6 6 4 I N D E X
Energy conservation, in psychology, 520
Energy-momentum conservation, in general rel-
ativity. See Relativity, general theory of: en-
ergy-momentum conservation
England: AE’s planned visit to, 378, 401, 603c;
relief aid to Germany, 387
Enriques, Federigo (1871–1946), on confirma-
tion of general theory of relativity, 517
Entente. See Allied occupation of Germany, end
of; Allies
Entropy constant, 472n
Epidemics, in Russia, 202, Zangger on fighting
against, 204
Epistemology and relativity: AE on, 267; Sellien
on, 155
Epp, Franz Ritter von, 63n
Epstein, Paul (1883–1966): xl, xlix, 7, 192, 196,
333–334, 339, 353, 382, 405, 498, 578c; fi-
nancial problems, 152, 344; helps Edith Ein-
stein, 47, 49–50; Jewish matters, 152, 197,
222, 240; no academic position for, 457; on
AE’s qualities, 395; on Eliasberg, 394–395;
on his learning Hebrew, 197; on need for pop-
ular publications on science, 395; on political
views of Thomas Mann, 394; on theory of ra-
diometer effect, 47, 49–50; passport difficul-
ties, 49; position at University of Zurich,
381–382, 395–396, 403, 458n, 483; prepared
to teach at Hebrew University, 180; scholar
of international significance, AE on, 405
Equation of motion, in five-dimensional theory,
57n
Equipartition theorem: 318n; AE and Mises on,
276, 290, 318
Equivalence hypothesis: 268n; demonstration of,
601c
Erdmann, Benno (1851–1921), helps Schlick,
478
Ergodic hypothesis: 318; AE on, 276; Mises on,
290
Erklärung in Sachen Liebknecht-Luxemburg,
AE signs, 17n, 551c
Erzberger, Matthias (1875–1921), 29n, 387
Escherich, Gustav von (1849–1935), 400
Ether: 232; of Stokes and Planck, 472–473
Ether and Relativity, AE’s inaugural lecture at
University of Leyden, 353, 355, 364, 371,
402, 456, 469, 482–483
Ethnic Germans, plebiscite in the East, 349
Euclid, 388, 413
Euclidean solution of vacuum Einstein equa-
tions, 393n, 403n
Evershed, John (1864–1956): xxxviii, 244, 287,
325n, 330, 355, 401; on daytime observation
of gravitational light deflection, 244
Ewald, Peter (1888–1985), 75
Exchange, of German and foreign scholarly liter-
ature, 514–515, 605c
Exchange rate: German mark to Dutch guilder: 8
September 1919, 151n; 11 December 1919,
290n; German mark to Swiss franc: 26 No-
vember 1918, 91n; 5 September 1919, 148;
15 October 1919, 195; mid-November 1919,
235n; 15 December 1919, 303n; January
1920, 345; 26 March 1920, 487n
Exner, Franz S. (1849–1926): 251, 398–399; re-
tires, 366n, 428
Fabian Society, Kessler on, 553c
Fabre, Lucien (1889–1952): 530, 536; plans pop-
ular article on relativity, 531; requests AE’s
opinion on his papers, 531
Fajans, Kasimir (1887–1975), 386, 503
Fechner, Theodor, on time as fourth dimension,
556c
Fehling, Margarete, née Planck (1889–1917),
59n, 269n
Feiwel, Berthold (1875–1937), 181n, 327n
Fermat’s principle: 220; in optics, 208
Fichter-Bernoulli, Fritz, 303n
Field equations: in five-dimensional theory, 66;
tracefree, 85n
Fischer, Emil (1852–1919): 487, 488n, 583c,
603c; death, 108
Five-dimensional theory: cosmological problem
in, 39, 76; elementary electric charge in, 39;
equation of motion in, 57n; equation of mo-
tion of electron in, 66; field equations in, 66;
general covariance in, 56; geodesics in, 39,
46, 56; Lagrangian in, 66; mass density in,
57n; neutral matter in, 68n; of Kaluza, l, 38–
39, 46, 56, 65–67, AE on, 39; of Nordström,
39n. See also Unified field theory
Fixed stars astronomy, 293
Fizeau, Armand, 209
Flamm, Ludwig (1885–1964), 75, 252
Fleck, Albert, on stars and atoms as closed non-
Euclidean systems in Euclidean spacetime,
454–455