Ludwig Boltzmann (1844–1906)
Austrian physicist and philosopher of science. His contributions to the development of the kinetic theory of gases and statistical mechanics are very important. He tried to define the thermodynamic concept of entropy in terms of mechanical and probabilistic concepts, and proved the H-theorem which is a mechanical version of the second law of thermodynamics. However, there remained difficult problem of explaining irreversibility. Even in the 21st century, time's arrow is one of the scientific and philosophical enigmas.
As a philosopher, he defended atomistic method in physics against Mach's instrumentalist position. This controversy between realism and anti-realism (there are many versions of each) is another instance of long-standing problems in philosophy.
The life of Ludwig Boltzmann, one of the greatest of all nations and all times, was outwardly quiet. From childhood he lived in a security and material comfort. In contrast of his revered teacher Josef Stefan and to his older, beloved frie nd, the remarkable physicist and chemist Josef Loschmidt, he did not have to work his way up from village poverty to a university position. He did not have to help illiterate parents on their farm like Stefan, nor did he have to tend cattle in his youth and then earn his way by tutoring and by working as a factory chemist like Loschmidt. Coming from a comfortable middle-class family and helped along by his devoted mother, he had the good fortune as a young man to be able to concentrate on his studies.
Ludwig Eduard Boltzmann was born on February 20, 1844 in a house on the main street of the Landstrasse district of Vienna, the son of an "Imperial and Royal Cameral-Concipist," a tax official. His grandfather, who had moved to Vienna fro m Berlin, was a clock manufacture. Lugwig’s mother, Katharina Pauernfeind, came form Salzburg.
Soon after Ludwig’s birth the family moved to the Upper Austria, first to Wels and later to Linz, where Lugwig attended high school. He was an ambitious and eager student - too eager, as he later thought with regret, having come to reject blind am bition. An interest in nature distinguished the boy who collected butterflies and studied plants. At 15, Boltzmann lost his father.
Later Boltzmann studied physics at the University of Vienna. Among his teachers were Joseph Petzval, who greatly advanced the construction of photographic lenses, Anrease von Ettingshausen, and above all, Josef Stefan, whose work on radiation Bolt zmann continued. He received his doctorate in 1866 and gave his inaugural address as Privationdozation (lecturer) in 1867. After working with Stefan for two more years he was appointed the Professor of Mathematical Physics at the University of Graz in the province (Kronland) of Styria.
Boltzmann spent several months at Heidelbery with Robert Bunsen and Leo Konigsberg in 1869 and then in Berling with Gustav Kirchoff and Herman von Helmholrz in 1871. After the period from 1873 to 1876 as the professor of Mathematics at the Univers ity of Vienna he returned to Graz to take the chair of Experimental Physics, this time for a longer period. By now Boltzmann was well know in the scientific world, and talented young people, such as Svante Arrhenius from Sweden and Walther Nernst from Ge rmany, came to study with him in the mid-eighties. Wilhelm Ostwald, one of the founders of physical chemistry, also visited Boltzmann at Graz. There he met Nernst, who later became his closest collaborator at Leipzig.
In 1877 Boltzmann used statistical ideas to gain valuable insight into the meaning of entropy. He realized that entropy could be thought of as a measure of disorder, and that the second law of thermodynamics expressed the fact that disorder tends to increase. You have probably noticed this tendency in everyday life! However, you might also think that you have the power to step in, rearrange things a bit, and restore order. For example, you might decide to tidy up your wardrobe. Would this lead to a decrease in disorder, and hence a decrease in entropy? Actually, it would not. This is because there are inevitable side-effects: whilst sorting out your clothes, you will be breathing, metabolizing and warming your surroundings. When everything has been taken into account, the total disorder (as measured by the entropy) will have increased, in spite of the admirable state of order in your wardrobe. The second law of thermodynamics is relentless. The total entropy and the total disorder are overwhelmingly unlikely to decrease.
Around 1881, Boltzmann efforts were associated with J.C. Maxwell. Maxwell worked to try to explain the thermodynamics of gases. Boltzmann introduced the Ehrenfest urn Model, an example is the probability formulation in Markov chain terms.
The versatility that permitted Boltzmann to teach both mathematics and experimental physics is astounding. But in 1890 the satisfying opportunity finally arose to devote himself fully to the subject closest to his heart. He was appointed to the c hair of Theoretical Physics at the University of Munich in Bavaria, Germany.
In 1893 Stefan died and Boltzmann succeeded him as Professor of Theoretical Physics in his native Vienna. In1900, on the invitation of Ostwald, he went to the University of Leipzig, but in 1902 he returned to his former position, which had been ke pt open, in Vienna. The Emperor, Francis Joseph, reappointed him on condition that Boltzmann give his word of honor never to accept a position outside the Empire again. Boltzmann remained Professor in Vienna until his death on September 5, 1906. On his tombstone there is the inscprition S= K ln W.
At Vienna Boltzmann taught not only physics but in 1903 he also committed himself to teach a university course "Methods and General Theory of the Natural Sciences," in which he lectured three hours every week on problems of philosophy. T hus he became a kind of successor to Ernst Mach, who held the chair for "History and Theory of the Inductive Sciences" but who had been forced to retire prematurely in 1901 after a stroke.
Boltmann’s greatness was recognized during his lifetime. He was honored nationally and internationally. He was elected to membership or honorary membership in many academies, received an honorary doctorate from Oxford, and was also awarded medals . On the occasion of his sixtieth birthday, 117 of the world’s most prominent scientists- even including some from Russia, America, Australia, and Japan- contributed to the festschrift edited by Stefan Meyer, Boltzmann’s collaborator (Assistant). Meyer subsequently served for many years as the highly esteemed Director of the Radium Institute of the Austrian of Academy Sciences.
Boltzmann's contribution was vital, but had a tragic outcome. Towards the end of the nineteenth century several puzzling facts (which eventually led to quantum theory), triggered a reaction against 'materialist' science, and some people even questioned whether atoms exist. Boltzmann, whose work was based on the concept of atoms, found himself cast as their chief defender and the debates became increasingly bitter. Always prone to bouts of depression, Boltzmann came to believe that his life's work had been rejected by the scientific community, although this was far from being true. In 1906, he committed suicide. If despair over rejection, or frustration over being unable to prove his point, were contributing factors the irony would be great indeed. Soon after Boltzmann's death, clinching evidence was found for atoms, and few would ever doubt their existence again.