Mass Centre in Relativity
Abstract
UNDER this title, in NATURE of April 13, p. 587, Prof. M. Born and K. Fuchs gave some relations between the total and a relative momentum vector of a system of two free particles. They only define the magnitude, not the direction of their relative momentum vector. I believe things become clearer by the following statement. Let Va, Wa (a = 0, 1, 2, 3) be (1 + 3)-dimensional velocity time-space vectors of the particles (V2 = W2 = c2), and m1, m2 their scalar masses. Their individual energy-momentum vectors being ia = m1Va and ja = m2Wa we may define the total energy-momentum vector by the relative energy-momentum vector by These definitions entail two identities which are equivalent to equations (4), (5), (6) of Born and Fuchs.
- Publication:
-
Nature
- Pub Date:
- June 1940
- DOI:
- 10.1038/145933a0
- Bibcode:
- 1940Natur.145..933F