After a year of post-graduate research in Edinburgh, during which he acted as Nichol Assistant to Professor MacGregor, Carse moved for the years 1904 to 1907 to Emmanuel College, Cambridge, and the Cavendish Laboratory, where he worked under and won the regard of Sir J J Thomson, and followed the lectures of Sir Joseph Larmor and Sir Robert Ball.
In 1907 Professor MacGregor, knowing his man, recalled Carse as a Lecturer in Natural Philosophy to Edinburgh University. There, but for service from 1916 to 1918 at the Royal Arsenal, Woolwich, as an expert on optical supplies, he remained as a Lecturer till 1923, and thereafter as Reader till his retirement on September 30, 1948. During the earlier part of that period he lectured also on Statistics, and during practically all of it he was in sole charge of the Department of Medical Physics. In the interregnum between Professors Barkla and Feather, Carse was the acting Head of the Department of Natural Philosophy, guiding it with wisdom and tact.
The University had in Dr Carse (he was awarded his D.Sc. in 1908 for a thesis on "Emission of Positive Electricity from Heated Metals and Salts") one of its most devoted servants, not only in teaching and the research work of the Physical Laboratory, but in academic administration. For he was a member of the Senatus Academicus (from 1926), the Faculties of Arts and Science, and the Boards of Studies in Science, Medicine and Commerce, and a Director of Studies for Arts from 1922 and for Science from 1941. Moreover he served on many ad hoc committees, and represented the University on such outside bodies as the Edinburgh Provincial Committee for the Training of Teachers, the Edinburgh and S. E. Scotland Regional Advisory Council for Technical Education, the Joint-Recruiting Board, and the East Lothian Educational and the Heriot Trusts.
Perhaps the last, to which he belonged from 1927 to 1948, was the one nearest his heart. He was Vice-Chairman from 1934 to 1947. No other Governor had a better record of attendances or gave more unstintedly of his time and practical common sense on the Trust itself and its committees, and as its representative on the Boards of the Edinburgh and East of Scotland College of Agriculture and of the Heriot-Watt College.
Another Board on which he did good work for many years, for four of them (1935-36 and 1946-47) as Vice-President, was that of the Royal Scottish Society of Arts, of which he was elected a Fellow in 1924.
As a teacher Dr Carse made his mark on generations of Arts, Science and Medical students, and will be remembered by them with deep respect and genuine affection. He took and retained a lively interest in every student with whom he had anything more than a casual contact; but to all, even those who knew him only as an occasionally consulted Director of Studies, he was all helpfulness and painstaking advice. He was not the man to scamp any detail or to leave anything to chance; and simplicity and clarity, fullness and aptness characterised his exposition. He had patience, curiosity and objectivity, and exactitude in a high degree. His was indeed an inquiring mind.
That love of inquiry was by no means limited to the strictly scientific. For Dr Carse carried it over to his many extramural interests and hobbies, from snooker to detective fiction. Any kind of technical process appealed to him, and he was not satisfied till he grasped its principles. Among his chief interests was the collection and study of engravings, etchings, stamps, woodcuts, Japanese and Baxter prints and the like. He was also knowledgeable in the Scottish school of painting of the last hundred years. The news of the day, international, national, local, sporting and, not least, financial, he followed with an informed attention. Keenly interested in people, he won and kept his many friends by his utterly unaffected manners, his lack of egoism, his whimsical and unexpected humour, and his readiness to talk (and listen) on any subject, the big not being too serious or the little too trivial.
Dr Carse's publications in book form were Notes on Practical Physics (with Professor C G Barkla) and A Course in Fourier Analysis and Periodogram Analysis for the Mathematical Laboratory (with George Shearer), both published for the first time in 1915 and reissued with revisions. In the planning of another standard reference work, Tables of Physical and Chemical Constants and some Mathematical Functions by G W C Kaye and T H Laby, 1911, Dr Carse had a share, which in the current (tenth) edition is still gratefully mentioned. In addition Dr Carse contributed many papers (some of them in collaboration with colleagues) on meteorological, optical, radiological, magnetic and thermodynamic subjects to the Proceedings of this Society and of the Cambridge Philosophical Society, the Journal of the Scottish Meteorological Society, the Educational Times and the Transactions of the Optical Society. He also wrote the section on "Meteorology" in Professor R G Linton's Veterinary Hygiene, 1921, and (with John Urquhart) the articles on "Integrometers", "Planimeters" and "Harmonic Analysis" for the Handbook of the Exhibition at the Napier Tercentenary Celebration, 1914.
Dr Carse is survived by his widow and one son.
He was elected a Fellow of the Society in 1905.