London: Taylor and Francis, 1928. Three Quarter Leather. First Edition. ix, 1272 pp. 8vo. 21 Plates. In original brown buckram full cloth binding with gold embossed titling to spine. Only indication of ex-library status is a blind embossed library stamp on the title page and the checkout slip pasted to the last free endpaper. Very clean within. Fine.
“Hubble’s Law” is the linear relationship between the velocity with which distant celestial objects are receding from us and their distance from us. It is named Hubble’s law because American astronomer Edwin Powell Hubble was the first to convincingly demonstrate this law and illustrate it clearly with a chart.
Hubble was not the first to consider a linear relationship between velocity and distance. A few others preceded him, most notably American physicist Howard Percy Robertson (1903-1961). In 1928, a year before Hubble proposed his “law,” Robertson proposed the relationship based on his analysis of Einstein's general theory of relativity and verified it with data from Slipher and Hubble.