Evening star., 1936-06-02

Heavy artillery of creation-atoms, ions
and molecules shot from exploding stars
through the dusty vastnesSes between
the stars at speeds comparable to that
of light and with energies of ten million
or more voltS-conStitute hitherto I'M
considered factor in CoSmic mechanics,
according to a communication just made
public by the National Academy of
Sciences here from Dr. F. ZWicky Of the
California Institute of Technology.
This heavy artillery, as pictured by
DR.. Zwicky, may be an important part
of the armament of order against chaos
in the eternal war whose battlefelds are
the great, thin duSt-cloudS of space and
the tenuous upper atmospheres OF stars
and planets.
He calls it the atomic ray" So far
as energies are concerned such rays fall
in the unexplored gap between the hard
est of x-rays and the still mysterious
cosrnic rays whose individual particles
have energies of more than a billion
volts. Yet they can hardly be consid-
cred as falling in the radiation spectrum.
Their speeds are considerably less than
that of light. They consist of relatively
enormous material particles compared
with the light corpuscles or photonS
which make up most radiation, or with
electronS, photonS, neutronS, ETC., which
are the fundamental constituents of
matter Considered in relation to any
of these, they are like torpedoes COM
pared to bullets. Each particle is either
an entire atom, an atom stripped of some
of it's outer electronS, or even whole
molecule.
The chief source of these atomic rays,
DR.. ZWicky says in his communication
to the National Academy, is the nova,
or exploding star, which suddenly ex-
pands to hundreds of times its original
brightness. The nova is the cannon
from which the heavy shells are fired
with such tremendous energies into the
almost empty light years of space.
Such a cosmic bombardment, Dr..
Zwicky says, continually would be
smashing into the edges of the great
dust clouds, billions of miles in diameter
and far more tenuous than the most
perfect earthly vacuum. The bullets
smash into the atoms and molecules of
such a dust cloud, driving them inward
and thus helping to preserve them as a
compact mass from which eventually
another star might be born. There is
little likelihood that such projectile
would go through one Of the dust clouds.
It would be bound before penetrating
very far to strike some atom. The mean,
free path of one of them, DR.. Zwicky
calculates, cannot be much more than
the distance traversed by light in
year, or approximately six trillion miles
The atomic rays, he points out, are not
the only force tending to preserve the
dust clouds in definite shapes, nor the
most important. The greatest force is
that of gravity which ties each particle
to the center of the mass. Acting to the
same end is the pressure of light exerted
on the fringes of the system from all
directions. But the bombardment, DR..
Zwicky explains, constitutes an essential
factor which astronomers hitherto have
failed to consider and it may explain
some puzzling features. Among these
are the sharp outlines of some OF the
nebulae and the distinct outlines of
MANY interstellar dust clouds. He is
preparing further report which will
explain more fully their nature.
The effect of the cosmic heavy artillery
bombardment also is seen in the very
tenuous atmospheres of the giant stars,
the tails of comets. the upper parts OF
the earths atmosphere, etc. Thus, Dr.
zwicky points out. the spectra OF those