Ludwig Boltzmann

Ludwig Boltzmann ForMemRS
Boltzmann in 1902
Born	Ludwig Eduard Boltzmann (1844-02-20)20 February 1844 Vienna, Austrian Empire (now Austria)
Died	5 September 1906(1906-09-05) (aged 62) Tybein, Gorizia and Gradisca, Austria-Hungary (now Duino, Friuli-Venezia Giulia, Italy)
Alma mater	University of Vienna (PhD, Dr. habil.)
Known for	See list Boltzmann brain Boltzmann constant Boltzmann distribution Boltzmann's entropy formula Boltzmann equation Boltzmann factor Boltzmann relation Boltzmann–Matano analysis Maxwell–Boltzmann distribution Stefan–Boltzmann law Maxwell–Boltzmann statistics Canonical ensemble Detailed balance Epistemological idealism Equipartition theorem Ergodic hypothesis Materials with memory Microscopic reversibility Phase space Softmax function Statistical mechanics H-theorem
Awards	ForMemRS (1899)[1]
Scientific career
Fields	Physics
Institutions	University of Graz University of Vienna University of Munich University of Leipzig
Thesis	Über die mechanische Bedeutung des zweiten Hauptsatzes der mechanischen Wärmetheorie (1866)
Doctoral advisor	Josef Stefan
Other academic advisors	Robert Bunsen Hermann von Helmholtz Gustav Kirchhoff Leo Königsberger
Doctoral students	Paul Ehrenfest Philipp Frank Gustav Herglotz Franc Hočevar Ignacij Klemenčič
Other notable students	Lise Meitner Stefan Meyer
Signature

Ludwig Eduard Boltzmann ForMemRS (/ˈbɒltsmən/,^[2] US also /ˈboʊl-, ˈbɔːl-/,^[2][3] Austrian German: [ˈluːdvɪɡ ˈbɔltsman]; 20 February 1844 – 5 September 1906) was an Austrian physicist and philosopher. His greatest achievements were the development of statistical mechanics and the statistical explanation of the second law of thermodynamics. In 1877 he provided the current definition of entropy, ${\displaystyle S=k_{\rm {B}}\ln \Omega }$, where Ω is the number of microstates whose energy equals the system's energy, interpreted as a measure of the statistical disorder of a system.^[4] Max Planck named the constant k_B the Boltzmann constant.^[5]

Statistical mechanics is one of the pillars of modern physics. It describes how macroscopic observations (such as temperature and pressure) are related to microscopic parameters that fluctuate around an average. It connects thermodynamic quantities (such as heat capacity) to microscopic behavior, whereas, in classical thermodynamics, the only available option would be to measure and tabulate such quantities for various materials.^[6]