Hubble's Law graph. This graph shows data for the velocity of galaxies (v, left) plotted against the distance to the galaxies (d, right). The resulting straight-line graph means the two values are proportional, related by a constant called the Hubble constant (H). This result was obtained in 1929 by the US astronomer Edwin Hubble (1889-1953), based on nearly a decade of observations made of the Doppler shift (redshift) of distant galaxies. This work supported theories that the universe is expanding, and the age of the universe (about 14 billion years) was calculated from the observed value of the Hubble constant.