The Wilmington morning star., 1945-08-20
n HOWARD W. BLAkEsLEE
p ;,ted Press Science Editor

p. a,ciated Press Science Editor
~, WV YORK, Aug. 10 R A
N.Y. ;,,side of a bomb is the Off
gun description of the principle
fla .,s mechanism of the atomic
e o. dropped on Japan.
W This new kind OF gun shoots ex-
i !,.e atoms into another mass
p0s toms, and all this occurs in.
o. NJ the bomb. At the moment OF
sseoct of the two masses of
ln 'aos the explosion occurs, al
' ao their joining, not the i'm
'' ..t is the cause.
pe Nav materials had to be fabri-
Nv. for various parts of the bomb
es.chanism and these substances
~. worth much more than gold.
nc Mo principles are described in
~ l otficial War Department re-
, 'n written by DR.. H. D. Smith
~, y. princeton, one of the consulting
'' IN this bomb the atoms which
.,it are the powder, and neutrons
, ,re the sparks. The atoms are
, w. 235 or Plutonium, a new
ssn,ical element discovered and
.s.veloped for the atomic bomb.
Tho Ts cryptic report from Guam
..,t the second bomb MADE the
fret obsolete probably refers to
. .he fact that the first used the
rrrsni,iIn powder, while the second
used Plutonium.
Tho sparks - the neutrons are
,,1 electrical bits of elemental
matter found only in the cores OF
.toms One neutron is so small
tb,t six hundred billion of them
lthe war has cost the United
st,tes three hundred billion dol.
,.rs, weighs only one-fifth of the
weight Of a five-cent coin. Such
snarks are flying around all the
hme Nature produces them when
,osnic rays hit atoms of air or
earth If the neutrons happen to
bit the core of the atom, more
reutrons are knocked loose to
shoot like bullets for hundreds of
feet They penetrate air, men,
walls and even steel that may be
in their paths. They are the most
penetrating things known to sci
ence In addition to cosmic rays,
The Alpha particles which fly from
radium may set loose neutron
sparks. Finally, some of the atoms
Of Uranium 235 and of the new
metal plutonium. explode spon.
/ taneouslv, which shoots more OF
the neutron sparks.
Everywhere, all the time, these
unseen atomic sparks are flying.
When they hit an atom of the ex-
plosive metallic powders, the core
splits, and 10 new neutrons come
fving out.
To produce an atomic bomb that
will explode, it is necessary only
to have a large enough mass OF
the 235 or the Plutonium atoms
packed closely together. Nature
does the rest-she sets off an ex-
p!osion in the thousandth of a Sec
ond, by her neutron sparks.
But the mass of these atoms nee
essary before there can by any
explosion is quite large. The re-
port said that this mass was fig.
ured theoretically as between two
pounds and 400 pounds Of either
metal. What the actual experi-
ments showed to be the smallest
mass which could be handled with
out premature explosion is still Sc
crot,
The bomb is made by assemb-
line number of these chunks of
not yet explosive size. That is
where the gun comes in. 1t shoots
sore Of these chunks at the others
III the bomb used as a target. The
Instant they come together t h e
cltv-busting explosion occurs.
The secrets are not these prin-
cloles, but how the engineers were
able to make them work in a prac-
teal bomb. The report points out