The New York herald., 1921-06-19

half the speed of the earth's rotation
what would be an hour to us as meas
ured by our clocks or by the sun would
be half an hour to him as measured
by the sun.
In his Special Principle of Relativ-
ity Einstein considers only uniform
motion Gnertia) in his General Prin-
ciple of Relativity he takes up the
question of accelerated Increasing or
decreasing) motion (gravitation). The
velocity of a body falling to the earth
increases 32 feet each second, and the
velocity of a body thrown up from the
earth decreases 32 feet each second.
And wherever there is matter there is
gravitation and accelerated motion.
The velocity of light. although a
constant to observers on uniformly
moving systems, is not constant to
observers in gravitational fields. be-
rause it is subject to gravitation. A
ray of light coming from a distant
star is DETECTED as it passes our sun;
the velocity of the ray of light is in
creased as it approaches it, just as an
object falling to the earth, and de-
creased as it passes away from it. The
DETECTION of light rays as they pass
our sun, one of Einstein's three pre-
dictions, was verified by astronomers
in 1919.
There is an epoch making conclusion
to be drawn from this, which is that
inertial mass and gravitational mass
are the same. For if a ray of light
having only uniform motion Gnertia)
is subject to gravitation then the mass
of matter itself must be affected by
it's velocity; that is, if the velocity of
body increases or decreases its mass
increases or decreases
This explains the moving forward
Of the peaihelion (point nearest the
SUM of Mercury short distance each
year, fact which Newton's laws
failed to account for. Having its
greatest speed at this point. as is the
case with all planets Mercury will
therefore have its greatest mass here,
and this sudden increase in mass Will
cause ii to shoot forward slightly
Einstein's third prediction that the
lines of any element in the solar spec
trum will. because of gravitation,. be
slightly shifted toward the red rays.
has not yet been verified.
According TO Euclidean geometry
the straight line is always the short
est distance between two points. But
the nearest approach to an absolutely
straight line in space is a ray of
light. and the path of a light wave is
not straight in gravitational fields. as
we have seen in the case of a light
wave passing the sun. The reason for
this. according to Einstein. is that the
space around matter is curved. and.
consequently. the shortest path for
ray of light, which is measurement
for both space and time. is a curved
path Euclidean geometry. which rests
on the axiom that the shortest dis
tance between two points is always
III gravitational fields.
The system of geometry offered by
Einstein as equivalent for the state
ment of general physical laws is an
intricate form Of mathematics. formu-
lated by the mathematicians Gauss.
Looatchewsl<y, Minkowslxi and others.
The significant aspects of Einstein's
theories for the layman are:
! L. Space and time measurements are
purely relative.
2 Inertial mass and gravitational
r1ass are the same: in other words.
energy and matter are only different
manifestations OF a more fundamental
aspect of nature.