General Relativity
The stress-energy tensor is a second-order tensor field containing energy-momentum densities, energy-momentum fluxes, and shear stresses, of a mass-energy distribution. The divergence of this tensor vanishes:
because energy and momentum are conserved. This is an important constraint on the form the Einstein field equations take in general relativity.
Read more about this topic: Continuity Equation
Famous quotes containing the words general and/or relativity:
“A general is just as good or just as bad as the troops under his command make him.”
—Douglas MacArthur (1880–1964)
“By an application of the theory of relativity to the taste of readers, to-day in Germany I am called a German man of science, and in England I am represented as a Swiss Jew. If I come to be regarded as a bête noire the descriptions will be reversed, and I shall become a Swiss Jew for the Germans and a German man of science for the English!”
—Albert Einstein (1879–1955)