By Lorenz Friedrich Beck
"I could just as easily have become a philologist or a historian. What led me to hard science was a course of mathematical lectures which I attended at the university and which gave me an inner satisfaction and animation," wrote the world-famous physicist Max Planck. Planck's long life and scientific works are a sui generis reflection of both the optimism and the tragedy of the past two centuries, the belief in science and its failure.
Planck was born in Kiel on 23 April 1858 into a Swabian family which had produced several prominent theologians and legal scholars. Following the family's move to Munich, the rest of Planck's life was informed by the city with its intellectual and artistic influences. The young Planck was a hard-working and gifted schoolchild who had a sense of duty from an early age, and was loved for his affectionate and amiable nature. Having passed his Abitur with flying colours, he enrolled at the University of Munich. A study trip to Berlin made a formative impression on him, giving him the opportunity to attend lectures by the leading physicists of his time, Hermann von Helmholtz and Gustav Kirchhoff.
Planck obtained his doctorate in Munich in 1879 with a dissertation entitled "On the second law of thermodynamics". By the age of 22 he had already earned his postdoctoral lecturing qualification and worked as an unsalaried lecturer at the University of Munich, where he continued his work in the field of heat theory. In 1885 he was appointed associate professor in physics at Kiel University – Planck maintained strong ties to his native town. Four years later he moved to Berlin, where he was appointed full professor in 1892 and was made a full member of the Prussian Academy of Sciences in 1894. His academic career picked up momentum dramatically following publication of the award-winning study entitled "The principle of the conservation of energy". In 1905 the German Physical Society appointed him Chairman, in 1913 Planck was made Principal of the university, in 1915 he became a Knight of the Order of the Pour le mérite for the arts and sciences, and in 1921 he was named Chairman of the Society of German Researchers and Physicians. His most important scientific accomplishment came in 1899 with the discovery of the natural constant, known as Planck's quantum of action, from which he formulated Planck's radiation law and thus founded quantum theory, which revolutionised modern physics. And for which he was awarded the Nobel Prize in 1918.
Planck was also fortunate in his private life initially. His first marriage to banker's daughter Marie Merck produced four children. The couple lived an active life full of music and society in the prosperous Berlin suburb of Grunewald. "Planck loved cheerful, spontaneous conviviality, and his home was the centre of such conviviality," wrote his assistant Lise Meitner on the subject of Planck's hospitality. But his personal happiness did not remain unclouded for long: Planck lost his wife as early as 1909, his eldest son fell at Verdun, and in 1917 and 1919 his twin daughters each died giving birth to their first child. His second wife proved a valuable support to him at this time.
After the war, Planck was regarded as the authority on physics in Germany and in 1920 he co-founded the Notgemeinschaft der Deutschen Wissenschaft (the Emergency Association of German Science, the predecessor of today's German Research Foundation) for the advancement and reconstruction of research. In 1930, at the age of 72, he assumed another office of great responsibility – the presidency of the Kaiser Wilhelm Society for the Advancement of Science. Planck held the office of President until 1937; after the National Socialists seized power, he was confronted with difficult political questions and complex issues relating to the organisation of research. His actions were marked by a fundamental loyalty to the state and an effort to retain the Kaiser Wilhelm Society and its status. But many a compromise proved unavoidable, even within the Society. On the other hand, Planck spoke up for colleagues at risk and demonstrated courage and fortitude in staging the 1935 memorial seminar at Dahlem's Harnack House for Fritz Haber, who had been expelled and died in exile. He also managed to keep a number of Jewish scientists employed for a time at institutes of the Kaiser Wilhelm Society. At the insistence of the Nazis, Planck did not put himself up for re-election and in the end was able to delay but not prevent the Gleichschaltung (Nazification) of the Kaiser Wilhelm Society. He resigned from the Academy of Science in 1938 in protest of the Gleichschaltung of that organisation. By then very aged and having been bombed out in Berlin, the arrest and execution in January 1945 of his son, Erwin, who had been involved in the July 20 plot, was another heavy stroke of fate for Planck.
It was ultimately due to Planck's great international reputation that the organisational form of the Kaiser Wilhelm Society withstood the war. In 1945 he became its President once more in an acting capacity, he was the only German scientist invited by the Royal Society to attend the Newton Celebration in London in 1946, and was Honorary President following the foundation of the Max Planck Society in the British zone. Planck died a highly honoured man in Göttingen on 4 October 1947, having reached almost 90 years of age.