The author of the quantum theory livedlong enough to see his discovery affect all branches of science and all human life. Last week Max Karl Ernst Ludwig Planck, 89, one of history’s greatest discoverers, died.
Planck was born in Kiel, Germany, in 1858, and grew up in the placid, self-satisfied world of 19th Century physics. He became a professor at the University of Kiel, married the daughter of a Munich banker, played the piano and composed music, lived the good intellectual life of Germany’s pre-World War I golden age. Outwardly, he did not appear to be a world-shaking revolutionist.
But in Planck’s particular specialty, thermodynamics (the behavior of heat), there was a “revolutionary situation.” Planck (and many others) had been studying the effect of a body’s temperature upon the wavelengths of the light and heat which it radiates. They suspected that a fundamental relationship was lurking somewhere, but could not find it.
Planck attacked the problem in a new way and arrived at a revolutionary idea that shook the world of physics: that energy is actually radiated in small packages, not continuously, as everybody thought.
Triumphant Work. Imbedded in Max Planck’s Law of Radiation (published in 1901) was something vastly more important: Planck’s “universal constant” (6.624 x 10 -27 erg-seconds), now considered one of the three fundamental figures in the universe.* Planck’s constant enabled Einstein to conceive the “photon” (particle of radiation). It also made possible Niels Bohr’s model of the atom. It turned up in spectroscopy, in the study of X rays, in electronics. Upon it is based the whole science of quantum (wave) mechanics.
Triumphant Life. Planck himself had triumphs, too. He became rector of the University of Berlin, and won the 1918 Nobel Prize for Physics. But when the Nazis came into power, German scientists with Jewish blood (including Einstein) were hounded out of the country. Many “Aryan” scientists fled too; but old Max Planck stayed behind. In 1934 (he was 76), he went in person to Hitler, to demand an end of Jewish persecution. Hitler turned his back while the old man talked. The following year, Planck was removed from the presidency of the Kaiser Wilhelm Gesellschaft (a scientific society). When he celebrated his 80th birthday in 1938, the Government sent no representative.
After the fall of Germany, Planck lived in a two-room apartment in the university town of Gottingen, where he died last week, surrounded by the ruins of his world.
* The others: the charge of the electron (1.591x 10 -20 e.m.u.), and the speed of light in a vacuum (186.285 miles per second).
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