Autograph manuscript draft of a page of a scientific paper on unified field theory, in German

EINSTEIN, Albert

Published by [Princeton, NJ, 1940

About this Item

A PAGE OF AN UNPUBLISHED MANUSCRIPT ON UNIFIED FIELD THEORY. One page of an autograph manuscript by Einstein, apparently unpublished and unstudied. It appears to relate to Einstein's work on 'asymmetric' unified field theory, an approach to UFT which began in 1925 with his paper 'Einheitliche Feldtheorie von Gravitation und Elektrizität,' and which he took up again in 1945 in his article 'Generalization of the relativistic theory of gravitation'. This approach dominated his work from the mid 1940s until the end of his life. The essential idea is to relax the requirement that the metric of spacetime to be symmetric, the idea being that the symmetric part of the metric would represent gravitation as usual, and that the new antisymmetric part would be identified with the electromagnetic field. If successful, this would represent a unification of gravitation and electromagnetism. However, "Einstein himself realized soon after the publication of [the 1925 paper] that the results were not impressive. He expressed this in three letters to Ehrenfest. In the first one, he wrote, 'I have once again a theory of gravitation- electricity; very beautiful but dubious'. In the second one, 'This summer I wrote a very beguiling paper about gravitation-electricity . but now I doubt again very much whether it is true'. Two days later, 'My work of last summer is no good'" (Pais, p. 344). "Einstein's efforts to master the non-symmetric case were far more elaborate during the last decade of his life than they had been in 1925 . The major part of this work was done in collaboration, however, first with Ernst Straus, then with Bruria Kaufman, his last assistant . The plan was to construct from these ingredients a theory such that (as in 1925) the symmetric and antisymmetric parts of [the metric] would correspond to the metric and the electromagnetic field, respectively, and to see if the theory could have particle-like solutions. This plan had failed in 1925. It failed again this time . In his own words (written in December 1954), 'In my opinion, the theory presented here is the logically simplest relativistic field theory which is at all possible. But this does not mean that nature might not obey a more complex field theory'. It must be said, however, that, once again, logical simplicity failed not only to produce something new in physics but also to reproduce something old. Just as in 1925, he could not even derive the electromagnetic field equations in the weak-field approximation" (ibid., pp. 348-349). Although Einstein was ultimately unsuccessful, a similar vision was realized in the decades after his death in the construction of the 'standard model', a unified theory of electromagnetism with the weak and strong nuclear forces (which were unknown in Einstein's time), and efforts to incorporate gravity into the model continue to this day. The present leaf is page 11 of a manuscript whose title (and author(s)) are unknown. Page 10 of what is presumably the same manuscript was sold at Christie's, 14 July 2021, lot 44, £106,250. "The first original approach [to UFT] put forward by Einstein himself was published in a paper of 1925 in which also the term 'unified field theory' appeared for the first time in a title. In that paper, he explored a metric-affine approach, i.e., he took both a metric tensor field and a linear affine connection at the same time as fundamental variables. Both connection and metric were assumed to be asymmetric. Parallel transport then again defines a Ricci tensor and a Riemann curvature scalar, and Einstein defined tentative field equations in terms of a variational principle, taking the Riemann scalar as a Lagrangian just as in standard general relativity. As regards the interpretation of the mathematical objects, he tried to associate the gravitational and electromagnetic fields with the symmetric and anti-symmetric parts of the metric field. In his attempt to recover the known cases, he could show that the metric was symme. Seller Inventory # 6031

Bibliographic Details

Title: Autograph manuscript draft of a page of a ...

Publisher: [Princeton, NJ

Publication Date: 1940