Ludwig Boltzmann (February 20, 1844 - September 5, 1906) was an Austrian physicist famous for the invention of statistical mechanics.
Boltzmann was born in Vienna, Austria-Hungary (now Austria).
Boltzmann committed suicide in 1906 by hanging while on holiday in Duino near Trieste in Italy. The motivation behind the suicide remains unclear, but it may have been related to his lingering resentment over establishment science's rejection of his theories. Today, his formula for entropy S is famous:
where kB = 1.380658(12) × 10-23 J K-1 is the Boltzmann constant and P is the number of possible microscopic states which give the same thermodynamical state that a system may be in. Indeed this formula, as he published it in the nomenclature of his day, is engraved on Boltzmann's tombstone at the Vienna Zentralfriedhof.