518
DOC.
25
SOLVAY DISCUSSION REMARKS
properties
such
as
the
damping
of
atomic oscillations
than
it
should be
according
to
the
explanation
given
in
Einstein
1905i
(Vol.
2,
Doc.
14), §8.
For
a
historical overview
of
alternative
explanations
of the
photoelectric
effect,
see
Stuewer 1970
and Wheaton
1978.
No.
242
(Sommerfeld et
al.
1914,
p.
315;
Sommerfeld
et
al.
1912,
p. 390)
[2]0)
Bei
Sommerfelds Theorie
des
photoelektrischen
Effektes dürfte Pro-
portionalität
der Anzahl der
pro
Zeiteinheit emittierten Elektronen mit der
Lichtintensität
nur
dann
resultieren,
wenn man
das Vorhandensein einer
Dämpfung
der
Schwingungsbewegung ganz
ausschliesst.
IX.
Langevin
In
his
lecture, Langevin
reviewed
the
kinetic
theory
of
magnetism
and in
particular
the work of Pierre
Weiss.
Following
on a
suggestion
made earlier
by Gans, Langevin
attempted,
in the last
part
of
his lecture, to
use
Sommerfeld's
principle
(see
above)
in
a
speculative
construction of
a
molecular model of
magnetization.
He assumed that
an
electron circulates around
a
center
that
attracts it
by a
force
characterized
by
a
power law,
and
he obtained, in
this
way, a
rough agreement
with
experiment.
In the
discussion
following
Weiss's
presentation
of
his
theory
on an
earlier
occasion,
Gans
mentioned
that
Einstein had
recently suggested
to
him
an
explanation
of the units of
magnetism
by
quantizing
rotations
(see
Weiss
1911;
this has been noted
in
Kuhn
1978,
p.
312,
fn.
40).
In
a
letter written
to
Lorentz
soon
after the
Solvay meeting,
Einstein
remarked: "The
case
of electrons in
a
magnetic
field
already
mentioned
in
Brussels
is
interesting,
but
not
as
much
as
I
thought
in Brussels.... In
any case,
the
thing
seems
to
show
that
mechanics
already
ceases
to
hold for the electron
moving
in
a
magnetic
field"
("Der
schon in Brüssel erwähnte Fall der Elektronen im
Magnetfelde
ist in-
teressant,
aber nicht
so
sehr,
wie ich in
Brüssel
meinte....
Immerhin scheint die Sache
zu zeigen,
dass die Mechanik schon für das im
Magnetfeld bewegte
Elektron
nicht
gelte")
(Einstein
to H.
A.
Lorentz,
23 November
1911).
This discussion remark
is
transcribed from
Langevin
et
al.
1914,
p.
328. See
also
Langevin
et al.
1912,
p.
405.
A manuscript
version does
not exist.
Es
wäre
interessant,
die
obige Berechnung
auf
ein
einzelnes Elektron
im
magnetischen
Felde anzuwenden.