Rudolf Ludwig Mössbauer (German spelling: Mößbauer; ; 31 January 1929 – 14 September 2011) was a German physicist best known for his 1957 discovery of recoilless nuclear resonance fluorescence, for which he was awarded the 1961 Nobel Prize in Physics. This effect, called the Mössbauer effect, is the basis for Mössbauer spectroscopy.