Background radiation is low intensity ionising radiation which is always present in the environment. Most background radiation comes from natural sources such as cosmic rays and some types of rocks (for example granite in the Earth's crust); the rest - about 13 percent - comes from artificial sources. Of the artificial sources the one that contributes most to the
background radiation is the medical use of radioactive materials: other sources are the nuclear industry and fallout from weapons tests, television screens and luminous paint. When the radiation from a specific source is measured, the background radiation must be deducted from the result to make it accurate. Research Background Radiation
cosmic background radiation or 3 degree radiation, is electromagnetic radiation left over from the original formation of the universe in the Big Bang around 15 billion years ago. It corresponds to an overall backgroundtemperature of 3K (-2700C/-4540F), or 30C above absolute zero. In 1992 the Cosmic Background Explorer satellite, COBE, detected slight 'ripples' in the strength of the backgroundradiation that are believed to mark the first stage in the formation of galaxies.
Cosmic background radiation was first detected 1965 by the American physicists Arno Penzias and Robert Wilson, who in 1978 shared the Nobel Prize for Physics for their discovery. Research Cosmic Background Radiation
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Abbreviations
Research Background Radiation
