Invariant Mass
The invariant mass is the ratio of four-momentum to four-velocity:
and is also the ratio of four-acceleration to four-force when the rest mass is constant. The four-dimensional form of Newton's second law is:
Read more about this topic: Relativistic Mass Distortion
Famous quotes containing the word mass:
“In the mass of mankind, I fear, there is too great a majority of fools and knaves; who, singly from their number, must to a certain degree be respected, though they are by no means respectable.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)