Evening star., 1952-02-18
Discovery Complicotes
Inner Theory of Atom
Explosion Of Kappa Meson
Puzzles World Physicists
By Thomos R. Henry

A jet bomb on the inside of the atom
has been found by European physicists.
This is the kappa meson. apparently
new fundamental particle Of matter
and an infinitely Short-lived material
ization of the cement energy which
holds creation together.
During its existence, measured In
billionths of second, 1t weighs about
1900 times as much as an electron. the
lightest of all the basic particles Of
breaks up into three other particles so
that the picture of its explosion Is that
OF three-pronged star.
The, discovery greatly complicates the
already highly complicated picture Of
the structure Of the atom. The existence
Of the particle first was demonstrated q
few months ago by physicists Of the
University of Bristol in England. accord
ing to a report to the once Of Naval
Research here. Within the past few
weeks it also has been reported from the
laboratories Of the Ecole Polytechnique
in Paris.
New Particle Indicated.
Both these reports agree on the gen.
eral characteristics Of the new particle.
Now the picture again has been compli-
Gated by the discovery, on Photographic
plate exposed on a rocket at an altitude
of $4,000 feet. Of a probable new particle
Of the same general nature but which
breaks In two, rather than three, pieces.
This was determined by DR.. D. T. King
of the University of Bristol.
There now are at least three-possibly
four or even more-kinds of mesons.
First is the pi meson. weighing 280 times
as much as an electron, with q lifetime
outside the atom Of about fifty-mil-
lionths Of a second. Second is the mu
meson, 210 times the weight of an elec-
tron. with lifetime of -millionthS
OF second. Both these revert into the
energy out Of which they were created.
They result from disintegration of atoms
struck by cosmic rays. The nature of
the particles into which the new kappa
mesons disintegrate is not clear, but they
may well be electrons and pi and mu
meSonS.
The existence Of the mesons as a
discrete entity was predicted Just before
the war by the Japanese physicist, H.
Yukawa. now at Princeton, and his pre-
dictions since have been abundantly
confirmed
Physical laboratories throughout the
world are being urged to watch out for
the new kappas.
The most virulent wheat disease vet
known in North America is worrying
Department Of Agriculture specialists.
1t Is known only as Strain 15-B of
wheat stem rust, and its range extends
generally over the entire wheat-growing
area from Mexico to Manitoba and from
Iowa westward. With favorable weather
onditions-which also would be the
ideal conditions for wheat itself-this
blight might easily cause enormous
losses.
The only recourse now known is to
breed wheat varieties resistant to the
fungus. Several have been developed by
the Agriculture Department plant
breeders, and extraordinary pressure Is
now on them. None are commercially
desirable. Ordinarily from eight to ten
years Is required to produce and intro
duce q new wheat. Disease resistance
itself Is not enough II the requirements
Of yield, quality of grain and strength Of
straw are not met.
Perhaps the most accomplished yet is
the introduction Of a new variety by
the Rockefeller Foundation for Agricul-
tural Research In Mexico. This u
adapted to highly specialized require
ments, however, and will be OF little
value in the United States, except pos
sibly for q limited area In Southern
Texas.
For the past half-century stem rust
has been one of the most feared Of all
grain maladies. but prior to 1850 re-
sistant varieties had been bred for all
the commercial types. But. all the time
there was the lurking possibility Of
trouble.
Originated From Cross.
Two summers ago 15-B made its first
appearance in the fields and spread
rapidly over the whole wheat area. 1t
differed from the familiar strains mainly
in it's greater virulence and the fact that
practically all known varieties were
susceptible.
There can be very little question, say
Agriculture Department specialists. that
the strain originated from q cross be-
tween two strains Of stem rust which
occurred on the leaves Of barberry
UuSIlGS. 4IC UdIUCA4y ID dAl CooCAtAdh
host to the pest during one stage OF its
life cycle.
Throughout the wheat-growing areas
themselves the barberry has been fairly
well eliminated, but hedges of this red
berried bush still are fairly common in
the East, and the spores Of the rust
are carried westward by the high winds.
There also is the possibility although
the Department of Agriculture plant
breeders are quite skeptical-that the
virulent strain originated as "muta-
tion"-a quite abrupt change in heredi-
tary characters.
Last summer was not well-adapted
either for the rust or for wheat itself.
1t requires high temperature and plenty
Of moisture.