The planet Earth orbits the Sun in what is often considered to be empty space but is in fact full of very small charged particles speeding in all directions. The situation can be compared to the Earth having to constantly travel in a light shower of rain and with the atmosphere acting like an umbrella. The 'rain' is made up of charged particles called 'Cosmic Rays'. The name cosmic ray was given long ago to invisible ionising radiation that could mysteriously discharge an electroscope even when the electroscope was heavy insulated. Early scientists quickly established a relationship between the rate of charge loss and altitude, i.e. a gold-leaf electroscope would loose its charge much faster at the top of a mountain than at sea level, . Many clever experiments led scientists to suspect that invisible radiation was coming from the sky and penetrating the electroscope thus neutralising the charge, . The nature of the ionising radiation and its origin has remained one of the primary areas of research in astrophysics over the last hundred years. This article gives an overview of elemental cosmic radiation and also presents the results from an experiment to measure the upper charge regions of the cosmic radiation spectrum.
Keane, Dr. Anthony J.
The ITB Journal:
1, Article 8.
Available at: http://arrow.dit.ie/itbj/vol3/iss1/8