Hubble's law Proposed by Edwin Hubble (1929), it claimed a linear relation between the distance of galaxies from us and their velocity of recession, deduced from the red shift in their spectra. The Hubble constant (symbol H₀) is the rate at which the velocity of recession of galaxies increases with distance from us. The inverse of the Hubble constant is the Hubble time, which gives a maximum age for the Universe on the assumption that there has been no slowing of the expansion.

Hubble's law As formulated in 1936 by the American astronomer Edwin Powell Hubble (1889–1953) and his colleague Milton Lasell Humason (1891–1972), the distance to a galaxy in light-years is equal to one-hundredth of its red-shift velocity in miles per second.