Electromagnetic Radiation Essay

7951 Words Jun 8th, 2012 32 Pages
INTRODUCTION

Radiation, flow of atomic and subatomic particles and of waves, such as those that characterize heat rays, light rays, and X rays. All matter is constantly bombarded with radiation of both types from cosmic and terrestrial sources. This article delineates the properties and behaviour of radiation and the matter with which it interacts and describes how energy is transferred from radiation to its surroundings. Considerable attention is devoted to the consequences of such an energy transfer to living matter, including the normal effects on many life processes (e.g., photosynthesis in plants and vision in animals) and the abnormal or injurious effects that result from the exposure of organisms to unusual types of radiation or
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By 1904 Dally had developed severe ulcers on both hands and arms, which soon became cancerous and caused his early death.
During the next few decades, many investigators and physicians developed radiation burns and cancer, and more than 100 of them died as a result of their exposure to X rays. These unfortunate early experiences eventually led to an awareness of radiation hazards for professional workers and stimulated the development of a new branch of science—namely, radiobiology.
Radiations from radioactive materials were not immediately recognized as being related to X rays. In 1906 Henri Becquerel, the French physicist who discovered radioactivity, accidentally burned himself by carrying radioactive materials in his pocket. Noting that, Pierre Curie, the co-discoverer of radium, deliberately produced a similar burn on himself. Beginning about 1925, a number of women employed in applying luminescent paint that contained radium to clock and instrument dials became ill with anemia and lesions of the jawbones and mouth; some of them subsequently developed bone cancer.
In 1933 Ernest O. Lawrence and his collaborators completed the first full-scale cyclotron at the University of California at Berkeley. This type of particle accelerator was a copious source of neutrons, which had recently been discovered by Sir James Chadwick in England. Lawrence and his associates exposed laboratory rats to fast neutrons produced with

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