Evening star., 1925-01-27
EXPLAINS MYSTERY
OF SHADOW BANDS
Physicist Says Eclipse Phe-
nomenon Originates in
Earth Atmosphere.
By the Associated Press

. By the Associated Press.
NEW YORK, January 27.-Flicker-
ing shadow bands which play over
earth Immediately prior to eclipses
of the sun. and generally are de-
scribed as unexplained phenomena
really are no mystery at all, accord
ing to r. w. Wood, professor of ex-
perimental physics at Johns Hopkins
University.
For 20 years 1t has been known
Or. Wood said today, that the turbu-
lence of earth's atmosphere, with hot
and cold currents in constant move
ment, caused Irregularities in the
density of the atmosphere, and that
these resulted in streaked shadows
when the moon o'ercast the sun as
on last Saturday.
Shadow bands can be seen when
ever a distant searchlight is focused
upon the wall of a white-hued build
ing, he said. Efforts to link such
features of an eclipse with the Elm
stein theory of lght-ray- bending
were called by DR.. Wood worse than
ronsensical."
Origin in Atmosphere.
Equally preposterous are attempts
TO explain them by the diffraction of
light by the moon." said Prof. Wood.
That they have their origin in the
circumstance that their direction of
motion is frequently observed to
change suddenly with the wind
These changes in the direction of
the wind need not, however, be ap-
parent at the earth's surface. Fail
ure to observe the bands on the
wings of high-fying airplanes has
been cited as proof of the atmos-
pheric origin of the bands. This
however has
theory, for the same failure to OBJ
serve them would be met, even if
they originated, in the atmosphere
above the plane.
Invisible on Plane.
"It must be remembered that the
plane Is moving through the air at
high speed, and the shadowy bands
would cross the wings with Il velocity
of a mile or more a minute, and hence
. be quite invisible"
The outstanding result of the solar
eclipse will be its effect on the Elm
stein theory of relatively, DR.. Harold
Jacoby, professor of astronomy at Co
lumbta University, said today.
Charles Lane Poor, professor of ce-
lestial mathematics at Columbia, OBJ
tanned photographs of the eclipse at
Yale University with special cameras,
and 1t is study of these plates that,
~SOOA olIi5 " IL JdCODNY MAY prove OF
disprove the relativity theory.
Importance to Radio.
Although 1t was said that months,
perhaps years, may be required before
definite conclusions can be reached on
data collected by scientists watching
the eclipse, DR.. Alfred n. Goldstein,
chief brodcast engineer of the Radio
Corporation of America, announced
today discovery regarded as of espe-
cial Importance to the radio industry.
He said that tests with 75-meter
short broadcasting waves had shown
that during the partial and total
eclipse these waves disappeared, while
broadcasting on $50 meters was not
notioeably affected. The experimental
signals were sent from the General
Electric Company'S station at Sche-
nectady, N. Y, and received here.
The conclusion reached from this
test, which was conducted for four
days, beginning two days prior and
ending two days after the eclipse, is
that the present standard of wave
lengths, between 220 and $50 meters,
is the correct one, he said. DR.. Gold
stein asserted that, as a result of this
experiment, owners of radio receiving
sets need not be concerned about the
establishment of wave lengths out of
this range.
The first color pictures of the suns
corona during a total eclipse, which
were taken under the auspices of the
Scientific American, at the East
hampton High School, were said today
TO be highly satisfactory.
Edward Hewitt, brother of Peter
Cooper Hewitt, the inventor, sue
ceeded in obtaining three pictures, in
each of which prominences of the sun
can be plainly seen. Twenty such
"prominences" are visible on these
plates, Hewitt said.