Pierre Varignon

Pierre de Varignon (also Pierre Varignon ) (* 1654 in Caen, † December 23, 1722 in Paris) was a French scientist, mathematician and physicist.

Curriculum vitae

He was first minister in 1676, studied at the Jesuit College in Caen until 1682 theology and philosophy, and has been a priest in 1683 in Caen. 1686 he went to Paris to study mathematics at the College Mazarin de Paris. He was a member of the 1688 Department of geometry of the Royal Academy of Sciences in November. In 1699 he got his first title of King Louis XIV in 1704 he became professor of mathematics. According to other, less credible information ( encyclopedia of scientists ), he has been Professor in 1688. That would, however, already been two years after beginning his studies. - From 1710 to 1712 he was Under - Director and then Director of the Academy until 1719.

Varignon dealt with in addition to the mathematics of theoretical mechanics and dynamics.

Mathematical work

He has found 1710 named after him sentence of Varignon. This is a theorem which states that the figure obtained when connecting the middles of any quadrilateral with one another, is always a parallelogram.

Varignon also described hyperbolic and logarithmic spirals in which the radius varies with the angle of rotation.

Physical work

Mechanics / Statics

In 1688 he proved the composition of forces in a parallelogram of forces, which had been previously described by Simon Stevin ("Law of parallelogram of forces "). According to other data ( see Web TU Freiberg ), it was not until 1710, the " Law of parallelogram of forces ", but is probably the parallelogram theorem meant. - He also dealt with the moment of force (torque), the balance of fluids and their movement. Varignon one of the pioneers of engineering mechanics and created, among other bases for the structural analysis. 1690, he also developed a mechanical explanation of gravitation.

Kinematics

In two publications of the Academy on July 5, 1698, January 20, 1700, he defined the instantaneous speed (speed of the moment ) and the acceleration of a body using the differential calculus by Leibniz on the direction of motion of a solid body. Showing that it is possible to derive the acceleration of a body of its instantaneous speed by a simple differentiation. The acceleration is the derivative of the velocity. He therefore applied to the calculus to physical problems.

Writings

  • Projet d'une nouvelle mécanique in 1687 (or 1689)
  • Nouvelles conjectures sur la pesanteur 1690
  • Nouvelle mécanique ou Statique 1725
  • Éclaircissements sur l' analyze the infiniment petits et sur ​​le calcul exponential of the Bernoulli 1725
  • Traité du mouvement et de la mesure des eaux jaillissantes 1725
  • Eléments de Mathématiques 1731
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