14 March marks the 115th anniversary of the birth of an outstanding scientist and an organizer of science, a founder of the Romanian School of Theoretical Physics, Academician Șerban Ţiţeica (1908 – 1985), JINR Vice-Director in 1962 – 1964 and, a member of the Scientific Council of the Institute in 1964 – 1976.

Șerban Țițeica was born in Bucharest in the family of a famous mathematician Gheorghe Țițeica. After finishing school, he entered the Faculty of Natural Sciences of the University of Bucharest, at which he received a degree in physics, chemistry, and mathematics. At the same time, he was studying at the National University of Music Bucharest on the Harmony and counterpoint speciality.

In 1930, he entered the postgraduate courses of Leipzig University. A Nobel laureate Werner Heisenberg was his supervisor. The dissertation by Țițeica “The behaviour of electric resistance of metals in magnetic field” was published in one of the oldest scientific journals “Annalen der Physik” in 1935 and provided the quantum theoretical explanation of the experimental data obtained by Pyotr Kapitsa in strong magnetic fields in 1929. Thus, Șerban Țițeica was the first to suggest the quantization of electron motion in a magnetic field. This work was the forerunner of the modern theory of hopping conductivity.

In addition to the quantum theory of electrical conductivity of metals in magnetic fields, the topics of his main scientific papers were the absorption of heavy charged particles in matter, positron theory, quantum theory of radiation, thermodynamics, and group theory.

In 1937, Țițeica returned to Romania, where he started his scientific career as a Professor of Mathematical Analysis at POLITEHNICA of Bucharest and a docent at the Faculty of Natural Sciences of the University of Bucharest. From 1941 to 1948, he was a Professor of Physics at Alexandru Ioan Cuza University of Iaşi. Afterwards, for thirty years, until 1978, he was Head of the Department of Thermodynamics and Statistical Physics at the University of Bucharest.

As a teacher, Șerban Țițeica gave lectures on various fields of theoretical physics such as theoretical mechanics, thermodynamics and statistical physics, electrodynamics, quantum mechanics, nuclear theory, and elementary particle theory. The students highlighted the clarity, brevity, and elegance of his lectures. His textbooks “Statistical Physics and Old Quantum Mechanics”, “Elements of Statistical Physics”, “Thermodynamics” and “Quantum Mechanics” made a significant contribution to the professional growth of future generations of Romanian scientists.

Șerban Țițeica combine teaching with work at the Institute of Atomic Physics, one of the leading scientific centres in Romania, which was headed by another outstanding Romanian scientist Horia Hulubei at that time. For several decades, Șerban Țițeica worked at this Institute – first as Head of the Department of Theoretical Physics, and later, since 1956, as Vice-Director. At the Institute, he founded the Romanian School of Theoretical Physics that comply with the highest international standards. The fact that the Institute of Atomic Physics became one of the authoritative scientific centres of the world, it owes much to the advice that Șerban Țițeica gave to his students, his tireless scientific and organizational work.

Thanks to Academician Țițeica, one of the best libraries in Europe was created at the Institute. His work as the Chief Editor of two physics journals “Revue Roumaine de Physique” and “Studii si Cercetari de Fizica”, published by the Romanian Academy, guaranteed worldwide recognition of publications.

In 1955, Țițeica was elected a member of the Romanian Academy of Sciences. Since 1963, he was its Vice-President for 22 years. He also was the President of the Academy for one year. In 1965, he was elected a foreign member of the Division of General and Applied Physics of the USSR Academy of Sciences. Since 1967, he was a foreign member of the Saxon Academy of Sciences and Humanities. In 1970 – 1975, he was a member of the Council of the European Physical Society.

Șerban Țițeica was a man of encyclopedic culture. In addition to deep knowledge in various fields of mathematics and physics, he also had profound knowledge in music, art, and literature. He was a virtuoso pianist. He read books in the original in English, French, German, Russian, and ancient Greek. In addition, he was good at philosophy, loved mountains very much, was a tireless mountain climber. Together with his older brother, physicist Radu Țițeica, he climbed the Bucegi mountains in Romania several times and described new routes for mountain climbers as a pioneer.