New-York tribune., 1921-05-11
Eir1steirl Finds
Proofs i'm Sum
And Mercury
Saws Planets Failure to-
Move i'm Fixed Ellipse
and Rotation of Its Axis
Was q 100 Year Puzzle
Fits Relatively Theory
Light Bends Near Sol as
Seen During Eclipses, He
Tells Princeton Audience

PRINCETON, NJ j., May lo.---Another
eauacity crowd greeted Professor Al
bert Elnstein, propounder of ths Ia
mous theory of relativiSy. when he was
introduced by President John Grier
Hibban. of Princeton University, at his
,scond lecture on "Relaeivity Of Mat
sers in McCosh Hall hers this after
noon.
The most important phase Of to-day's
address was the lecturers expression
of confidence in his theory. As the
question OF whether all spectral Tines
coming from elements in the sun should
he shifted slightly toward the red end
Of the spectrum. is still matter of
controversy and has not been estab-
l,shed enpirieally. it was easy to ap-
preeiaSa Professor Einstein's genuine
assurance and confidence in this unique
ssisn4ifc advance.
The following is an excerpt frcgn the
resume given by Professor E. Plimpton
Adams, Immediately after DR.. Elm
STEMS address. in an effort to explain
to the uninitisted some of the difficult
parts Of the lecture, which was given
IN German:
Discusses Newton's Laws
"Now as TO the consequences OF the
general theory of relatively: First OF
sll one thing is necessary. If the gen.
sral theory is 60 be true 1t must result
that the laws of gravitation, deduced
from the general theory of relatively,
are at least SIS accurate when tested
astronomically as the Jaws derived
from Newton's laws of molten and
Nswton's laws OF gravity. and this con-
clusion has been completely verified,
that the difference between the numeri-
cal results of the general theory Of
relativity and remarkably near the
same as the numerical agree .ent in
the case of Newton's laws.
"There is one theory, however, which
the general theory OF relativity re-
moves, which has been g difficulty for
over 100 years in the Newtonian theory
Of gravitation. That is in respect 60
the motion of the planet Mercury. In
stead of the planet Mercury describing
an ellipse which remains a fixed ellipse
With respect 20 the fixed stars, the axis
OF this ellipse continually rotates in
the direction of the rotation OF the
planet about the sun.
Proof Found In Mercury
aThis rotation amounts TO about
forty-two seconds Of arc in 100 years
and has been for long time very
puZzling difficulty in the dynamic
theory. The general theory of rela-
tivity predicts in such q case q revolu-
tion of almost exactly this same
anacunt--forty two seconds in 100 years
the same amount that has been OBJ
served, and that of course, is q re-
narkabla result of the general theory.
There is one other result, however,
OF the general theory which is even
more remarkable for the reason that
the result was predicted before the
experimental fact was determined, and
that has TO do with the sending of
light when it travels near heavy
body, as in particular, the light from a
star which can be observed at the
time of total eclipse of the sun.
When this light passes near the
sun, there is an extremely slight bend
ing Of the light, hut one which was
found by the two English expeditions
sent out 20 agree within about 10 per
cent Of the amount predicted by the
theory. And that is, OF course, really
the more remarkable result Of the
general theory Of relativity, In that
1t has predicted a result which was
not previously known"