Translator's Preface
This volume contains several of Albert Einstein's
most
important papers
on
both
quantum theory
and
the
theory
of
general
relativity.
The translator's task
was
to
try
to
preserve
in
English
Einstein's
peculiar style
of
writing,
which reflects the
kaleidoscope
of his
complex thought
processes.
Unlike
many
of
his
contemporaries,
Einstein
preferred
to
write
more
in the
way
he talked in the lecture
hall,
mentioning
with didactic skill
every thought
to
be considered
at
each
step
from
one
formula
to
the next.
Occasionally
this
taxes
even
German
grammar
which,
admittedly,
is
more
tolerant of
very
long
sentences
than,
for
example,
English.
Thus,
the
translator
put
higher
value
on
the
tracing
of the
psychology
of Einstein's
thought processes historically
and
didactically
than
on
linguistic
elegance.
It is
well
known that Einstein
was one
of
the
first
physicists
to
make
extensive
use
of
tensor
calculus in his
numerous papers. Understandably,
this
was an
unfamiliar
challenge
to
the
typesetters
of scientific
journals-and
typographical errors
were
numerous,
as
every
reader
of
the
originals
has realized. In
a
text-critical edition these
need
to
be
annotated,
as
has been done
by
the
editors, in
square
brackets
[
],
and
by
the
translator
and
consultant
in
curly
brackets
{
}.
The
majority
of
typos
are
trivial
mistakes
in
subscripted or superscripted
indices;
this also demonstrates that these
errors
did
not
originate
with
Einstein,
no
matter
what his detractors
said,
especially
those who also had
other than
truly
scientific motives.
Einstein,
anxious like
every
author
to
see
his
important papers published
as soon as
possible, perhaps may
have been
negligent
in
proof reading,
or
he wanted
to
spare
the
typesetter
the then
laborious
manual work of
correcting
a
printing plate precisely
at
several cumbersome formulas. And
so
the
typos
are
still there.
We
felt, however,
that the scientific
community
is better served if these
distracting
typos-while
still
pointed
out
in the
margin
and
in annotations-are
not
dragged
on
forever
through
all translations. We tried
to correct
in the
English
translation
all
those
that
came
to
our
attention
in text
or
formulas,
while
being cognizant
of the fact that
many
indices in
the
German
originals are
difficult to
decipher.
For
reasons
of historical reference the
page
numbers of the
original journals
are
usually
also
inserted in the
margins
at
the
appropriate places
of the translation in
brackets
(e.g., [p. 123]).
Longer quotations
in
German which
occur
in
the
editors'
notes
sometimes without
translation
(e.g.,
in
Documents
26
and
42)
have
also
been translated here and
appended
as
additional
notes at
the ends of these
papers.
We would like to
thank
Prof.
E. A.
Spiegel
for editorial
help
with Document
39.
We also
owe
thanks
to
Alice
Calaprice,
senior editor of the Einstein
Project
at