670 DOCS.
635,
636
OCTOBER
1918
Elektrizität”
[On
the
Elementary
Quanta
of Matter
and
Electricity”] (Drude’s
Annalen, pp. 564-566,
1901).[3]
With this
work,
the
named
author
not
only provided
the
first exact determi-
nation
of
the
absolute
size
of
atoms[4] but,
in
particular,
also laid the foundations
for
quantum
theory,
which
only recently
was
revealed to be
so
eminently
fruitful
for
the
whole of
physics.
Planck’s theoretical
accomplishment
also forms
the
ba-
sis
of Bohr’s
theory
of
spectra
and
thus
constitutes the
most
highly significant
advance made in recent
years
in
our
knowledge
of atomic
structure.
In utmost
respect,
A. Einstein.
P. S. I
do
not
have
the
mentioned articles
at
hand.
However,
I
hope
that the
validity
of
my proposal
does not suffer from
the
fact
that
I
cannot enclose them
herewith, especially considering
that the
referenced articles
are
available
at
any
physics
library.
636. To
Friedrich
Adler
[Berlin,]
20
October
1918
Dear
Adler,
Three
recent
papers
exist
that
have
securely
proven,
so
to
speak,
that the
relativistic
equations
of motion of
the
electron
are
applicable
(e.g.,
in
comparison
with
Abraham’s).[1]
1)
One
by
Cl.
Schaefer and
one
of his students[2]
[very
precise
measurements]
according
to
the method
by
Bucherer
(Published
in
the
Annalen).[3]
2)
One,
where
the
applicability
is
indirectly
deduced from
certain
anomalies of
spectral
lines
(Sommerfeld
and
one
of
his
students).[4]
3)
One
by Guye
and
Lavanchy following Ratnowsky’s
method
(Extr.
des
Archives
...
Geneva,
1916,
last
quarter)[5]
The
last
article
was
the
only
one
I could find
among
the chaos of
my things!
If
mailing
were
not
so
damnably inconvenient,
I
would send
you
the
separate.
My
popular
little
writing,
which
I
wanted
to
send
you,
also
came
back[6]
I
did not
use
the
example
with
the
contacts in
my
little
essay;[7]
it would
have
become too
lengthy.
On
the other
hand,
the
clock
paradox
was
discussed in
detail,
also from
the
point
of
view
of
the
general
theory
of
relativity. Substituting
the
current
with
an
electron
moving
at
the
speed
of
light
in
your
example
is