Spielen Gravitationsfelder im Aufbau der materiellen Elementarteilchen eine wesentliche Rolle? (Do Gravitational Fields Play an Essential Role in the Structure of the Elementary Particles of Matter?) extract from Akademie der Wissenschaften, Berlin 1919, pp, 349-356

Berlin: Akademie der Wissenschaften, 1919. 1st Edition. FIRST EDITION, BOUND EXTRACT OF ONE OF EINSTEIN'S MORE SIGNIFICANT MODIFICATIONS OF GENERAL RELATIVITY, THIS SPECIFICALLY MARKING THE BEGINNINGS OF HIS UNIFIED FIELD THEORY - an approach he remained committed to for the remainder of his life.

"The major interest of this paper is that [Einstein's] attention [had] now shifted from possible quantum modifications of general relativity to the search for a unified theory of the electromagnetic and gravitational fields, on the basis of which he hoped to explain the structure of matter. Quantum effects are to be derived from such a theory, rather than postulated ad hoc" (Iyer and Bhawal, Black Holes, Gravitational Radiation and the Universe, pp. 525-526). "As so often the case in relativity, the story of quantum gravity begins with Einstein himself. Soon after the final formulation of general relativity, he pointed out the need for a quantum modification of the theory. In his first paper on gravitational radiation [the 1916 paper "Approximate Integration of the Field Equations of Gravitation"], Einstein argued that quantum effects must modify the general theory of relativity...Two years later, he reiterated this conclusion [the 1918 paper "On Gravitational Waves]: 'As already emphasized in my previous paper, the final result of this argument, which demands a [gravitational]energy loss by a body due to its thermal agitation, must arouse doubts about the universal validity of the theory. It appears that a fully developed quantum theory must also bring about a modification of the theory of gravitation.'

"[Einstein, writing in the 1919 paper offered here] soon began to speculate whether gravitation plays a role in the atomistic structure of matter: 'There are reasons for thinking that the elementary formations which go to make up the atom are held together by gravitational forces... The above reflections show the possibility of a theoretical construction of matter out of the gravitational field and the electromagnetic field alone... "In order to construct such a model of an 'elementary particle,' Einstein shows that it is necessary to modify the original gravitational field equations" (ibid).

In this paper, Einstein " visualized the relations in spherical space and discussed the field equations in general relativity from the point of view of the cosmological problem and the problem of the constitution of matter" (Calaprice, Einstein Almanac, 77). He had come to believe that geometrized unified field theories were likely the path to progress in theoretical physics.

"Einstein remained committed to this approach for the rest of his life: the search for a 'natural' mathematical extension of the general theory in the hope that such a theory would somehow explain the quantization of matter and energy" (Iyer 526). CONDITION & DETAILS: Berlin: Akademie der Wissenschaften. Complete bound extract. Tightly bound in black cloth and marbled paper boards. 4to. (10.5 x 7.5 inches; 263 x 188mm). The boards and text are bright and clean. Small closed tear right upper inner margin; barely visible. Near fine condition.