Max Planck

Max Karl Ernst Ludwig Planck (1858-1947) was a German theoretical physicist whose revolutionary discovery of energy quanta fundamentally transformed physics and earned him the 1918 Nobel Prize. Born in Kiel into an academic family where his father served as Professor of Constitutional Law, Planck developed early interests in mathematics and science that would shape his groundbreaking career.\n\nPlanck studied at the Universities of Munich and Berlin under renowned physicists including Kirchhoff and Helmholtz, earning his doctorate in 1879 with a dissertation on the second law of thermodynamics. His academic career progressed from Privatdozent in Munich (1880-1885) to Associate Professor at Kiel (1885-1889), before succeeding Kirchhoff as Professor at Berlin University in 1889, where he remained until his retirement in 1927.\n\nThe defining moment of Planck's career came in 1900 when he solved the black-body radiation problem that had puzzled physicists for years. By combining equations from Wien and Rayleigh, he announced his radiation formula in October 1900. More importantly, in December 1900, he presented his theoretical explanation at the Physikalische Gesellschaft in Berlin, introducing the revolutionary concept of energy "quanta" - discrete packets of energy rather than the continuous flow assumed by classical physics.\n\nThis discovery established the Planck constant (h), now fundamental to quantum mechanics, with his calculated value of 6.55 × 10^-27 erg-seconds remarkably close to today's accepted value. Though Planck initially viewed quanta as a mathematical necessity rather than physical reality, his work laid the foundation for quantum mechanics and modern physics.\n\nPlanck served as permanent secretary of the Prussian Academy of Sciences (1912-1938) and president of the Kaiser Wilhelm Society (1930-1937), later renamed the Max Planck Society in his honor. Beyond science, he was an accomplished pianist who considered music as a potential career and regularly held concerts in his home.\n\nDuring the Nazi period, Planck demonstrated moral courage by directly appealing to Hitler against racial policies while choosing to remain in Germany to preserve what he could of German physics. He faced personal tragedy during WWII when his home was destroyed by bombing, yet maintained his scientific integrity throughout.\n\nPlanck's reluctant acceptance of his own quantum theory earned him the title "reluctant revolutionary." He championed Einstein's relativity theory early on and, along with Einstein and Schrödinger, remained opposed to the probabilistic interpretation of quantum mechanics that later developed. His legacy as originator of quantum theory fundamentally altered humanity's understanding of atomic and subatomic processes.