246 DOC.
21
THEORY OF RELATIVITY
Doc.
21
Theory
of
Relativity1
by
Albert Einstein
[In:
Die Kultur
der
Gegenwart.
Ihre
Entwicklung
und ihre
Ziele.
Paul
Hinneberg,
ed. Part
3,
sec.
3,
vol.
1,
Physik.
Emil
Warburg,
ed.
Leipzig:
Teubner,
1915, pp.
703-713
(the
first
section
of
the
paper),
and in Die Kultur
der
Gegenwart.
Ihre
Entwicklung
und ihre Ziele.
Paul
Hinneberg,
ed.
Part
3,
sec.
3,
vol.
1,
Physik.
2d
rev.
ed. Ernst
Lecher,
ed.
Leipzig
and
Berlin:
Teubner,
1925,
pp.
794-797
(section
II
of
the
paper)]
[2]
It
is
hardly possible
to
form
an
independent judgment
about the
legitimacy
of the
theory
of
relativity
unless
one
is
at least somewhat
acquainted
with the
experiments
[3]
and trains of
thought
that
preceded
this
theory.
These
must
therefore be discussed
first.
Luminiferous
Ether
The
phenomena
of interference and refraction of
light compelled
the
physicists
to
view
light
as a
wavelike
process.
Until the end of the last
century
it
was
thought
that
light
consisted in mechanical oscillations of
a
hypothetical
medium,
the ether. For
since
light
also
propagates
in
empty space,
it
was
not feasible
to
conceive the
wave
processes
that make
up
the
light
as
processes involving
the motion of
ponderable
matter.
When toward the end of the last
century
the
electromagnetic theory
of
light
gained
the
upper
hand,
this
conception changed only insubstantially,
in
that
light
was
no longer
conceived
as a
motion of
the
ether,
but rather
as an
electromagnetic process
in
the ether.
Still,
the conviction
persisted
that
in
addition
to
ponderable
matter
there
must
exist
a
second
matter,
the
ether,
which
is to be
considered the carrier of
light
[4]
(cf.
Article
26).
Does
the
"Luminiferous
Ether"
Take
Part
in the Motions of Matter?
Fizeau's
Experiment
This
conception
led
to
the
question
of how
this
ether behaves
mechanically
with
[1]
1A
view diverging from the one presented here
is
defended
in
Article
1
of this volume.