Inventors
The History of the Atomic
Bomb
Development and
History of the Atomic Bomb and The Manhattan Project
"My God, what have we done?" - Robert
Lewis, the co-pilot of the Enola Gay, the B-29 that dropped the first atomic
bomb.
On August 2, 1939, just before the
beginning of World War II, Albert
Einstein wrote to then President Franklin D. Roosevelt. Einstein and
several other scientists told Roosevelt of efforts in Nazi Germany to purify
uranium-235, which could be used to build an atomic bomb. It was shortly
thereafter that the United States Government began the serious undertaking
known then only as "The Manhattan Project." Simply put, the Manhattan Project
was committed to expediting research that would produce a viable atomic
bomb.
The most complicated issue to be
addressed in making of an atomic bomb was the production of ample amounts
of "enriched" uranium to sustain a chain reaction. At the time, uranium-235
was very hard to extract. In fact, the ratio of conversion from uranium
ore to uranium metal is 500:1. Compounding this, the one part of uranium
that is finally refined from the ore is over 99% uranium-238, which is
practically useless for an atomic bomb. To make the task even more difficult,
the useful U-235 and nearly useless U-238 are isotopes, nearly identical
in their chemical makeup. No ordinary chemical extraction method could
separate them; only mechanical methods could work.
A massive enrichment laboratory/plant
was constructed at Oak Ridge, Tennessee. Harold C. Urey and his colleagues
at Columbia University devised an extraction system that worked on the
principle of gaseous diffusion, and Ernest O. Lawrence (inventor of the
Cyclotron)
at the University of California in Berkeley implemented a process involving
magnetic separation of the two isotopes.
Next, a gas centrifuge was used to
further separate the lighter U-235 from the heavier, non-fissionable U-238.
Once all of these procedures had been completed, all that needed to be
done was to put to the test the entire concept behind atomic fission ("splitting
the atom," in layman's terms).
Over the course of six years, from
1939 to 1945, more than $2 billion was spent during the history of the
Manhattan Project. The formulas for refining uranium and putting together
a working atomic bomb were created and seen to their logical ends by some
of the greatest minds of our time. Chief among the people who unleashed
the power of the atom was J. Robert Oppenheimer, who oversaw the project
from conception to completion.
Finally, the day came when all at
Los Alamos would find out if "The Gadget" (code-named as such during its
development) was going to be the colossal dud of the century or perhaps
an end to the war. It all came down to a fateful morning in midsummer,
1945.
At 5:29:45 (Mountain War Time) on
July 16, 1945, in a white blaze that stretched from the basin of the Jemez
Mountains in northern New Mexico to the still-dark skies, "The Gadget"
ushered in the Atomic Age. The light of the explosion then turned orange
as the atomic fireball began shooting upwards at 360 feet per second, reddening
and pulsing as it cooled. The characteristic mushroom cloud of radioactive
vapor materialized at 30,000 feet. Beneath the cloud, all that remained
of the soil at the blast site were fragments of jade green radioactive
glass created by the heat of the reaction.
The brilliant light from the detonation
pierced the early morning skies with such intensity that residents from
a faraway neighboring community would swear that the sun came up twice
that day. Even more astonishing is that a blind girl saw the flash 120
miles away.
Upon witnessing the explosion, its
creators had mixed reactions. Isidor Rabi felt that the equilibrium in
nature had been upset -- as if humankind had become a threat to the world
it inhabited. J. Robert Oppenheimer, though ecstatic about the success
of the project, quoted a remembered fragment from the Bhagavad Gita. "I
am become Death," he said, "the destroyer of worlds." Ken Bainbridge, the
test director, told Oppenheimer, "Now we're all sons of bitches."
After viewing the results several
participants signed petitions against loosing the monster they had created,
but their protests fell on deaf ears. The Jornada del Muerto of New Mexico
would not be the last site on planet Earth to experience an atomic explosion.
Scientists Who Invented the Atomic
Bomb under the Manhattan Project: Robert
Oppenheimer, David Bohm, Leo Szilard,
Eugene Wigner, Otto Frisch, Rudolf Peierls, Felix Bloch, Niels Bohr, Emilio
Segre, James Franck, Enrico
Fermi, Klaus Fuchs and Edward
Teller. View a copy
of the letter Einstein wrote Roosevelt that prompted the Manhattan
Project.
Atomic
Bomb Detonation at Hiroshima
As many know, the atomic bomb has
been used only twice in warfare. The first was at Hiroshima. A uranium
bomb nicknamed "Little Boy" (despite weighing in at over four and a half
tons) was dropped on Hiroshima August 6, 1945. The Aioi Bridge, one of
81 bridges connecting the seven-branched delta of the Ota River, was the
target; ground zero was set at 1,980 feet. At 0815 hours, the bomb was
dropped from the Enola Gay. It missed by only 800 feet. At 0816 hours,
in an instant, 66,000 people were killed and 69,000 injured by a 10-kiloton
atomic explosion.
The area of total vaporization from
the atomic bomb blast measured one half mile in diameter; total destruction
one mile in diameter; severe blast damage as much as two miles in diameter.
Within a diameter of two and a half miles, everything flammable burned.
The remaining area of the blast zone was riddled with serious blazes that
stretched out to the final edge at a little over three miles in diameter.
Nagasaki
On August 9, 1945, Nagasaki fell
to the same treatment. This time a Plutonium bomb nicknamed "Fat Man" was
dropped on the city. Though "Fat Man" missed its target by over a mile
and a half, it still leveled nearly half the city. In a split second, Nagasaki's
population dropped from 422,000 to 383,000. Over 25,000 people were injured.
Japan offered to surrender on August
10, 1945.
NOTE: Physicists who have studied
these two atomic explosions estimate that the bombs utilized only 1/10th
of 1 percent of their respective explosive capabilities.
Byproducts of Atomic Bomb Detonations
While the explosion from an atomic
bomb is deadly enough, its destructive ability doesn't stop there. Atomic
bomb fallout creates another hazard as well. The rain that follows any
atomic detonation is laden with radioactive particles, and many survivors
of the Hiroshima and Nagasaki blasts succumbed to radiation poisoning.
The atomic bomb detonation also has
the hidden lethal surprise of affecting the future generations of those
who live through it. Leukemia is among the greatest of afflictions that
are passed on to the offspring of survivors.
While the main purpose behind the
atomic bomb is obvious, there are other by-products of the use of atomic
weapons. While high-altitude atomic detonations are hardly lethal, one
small, high-altitude detonation can deliver a serious enough EMP (Electro-Magnetic
Pulse) to scramble all things electronic, from copper wires to a computer's
CPU, within a 50-mile radius.
During the early history of The Atomic
Age, it was a popular notion that one day atomic bombs would be used in
mining operations and perhaps aid in the construction of another Panama
Canal. Needless to say, it never came about. Instead, the military applications
of atomic destruction increased. Atomic bomb tests off of the Bikini Atoll
and several other sites were common until the Nuclear Test Ban Treaty was
introduced.
Part Two: Nuclear
Fission/Nuclear Fusion
Mary
Bellis
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