Editing Cosmic ray (section)

==Etymology==
The term ''ray'' (as in [[optical ray]]) seems to have arisen from an initial belief, due to their penetrating power, that cosmic rays were mostly [[electromagnetic radiation]].<ref>{{cite web|author=Christian, Eric|title=Are cosmic rays electromagnetic radiation?|publisher=NASA|url=http://helios.gsfc.nasa.gov/qa_cr.html#em|archive-url= https://web.archive.org/web/20000531200225/http://helios.gsfc.nasa.gov/qa_cr.html#em|url-status=dead|archive-date=31 May 2000|access-date=11 December 2012}}
</ref> Nevertheless, following wider recognition of cosmic rays as being various high-energy particles with [[invariant mass|intrinsic mass]], the term "rays" is consistent with known particles such as [[cathode ray]]s, [[anode ray|canal rays]], [[alpha particle|alpha rays]], and [[beta particle|beta rays]]. Meanwhile "cosmic" ray [[photons]], which are quanta of electromagnetic radiation (and so have no intrinsic mass) are known by their common names, such as ''[[gamma ray]]s'' or ''[[X-ray]]s'', depending on their [[photon energy]].