Evening star., 1936-05-05
STARS, MEN AND ATOMS
notebook of Science Progress in Field,
Laboratory and Study.
RY THOMAS r HENRY
BY THOMAS r. HENRY.

testimony. Meteors, mostly very tiny,
enter the atmosphere in such great num-
bers that in 100000 years, it is esti-
mated, 19 feet of meteoric dust would
have fallen on the earth. This would
amount to blanket more than 500 feet
thick in 1.800000,000 years. Nothing
of the sort is found. There are hardly
even traces of this dust in the sediments.
OF course. over such an enormous pc
riod the dust particles might have un-
dergone such chemical changes as to
make them indistinguShable. Mr.
Whitney insists, however, that there
should be numerous fossil meteorites in
the sediments, and these have not been
found.
Both the helium and meteoric dust
measures, he admits, cannot be conSid-
cred conclusive in themselves. But, he
insists. one of the strongest evidences
that the earth is not as old as is esti-
mated has been overlooked-the amount
of water produced by volcanoes. Where
did the water in the earth's oceans come
from in the first place? Most students
of geophySics now agree that it came
from the interior of the earth, through
the vents of volcanoes. 1t is calculated
that 100 volcanoes, each sending out as
much water as Mount Etna today, would
have supplied all the water in the oceans
II they had been in continuous opera
tion for 1900 y0O0, 900 years.
"Yet, now" Mr.. Whitney saws, "the
interior of the earth should be fairly
well depleted of its original water and
certainly water should have been pro-
duced in immeasurably greater quanti-
ties anciently when the magma held
most of its original content. The output
OF water from the comparatively recent
Lava flows OF the Pacific Northwest and
the Deccan, to say nothing of other
fairly recent volcanic material, must
have been immeasurably greater than
from single vent on Etna or from a
thousand such vents. And since the
early ocean unquestionably must have
contained much water, only a small frac-
tion of 1,8O0,OOO,OO0 years would be
needed to provide their present content
of water.
"The salt in the ocean testified that
the ocean is not old. Now the water
itself gives the same testimony. This
is also supported by the small quantity
of helium in the atmosphere and by
the absence of fossil meteorites in an
cient sediments. The postulate upon
which the idea of an old earth was first
built, that the sediments came almost
entirely by gradual deposit, should itself
be discarded. Little remains to favor
the doctrine of an old earth except the
measure of radioactivity, but if this is
contradicted by such an array of evi-
dence, something must be wrong about
it."
DR.. Alfred c. Lane, chairman of the
National Research Councils committee,
admits that Mr. Whitney's arguments
are quite forceful.
The objections are hard to sur
mount" he says, IF we assume an at
mosphere. an ocean and a size of con-
tinents throughout geologic time ap-
proximately as at present. But If we
believe that more gases, including
chlorine and water, are exuded from the
earth than absorbed. so that both atmos-
phere and ocean depth have increased,
and continent size varied, his objections
are not insurmountable. If We can take
the present rate of lowering of the
whole Mississippi Basin by erosion as
any criterion of the rate of erosion, then
a scale of ages such as the committee
favors Is reasonable.