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

D. Roosevelt.

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

Churchill.

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

occurs.

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

towards illnesses.

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.