Chicago: University of Chicago, 1930. 1st Edition. FIRST EDITION OF HUBBLE’S FORMULATION OF A LAW (NOW KNOWN AS THE HUBBLE-REYNOLDS LAW) THAT GIVES THE OBSERVED SURFACE BRIGHTNESS PROFILE OF ELLIPTICAL GALAXIES AS A FUNCTION OF PROJECTED RADIAL DISTANCE.
HUBBLE: The law was first formulated by John Henry Reynolds in 1913 from his observations of galaxies (then still known as nebulae). It was later re-derived by Hubble in 1930 specifically in observations of elliptical galaxies. The Hubble-Reynolds empirical law of observational cosmology states that the velocities at which galaxies in theuniverse recede from one another is directly proportional to the distances between them.
“This law, remarkable because of its simplicity, predicts a deficit of light close to the center and more light in the outer envelope of a galaxy” (Matzner, Dictionary of Geophysics, 230).
HALE: The purpose of Hale’s paper was “to describe in detail some of the rapid motions of hydrogen flocculi near sun-spots” (Hale, Abstract, p. 73). A spectrohelioscope is a type of solar telescope Hale invented in 1924 that allowed the Sun to be viewed in a selected wavelength of light. “It is one of the ingenious features of Dr. Hale's design for his spectrohelioscope that flocculi with large radial velocities, especially differential velocities along their length, can be picked up and their velocities quickly measured by means of the ‘line-shifter’” ( Nature, 126, page 70 (1930). Item #1638
CONDITION & DETAILS: Chicago: University of Chicago Press. Complete. Ex-libris marking on the front flyleaf and pastedown. NO spine markings whatsoever. 4to (9.75 x 6.75 inches). , vi, , 4. Twelve plates and in-text illustrations throughout. Tightly bound in red buckram. Gilt-lettered at the spine. Bright and clean throughout. Very good +.