Johann Heinrich Lambert

See also: Lambert

Johann Heinrich Lambert (August 26th 1728 with Mulhouse - September 25th 1777 with Berlin) is a Mathématicien, Physicien and Alsatian Astronome of the 18th century, in fact Swiss and German of French ascent, because born in Mulhouse which formed part of Switzerland then. He wrote exclusively in German, his native tongue.

Biography

Of father dressmaker, of a family of seven children, Johann was not likely to reach the higher learning. At the twelve years age, it left the school to help its family. However in the evening it continued to study sciences. At the fifteen years age, he worked in the iron and steel industry, then earned his living in a newspaper, the Basler Zeitung . He benefitted from it to study the Mathématiques, the Philosophie and the Astronomie. In 1748, the editor recommended it as tutor in the family of the count Peter von Salis. This employment left him sufficient time to reach its private library. At this point in time it was initiated with mathematical research.

Noticed by the scientific community, it published its first work in 1755. After some voyages, it is established with Augsburg in 1759 as publication director. It was invited by Euler with Berlin in 1764.

It is known in Géographie for the projection which bears its name; obligatory for the establishment of the topographic Chart of France, it consists of 4 conical projections, in conformity, taken along the Méridien of Paris, into 4 parallel S equidistant.

So it prepared the study of the transformations in conformity (the plan of Argand and the Complex numbers of Gauss are posterior 30 years).

Its treated of prospect (1759, 1774) precedes work by Monge, continued by Poncelet. It creates a Perspectographe which bears its name.

Worried by the representation the depth in Painting and the representation of the transparency of the air, it states the law of Lambert in photometry (1760).

Its work on the layouts with the rule and the compass leads it to discuss of famous the postulate of Euclide on the parallel (1786), and to prove the irrationality of π (1768). He studied the hyperbolic trigonometry.

In Astronomy, finding the results of Euler on the parabolic trajectories (of null energy) of the Comet S, it prolongs them by the Théorème of Lambert on the elliptic orbits (3 dated positions make it possible to determine the Keplerian movement of a satellite ) (1761). One owes him of many articles of spherical Trigonométrie (1770), but without the solid concept of Angle being still clearly defined.

  • It was one of the creators of the photometry.

  • It played a precursory part in the Logique symbolic system.
  • Important work in Theory of knowledge (1764).

See too

Related articles

External bonds

  • Works of Lambert digitized by the SCD of [[University Louis Pasteur] of Strasbourg] the
  • Lambert

Random links:Cardiganshire | Courtesy | Z 5600 | Benton file | Filmfare Awards 1998 | Cerovac (Smederevska Palanka) | Voiture_de_kit