An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The speed with which a → galaxy cluster recedes from us is directly proportional to its distance. It can be stated as v = H₀d, where v is the recessional velocity, H₀ the → Hubble-Lamaitre constant, and d the distance. See also → Hubble-Lemaitre flow. It should be underlined that Hubble was not the first to discover the → velocity-distance relation. Two years before Hubble, in 1927, Georges Lemaître (1894-1966) had derived the relation and published it in a paper in French which remained neglected (→ Friedmann-Lemaitre Universe).

The International Astronomical Union (IAU) at its 30th Meeting approved the Resolution B4 proposed by the IAU Executive Committee recommending the use of Hubble-Lemaitre law instead of Hubble's law, after Edwin Hubble (1889-1953), the American astronomer who published his results in 1929 and Georges Lemaître, Belgian priest and astronomer, who published a paper on the expansion of the Universe in 1927; → law.