With the death on February 16th of James McConnell, Ireland has lost one of its most distinguished scientists and the doyen of Irish theoretical physicists. He was born in Dublin on February 25th 1915, the second child of James Robert McConnell, pharmacist, and Frances nee Lennon. Educated at O'Connell's School, he entered University College Dublin in 1932 and graduated four years later with a first-class Honours MA degree in mathematics. During this time he came under the influence of the distinguished mathematical physicist and pontifical academician A. W. Conway (1875-1950) who aroused in McConnell an interest in relativity and quantum theory and was to become his mentor.
On leaving UCD he decided to seek ordination to the priesthood. After a year at Holy Cross College, Clonliffe, he was sent to study at the Lateran University of Rome. He was ordained a priest in 1939 and completed his studies at the Lateran in 1940, being awarded the degrees BD, BCL in canon law, and STL in theology. While at the Lateran he enrolled as a student of mathematical science at the Royal University of Rome (La Lapienza) and gained the degree of Doctor of Mathematical Sciences in 1941.
Despite wartime difficulties, he managed to return to Dublin in 1942 and with Conway's support was appointed Scholar at the School of Theoretical Physics of the newly founded Dublin Institute for Advanced Studies (DIAS), where he came under the guidance and inspiration of the world-renowned physicists Erwin Schrodinger (Nobel Laureate 1933) and Walter Heitler. His initial researches were in non-linear electromagnetic theory but he soon began a detailed study of the theory of the negative proton, or antiproton, whose existence was not confirmed until 1955.
In 1945 he was appointed Professor of Mathematical Physics at St Patrick's College, Maynooth, where he continued his researches into the theory of fundamental particles, publishing extensively, including two monographs. Following his appointment in 1968 to a senior professorship in the School of Theoretical Physics of the DIAS, his research interests changed and he took up the study of the theory of rotational Brownian motion. He wrote many papers on this topic, and in due course wrote two more monographs which dealt with the electric and magnetic properties of matter. His writings are characterised by thoroughness, precision, and clarity. He spent the year 1959-60 as a visiting professor at Fordham University, New York; he also held visiting professorships at Laval University, Quebec, 1964, and at Salford University (1976-80). For his early researches he was granted the DSc degree by the National University of Ireland in 1949, the same year in which he was elected to membership of the Royal Irish Academy. To every task that he undertook he brought an infectious and cheerful enthusiasm.
Beyond his obvious intellectual gifts, which he bore lightly, he had considerable administrative talent. At Maynooth he was Dean of the Faculty of Science from 1957 to 1968, and Registrar from 1966 until 1968; at DIAS he was Director of the School of Theoretical Physics between 1969 and 1972; and he was Secretary of the Royal Irish Academy from 1967 to 1972, having served as chairman of the National Committee for Mathematics, 1960-64, and of the National Committee for Physics, 1965-68. He was a foundation member of the European Physical Society and was on its Council 1969-71. From 1982 until 1988 he was chairman of the European Molecular Liquids Group.
In recognition of his contributions to science he was awarded the Boyle Medal by the Royal Dublin Society in 1986. He had the rare distinction of being appointed to the Pontifical Academy of Sciences in 1990 by Pope John Paul II, who made him a Prelate of Honour in 1991.
James McConnell was a friendly, unassuming and generous man, who was full of vitality and had an infectious enthusiasm for all his undertakings. He was sustained in his late years of failing health by his faith and the devoted care of the Carmelite Sisters for the Aged and Infirm at Our Lady's Manor, Dalkey. Requiescat in pace.