The Indianapolis times. [volume] (Indianapolis [Ind.]) 1922-1965, 1933-08-19
-DIetz on Science
EARTH SWINGS
IN SIX-LAYER
OCEAN OF AIR
Both Animal and Vegetable
Life Depend Upon
Atmosphere.
BY DAVID DIETZ
scripps Howard Science Fditoy

We 1--we at the bottom Of an
ocean. Ordinarily We forget this
fact. But when we come TO study
the weather. we are reminded Of IL.
We walk around on the bottom of
the oceans OF water. And when we
ride In airplanes or airships we are
swimming in the ocean Of air Just
as f1sh swim in the oceans of
water.
Our weather is the result of cur
rents and shifting conditions in this
ocean Of air. And. Of course, life
itself is possible because Of this
ocean. Life requires the oxygen in
the atmosphere. But II the atmos-
phere we're pure oxygen, life would
not last very long.
II We breathed an atmosphere of
pure oxygen. it would increase the
chemical activities of our bodies to
point where We could not survive
Fortunately, the atmosphere is only
about one-fifth oxygen. The re-
mainder is chiefly nitrogen. an in
ert gas which takes no direct part
in the chemical activities which are
associated with breathing.
But the other constituents of the
atmosphere have their roles in the
scheme Of life. Plants require the
carbon dioxide which is in the at
mosphere.
Plants also require the nitrogen,
but they can not use it in its pure
form. II is available 10 them only
after certain bacteria, the so-called
nitrogen fixing bacteria. have
changed it into soluble salts which
the roots Of plants can absorb from
the soil.
Pull Saves Air
The force Of gravitation is re-
sponsible for the earth retaining an
atmosphere. The tendency of the
molecules OF gas which compose the
atmosphere is to fly off into space.
This tendency is counteracted by
the earth's gravitational pull.
The atmosphere is denseSt closest
TO the earth's surface. AS one as
cends into it, it grows thinner and
thinner
If the atmosphere had a uniform
density from top 10 bottom, II would
extend only to a height of five
miles above the earth's surface.
At height Of thirty miles, the
air is only one-hundredth as dense
as ii Is at the earths surface AT a
height of fifty miles. the atmosphere
has become so thin that it does not
exert any appreciate pressure.
There is some air at this height,
however, as is proved by the re-
fraction or bending of the suns
rays, and by the fact that meteors
or shooting stars" become visible
at this height
Just how far the atmomsphere
does extend is a matter of opinion
Some authorities think that there
may be slight traces of air at a
height of 200 miles. DR. Willis
Luther Moore. former chief of the
United States weather bureau, is of
the opinion that the atmosphere
gives out at a height of about 100
miles.
Meteorologists are very much in
terested in studying the upper
reaches of the earth's atmosphere,
because they think that many of
the weather conditions at the sur
face are the result Of what is going
on at high attitudes.
Six Atmospheric Layers
Meteorologists divide the earth's
atmosphere into six layers, or 70
state it more technically, into six
concentric "atmospheres."
The innermost layer, the one next
to the surface of the earth, is called
the troposphere. 1t extends up to a
height OF about six miles,
The second layer is called the
stratosphere. II is sometimes called
the isothermal layer because its
temperature is everywhere and al
all times the same. about 100 de-
grees below zero on the Fahrenheit
thermometer.
The third layer is at a height OF
about thirty-six miles. II is known
as the meteoric region because me-
teors become visible in this layer
The fourth layer is at height OF
about fifty miles It is called the
Kennedy Heaviside layer. in honor
of the two scientists who advanced
theories about its behavior. Radio
fans are familiar with it, It is the
layer of electrified or ioniZsd all
which acts as a ceiling to reflect
radio waves.
The fifth layer is known as the
auroral layer. II is extremely thin
and extends upward from a height
Of sixty miles. The auroral displays
are thought to occur in this layer
Some authorities place a sixth
layer beyond the auroral layer. II
has been called the empyrean layer
and gradually trails off into the
emptiness of outer snare