FRIEDMAN, ALEXANDER & ALBERT EINSTEINBiblio.com
Über die Krümmung des Raumes. Über die Möglichkeit einer Welt mit konstanter negativer Krümmung des Raumes. Einstein's two remarks to the first paper: Bemerkung . Notiz . - THE CURVATURE OF SPACE
1922ref. 34667Berlin Julius Springer 1922-24. 8vo. In: "Zeitschrift für Physik" Vol. 10 pp. 377 ff.Vol.11 pp.326 vol.16 pp.228 vol.21 pp.326-332. The entire four volumes offered here. Contemporary half cloth bindings. Two landmark papers in the history of cosmology: All first editions. In 'Über die Krümmung des Raumes' Friedman derived the non-stationary solutions to Einstein's field equations. Einstein quickly responded in a short comment 'Bemerkung' in which he expressed his suspicion of such a model of the Universe and apparently pointed out an error in Friedman's calculations. However Friedman now wrote a letter to Einstein in which he enclosed his full calculations. Shortly after this Einstein submitted a short notice Notiz in which he admitted that he himself had performed a calculation error and that Friedman's solutions which shed new light on the matter were valid. Friedman's expanding universe model was corroborated by Edwin Hubble's red-shift observations in 1929. In 'Über die Möglichkeit einer Welt mit konstanter negativer Krümmung des Raumes' Friedman derived the Friedman-equations and demonstrated that he had command of all three Friedman-models describing positive zero and negative curvature respectively nearly a decade before the independent discoveries of the same models by Lemaître Robertson and Walker. hardcover
