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Redalyc.Josef Stefan. Radiation, Conductivity, Diffusion, and Other Revista CENIC. Ciencias Químicas ISSN: 1015-8553 [email protected] Centro Nacional de Investigaciones Científicas Cuba Wisniak, Jaime Josef Stefan. Radiation, conductivity, diffusion, and other phenomena Revista CENIC. Ciencias Químicas, vol. 37, núm. 3, 2006, pp. 188-195 Centro Nacional de Investigaciones Científicas La Habana, Cuba Disponible en: http://www.redalyc.org/articulo.oa?id=181620527013 Cómo citar el artículo Número completo Sistema de Información Científica Más información del artículo Red de Revistas Científicas de América Latina, el Caribe, España y Portugal Página de la revista en redalyc.org Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Revista CENIC Ciencias Químicas, Vol. 37, No. 3, 2006. Josef Stefan. Radiation, conductivity, diffusion, and other phenomena Jaime Wisniak. Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel 84105, Email: [email protected]. Recibido: 17 de julio de 2005. Aceptado: 5 de noviembre de 2005. Palabras clave: conductividad térmica de un gas, radiación, cuerpo negro, ley de la cuarta potencia, fusión de la capa de hielo polar, coeficiente de difusividad, tono, sonido, ley de radiación. Key words: thermal conductivity of gases, radiation, black body, fourth-power radiation law, melting of the polar ice, diffusivity coefficient, pitch of sound, radiation law. RESUMEN. A Josef Stefan (1835-1893) le debemos el desarrollo de un método his parents are said to have been il- preciso para medir la conductividad de un gas, la determinación empírica de la literate. ley que describe la radiación de un cuerpo negro (la ley de la cuarta potencia), el Josef attended primary school in análisis del movimiento de la interfase en la fusión de la capa de hielo polar, un his hometown where his teachers método para medir el coeficiente de difusividad y un análisis del tono de un observed his talents and recom- sonido. Aun cuando la derivación de Stefan de la ley de radiación se basó en mended further schooling. In 1845 datos experimentales de otros que más tarde se probó que estaban errados, he entered the Klagenfurt gymna- Boltzmann demostró posteriormente su validez usando argumentos termodi- sium and graduated eight years later. námicos. In school he showed a particular interest in learning the Slovenian ABSTRACT. To Josef Stefan (1835-1893) we owe the development of a precise method for measuring the heat conductivity of gases, the empirical determina- language and literature. After gradu- tion of the law describing the radiation from a black body (fourth-power radia- ation he moved to Vienna to study tion law), analysis of the moving interface in the melting of the polar ice, a method Mathematics and Physics at the for measuring the diffusivity coefficient, and analysis of the pitch of sound. Philosophical Faculty of the Univer- Although Stefans derivation of the heat radiation law was based on experimen- sity of Vienna. In 1857, while in his tal data of others, which were later proven to be wrong, Stefans equation was fourth year of studies, he passed the later proven to be correct by Boltzmann based on theoretical thermodynamic teachers examination. At that time reasoning. he was already giving physics lec- tures for pharmacy students. After passing the examination he also taught at a private secondary school LIFE AND CAREER (the oberrealeschule in the inner Josef Stefan (Figures 1 and 2) is State) and even took part in admin- well known for his discovery of the istering the school as deputy school- fourth-power heat radiation law that master.3 carries his name. Most of the publi- On his own initiative he began cations related to him describe this research in theoretical physics, pre- particular contribution, but almost pared two papers and sent the third none give personal details about his to the Academy of Science. Its read- life or his seminal contributions to ing at the Academy was well re- other physical and thermodynamic ceived and attracted the interest of subjects.1-3 Only Strands pamphlet Carl Ludwig (1816-1895), a well- goes into some details and his work known professor of Physiology, who will be used here. invited him to collaborate in experi- Josef Stefan was born on March mental work at the Institute of 24, 1835, at St. Peter, now a part of Physiology. Stephan accepted his in- Celovec (Klagenfurt). He was the il- Fig. 1. Josef Stefan (1835-1893). vitation and worked with Ludwig on legitimate child of Marija Startinik the flow of water through tubes. who worked as a maid. Josef was In 1858 Stefan passed his final eleven years old when his mother ing and bakery products; the family examination at the university, the married his father and went to live was poor but could afford to provide philosophical rigorosum, and was with him. At that time his father had the child with basic education, an granted his doctorate. The following just opened a shop for selling mill- important attitude considering that year he became Privatdozent in 188 Revista CENIC Ciencias Químicas, Vol. 37, No. 3, 2006. laboratory at the Institute, where he also lived. He did not travel and par- ticipate at scientific meetings that were organized in Europe already at that time. According to Strnad3 Stefan could well have become a Slovenian poet if he had not chosen physics. While living in Carinthia, German was spoken in towns at that time but Slovenians populated the country. In 1848 the Slovenian language be- came an obligatory subject and also a subject at the general examination for Slovenians and a non-obligatory subject for the others. When this event took place Stefan was in the fifth class and from there on he be- gan to write poems in Slovenian under the tutorship of Anton Janezic (1829-1869). In the same year (1849) he and his schoolfellows launched a manuscript literary journal called Slavija. Some of the poems written by Stefan were later published in Slovenian journals appearing in Austro-Hungary. Up to 1853 the po- ems were signed Stefan, late on ei- ther Stefan or with a pseudonym, mainly J. A. Spleteni, after the mean- Fig. 2. Stamps issued by Slovenia and Austria honoring Stefan. ing of the Greek word stephanos (in- terlaced).3 In addition, he started publishing popular scientific articles Mathematical Physics and as such he Andreas von Ettingshausen (1796- in Slovenian magazines and thus was officially entitled to lecture at 1878), retired owing to illness and contributed to the development of the University. In 1860, thanks to the the position was offered to Stefan.3 Slovenian language in natural sci- proposal of Ludwig and his colleague Stefan was a brilliant experimen- ence. Ernst Wilhelm Brücke (1819-1892) he talist and well-liked teacher. He was Stefan was known as a cheerful was elected a corresponding member dean of the Philosophical Faculty youth who loved singing, took part of the Imperial Academy of Sciences. during 1869-1870 and rector mag- in choirs, and was even involved in All these achievements did not ad- nificus of the University in 1876- organizing them. In 1891, two years vance Stefans chances for obtaining 1877. In 1860 he became a corre- before his death, he married the a position at the Institute of Phys- sponding member of the Imperial widow Marija Neumann. By the end ics, which would allow him to carry Academy of Sciences (Mathematics of 1892 he had an apoplectic stroke his own research. Nevertheless, the and Natural Sciences Class) and in when he was visiting a friend. For a situation improved. Both professors 1865 he was promoted to member. In couple of weeks he lay unconscious of physiology persuaded a high offi- 1875 he was appointed secretary of and could not be moved back home. cial in the ministry of education to the mathematics-science class of the Then his health improved somewhat attend one of Stefans lectures. The same and served as its vice-presi- and he was transferred to his apart- official was so impressed by the lec- dent from 1885 until his death in ment at the Institute where he died ture that when a new position of full 1893. on January 7, 1893, at the age of fifty- professor (Professor Ordinarius) of In the meantime, he pursued re- eight. mathematics and physics was opened search actively and published sev- Josef Stefan may be considered it was offered to Stefan. Thus, in eral papers in the proceedings of the the best-known Slovenian physi- 1863, at the age of 28 he became the Academy that attracted the interest cists; as one of the leading physicists youngest full professor in the of the scientific community. For one of the Austro-Hungarian Empire he Austro-Hungarian Empire. A series of them (on the subject of the nature took advantage of the possibilities a of fortuitous events catapulted his played by non polarized light) he prosperous capital could offer. His scientific career ahead. First, was awarded the Lieben Prize dedi- increased work in physics separated Wilhelm Joseph Grailich (1829-?), cated to best scientific paper which him little by little from taking take who was expected to take over the was written by an Austrian citizen part in Slovenian affairs and contrib- post of Director of the Institute of during the last three years.2 uted to his alienation from Ljubljana. Experimental Physics [founded by He dedicated much of his time He was extremely active, as a provi- Christian Doppler (1803-1853) in to lecturing and his lectures were sional list of his duties around 1883 1850], died unexpectedly and thus a carefully prepared and carried out. shows: member of the faculty board, position at the Institute opened be- Stefan was a lone wolf; he rarely Director of the Institute of Physics, came available.
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