Editing Radiation (section)

== Discovery ==
{{further|Electromagnetic radiation#History of discovery}}

Electromagnetic radiation of wavelengths other than visible light were discovered in the early 19th century. The discovery of infrared radiation is ascribed to [[William Herschel]], the [[astronomer]]. Herschel published his results in 1800 before the [[Royal Society of London]]. Herschel, like Ritter, used a [[Triangular prism (optics)|prism]] to [[refract]] light from the [[Sun]] and detected the infrared (beyond the [[red]] part of the spectrum), through an increase in the temperature recorded by a [[thermometer]].

In 1801, the German physicist [[Johann Wilhelm Ritter]] made the discovery of ultraviolet by noting that the rays from a prism darkened [[silver chloride]] preparations more quickly than violet light. Ritter's experiments were an early precursor to what would become photography. Ritter noted that the UV rays were capable of causing chemical reactions.

The first radio waves detected were not from a natural source, but were produced deliberately and artificially by the German scientist [[Heinrich Hertz]] in 1887, using electrical circuits calculated to produce oscillations in the radio frequency range, following formulas suggested by the equations of [[James Clerk Maxwell]].

[[Wilhelm Röntgen]] discovered and named [[X-rays]]. While experimenting with high voltages applied to an evacuated tube on 8 November 1895, he noticed a fluorescence on a nearby plate of coated glass. Within a month, he discovered the main properties of X-rays that we understand to this day.

In 1896, [[Henri Becquerel]] found that rays emanating from certain minerals penetrated black paper and caused fogging of an unexposed photographic plate. His doctoral student [[Marie Curie]] discovered that only certain chemical elements gave off these rays of energy. She named this behavior [[radioactivity]].

Alpha rays (alpha particles) and beta rays ([[beta particle]]s) were differentiated by [[Ernest Rutherford]] through simple experimentation in 1899.<ref>{{Cite book |url=https://archive.org/details/londonedinburgh5471899lon/page/108/mode/2up |title=The London, Edinburgh and Dublin philosophical magazine and journal of science |date=1840 |publisher=London : Taylor & Francis |others=Smithsonian Libraries}}</ref> Rutherford used a generic pitchblende radioactive source and determined that the rays produced by the source had differing penetrations in materials. One type had short penetration (it was stopped by paper) and a positive charge, which Rutherford named ''alpha rays''. The other was more penetrating (able to expose film through paper but not metal) and had a negative charge, and this type Rutherford named ''beta''. This was the radiation that had been first detected by Becquerel from uranium salts. In 1900, the French scientist [[Paul Villard]] discovered a third neutrally charged and especially penetrating type of radiation from radium, and after he described it, Rutherford realized it must be yet a third type of radiation, which in 1903 Rutherford named [[gamma ray]]s.

Henri Becquerel himself proved that beta rays are fast electrons, while Rutherford and [[Thomas Royds]] proved in 1909 that alpha particles are ionized helium. Rutherford and [[Edward Andrade]] proved in 1914 that gamma rays are like X-rays, but with shorter wavelengths.

Cosmic ray radiations striking the Earth from outer space were finally definitively recognized and proven to exist in 1912, as the scientist [[Victor Hess]] carried an [[electrometer]] to various altitudes in a free balloon flight. The nature of these radiations was only gradually understood in later years.

The [[neutron]] and [[neutron radiation]] were discovered by [[James Chadwick]] in 1932. A number of other high energy particulate radiations such as [[positron]]s, [[muon]]s, and [[pion]]s were discovered by cloud chamber examination of cosmic ray reactions shortly thereafter, and others types of particle radiation were produced artificially in [[particle accelerators]], through the last half of the twentieth century.