The Word ‘Nuclear’ can have several meanings:
Something to do with the nucleus of an atom
Something involved in a nuclear reaction (fission, for example), such as nuclear waste or nuclear energy
Or a description of weaponry which takes its power from uncontrolled nuclear reactions
All of these definitions are essentially very similar. All of nuclear physics revolves around the nucleus of the atom, and reactions involving the nucleus breaking apart or joining together. The most notable nuclear reactions are fission and fusion. Fission is the process where the nucleus of an atom splits up into smaller pieces, various smaller nuclei, individual protons and neutrons and some photons in the form of gamma rays. Fission is an exothermic reaction, which means it gives out energy. This is the nuclear reaction used for nuclear power plants and nuclear bombs. Nuclear fusion is the opposite of fission, in other words two or more smaller nuclei join together to make one large nucleus. This is also an exothermic reaction.
[Diagram illustrating Nuclear fission and nuclear fusion]
The image most commonly associated with “Nuclear Physics” is perhaps that of a nuclear explosion, caused by an atomic bomb. Of course, this is just one example of the application of nuclear physics, with others including nuclear energy – a source of electricity that does not rely on fossil fuels-, and Radiotherapy, a vital method in modern medicine used for the destruction of harmful tumours.
The biggest argument against nuclear physics is the atomic bomb, arguably one of the most unpleasant inventions in mankind’s history. Not only is the explosion caused by the immense nuclear reaction one of the most devastating imaginable, but those who survive are killed off slowly by the fallout, and resulting radiation. On the other hand, nuclear physics has also provided us with an alternative form of energy, which could be considered “clean” compared to coal or oil, as it does not produce carbon dioxide. Unfortunately nuclear power stations do produce vast quantities of nuclear waste, which must be stored, and if something goes wrong with the power plant the results can be catastrophic. An example of this is the Chernobyl disaster, back in 1986, where an explosion in a reactor lead to an entire city of 14000 people to be evacuated, with several deaths from radiation poisoning occurring, and widespread environmental issues ensuing. One of the main components of nuclear reactions is radiation, which exists in many forms, as alpha, beta and gamma radiation, as well as others. Radiation is very much a double edged sword. Radiation can be absorbed by substances, and in the case of living cells can cause cell damage leading to radiation sickness, a generally deadly ailment, or cell mutation causing tumours, often cancerous ones. These unpleasant predicaments can occur to many people who are exposed to radiation, such as early X-ray operators, people living near the site of a nuclear explosion, or those who have to handle radioactive material. For many of these people the end result is death. But although it can be the cause of illness, Radiation can also be a cure, and a vital component in modern day medicine. The X-ray, once refined so that the levels were not high enough to place the patient or operator at risk, is endlessly useful for enabling doctors to examine the inside of a patient without having to cut them open, allowing them to see unpleasant things the patient may have swallowed, or damaged bones. Another use for radiation, quite astonishingly, is in the treatment of cancerous tumours. Although radiation can be a cause of these tumours, when directed in concentrated beams onto the affected tissue, it can kill the undesirable growth, without damaging the surrounding tissue.
Interestingly, nuclear fusion is a naturally occurring reaction, and takes place in every active star. Without this we would be pretty cold down here on earth. Of course that does not mean that man mad nuclear fusion reactions are an entirely good thing, however, as the reaction has, as yet, been impossible to control, and so is mainly mused for nuclear weapons.
In conclusion, nuclear physics, like most things, is neither completely good norcompletely evil. It is a tool that can be used for good, but can be a weapon, or an unintentional hazard as well.
References:
http://en.wikipedia.org/wiki/File:CNO_Cycle.svg
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