Editing Mössbauer effect (section)

== History ==
The emission and absorption of [[X-ray]]s by gases had been observed previously. It was expected that a similar phenomenon would be found for [[gamma ray]]s, which are created by [[atomic nucleus|nuclear]] transitions (as opposed to X-rays, which are typically produced by [[Quantum jump|electronic transitions]]). However, attempts to observe nuclear resonance produced by gamma rays in gases failed due to energy being lost to recoil, preventing resonance (the [[Doppler effect]] also broadens the gamma-ray spectrum). Mössbauer observed resonance in nuclei of solid [[iridium]], which raised the question of why gamma-ray resonance was possible in solids but not in gases. Mössbauer proposed that, for the case of atoms bound into a solid, a fraction of the nuclear events could occur essentially without recoil under certain circumstances. He attributed the observed resonance to this recoil-free fraction of nuclear events.

The Mössbauer effect was one of the last major discoveries in physics to be originally reported in the German language. The first reports in English were a pair of letters describing independent repetitions of the experiment.<ref>
{{cite journal
|last1=Craig |first1=P.
|last2=Dash |first2=J.
|last3=McGuire |first3=A.
|last4=Nagle |first4=D.
|last5=Reiswig |first5=R.
|year=1959
|title=Nuclear Resonance Absorption of Gamma Rays in Ir<sup>191</sup>
|journal=[[Physical Review Letters]]
|volume=3 |issue=5 |pages=221
|bibcode=1959PhRvL...3..221C
|doi=10.1103/PhysRevLett.3.221
}}</ref><ref>
{{cite journal
|last1=Lee Jr. |first1=L. L.
|last2=Meyer-Schutzmeister |first2=L.
|last3=Schiffer |first3=J. P.
|last4=Vincent |first4=D.
|year=1959
|title=Nuclear Resonance Absorption of Gamma Rays at Low Temperatures
|journal=[[Physical Review Letters]]
|volume=3 |issue=5 |pages=223
|bibcode=1959PhRvL...3..223L
|doi=10.1103/PhysRevLett.3.223
}}</ref>

The discovery was rewarded with the [[Nobel Prize in Physics]] in 1961, together with [[Robert Hofstadter]]'s research of [[electron scattering]] in atomic nuclei.