bravais lattices, particularly his 1848 discovery that there are 14 unique lattices in three-dimensional

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

line systems, correcting the previous scheme, with 15 lattices, conceived by Frankenheim three years before. Bravais published a memoir about crystallography in 1847. A co-founder of the Société météorologique de France, he joined the

French Academy of Sciences The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...

in 1854. Bravais also worked on the theory of

observational error Observational error (or measurement error) is the difference between a measured value of a quantity and its unknown true value.Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP. Such errors are inherent in the measurement ...

s, a field in which he is especially known for his 1846 paper "Mathematical analysis on the probability of errors of a point". In one of his later studies, he investigated the conical pendulum and the effects upon it by the rotation of the Earth, an effect similar in principle to the (planar) Foucault pendulum. Soon after Foucault published his results, Bravais was inspired to experimentally test and to mathematically investigate the conical system, leading to the publication "Memoir on the influence exerted by the rotation of the Earth on the oscillatory motions of a conical pendulum", in 1854. The mountain Bravaisberget, in

Svalbard Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norway, Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. North of continental Europe, mainland Europe, it lies about midway be ...

, is named after Bravais.

References

{{DEFAULTSORT:Bravais, Auguste 1811 births 1863 deaths People from Annonay Members of the French Academy of Sciences 19th-century French physicists École Polytechnique alumni Collège Stanislas de Paris alumni