1923
by Einstein, Albert
1923. Offprint from Zeitschrift für Physik 16 (1923). Single sheet, unpaginated. 230 x 155 mm. One corner creased but very good. First edition, offprint issue. Einstein's second response to Friedmann's groudbreaking paper on equations governing the expansion of space, which made a valuable contribution to Einstein's theory of relativity and admitted the possibility of an expanding universe. Einstein at first believed that Friedmann's reasoning was incorrect, then corrected his own objection in the present brief "Notiz" and called Friedmann's results "clarifying." Pais, Subtle is the Lord, p. 288. Weil, Albert Einstein Bibliography, 130. (Inventory #: 43318)