DOC.
7
RELATIVITY
LECTURE NOTES
67
[1]This
document
is
dated
on
the
assumption
that
Einstein
prepared
these
notes
for
his
course
in
winter
semester
1914/1915
at
the
University
of
Berlin,
16
October 1914-15 March
1915 (see
Berlin
Verzeichnis
1914,
title
page).
[2]The
exposition
of
special
relativity
and
covariant
electrodynamics
in
these lecture
notes
shows
many
similarities with the
treatment
in
an
unpublished manuscript
on
special relativity
from
1912 to 1914 (see Vol.
4,
Doc.
1).
In
the
following,
this
manuscript
will
simply
be
re-
ferred
to
as
"Vol.
4,
Doc. 1."
These lecture
notes
also
follow rather
closely
the section
on
spe-
cial
relativity
and
covariant
electrodynamics
of the
course on
electricity
and
magnetism
that
Einstein
gave
at
the
ETH in
winter
semester
1913/1914
(see
the lecture
notes by
Eduard
Sidler
in
SzZE
Bibliothek, Hs. 1067:15,
and their
summary in Vol.
4, Appendix A;
see
also Einstein's
notes
for
part
of this
course
in Vol.
4,
Doc.
19).
[3]The
idea of
geometry
as
part
of
physical
science is also
expounded
in Vol.
4,
Doc.
1,
[pp.
21-22],
and
in
the first section of Einstein's
popular
book
on
relativity
from
1917,
Einstein
1917a
(Doc. 42).
[4]See, e.g.,
Laue
1913, §2,
or
Vol.
4,
Doc.
1, [pp.
15, 20],
for discussions of Fizeau's
ex-
periment.
[5]See, e.g.,
Lorentz
1909, §§156-164,
for Lorentz's derivation of the
dragging
coefficient.
[6]See,
e.g.,
Laue
1913,
§2,
for
a
discussion of aberration. Stellar aberration
is
also
a
topic
in
Einstein's
first
paper
on
special relativity,
Einstein 1905r
(Vol. 2,
Doc.
23).
[7]See
Vol.
4,
Doc.
1,
Section
One,
for
a more
detailed
exposition
of Lorentz's
electrody-
namics.
[8]In
the
following
calculation of the determinant
above,
second-order
quantities
are ne-
glected.
The
speed
of
propagation
of
light
in
the
running water V
is
written
as
V
=
V0
+ A,
where
A
is
a
small
quantity. Subscripts
x are
suppressed.
See
also Einstein's calculation
in Vol.
4,
Doc.
1, [p.
15].
[9]"V"
should
be
"V0."
[10]"e2"
should be
"Je."
[11]See,
e.g.,
Laue
1913,
§2,
Pauli
1921,
sec.
36,
and
Vol.
4,
Doc.
1, [p. 7],
for discussions
of the
experiments
of
Röntgen,
Eichenwald,
and Wilson. The
experiments
by
Röntgen
and
Eichenwald showed that
a
dielectric
moving
in
an
electric
field
produces
a
magnetic
field
due
to
the motion of induced surface
charges (see Röntgen 1888
and
Eichenwald
1903, 1904); in
Wilson's
experiment
the motion of
a
dielectric
in
a
magnetic
field
was
shown
to
induce
a po-
larization
in
the dielectric
(see
Wilson
1904).
[12]See
Lorentz
1895.
[13]Without the
Lorentz-Fitzgerald
contraction
hypothesis,
Lorentz's
theory
of
1895
could
not account
for the
negative outcome
of the
Michelson-Morley experiment
nor
of other
sec-
ond-order
experiments to
determine the motion of the earth
through
the ether.
[14]A
factor -1/2
is
missing
in
the last
term.
[15]Einstein
had
on
earlier occasions characterized the Lorentz-FitzGerald contraction
as an
ad
hoc
hypothesis
(see,
e.g.,
Einstein
1915b
[Vol. 4,
Doc.
21],
p.
707;
see
also Lorentz's de-
fense in H.
A.
Lorentz
to
Einstein,
between
1
and
23
January 1915).
[16]See Ritz
1908a,
1908b for Walter Ritz's emission
theory
of
light.
Einstein
discusses
its
consequences
in Vol.
4,
Doc.
1, [pp.
21
and
20a].
[17]The
Dutch
astronomer
Willem
de
Sitter had shown that
an
emission
theory
of
light
was
incompatible
with observational data
on
the
motion of double
stars.
See De
Sitter
1913a,
1913b;
see
also Einstein's discussion
in Vol.
4,
Doc.
1, [p.
20a],
and
his
praise
of
De
Sitter's
work
in
Einstein
to
Paul
Ehrenfest, 28
May
1913
(Vol. 5,
Doc.
441).
[18]Possibly a
reference
to
work
by
Edouard
Guillaume,
in
which
it
was
shown that
a
speed
of
light exclusively
dependent on
the
speed
of
the
source
could
give
rise
to
local accumulations
of
energy uncompensated
by any
work.
In
a
comment
on
Guillaume's
presentation
of this
re-
sult
at
a
meeting
of
the
Societe suisse
de
physique
in
Basel
(see
Guillaume
1914),
Einstein had
pointed out
that
through
the
same
mechanism
one
could
give
a
body
a
higher temperature
than
its
surroundings,
without
any
compensation
elsewhere.