The 1975 (inaugural year) Boltzmann Medal awarded to theoretical physicist Kenneth G. Wilson. Wilson would later win the Nobel Prize in 1982 for his work on phase transitions, providing profound insight into the field of statistical physics and quantum mechanics. The Boltzmann Medal is the most esteemed prize awarded to physicists working in the field of statistical mechanics. Named after physicist Ludwig Boltzmann, only 24 medals have been awarded as winners are selected once every 3 years. This 10kt gold medal features the relief portrait of Ludwig Boltzmann to front, with his name and the years of his birth and death. Verso features raised lettering which reads, ''I.U. P.A.P. / COMMISSION ON THERMODYNAMICS AND STATISTICAL MECHANICS'', in addition to cursive etching in center: ''Kenneth G. Wilson / 1975''. Rim includes stamp: ''BIRKS 10K''. Medal weighs 104 grams or just over 3.6 oz. and measures 2.5'' in diameter. Some tarnishing to both sides, overall very good condition. With an LOA from Kenneth Wilson's widow.