Evening star., 1939-01-28

lOIy Ol LIT. ". mann anu not yet
reported in the scientific world.
Yesterday afternoon Dr. Hahn's Off
cial report came to them and last
night the great atom smashing ma
chimes of the Carnegie Institution
and of Columbia University were
being put to work in efforts to dupli-
cate the results by producing atoms
that literally break in two and in
doing SO release energy equivalent
to more than 0O00O,00O volts. Such
energies hitherto have been pro-
duced only in the interiors of the
sun and the stars.
The details of DR.. Hahns report
are prosaic enough, until the tre-
mendous implications are realized.
He was working with synthetic
element" ekauranium. 1t originally
was produced by Prof. Fermi by
bombarding uranium, heaviest and
most complex of the elements and
parent substance of radium, with
slow neutrons, the cannonballs of
atomic physics. The uranium atoms
will occasionally pick up some of
these slow neutrons. When one is
added to the urnaium nucleus a
new element is produced, heavier
than anything known in nature.
Traces of Earth Barium.
The German physicists momen-
tous discovery was simply that one
of his preparations of ekauranium
contained traces of another element,
the rare earth barium. He knew it
was not there in the first place. The
only place it could have come from
was out of the ekauranium itself
1t could be produced from ekauran-
ium only if the ekauranium atom
split in two. 1t would require a
100000 0000-volt explosion" to split
an ekauranium atom in two. Hence
that is what must have happened.
The ekauranium atom has an
atomic weight of 239-that is, 1t is
239 times heavier than an atom OF
hydrogen, lightest of elements. All
but a negligible part of this weight
is contained in the nucleus, or CEN
tral mass. around which the prac-
tically weightless outer electrons re-
volve like planets around the sun.
The barium atom has an atomic
weight of 146. 1t must have come
out of the ekauranium together with
some other substance with an atomic
weight of SO. This corresponds to
the weight of the very rare element
masyrium in the atomic table.
Tremendous forces are required to
hold together the protons, or posi-
lively charged electrical particles
and the similar unchanged particles
the neutrons, which make up the
nucleus of an atom. These forces
are infinitely the greatest known
in nature. Although long postu-
lated, they were first actually dem
onstrated and measured at the
Terrestrial Magnetism Laboratory OF
the Carnegie Institution here three
years ago. They are trillions OF
times greater than the forces OF
gravity for particles of equal size.
Force Increases With Weight.
Physicists can calculate the mag
nitude of these binding forces fol-
all sorts of atoms. They are rela-
lively very great for the lighter ele-
ments, but they do not increase pro-
portionately as one goes up the
atomic table, except that there is a
rapid increase when the very heavy
elements are reached.
For this reason the sum of the
total binding forces in the nuclei
of barium and masyrium are about
O0,00O,0O0 volts less than the bind
ing force of the uranium, or ekau-
ranium nucleus. Energy cannot be
destroyed. The only possible con-
clusion is that when ekauranium
breaks up into the other two ele-
ments that much energy must be
set loose. Stated in another way, it
would require that much energy to
split a uranium atom in such way
Such a phenomenon as this split.
ting hitherto has not been dreamed
of on earth. It is totally different
from the familiar radio activity
best known in the cases of uranium
and radium. Uranium in nature
found chiefly in the Belgian Congo
and near Great Slave Lake in North.
ern Canada-is unstable and every
now and then an atom will shoot
out a tiny particle of energy. Thi.
breaks it down into radium. The
process is very slow. Half Of 8
given mass of uranium will disinte-
CRATE in this manner in a billion
years.
The resulting radium also is very
unstable and gives of various sorts
Of emanations-nucleii Of helium
atoms, electrouS, and radiation simt-