5 7 2 D O C . 7 1 P R I N C E T O N L E C T U R E S
I.e., Lorentz transformations of the form given in eqs. (28)–(29).
The manuscript has “die nebenstehende Skizze” instead of “Fig. 1.” None of the figures are in
The manuscript has j instead of j everywhere. In the second German edition , , and
are corrected to (should be ), , and , respectively.
With the alternatives suggested by Einstein, charge conservation would be violated. The partial
derivatives here should be with respect to the time t, not to l.
In the second German edition, the expression for has been corrected so that the h in the
numerator reads .
The manuscript has “tiefer zu erfassen,” rather than “formal zu erfassen.”
In the manuscript, “mit der Lichtgeschwindigkeit als Einheit” is changed to “mit der Lichtzeit
als Zeiteinheit” and is then changed back.
In the manuscript, a deletion follows “leistet:” “〈Sie verknüpft ferner〉.”
In the second German edition is added after the expression , with the intervening
comma replaced by a semicolon.
In the manuscript, eq. (39) erroneously has instead of .
In the manuscript, “〈in ähnlichem Sinne äquivalent wie Wärme und〉” follows “sind also.”
In the second English edition, this footnote is replaced by: “The emission of energy in radioac-
tive processes is evidently connected with the fact that the atomic weights are not integers. The equiv-
alence between mass at rest and energy at rest which is expressed in equation (44) has been confirmed
in many cases during recent years. In radio-active decomposition the sum of the resulting masses is
always less than the mass of the decomposing atom. The difference appears in the form of kinetic
energy of the generated particles as well as in the form of released radiational energy.” For a historical
discussion, see Siegel 1978.
The qualification “quasi-stationär bewegte” is missing in the manuscript.
Deleted at this point (before “Untersuchungen”) in the manuscript: “〈zahlreiche〉.” In Einstein
to Friedrich Adler, 20 October 1918 (Vol. 8, Doc. 636), the results reported in the following papers
are cited as providing strong confirmation for the relativistic predictions of the motion of an electron:
Neumann 1914, Schaefer 1916, Glitscher 1917, and Guye and Lavanchy 1916. See also Lorentz 1915,
p. 339. For historical discussions of these experiments and similar earlier experiments by Walter
Kaufmann and others that seemed to contradict the relativistic predictions, see Miller, A. 1981.
This footnote is not in the manuscript.
Inserting eq. (48) for and using eqs. (32) and (33), one can rewrite as
. The first term vanishes, since it is a contraction of a part symmetric
in α and ν, and a part antisymmetric in α and ν. See note 34 to Doc. 12, Einstein 1916b (Vol. 6, Doc.
27), sec. 2, and Einstein 1919a (Doc. 17), p. 53.
See Planck 1908 for the formulation of mass-energy equivalence in terms of the relation
between momentum density and energy current density.
Instead of “Das Resultat” the manuscript has “Wir konstatieren also aus dieser Betrachtung,”
and in the manuscript the sentence ends at “hat,” with the word “Dies” beginning the next sentence.
This generalization was put at the center of relativistic mechanics in Laue 1911.
For a discussion related to this question of the singularity model of matter, see Doc. 63, note 6.
For Einstein’s ideas on the constitution of elementary particles, see Einstein 1919a (Doc. 17).
See also references to the works of Mie, Hilbert, and Weyl in notes 3, 4, and 5 of Doc. 17.
In the second German edition, this equation is numbered (50a) .
This paragraph was slightly revised in the second German edition. In the first sentence, “die
rechte statt der linken Seite in obiges Integral” was replaced by “letzteren Ausdruck in (50a).” In the
last sentence, “Setzung des Energietensors” was replaced by “Formulierung des Energie-Impuls-
See treatment in Einstein 1916e (Vol. 6, Doc. 30).
In the manuscript, “tangentialen” replaces “〈senkrechten〉.”
h12 h hhz
dτ dτ dl =
Tμν ∂xν ⁄ –∂Tμν
ϕαν ϕμαJα +