Time&Eternity

290 notes to chapter 3
menten, während sie stets dazu neigen, Meßgenauigkeiten zu überschätzen” (It is really
rather strange that human beings are normally deaf to the strongest arguments, while they
are always inclined to overestimate measuring accuracies). From Einstein’s letter to Max
Born dated May 12, 1952, in Einstein and Born, Briefwechsel 1916–1955, 258; trans., 192. Cf.
also “§ 14. Der heuristische Wert der Relativitätstheorie,” in Einstein, “Über die spezielle
und die allgemeine Relativitätstheorie,” 452f.
140. The principle of relativity is, however, not Einstein’s invention. In mechanics, the
so-called Galilean principle of relativity applies (“Wenn die Gesetze der Mechanik in
einem bestimmten System gelten, so gelten sie auch für alle andern Systeme, die sich relativ
zu jenem gleichförmig bewegen” (If the laws of mechanics are valid in one CS [co-ordinate
system], then they are valid in any other CS moving uniformly relative to the first).
Einstein and Infeld, The Evolution of Physics, 165. In the case of Einstein, however, the
principle of relativity was “in den Rang einer fundamentalen Eigenschaft aller Naturgesetze
emporgehoben” (elevated to the level of a fundamental property of all natural laws).
Wild, “Wie kam die Zeit in die Welt?,” 163.
141. Fölsing, Albert Einstein—Eine Biographie, 237f.
142. Ibid., 238ff.
143. Bergmann, “The Space-Time Concept in General Relativity,” 150.
144. It should not be forgotten, however, that this boundary moves at a speed of ca.
300,000 km/s. Nevertheless, when one looks into space, space and time merge, since a
look into the distance is simultaneously a look into the past. If we were to receive a message
today at the speed of light from a civilization located one hundred light years away,
then this would link our present time with their past of one hundred years ago. If we immediately
sent an answer, then our present time would thereby be “simultaneous” with
their future in one hundred years.
145. Wild, “Wie kam die Zeit in die Welt?,” 163.
146. Einstein and Infeld, The Evolution of Physics, 185.
147. “.l.l. dessen Ergebnis einem Todesurteil für die Hypothese von dem ruhenden
Äthermeer gleichkommt,” ibid., 185; trans., 183.
148. “.l.l. ‘enfant terrible’ unter den physikalischen Substanzen,” ibid., 186; trans., 184.
149. Example: An observer observes an object that moves relative to him/her at the velocity
of v 1 . Relative to this object, on the other hand, another object moves at the velocity
of v 2 . This second object then moves for the observer at the velocity of v 1 + v 2 , which represents
no problem for velocities in the everyday sphere. If, however, for example, v 1 and v 2
each amounted to three-fourths of the speed of light c, then this would result in the sum of
1 1/2 c, which, however, would violate the theorem that the speed of light cannot be exceeded.
150. Einstein and Infeld, The Evolution of Physics, 198–202. According to E = mc 2 , mass
would then approach infinity.
151. x, y, and z specify the space coordinates, and t the time coordinates, of an event; v
stands for velocity.
152. “Ist die Trägheit eines Körpers von seinem Energieinhalt abhängig?,” in Annalen
der Physik 18 (1906): 639–41. Cf. also “E = MC 2 ” and “An Elementary Derivation of the
Equivalence of Mass and Energy” from 1946 in Einstein, Out of My Later Years, 49–53 and
116–19.
153. “Die Mittel, mit denen die Natur erkannt wird, sind nichts anderes als Teile eben
dieser Natur,” Mittelstaedt, Philosophische Probleme, 31.
154. Ibid., 44.
155. “.l.l. daß die bisherige Relativitätstheorie in weitgehendem Maße zu verallgemeinern
sei, derart, daß die ungerecht scheinende Bevorzugung der gleichförmigen Translation