Stefan Procopiu                                                                                                                                                                                                   >> RO

Romania’s cultural and scientific heritage includes the achievements of remarkable personalities who consolidated the Romanian image and prestige abroad and among them scientist Stefan Procopiu has a central position. Appreciated and renowned in the national and international scientific environment, he received, unfortunately, too little reward for his outstanding contribution to the development of physics.
Youth and Studies
Stefan Procopiu was born in Bârlad, on 19 January 1890, as the eldest son of the seven children of Ecaterina and Emanoil Procopiu. The young Stefan Procopiu attended the primary, secondary and high studies at "Rosca Codreanu" High School of Bârlad, where he was guided by renowned teachers dedicated to their educative mission. While a high school student, Procopiu read and studied a lot, directing his attention to all branches of sciences, to matters fundamental for the understanding of the universe, with the aim of finding out “the meaning of reality and life”. He was a contemporary of the remarkable discoveries in the fields of physics, chemistry and biology at the end of the 19th century and beginning of the 20th, and which inaugurated a new orientation of sciences, in general, resulting in a revolution of concepts and research methods available at the moment.
The high school period is characterized by the lectures sustained at the “Stroe Beloescu” Society of Bârlad, and which were real preparatory exercises for the achievement of his future scientific papers. In order to be able to approach specialized scientific materials, he accurately learnt French and German. In 1908, he graduated magna cum laudae the “Rosca Codreanu” High School of Bârlad.           Taking into account his vocation and passion for natural sciences, he chose the Faculty of Natural Sciences of Iasi University, a European level institution. He attended for a while the courses of professors Paul Bujor and Petre Bogdan in parallel to those of the Faculty of Medicine. In few months, he gave up the study of natural sciences and became a student of the Faculty of Physico-Chemical Studies.           During this period, the University was employing the renowned professor of physics Dragomir Hurmuzescu (1865- 1954), PhD in physics, degree obtained in Paris, under the coordination of professor Gabriel Lippman. Hurmuzescu was teaching a course of modern physics, in line with the latest discoveries of the epoch. In 1912, he obtained the license in physics (diploma no. 1266) with the remark “very well”.
Scientific Activity
Procopiu dedicated himself to science and research from the time he was still a student. The first remarkable results of his research were published in 1913, in Bulletin scientifique de l’Académie roumaine de sciences, within the famous paper Determining the Molecular Magnetic Moment by M. Planck’s Quantum Theory. After studying Planck’s quantum theory and Langevin’s magnetism theory, Procopiu was the first to establish in the whole world the value of the molecular magnetic moment also named the theoretic magneton, M=he/4?m.          It is recognized that Stefan Procopiu calculated the value of the theoretic magneton two years before prof. A. Bohr of Denmark. In the Romanian specialized literature, this discovery is known as the Bohr-Procopiu magneton. The 1912 discovery of Procopiu’s consecrated him among the world famous physicists.         In 1912 he became junior assistant at the University of Iasi, starting this way his academic carrier. The transfer to Bucharest of prof. Dragomir Hurmuzescu, determined Procopiu’s decision of following his guiding model. Between 1913-1919, he activated at the Physics Faculty of Bucharest, initially as a temporary assistant and then as a coordinator within the Laboratory for the Applications of Heat and Electricity. In Bucharest, in 1913, given his focus on technical matters, Procopiu published the paper Experimental Research on Wireless Telegraphy, while in 1916 he invented a device for locating and establishing the depth of bullets in the bodies of the wounded.

In 1919, he obtained an Adamachi scholarship and left for Paris in order to undertake his PhD studies. In Paris, he attended the courses of famous scientists of the epoch, such as Gabriel Lippman, Marie Curie, Paul Langevin, Aymé Cotton.
		The PhD coordinator was initially prof. Gabriel Lippman (who had also directed the theses of Constantin Miculescu and Dragomir Hurmuzescu). Due to prof. Lippman’s death, the coordination of Procopiu’s thesis was taken over by prof. Aymé Cotton. In 1921, Procopiu discovered and analyzed in the Physics Laboratory of Sorbonne University a new optical phenomenon which consisted in the longitudinal depolarization of light by suspensions and colloids. This discovery was presented in the meeting of the Science Academy of Paris on 8 August 1921. In 1930, the above phenomenon was designated as Procopiu Phenomenon by prof. A. Boutaric.

On 5 March 1924, Procopiu obtained the title of doctor in physics with the work On The Electric Brefringence of Suspensions, sustained in frnt of a commission including coordinator prof. Aymé Cotton, and cross-examiners Charles Fabry and H. Mouton. The PhD thesis was published by Masson Publishing House of Paris and sent to the most renowned physicists of the epoch but also prof. Procopiu’s close friends.
On 5 March 1924, Procopiu obtained the title of doctor in physics with the work On The Electric Brefringence of Suspensions, sustained in frnt of a commission including coordinator prof. Aymé Cotton, and cross-examiners Charles Fabry and H. Mouton. The PhD thesis was published by Masson Publishing House of Paris and sent to the most renowned physicists of the epoch but also prof. Procopiu’s close friends. Another important discovery, resulting from prof. Procopiu’s research, is the electromotive force of galvanic elements. In the field of ferromagnetism, he undertook numerous studies whose results were published in many specialized magazines in Romania and abroad. Thus, in 1930, studying the Barkhausen effect, which consists in transferring alternative current through wires of ferromagnetic material, he discovered a circular effect of magnetic discontinuity. In 1951, this effect was named Procopiu Effect. A significant technical application of this effect was achieved by the American physicist Roman Storski in creating calculation devices.
Another domain, whose research was initiated in Iasi in 1931 by prof. Procopiu and was carried out along several decades was the ground magnetism, which had very important results for Romania.

Pedagogic Activity

Back in Romania in 1925, with an unquestionable scientific renown in the field of physics, on 15 January Procopiu was appointed a professor in ordinary of the Gravitation, Heat and Electricity Department of “Al. I. Cuza” University of Iasi, department which he coordinated until 1962, the year of his retirement.           The activity of researcher and professor carried out by Stefan Procopiu contributed to the reorganization of the physics education in Iasi. Focusing on experience, Procopiu created a serious school of experimental physics in Romania, considering that “knowledge is obtained by learning but things noticed and experiments considerably contribute to fixing knowledge”.           The courses taught by prof. Procopiu were real models for the presentation of the content, form, quality and teaching method. He always checked laboratory experiments by presence as experience had to exactly illustrate the phenomenon and the demonstrations had to be perfect. In order to help his students, Procopiu published his course in two volumes. Introduction in Electricity and Magnetism¸ volume I, was published in 1929, in a first edition, and in a second edition in 1938, while volume II, Electricity and Magnetism, was published in 1939. In 1948 he published the volume Thermodynamics.           He was permanently concerned by the necessity of endowing laboratories with modern equipment, libraries with new scientific books destined to both his students and assistants. He directed the young to PhD research and training courses abroad. During the period 1925-1963, Procopiu coordinated 13 PhD theses which were prepared in the electricity laboratory of the Faculty of Physics, and treated themes he had proposed.           He also taught Physics to the Faculty of Electrotechnics of the Polytechnical University of Iasi, considering technical developments as very important, as a branch of science.

Humanistic Activity

The scientific personality of prof. Procopiu was harmoniously combined to the one of the man of culture. Testimonies of his closest friends, prof. C.V.Gheorghiu, prof. Mircea Savul, acad. Eugen Badarau and acad. N. Barbulescu, illustrate his love of literature, music, art and trips. Among Romanian painters, he prefered Stefan Luchian, while his favourite foreign artists were Rembrand, El Greco, Brueghel. In sculpture, he prefered Rodin. In literature, he most appreciated the great William Shakespeare, then Goethe, Rabelais, Voltaire, Anatol France, Molière, Paul Valery. Beethoven’s classic music was the dearest to prof. Procopiu.           Maybe his most interesting passion was the one for philosophy, and during his lifetime he wrote numerous articles reflecting his philosophic thinking. Will Durand’ famous words “Science gives us knowledge: philosophy alone can give us wisdom” formed one of Procopiu’s life principles.           He collaborated to the magazine Notes of Iasi and for 10 years, together with C.V. Gheorghiu, he was co-director of the scientific magazine Adamichi, where he published a series of important articles on the structure of the atom, biographies of A. Einstein, Vasile Karpen, Dragomir Hurmuzescu etc.