In Edirne, an ancient capital of the Ottoman Empire located near the borders to Greece and Bulgaria, exits an old train station in Karaağaç, a region surrounded by Karaağaç (Black) trees, built at the turn of the century. The brick building is symmetric and elegant; its two slim towers house the main waiting hall of the station between two wings extended to the left and right. The station is “old” because no trains arrive here any more; no rail roads remain any longer. Many years have gone by since the station has ceased to function. Yet, the structure still stands solidly without a slightest sign of yielding to the strong winds of the daily morning storms. A locomotive with the plate number reading “550220” which sits behind the building is the only visible reminder that this was once a train station. This old station is now the International Centre for Physics and Applied Mathematics of Trakya University where the Barut Memorial Conference on Group Theory in Physics was held for December 19-26, 1995.
Symmetry was the main theme of the memorial conference. Group theory is a mathematical tool that physicists use to analyse and understand symmetries in Nature. Symmetry was indeed one of the fundamental themes that Asım O. Barut pursued throughout his academic life. Admiration of symmetries is widely conspicuous and recurring in the Islamic culture. Each mosque has a symmetric exterior structure and an interior which is designed intricately by colourful geometric patterns. It is probably no accident that many physicists from Turkey, including Barut, Gürsey and İnönü, made important contributions to physics via group theory.
Symmetry entered into modern physics in relation with the invariance principle. Group-theoretically, symmetry is described as something which remains unchanged under the actions of a transformation group. For instance, the conversation of energy may be conceived as a consequence of its invariance under the time translation, representing the fact that time flow is uniform; and the rotational symmetry or the isotropy of space about a point leads to the conservation of angular momentum about the point. Wigner has pointed out that symmetry implies the presence of an irrelevant notion . For a conservative system, it is irrelevant to ask when the total energy of the system is conserved. There is no preferred direction when space is isotropic. The isospin formalism was introduced after the observation that the distinction between a proton and a neutron is unimportant in a nucleus. Supersymmetry is meaningful only in an environment where the distinction between a boson and a fermion is irrelevant. In fact, symmetry has played an important role of the guiding principle in modern physics. Although geometric symmetries may have been impressed firmly in Asım’s mind since his youth, he went further beyond the static symmetries to explore new symmetries.
As observation confirms, symmetry in Nature is often imperfect. In the Chinese and Japanese culture, beauty is found when symmetry as a reality. In fact, breaking of symmetry can reveal more details of the structure. Degeneracy of the spectrum may be resolved by symmetry breaking. However, for eyes that are trained to see symmetries as perfect, broken symmetry could be seen as a defect. Amid the symmetrical culture that Asım was brought up in, he could have been compelled to look for a greater symmetry framework within which such aberrations are tolerated. More specifically, he proposed to distinguish between the kinematic symmetry for classification of particles and the dynamical symmetry in interaction of particles . Then he reached the idea of the dynamical group, by which he derived the mass spectra of particles and other properties related to a composite system. He placed his faith in symmetries. He attempted to locate a symmetry group in the grand scheme and to interpret what the irreducible representations of the symmetry group may imply. His particular preference was the conformal group, SO(4,2), as a dynamical group, to cover a wide class of composite systems .
Asım Barut spent a considerable period of time in exploring how far he could go with the idea that elementary particles can be viewed as a composite of protons and leptons. He was not particularly antagonistic to the quark model but rather stubbornly insisted on investigating other possibilities. In 1966, an interesting conversation took place between Asım and Professor Sudarshan in the discussion session of Asım’s talk in the Milwaukee conference on Non-compact Groups, recorded in the proceedings . After Asım made a comment that he did not elaborate whether or not quarks exist but he wished to interpret his results in a slightly different fashion other than in therms of the existing quarks, Professor Moffat made a remark which seemed indistinct Then, the conversation took place as follows:
Sudarshan: Could I make Moffat’s comment to read as a question to the effect: Do you believe that there are quarks?
Barut: Am I to answer to the fact that they will be found by experiments and how soon?
Sudarshan: Within the next five years?
Barut: I believe they will not be found.
Sudarshan: Would you like to make a bet of five dollars?
Apparently Asım was not a stubborn antagonist or a cynical skeptic of the quarks, but he did not want to hold a blind belief in the quarks. Although the quark model is indeed highly plausible and the best model so far available, it is also the fact that quarks have not yet been found as isolated physical entities. Asım was courageously and openly advocating that alternative models must be investigated unless Nature rejects them. In fact, Asım was not the only person who had this attitude. Heisenberg and his collaborators made a considerable effort to investigate an alternative model.
Asım Orhan Barut was born in June 24, 1926 in Malatya of Turkey. Malatya is a city near the upper Euphrates and inhabited by the proud descendants of the Hittites who had technology of producing iron as early 15.0000 B.C. In the midst of the World War II, Asım, an adventurous teenager, left his town to Switzerland while passing through war-torn cities in Europe. Asım had a scholarship from the Turkish Government to study the engineering of rail roads . However, he chose to study physics instead of engineering at the Swiss Federal Institute of Technology (ETH) in Zurich. He finished his diploma in physics in 1948 and his Ph. D. in 1952.
Asım’s first scientific paper was published in 1951 under the title “Die Laufzeit, elektronenbahnen, Kathodenfeldstärke und Potential der Raumladungsdiode für jede Anfangsgeschwindigkeit, Anfangsrischtung und Strom,” in Zeitschrift für Angewandte Mathematik und Physik 2, 35-42 (1951). This was based on his diploma work. In this paper with a lengthy title, proposed a new method to calculate, according to the abstract, “the transit times of electrons, the cathode field, the potential and the electron paths as a function of two reduced parameters alone for all values of the initial velocity and current under partial and complete space charge” by using a non-linear differential equation. This might give us an impression that at this point Asım had started his career as a theoretical and applied mathematical physicist. Surprisingly, for his doctoral thesis, Asım turned himself into a research involving experiments. His Ph.D. thesis kept in the ETH library is entitled, “Electronenoptisches und statistiches Verhalten der Gittervervielfacher.”
Asım’s stay in Switzerland was not only academically successful but also socially fruitful. Asım met a beautiful girl named Pierrette in Zurich and fell in love. He as a scholarship holder from the Turkish Government was not allowed by a provision to get married to a girl in Switzerland. Asım and Pierrette went to the New World where they got married and started to build their new life together . After the World War II, the United States, as the greatest power in the world, was prosperous and open to many foreign scientists. Asım continued to move from Chicago to Syracuse, to California and finally settled in Boulder, Colorado, a town nested in the arms of the Rocky Mountains. The Baruts eventually had three children, one son and two daughters.
Asım Barut was a travelling physicist. He was constantly on the road and enjoyed attending meetings and visiting various research institutions in the world. It is not uncommon for Barut to be giving a lecture in the University of Munich on a Wednesday, then be in Ankara or Trieste on Friday in the same week. A colleague once asked Mrs. Barut, “Where is Asım now?” Her response was, “I don’t know. He could be anywhere. I would not be surprised if he was at the North Pole!” Unbeknownst to Mrs. Barut, Asım was coincidentally at a point less than a few hundred kilometres away from the North Pole, attending a conference in Finland .
Asım Barut’s contributions to the fields of theoretical and mathematical physics are enormous, a partial list of which can be found in an article written for Asım’s sixty-fifth birthday . Asım authored or co-authored more than five hundred articles in journals and books. There are more than twenty books edited or co-edited by Barut for lecture notes and conference proceedings. He is also the author of three books [8,9,10] and the co-author of a fourth book . These books are all considered as classics in modern physics. Many students and physicists have greatly benefited from these publications, of which a number of speakers have expressed their appreciation in this conference.
Asım had a large number of collaborators in the places where he travelled. Asım’s enthusiasm encouraged many young scientists throughout the world in countries that were well developed as well as ones that were not. His stimulating lectures inspired many scholars. Asım was not only respected for achieving the high level of scholarship but also admired for his charming personality and warm friendship.
Asım Barut was laid to rest on December 5, 1994 in Denver, Colorado. “But try to remember that a good man can never die. The person of a man may leave... but the best part of a good man stays. It stays forever.” The short note was inscribed with lines from The Human Comedy by Willliam Saroyan, which was sent by the Barut family in loving memory of Asım Barut. We all miss both the mind and the man.
At the opening of the conference, Mrs. Pierette Barut dedicated Asım Barut’s bronze bust, which was donated by his relatives in İstanbul, to the main lecture hall where the conference was held. In this central hall of the old trains station, the remnants of the old ticket counter could be recognized at a corner if you were to look very closely. The bronze of Asım stands at another corner gazing out appealingly as if he was once installed in an office of the station master there. A young student, walking into the hall and seeing bronze, may even think that it is the bust of a station master in the past. But, the student may not be too far wrong. Indeed, Asım, once a holder of the railroad scholarship, had returned to a railroad station which had given him the inroads to the modern world of physics. Asım had, in fact, chosen the road less travelled and had provided tickets for a new generation of young physicists to follow their dreams and inspirations.
 E. P. Wigner, Symmetries and Reflections, (Indiana Univ. Press, Bloomington, 1967) p.31
 A. O. Barut, in Non-Compact Groups, ed. Y. Chow (Benjamin, New York, 1996) p.1.
 A. O. Barut, in De Sitter and Conformal Groups and Their Applications, eds. A. O. Barut and W. E. Brittin (Colorado Assoc. Univ. Press, Boulder, 1967) p.3.
 Y. Chow, ed. Non-Compact Groups, (Benjamin, New York, 1996) p.22.
 Private conversation with Mrs. Barut.
 Private conversation with Mrs. Barut.
 A. Inomata, A. van Merwe and R. Wilson, To Asım Orhan Barut on His Sixty-Fifth Birthday, Found. Phys. 23, 173 (1994)
 A. O. Barut, Elektrodynamics and Classical Theory Fields and Particles, (Macmillan, New York, 1964).
 A. O. Barut, The Theory of the Scattering Matrix, Dynamical Groups and Generalized Symmetries, (Macmillan, New York, 1967).
 A. O. Barut, Dynamical Groups and Generalized Symmetries in Quantum Theory, (Univ. Canterbury Press, Christchurch, 1972).
 A. O. Barut and R. Raczka, Theory of Group Representations and Applications, (Polish Scientific Publishers, Warsaw, 1980).
* Tübitak Yayınları, Asım Barut Memorial Conference, 21-27 December 1995