Verbal noun of → contract.
Fr.: contraction gravitationnelle
Decrease in the volume of an astronomical object under the action of a dominant, central gravitational force.
Fr.: contraction de Kelvin-Helmholtz
After the Scottish physicist William Thomson, also known as Lord Kelvin (1824-1907) and the German physicist and physician Hermann Ludwig Ferdinand von Helmholtz (1821-1894), who made important contributions to the thermodynamics of gaseous systems; → contraction.
Fr.: contraction de longueur
Same as → Lorentz contraction.
Fr.: contraction de Lorentz
The decrease in the length of a body moving in the direction of its length as measured by an observer situated in that direction. The shortening factor is [1 - (v/c)2]1/2, where v is the relative velocity and c light speed.
Fr.: contraction de tenseur
An operation of tensor algebra that is obtained by setting unlike indices equal and summing according to a summation convention.