“As is well known, Planck tried to retain for the second law of thermodynamics the status of an exact law of Nature despite contrary interpretations. Planck was fundamentally, at heart, committed to thermodynamics; and even though by his formulation of the quantum theory, he contributed to statistical notions more than anyone else, that was not basically his way of thinking. But for Smoluchowski, statistics was his life’s breath; for him the second law of thermodynamics was an approximation which Nature violated in its finest manifestations and which retained its validity only relative to our (macroscopic) circumstances.”
Arnold Sommerfeld, Zum Andenken an Marian von Smoluchowski,
Physikalische Zeitschrift 18 (1917) str. 533-539.

Marian Smoluchowski (1872-19170)

Marian Smoluchowski was born on May 28, 1872 in Vorderbrühl near Vienna in the family of an important official in the Austro-Hungarian administration. He graduated from the so-called “Theresianum”, a famous high school in Austria, and then studied physics at the University of Vienna. After receiving Ph.D. in 1895, he spent two years abroad working in laboratories of well-known contemporary physicists: Gabriel Lippmann (in Paris), Lord Kelvin (in Glasgow), and Emil Warburg (in Berlin). At that time, he measured the shift of temperature on the surface between a container and rarefied gas inside it, which confirmed the predictions of the kinetic theory of gases. In the autumn of 1897 he returned to Vienna, where he earned habilitation. Later he started lecturing at the University of Lvov, where in 1900 he was employed as an professor in the Department of Theoretical Physics (he was the youngest professor in the Austro- Hungarian Empire). 

In Lvov he studied, among other things the theory of Brownian motion. In 1904, he presented arguments for the possibility of observing the fluctuation of physical magnitudes caused by atomic structure of matter, which went against the received view of his time. He demonstrated, with a method different than Einstein’s, that the mean squared displacement of an observed Brownian particle is related to the Avogadro constant and the temperature of the liquid (Einstein-Smoluchowski equation). This explanation contributed to scientific community’s final acceptance of the existence of atoms.  

Marian Smoluchowski was also the author of other fundamental studies in kinetic-molecular theory of matter and statistical physics: in 1906 he initiated the theory of stochastic processes, in 1908 he explained critical opalescence, and gave (independently of Einstein) the answer to the question “Why is the sky of blue color?” In 1913 he published an important epistemologically statistical interpretation of the second law of thermodynamics. His studies inspired Richard A. Zsigmondy’s experimental research, awarded with the Nobel Prize in chemistry in 1925, as well as Jean B. Perrin’s studies in physics and Theodor H. E. Svedberg’s in chemistry, both awarded with the Nobel Prizes in 1926. Undoubtedly, Smoluchowski was one of the pioneers of employing stochastic processes as fundamental tools for studying physical phenomena and most of the presently used equations in micro- and nano-scale physics should be called after him. 

In 1913 Smoluchowski accepted the invitation from the Jagiellonian University and became the head of the Department of Experimental Physics. In the academic year of 1917/1918 he was elected the rector of the university. However, he did not enjoy this prestigious office for long: on September 5, 1917 he unexpectedly died of dysentery. 

Marian Smoluchowski and his brother Tomasz were among prominent European mountaineers: they staked out 24 new routes in Eastern Alps and were the first to climb 16 peaks. In Poland Marian Smoluchowski contributed immensely to the development of qualified mountaineering: he was, among others, the president of the Tatra Mountaineering Section, gathering the elite of Polish mountaineers in the early 20th century.

The unexpected death of Marian Smoluchowski had large impact on the international community of physicists. Obituaries were written by Arnold Sommerfeld and Albert Einstein, who called for remembering the distinguished Pole: „Everybody who knew Smoluchowski personally liked him not only as an enthusiastic researcher but as a noble, sensitive, and generous man...Fate has cut off his fruitful work as researcher and teacher too early; we shell, however, continue to esteem his example and his work.”, Naturwissenschaften 5 (1917) 107-108.]