Evening star., 1937-09-25
STARS, MEN AND ATOMS
Notebook of Science Progress in Field,
Laboratory and Study.
BY THOMAS r. HENRY.

Earth is washed by a 24-hour tide
from the sea of infinity.
Discovery of an hitherto unknown
physical phenomenon-the cosmic ray
day-has just been announced by DR.. S.
E. Forbush Of the terrestrial magnetism
laboratory of the Carnegie Institution of
Washington
Instruments set up at the Coast and
Geodetic Survey station at Cheltenham,
Md, show that these rays rise to maxi
mum at about IL am. every day, after
which they drop off to their minimum
numbers again. The findings are based
on continuous records since 1888.
These cosmic rays are by far the Short
est and most powerful wave-lengths Of
radiation. Power equivalent to a billion
volts or more it has been calculated, is
required to propel them with the force
at which they strike the earth. Compared
with them the most powerful X-rays are
feeble. Some of them will go through
a foot of lead.
At the Cheltenham observatory the
number of hits are counted by special
device-a lead inclosed chamber filled
with argon gas through which passes an
electric current which varies with the
number of ions, or electrically unstable
atoms, produced by the cosmic rays. Day
in and day out, for this latitude and ele-
vation, the number should be approxi-
mately "a per cubic centimeter per
second.
This varies regularly with the time Of
day, DR.. Forbush found, and reaches its
maximum just before noon. Roughly it
follows the progress of the sun and yet
it has been conclusively demonstrated
that coSmic rays do not come from the
sun and have no association with it.
They come from the vast reaches of outer
space beyond the solar and possibly be-
yond the Milky Way galaxy.
Rural folklore the country over de-
clares that moonlight has some sort Of
effect on crop growth. Whether it is sup
posed to be stimulating or depressing
depends on the local variation of the
superstition. Certainly the actual effect
if there Is any-muSt be small, but
plant Psychologists have not been abso-
lutely sure that it does not exist. When
all the factors that influence plant growth
are considered, it becomes very difficult
to assign any values to this one factor.
Some elements of the problem have
been attacked in experiments with the
effects of polarized light in plants con-
Quoted in the division of radiation and
organisms of the Smithsonian Institu-
ton, the results of which are reported
in paper by DR.. Earl S. Johnston.
Moonlight is 'polarized sunlight" re-
flected from the barren surface of the
earth's satellite. That is about the only
qualitative difference between moon
beams and sunbeams that science can
easily put its fingers upon. Their prop
critics of reflection and transmission have
become different for different directions
DR.. Johnston experimental with oat
seedlings, measuring the quantitative
effects of the two forms of light on two
fundamental phenomena of plant life.
One was phototropism, the tendency of q
plant to bend toward a source of illumi-
nation. Thus sunflower follows the
SUM-
This behavior is explained by the
finding that growth is slightly inhibited
on the illuminated side. The tip OF the
plant bends in the direction of least
growth. Thus measure of the amount
of phototropism induced becomes a
rather delicate measure of the growth
inhibiting effect of different wave bands
and intensitieS of light
The other was carbon dioxide assimi-
lation. The basic phe1 1omenon Of plant
growth is the capacity.or taking carbon