In the years up to 1948 research in the School had concentrated on two main areas: nonlinear field theory, and meson theory. Nonlinear field theory is an attempt to unify the electromagnetic field and the gravitational field. Schrödinger found a unified theory including also the meson field using a so-called affine connection, which, although aesthetically pleasing, did not turn out to be correct. Heitler had arrived in 1941 as Assistant Professor. He started work on the theory of mesons, which were at the time assumed to be the fundamental particles of the strong nuclear interaction. He formulated a theory of radiation damping for meson fields and applied this to elementary processes occurring in cosmic radiation as it traverses the Earth’s atmosphere.

On 24 July 1945 Walter Heitler was appointed Senior Professor, and he took over the Directorship on 14 December. Hwan-Wu Peng became Assistant Professor on 4 July 1945. There were many distinguished visitors, notably, Paul Dirac (Cambridge), Max Born (Edinburgh), Arthur Eddington (Edinburgh) , Wolfgang Pauli (Princeton), Lon Rosenfeld (Utrecht), James Chadwick (Liverpool), P.M. Blackett (Manchester), Neville Mott (Bristol), Rudolf Peierls (Birmingham), Laurent Schwartz (Paris).

Then, in 1948, John Lighton Synge was appointed Senior Professor. He was already an expert on general relativity but had a wide interest in various areas of classical physics and geometry. This brought the number of Senior Professors up to the intended number of three, but Heitler left the School on 1 October 1949 to take up a position as Professor at the ETH, Zürich, and Schrödinger took on the role of Director again. Heitler would maintain a strong connection with the School. He often came to Dublin for visits and some Scholars came to visit him for collaboration, in particular one of the future Senior Professors in the School, Lochlainn O’ Raifeartaigh. He thus still exercised a strong influence on the School and this maintained the expertise in the School in the field of Particle Physics. This expertise was reinforced by the appointment of Ernesto Corinaldesi as Assistant Professor. He stayed only for a year and a half, however, and the appointment of his successor, Yasushi Takahashi, took until 1958 due to illness. This was a very good appointment, and he was promoted to Professor in 1960. At that time O’ Raifeartaigh became Assistant Professor.

The arrival of Synge brought a new direction and dynamism to the School. Though his main interest was in general relativity and geometry, he had a broad interest in all fields of classical physics and researched a wide range of phenomena. Schrödinger resumed his opposition to the current interpretation of quantum mechanics in two papers in 1952.

In 1954 Cornelius Lanczos was appointed as Senior Professor after having been visiting professor the previous two years. His interests were in numerical analysis, which was of growing importance because of the development of the computer, and general relativity. This reinforced the reputation of the School in the field of general relativity and a large number of Scholars were inspired by this. Like Synge, Lanczos was also a very good public lecturer and gave several Statutory Public Lectures under titles such as: “Einstein, his life and work”, “Adventures in Space” and “Science and Understanding”.

There was now again the full complement of three Senior Professors in the School as initially intended, but in 1955 Schrödinger announced that he wished to resign from his position at the Institute for reasons of ill health.

Former Scholars of the School who got a position at one of the Dublin universities were given the opportunity to be Scholar without stipend. In 1953 it was decided to change their title to Assistant with an annual appointment, which was changed to Research Assistant in 1954 with triannual appointment. They were given formal rights of a desk in the Institute and access to the library.

In 1957 a plaque was designed to be placed at Broome Bridge (already renamed Hamilton Bridge, but this name still hasn’t stuck) to commemorate Hamilton, who was the inspiration for the Institute. The Institute has always been keen to look after its heritage, and when the birthplace of Hamilton in Dominick Street was due to be demolished, the Board made sure that photographs of the house were obtained and the existing plaque was put in custody until it could be re-erected. It similarly made sure that a plaque was affixed to the wall of No. 65 Merrion Square in memory of the late Professor Schrödinger after the move to Burlington Road in 1971 and another in memory of Prof. Synge after his death in 1995.

In January 1961 news came that Schrödinger had died. The Governing Board solemnly adopted the following motion proposed by Professor Synge:

“that the Governing Board of the School of Theoretical Physics records with sorrow the death of Professor Erwin Schrödinger on 4th January 1961 and extends deepest sympathy to his widow. The debt of the School to Professor Schrödinger is very great, not only on account of the enhancement of its prestige through the presence for 16 years of one of the great theoretical physicists of the age, but also by reason of his warm personal interest in the development of the School and his inspiring example as a man of imagination, energy and intellectual honesty.”

The 60s were years of modest expansion. The budget increased steadily. The Estimate for the financial year 1960-61 was £14,843; this rose to £22,500 for the year 1965-66 and for 1969-70 it had risen to £29,200. The computer became more prominent as a useful tool and the Board made a provision of £10,000 in its Estimate for 1963-64 for the purchase of a computer. This was not accepted by the Department, which suggested as an alternative that an agreement could be made with Trinity College for the use of their computing facilities. In January 1963 a fee of £30 a week was agreed for 10 hours of computing time per week. The Board pointed out, however, “…that this arrangement (made for one year only) would not give us a permanent guarantee of time, and we strongly urge that such permanent guarantee be secured by

• entering into agreement to pay £600 annually for a period of years, or
• making a capital payment.”

In the end, this arrangement turned out to be very satisfactory, so when the following year the possibility was raised of using the International Computers and Tabulators Centre instead, Professor Lanzcos wrote a memorandum saying that “the help offered in this respect by the well-trained scientific staff of Trinity College, in particular Dr. J. G. Byrne, the Director of the Computing Unit, is most welcome because it relieves the staff of the Institute of a responsibility which would require a great deal of time and effort on their part.” He also stated that the ICTC did not have a scientific section available, and that even if it were, it would be unlikely to operate under such favourable circumstances as in the agreement with Trinity College. In 1965 the agreement was extended to the School of Cosmic Physics.

Plans were also being made for a new building to house the School of Theoretical Physics at 9-10 Burlington Road. Initial plans were prepared by the Office of Public Works in 1963. But in April 1966 it transpired that still no provision had been made in the 1966-67 Estimates for work to commence on the new building. In September the Council therefore made a representation to the Minister for Education to start the erection of the new building at an early date. In the mean time, permission was sought for using the part of the premises at 64-5 Merrion Square vacated by the Department of Finance. The OPW then suggested a temporary move to Ansley House which was rejected by the Board on the grounds that two moves would be too disruptive to the work of the School. Finally, in June 1967, the Department of Education advised the Registrar that £40,000 had been provided for the new building in the current financial year. It remained for OPW to put the work to tender. The sum was part of an original total estimate of £65,000, but this had to be revised to between £90,000 and £100,000. Final plans for the building were completed by February 1969. It was put to tender in June 1969. After further revisions to the plan were approved in December, work was started, and in May 1971 the first Schedule for the allocation of rooms was discussed by the Board. At the end of 1971 the removal of the School was almost completed.

On the personnel front the 60s were also a time of progress. In 1963 Lochlainn O’Raifeartaigh was promoted to the pensionable post of Professor. He then requested permission to spend a two-year unpaid sabbatical as Visiting Associate Professor at Syracuse University (NY) from September 1964 until June 1966, which was granted and subsequently extended, by one year in the first instance and eventually by two years until September 1968. Meanwhile, preparations were under way to replace Professor Lanczos, who was due to retire in February 1968. In July 1964 the Chairman wrote to the Minister for Education with a proposal for the creation of a third permanent post as Professor. This was supposed to be a temporary arrangement in order to be able to attract a suitable candidate for the Senior Professor position. It was hoped that this person, when in place, would find that the amenities offered for scholarly activity in the School would offset the inequality in salaries between Dublin and elsewhere. This proposal was put on the long finger by the Government on the grounds that a report was due by the Commission on Higher Education. Eventually, in June 1967, the Department approved a proposal that the establishment of the School for the 5-6 years following Professor Lanczos’ retirement would be: 3 Senior Professors, an Assistant Professor and a Visiting Professor. The Board then proposed to advertise the Senior Professorships in contrast with established procedure, but this was rejected by the Council. Rev. Professor J. R. McConnell was appointed in February 1968 and Professor O’Raifeartaigh on 1 October 1968, bringing the complement of Senior Professors back to three. Professor Lanczos was appointed Professor Emeritus of the School. In July 1968, Takahashi resigned his position as Professor to take up a position in Edmonton. He returned as a visiting professor in 1971 and several times there after.

In June 1969 the Board took steps to obtain approval for a fourth Senior Professorship but this was refused by the Department. After almost 13 years as Director, Professor Synge resigned his directorship in January 1969 and was replaced by Rev. Professor McConnell.

In January 1967 the Board considered a Government proposal for the establishment of a National Research Council. The Board welcomed this in principle but commented

• 1. that the Council should be concerned with the whole range of science, pure and applied and that, although pure research is usually only a small fraction of a programme of research, it should be adequately funded
• 2. that the organisation of the Council should be as simple as possible in order not to consume too much time and energy of active scientists, and that its role should be to support rather than direct research programmes
• 3. that the proposed organisation is unwieldy and should be reduced to at most 14 members, and need not necessarily use up a “scientist of outstanding merit” to head it, though it should be a scientist with experience in research and scientific administration.

By 1968 it was felt that the title of the position of Technical Assistant, which had been created in 1945 upon recommendation by a Committee set up to resolve a dispute between the Registrar and the Director (Professor Schrödinger), needed to be changed. After several alternatives were suggested, the title of Secretary and Assistant Librarian was finally adopted by the Board, with a similar change of title in the School of Celtic Studies. This was subject to approval by the Department of Education, however, and this does not seem to have been forthcoming.

In January 1969 a new element was added to the work of the School. In recognition of the fact that their heavy teaching load prevented university staff to do research, the School agreed to give courses of lectures for advanced students, hoping that this offer would be taken up jointly by the different universities.

Research during the period 1948-70 covered an astonishing variety of fields and thus more than satisfied the original remit of the School as laid down in the Establishment Act of the Institute: “the investigation of the mathematical principles of natural philosophy and the application of those principles to the physical and chemical group of sciences and to geophysics and cosmology”. Interestingly, many of the Scholars did independent research on topics quite far removed from the main interests of the Professors. It is obviously impossible to do justice to 20 years of research here, but to give an impression of the wide range of subjects investigated, these are some of the main topics of research:

Professor Schrödinger did research on unified field theory, in particular with affine geometry. He also considered the fundamentals of Probability and applications of probability to cosmic ray counting.

Professor Synge’s main lines of work were in general relativity and classical physics, but he also worked on various other topics. He studied the hypercircle method in function space, the instability of the tippe-top, the Fourier transform method for elastic waves in a medium, the flow of energy for waves in an anisotropic material, the theory of measuring gravitational fields, gravitational effects for signals travelling to and from satellites and the spectral shift of gamma rays, the gravitational field of a steadily rotating body (with P. Florides) and the gravitational field of the Sun, and Newtonian hydrodynamics of a rotating fluid with applications to ocean waves on beaches.

Professor Lanczos worked in two main areas: general relativity and numerical analysis. He investigated conservation laws in general relativity, systems of orthogonal functions for non-hermitian problems. He obtained upper and lower bounds for energy levels of excited states and developed a method for approximating the gamma function with uniformly small errors. He also analysed high-frequency undulations in the metric in general relativity and considered noise in Fourier data, determining the cut-off point of a Fourier series required for a given accuracy.

Professor J. R. McConnell worked on the self-energy of particles with integral spin and representations of Lie groups.

Professor O’ Raifeartaigh worked on the S-matrix in nonlocal field theory, the problem of measuring the field strength of quantized fields using test particles, and representations of semisimple Lie groups. His most celebrated work was done on leave in Syracuse University. This concerned the question of combining Lorentz invariance and internal symmetries of elementary particles. He also worked on mass-splitting theorems and the hadron current algebra.

Professor Takahashi studied divergences in nonlocal field theory and a general theory of the invariant S-matrix. He proposed a method to relate strong and weak interactions and proposed a number of relations. He studied generalised statistics of particles and introduced a Hamiltonian formalism for quantising a system with a linear constraint. In 1965 he investigated the question of generalised conservation laws using a generalised Ward identity, now called the Ward-Takahashi identity.

Some notable work by Scholars:

W. Thirring applied the new theory of quantum electrodynamics due to Schwinger, Feynman and Tomonaga to pair creation by mesons and to Compton scattering.

H. F. Sandham worked on elliptic and hypergeometric functions and deduced results in number theory and the summation of series.

B. K. P. Scaife developed the theory of dielectric polarisation.

W. Israel investigated the speed of propagation of shock waves in a relativistic gas.

P. S. Florides calculated the gravitational field of the Earth to order 10 -16 and developed methods for approximating the gravitational field of a body of any shape at rest or in steady rotation.

K. S. Viswanathan studied a spherical magnetosphere model and derived an expression for the energy flux of a collision-free plasma.

There were seminars on a huge range of topics. The Easter and Christmas Symposium became a regular feature. Lecturers and students from Irish universities were supported financially to attend. There were many eminent visitors, who were occasionally invited to give the Statutory Public Lecture. Visitors of note were for example: W. Heitler (Zürich), H. S. Green (Adelaide), H. S. M. Coxeter (Toronto), A. Lichnerowicz (Paris), R. E. Peierls (Birmingham). L. Schwartz (Paris), M. Riesz (Lund), H. Froehlich (Liverpool), W. Kohn (London), F. A. E. Pirani (London), W. Thirring (Vienna), S. Mandelstam (Birmingham), ter Haar (Oxford) and L. Rosenfeld (Utrecht and Nordita).

by Professor T. C. Dorlas