Atomic Bomb Essay, Research Paper
During wartime, horrible atrocities against
all of humanity must be dealt with. Crimes against humanity,
as never witnessed before, and hopefully to never be seen again, occurred
during the course of World War II. America has always, and
most likely will always place a high value on American lives.
In order to protect these lives and to insure that the world is safe for
democracy, American leaders had to make a very tough decision, whether
or not to drop the atomic bomb on Japan. This act would essentially
trade Japanese lives for American lives. The Japanese were
responsible for hundreds of thousands of American casualties in the Pacific,
including the unprovoked attack on Pearl Harbor. With Japanese
forces showing no signs of surrender, American leaders made a decision.
This decision essentially changed the history of warfare forever.
An atomic bomb is any weapon that gets
its destructive power from an atom. This power comes when the matter
inside of the atoms is transformed into energy. The process by which
this is done is known as fission. The only two atoms suitable for
fission are the uranium isotope U-235 and the plutonium isotope Pu-239.
Fission occurs when a neutron, a subatomic particle with no electrical
charge, strikes the nucleus of one of these isotopes and causes it to split
apart. When the nucleus is split, a large amount of energy is produced,
and more free neutrons are also released. These neutrons strike other
atoms, which causes more energy to be released. If this process is
repeated, a self-sustaining chain reaction will occur, and it is this chain
reaction that causes the atomic bomb to have its destructive power.
The first type of atomic bomb ever used
was a gun-type. In this type two subcritical pieces of U-235 are
placed in a device similar to the barrel of an artillery shell. One
piece is placed at one end of the barrel and will remain there at rest.
The other subcritical mass is placed at the other end of the barrel.
A conventional explosive is packed behind the second subcritical mass.
When the fuse is triggered, a conventional explosion causes the second
subcritical mass to be propelled at a high velocity into the first subcritical
mass. The resulting combination causes the two subcritical masses
to become a supercritical mass. When this supercritical mass is obtained,
a rapid self-sustained chain reaction is caused. This type of atomic
bomb was used on Hiroshima, and given the nickname ?Little Boy? after Franklin
The second type of atomic bomb is an implosion
bomb. In this type a subcritical mass, which is in the shape of a
ball, is placed in the center of the weapon. This subcritical mass
is surrounded in a spherical arrangement of conventional explosives.
When the fuse is triggered all of the conventional explosives explode at
the same time. This causes the subcritical mass to be compressed
into a smaller volume, thus creating a supercritical mass to be formed.
After this supercritical mass is obtained, a self-sustained chain reaction
takes place and causes the atomic explosion. This type of atomic
bomb was used on Nagasaki, and given the nickname ?Fat Man? after Winston
The blast from an atomic bomb?s explosion
will last for only one-half to one second, but in this amount of time a
great deal of damage is done. A fireball is created by the blast,
which consists mainly of dust and gasses. The dust produced in this
fireball has no substantial effect on humans or their environment.
However, as the gasses expand a blast wave is produced. As this blast
wave moves, it creates static overpressure. This static overpressure
then in turn creates dynamic pressure. The static overpressure has
the power to crush buildings. The dynamic pressure creates winds,
which have the power to blow down trees. The blast pressure and fireball
together only last for approximately eleven seconds, but because it contains
fifty percent of the atomic bomb?s latent energy a great deal of destruction
In Hiroshima, the blast from the atomic
bomb was measured to be about four and a half to six and seven tenths tons
of pressure per square meter, while in Nagasaki the blast was measured
to be about six to eight tons of pressure per square meter. Because
of this dramatic change in the pressure most of the cities were destroyed.
The static overpressure in Hiroshima destroyed between sixty-two and ninety
thousand buildings, while in Nagasaki all of the buildings within three
thousand feet of the center of the blast were completely destroyed.
The static overpressure created a dynamic pressure that had winds up to
four hundred miles per hour. These winds caused minor scratches,
lacerations, or compound fractures, which came about when people and glass
fragments were projected through the air. By combining the results
of the static overpressure and the dynamic pressure one can begin to see
what damage was caused by the atomic bomb?s blast.
The thermal radiation produced by an atomic
bomb explosion will account for thirty-five percent of the atomic bomb?s
damage. Thermal radiation can come in one of three forms: ultraviolet
radiation, visible radiation, or infrared radiation. The ultraviolet
radiation is absorbed so rapidly by air particles that it has no substantial
effect on people. However, the visible and infrared radiation creates
an enormous amount of heat to be produced, approximately ten million degrees
Celsius at the hypocenter. This heat has two main effects.
The first is known as flash burns. The flash of thermal radiation
produces these flash burns right after the explosion. Flash burns
can be either first-degree burns (bad sun burns), second-degree burns (blisters,
infections, and scars), or third-degree burns (destroyed skin tissue).
The second type is known as flame burns. These are burns that come
from one of two different types of fires, which are created when flammable
materials are ignited by the thermal radiation. The first type is
called firestorms. A firestorm is violent, has raging winds, and
has extremely high temperatures; but fortunately it does not spread very
rapidly. The second type is called a conflagration. A conflagration
is when the fire spreads in a front. The thermal radiation produced
by the atomic bomb?s explosion will account for most of the deaths or injuries.
In Hiroshima and Nagasaki the thermal
radiation accounted for approximately twenty to thirty percent of the deaths
or injuries from the atomic bomb?s explosion. Those that were at
a distance of two and one half miles from the hypocenter received first
degree burns. Those that were at a distance of two and one quarter
miles from the hypocenter received second degree burns. Those that
were at a distance of one half of a mile from the hypocenter received third
degree burns. Ninety-five percent of the burns created from the thermal
radiation were by flash burns, and only five percent of the burns were
by flame burns. The reason for this low number of flame burns is
that only two to ten percent of the buildings caught on fire. By
combining the damage from both the flash and flame burns one can begin
to see the effects that an atomic bomb?s thermal radiation had. Approximately
sixty thousand in Hiroshima, and approximately forty-one thousand people
were either killed or injured from the thermal radiation.
The final effect that an atomic bomb caused
is the nuclear radiation produced from the fission process. The nuclear
radiation comes in the form of either Gamma rays or Beta particles.
Gamma rays are electromagnetic radiation originating in the atomic nuclei,
physically identical to x-rays. They can enter into living tissue
extremely easily. Beta particles are negatively charged particles,
identical to an electron moving at a high velocity. These forms of
nuclear radiation are measured in rads (radiation-absorbed-dose), which
is defined as the absorption of five ten millionths joule per gram of absorbing
material. During the initial nuclear radiation mostly Gamma rays
are emitted from the fireball. This period of initial nuclear radiation
lasts for approximately one minute. During the residual nuclear period
(fallout) the Beta particles and more of the Gamma rays are emitted.
The residual radiation has two stages: early fallout and delayed fallout.
In early fallout, the heavy and highly radioactive particles fall back
to the earth, usually within the first twenty-four hours. In delayed
fallout, the tiny and often invisible particles fall back to the earth,
and usually last from a couple of days to several years. The nuclear
radiation from the atomic bomb?s explosion was not the main cause of death,
but it did still have serious results.
In Hiroshima, the initial nuclear radiation
was spread over a distance of approximately fifty-three hundredths of a
kilometer. In Nagasaki, the initial nuclear radiation only spread
one and six thousandths of a kilometer. The reason why the nuclear
radiation was not the main caused of deaths or injuries was that the atomic
bomb was detonated so high in the atmosphere; approximately five hundred
and seventy meters in Hiroshima, and approximately five hundred and ten
meters in Nagasaki. Even without causing many deaths the nuclear
radiation probably caused the most serious effects. Those with definite
proof were those of increased rates of cataracts, leukemia, cancer of the
thyroid, cancer of the breast, cancer of the lungs, cancer of the stomach,
and mental retardation of babies. Those that had substantial but
not definite proof were those of tumors of the esophagus, tumors of the
colon, tumors of the salivary glands, and tumors of the urinary tract organs.
Those that had no definite or substantial proof were those of increased
rates of birth mortality, birth defects, infertility, and susceptibility
The blast, the thermal radiation, or the
nuclear radiation from an atomic bomb explosion will have severe effects
on both humans and on the environment in which they live in. The
only two cities that have ever experienced having an atomic bomb being
exploded on them were the Japanese cities of Hiroshima and Nagasaki during
World War II. In Hiroshima, the casualties have been estimated between
seventy-five and eighty thousand. In Nagasaki, the total number killed
was estimated at more that thirty-five thousand. The total number
severely injured was even greater than forty thousand.
In the 50 years since the first atomic
explosion, the promises and perils of nuclear science have touched nearly
every aspect of our culture and politics. The scientific development
surrounding the A-bomb has been a pivotal point in the world’s history,
launching us into the Atomic Age. We came close to nuclear inhalation
during the cold war, but its benefits have been much greater. We
have turned nuclear power into a reliable source of energy, and it has
provided us with many technological advances. In the future we can
look forward to using the technology discovered during the Manhattan Project
to create even better sources of energy. We are only at the beginning
of the Atomic Age, and there are endless possibilities for the future.