Heading: (Einstein, Albert)
Author: Freundlich, Erwin
Title: Die Grundlagen der Einsteinschen Gravitationstheorie
Place Published: Berlin
Publisher:Verlag von Julius Springer
Date Published: 1916
Description:

64 pp. Original foreword by Albert Einstein. (8vo) 22x14.5 cm (8¾x5¾"), original printed wrappers. First Edition.

This is the first book on Einstein's General Theory of Relativity by another author. An astronomical physicist and a close colleague of Einstein's, Einstein said of Freundlich (in his foreword) that he was "the first among fellow-scientists who has taken pains to put the theory [of general relativity] to the test." As early as 1911, Freundlich attempted at Einstein's personal request to make accurate measurements of Mercury's orbit and perihelion so as to confirm the then-nascent Theory of General Relativity. In 1914 he sought to measure the deflection of star light passing close to the sun during an eclipse, only to have the attempt aborted by the outbreak of the First World War. (A similar experiment carried out in 1919 famously confirmed the empirical validity of General Relativity.) Freundlich also made other tests of General Relativity based on gravitational redshift. In 1918 Freundlich became Einstein's full-time working associate. There appears to be a hand-written note by Freundlich (initialed "E") in the book at the bottom of page 34. There is an illegible ownership signature at the top of the title-page. The year 2016 marks the 100th anniversary of the General Theory of Relativity.

Slight toning and extremity wear to wrappers, spine leaning a touch; very good. Rare.