Wang said the new equations were the unique outcome ... solving general relativity problems and the energy-momentum tensor quantifies the density and current of energy and momentum in spacetime.

And, most famously, energy was equivalent to mass, proportional to each other based on the famous equation E = mc² ... the "energy-momentum density", that is, the energy and the momentum ...

The expression used for the imparted pressure on the surface of the liquid from the Helmholtz force density (equation (4)) has the same form as that using Minkowski momentum. A correct field ...

Density defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume. Momentum is a corner stone concept in Physics. It is a conserved quantity.

To solve the momentum paradox the authors prove that the special theory of relativity requires an extra atomic density to travel with the photon. In related classical computer simulations ...

Wang said the new equations were the unique outcome ... solving general relativity problems and the energy-momentum tensor quantifies the density and current of energy and momentum in spacetime.