galactic space radiation
81List of unusual units of measurement — For units of measure primarily used in countries where English is not the main language, see the article specific to that country, a list of which can be found in the systems of measurement article. An unusual unit of measurement is a unit of… …
82Cosmic infrared background — (CIB) is a mysterious infrared light coming from outer space. It is slowly being resolved into specific sources by infrared telescopes. In some ways it is analogous to the cosmic microwave background, but at shorter wavelengths. Contents 1… …
83Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
84Earth in science fiction — Earth An overwhelming majority of fiction is set on or features the Earth. However, authors of speculative fiction novels and writers and directors of science fiction film deal with Earth quite differently from authors of conventional fiction.… …
85List of Doctor Who monsters and aliens — This is a list of monsters and aliens from the long running BBC science fiction television series Doctor Who . The list includes some races which are not extraterrestrial, but are nonetheless non human. This list is meant to cover alien races and …
86Formation and evolution of the Solar System — Artist s conception of a protoplanetary disk The formation and evolution of the Solar System is estimated to have begun 4.568 billion years ago with the gravitational collapse of a small part of a giant molecular cloud …
87Tests of general relativity — General relativity Introduction Mathematical formulation Resources Fundamental concepts …
88White dwarf — For other uses, see White dwarf (disambiguation). Image of Sirius A and Sirius B taken by the Hubble Space Telescope. Sirius B, which is a white dwarf, can be seen as a faint pinprick of light to the lower left of the much brighter Sirius A …
89Ultra-high-energy cosmic ray — Unsolved problems in physics Why is it that some cosmic rays appear to possess energies that are theoretically too high? In high energy physics, an ultra high energy cosmic ray (UHECR) or extreme energy cosmic ray (EECR) is a cosmic ray with an… …
90Fermi paradox — The Fermi paradox is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations.The extreme age of the universe and its …
