Charles Augustin de Coulomb

Charles-Augustin de Coulomb (French: /ʃaʁl ogystɛ̃ də kulɔ̃/; Angouleme, June 14, 1736-Paris, August 23, 1806) was a French mathematician, physicist and engineer. He is remembered for having mathematically described the law of attraction between electric charges. In his honor, the unit of electric charge is called the coulomb (C).Among other studies, he owes the theory of straight torsion and an analysis of ground failure within soil mechanics.

Biography

He was educated at the École du Génie in Mézieres, graduating in 1761 as a military engineer with the rank of first lieutenant. Coulomb served in the West Indies for nine years, where he supervised the construction of fortifications on Martinique. In 1774, Coulomb became a correspondent for the Paris Academy of Sciences. He shared the first Academy Award for magnetic compasses and also received first prize for his classic work on friction, a study that was unsurpassed for 150 years.

Over the next 25 years, he submitted 25 papers to the Academy on electricity, magnetism, torsion, and torsion balance applications, as well as several hundred reports on engineering and civil projects.

Coulomb took full advantage of the different positions he held during his life. His experience as an engineer led him to investigate the strength of materials and to determine the forces that affect objects on beams, thereby contributing to the field of structural mechanics. In 1773, he published an essay on an application of the maximum and minimum rules to some statics problems, related to architecture, where he made use of the advanced tool of calculus of variations to study the bending of the beams, the thrust of the earth in the retaining walls and the balance of the vault in masonry. In this paper he defined the law of friction and made the first formalization of the concept of tangential stress, in addition to introducing what was later called the Coulomb method for evaluating the resistance of materials. The work was presented at the French Academy of Sciences by his former professor Bossut, on July 6, 1774.

Another contribution of Coulomb is the so-called Coulomb Theory about earth pressure, published in 1776, in which he gave a different approach to the problem of thrust on walls, considering fault wedges, in which the wall acts, and taking into account the angle of inclination of the wall and the ground on the retaining wall. Coulomb left a legacy as a pioneer in the field of geotechnical engineering for his contributions to the design of these walls.

He also made contributions in the field of ergonomics.

On February 26, 1790, their firstborn son, Charles-Augustin, was born. Seven years later, on July 30, 1797, he had his second child, Henry-Louis. Finally, on November 8, 1802, he married Louise Françoise LeProust Desormeaux, their mother.

Coulomb died in 1806, five years after becoming president of the Institut de France (formerly the Paris Academy of Sciences). His research on electricity and magnetism allowed this area of physics to break out of traditional natural philosophy and become an exact science. History recognizes him with excellence for his mathematical work on electricity known as Coulomb's Law.

Realizations

Apparatus used by Coulomb for the measurement of friction forces.

He was the first scientist to establish the quantitative laws of electrostatics, in addition to conducting extensive research on magnetism, friction, and electricity. His scientific research is collected in seven memoirs, in which he theoretically exposes the foundations of magnetism and electrostatics.

In 1777 he invented the balance of torsion to measure the force of attraction or repulsion that exert two electric loads each other and established the function that links this force with distance. With this invention, culminated in 1785, Coulomb was able to establish the principle, which governs the interaction between electrical loads, currently known as the law of Coulomb: F=kqq♫d2{displaystyle F=k{frac {qq'}{d^{2}}}}}.

He also studied electrification by friction, polarization and introduced the concept of magnetic moment. The coulomb or coulomb (symbol C), is the unit derived from the International System of Units for the measurement of the physical magnitude of amount of electricity (electric charge), named in his honor.

Works

• Théorie des machines simple (Paris: Bachelier, 1821)
• "Mémoires". Collection de mémoires relatifs à la physique (Paris: Gauthier-Villars, 1884)
• Recherches sur les moyens d'exécuter sous l'eau toutes sorts de travaux (1779)

Acknowledgments

• The electric charge unit, the assmbie, carries his name.
• It is one of 72 scientists whose name is registered at the Eiffel Tower.
• The moon crater Coulomb was named in his honor.