The Washington herald., 1921-06-30
The Herald -
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THURSDAY, JUNE 20. 1871.
FRENCH SCIENTISTS CONFIRM
EINsTEIN's THIRD THEORY.
Co. N heefiaO J
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EINsTEIN's THIRD THEORY.
French scientists have announced
that they have verified Einstein's
third prediction. that the wave
length of light from the sun ID
slightly longer than similar Light
produced on earth.
Monsieur A. Perot, in a recent
number Of Complies Rendus. the Of
iciSl journal Of the French AcsdepyI
OF Sciences. declares that his. re-
searches show that the wake length
Of the magnesium lines Of the sun
change in color toward the red. or |
longer by about two parts in al
million than the same kind Of light
produced here on earth. This, he
points out. is exactly the differences
that the Einstein theory requires.
Einstein's theory FIRST scored one
over Newton's when il accounted
for the shift OF forty-two seconds OF
arc that the planet Mercury takes
each century over and above that
allowed IL by the Newtonian law.
This discrepancy had puzzled as
tronomers for two centuries.
When is was announced that the
British astronomers who went TO
Africa to observe the eclipse OF the
sun on May ?, 1919 had found that
a ray of light passing close by the
sun is bent out Of its straight
course, this was the, second con-
firmation Of Einstein'S theory. and
that announcement set the general
public talking about the Einstein
theory.
The verihcation dat has just
been announced is the last Of the
three practical predictions that Elm
stein has suggested as cheokable
by observation. General acceptance
Of NJ. Perots findings and alrther
proof Of the deviation Of the light
rays in a gravitational field (as re-
ported hy the British eclipse expert
menO would practically amount to
proof Of the Einstein theory.
The Fraunhofer lines, used in
wave length measurement. can be
seen as dark lines on the solar
spectrum background and have their
origin in the reversing layer" of
the sun. 1t has been believed that
the pressure varies at different
parts Of this reversing layer" and
that this change in pressure caused
the difference in wave length be-
tween the solar light and the earth
VI
Perot by his interferometer meas
urements has come to the conclu-
sion that the magnesium vapor Of
the sun is practically at zero
pressure and not, as supposed, un-
der high pressure. and that the
Einstein theory is needed to ex-
plain the difference in wave length
between solar magnesium light and
the kind of magnesium light that
is produced here.
Previously he had found similar
differences when he compared the
cyanogen solar lines with light pro-
duced by that terrestrial cyanoeen
producer, the arc lamp. and as the
cyanogen vapor in the sun Is sup
posed to be under little or no
pressure. he considers this another
check OF the theory.
Now that NJ Perot has shown the
way, two other scientists have dug
into old data and report that even
these past records are proving that
Einstein is right
NJ. H. Buisson and Ch. Fabry
have considered data giving dff-
ferences Of wave length OF solar
and earthly rsdiations that were OBJ
tSined as early as 1896. At that
/ time the discrepancies were eN-
planned by assuming that the
pressures in the sun caused them.
But now. by Consldering pressure
absent or very low these two in
Nestigators show TO their saGisfac-
lon that the old observations can
be made to prove the E!usleIa
theory.