Evening star., 1940-06-15
Of Stars, Men
And Atoms
Notebook Of Science Progress
In Field, Laboratory
And Study
By Thomas r. Henry.

Is a 'Qeath ray possible?
Is there some band of radiation in
the energy spectrum which can be pro-
jected at high voltages for consider
able distance through air and kill within
a reasonably short time an organism as
large and complex as a man which gets
in its path?
Despite a skepticism which is close
to certainty that nothing of the kind is
possible United States physicists are
re-examining the field and at least one
alleged "ray which would kill squir-
rel at 100 yards" has been investigated
by Army officers. The whole thing,
physicists in Government laboratories
agree, is Just trifle less impossible than
perpetual motion, but there always re-
mains an lota of doubt as to whether
something has not been overlooked
Certainly there are, they agree, death
rays They would kill man. in few
days. First, however, it would be neces-
sary to catch the man and chain him in
front of them 1t would be about the
most expensive form of execution ever
heard Of. A death ray, to be of military
value, must kill freely moving indi-
yidual at least 100 yards away.
Ordinarily described as death rays"
are the wave lengths of ultraviolet light
just trifie shorter than visible blue
light in the spectrum Of the sun which
lie between 3,100 and 1850 Angstrom
units in length. They will kill ne-celled
animals and plants, such as bacteria,
which are irradiated with them They
are used, for example, in keeping free of
germs the atmosphere of hospital operv
atmg rooms. They are responsible for
severe cases of sunburn and the sunburn
sickness which sometimes follows due to
the systemic poisons produced in the
skin cells
They certainly would kill a man, over
an extended period, if he could be IRA
dlated with an amount Of them compare
bic to that which is contained in SUM-
light as it arrives at the outer edges of
the earths atmosphere This would be
impossible to duplicate with any terres-
trial apparatus. All life on earth would
soon come to an end were it not for a
thin layer of ozone, a peculiar form Of
oxygen, from 20 to 40 miles above the
surface OF the globe, which absorbs them
This serves as the planets armor plate
This layer is thinner in autumn than in
spring and is sometimes credited with
the decline and death Of vegetation even
before it is killed by the frosts.
1t is fatal to life because it is absorbed
n O hiph Innroo
One-celled plants and animals conSis.
OF very small aggregations of these mole
cules. They are killed by a bullet of
this particular wave band of light lust
as man would be killed BY a bullet
through the heart. In the same way the
layer of molecules which constitute the
outer skin of human being is killed
and the bullets get no farther into the
body That is the killing method of anv
lethal radiation
so any manmade bombardment of
this particular form of death ray" even
II 1t could be projected to anv consid-
cradle distance. would do no more than
give the enemy bad sunburn. About
the only way to make man-killing death
rays out Of them would be to blast a
hole in the ozone armor of the sky in
just the right place There are much
shorter and more powerfully propelled
ultraviolet rays. but, so far as it has been
possible to determine, they are harmless
to life because they are not absorbed bv
organic molecules
Beyond the ultraviolet in the energy
spectrum lie the X-rays-with mucn
greater penetrating power. Depending
on the wave length they range from soft
to hard The soft rays, those with the
longest wave lengths, are responsible for
H-ray burns and are considered as pure
waste by physicians in the treatment of
cancer
There is no question but that X-rays
will kill man. Many men were actu-
ally killed by them before present meth
ods OF protecting workers in X-ray labo-
ratorles were devised. But it is much
the same proposition as catching a bird
by putting salt on its tail. The most
powerful X-ray tubes will not project
a beam of radiation more than five or six
feet. x-rays cannot be focused They
are captured quickly by the molecules
of the air.