vis viva

Vis viva ( living force ) is a historical term for the "energy in motion " and goes back to Gottfried Leibniz. Its formula was for the kinetic energy, however, and thus twice as high as the actual value. But it was important that the speed went down in the square, which leads to a scalar quantity, and the interpretation as a conserved quantity.

Unlike Leibniz René Descartes and Isaac Newton kept the pulse of the fundamental conserved quantity. For Newton not the energy concept, but the concept of force ( Vis ) and causing changes in momentum played a central role.

Until the 19th century the term was used vibrant force for the energy, the accuracy of Leibniz's ideas was proved in the 18th century by Émilie du Châtelet.

The Vis Viva equation of celestial mechanics describes the movement or speed of bodies on Keplerian orbits as a consequence of energy conservation.