Max Planck

By Emre Yıldırım

Max Planck was the most conservative revolutionary in science — a classical physicist who broke physics in half trying to save it.

Born in 1858 in Kiel, Planck was a superb student of thermodynamics who was advised against physics because everything important had been discovered. He ignored the advice and made the blackbody problem his own: why do hot objects glow with the colors they do, and why does the glow shift as they heat — the question the steel industry needed answered. The classical formulas failed at high frequencies — the "ultraviolet catastrophe," predicting infinite energy. In 1900, in an act he called desperation, Planck found that the data fit perfectly if radiant energy comes in discrete packets — quanta — proportional to frequency: E = hν, with h a new constant of nature. He had introduced the quantum, and he spent years trying to take it back, hoping the discreteness was a mathematical trick rather than reality.

Reality disagreed. Einstein used quanta for the photoelectric effect in 1905; Bohr built the atom on them in 1913; and by the 1920s quantum mechanics — Heisenberg, Schrödinger, Dirac — had replaced the classical world entirely, the child devouring the reluctant father. Planck won the 1918 Nobel Prize and became the revered elder of German physics, secretary of the Prussian Academy, a man of deep integrity in an age that tested it mercilessly: the Nazis murdered his son Erwin for the July 1944 plot against Hitler, and Planck — who had stayed in Germany hoping to preserve its science — was broken. He died in Göttingen in 1947.

Planck's constant h is graven into the universe: the smallest unit of action, the grain of reality. He wanted to perfect classical physics and instead founded the physics of the twentieth century — reluctantly, rigorously, and irreversibly.

Impact on civilization

Planck's quantum hypothesis — energy in discrete packets, E = hν — founded quantum theory, the most successful and most revolutionary framework in science. It underlies atomic physics, semiconductors, lasers, and all of modern electronics; Planck's constant is a fundamental constant of nature, as basic as the speed of light. He broke classical physics trying to save it, and gave the twentieth century its deepest description of reality: the world is grainy at the bottom, and continuity was the illusion.