Edmund Taylor Whittaker was born at Southport on October 24, 1873. He wag of the Whittakers of Grindleton, near Clitheroe on the Ribble, a family which he was able to trace back through several generations,. From Manchester Grammar School he went up in 1891 to Trinity College, Cambridge, with an entrance scholarship. In 1895, in a Tripos list of great distinction, he was Second Wrangler, bracketed with J. H. Grace and followed by Alfred Young; T J I'A. Bromwich was the Senior Wrangler. In 1896 he was elected a Fellow of Trinity, in 1897 he was First Smith's Prizeman. His thesis, on automorphic functions, formed the foundation of his first long paper and at the same time indicated the source of much of his later inspiration, namely the work of Henri Poincaré,
His first book, Modern Analysis, was published in 1902. In its later editions, dating from the second in 1915, written in collaboration with G N Watson, it had a wide influence on the teaching of functions of a complex variable, and a still wider influence on the study of special functions and their differential equations. The partial differential equations of mathematical physics, and the special functions associated with them, were subjects of his enthusiastic interest at every period of his long life. In 1902 he published his general solution of Laplace's equation; in 1903 he introduced the confluent hypergeometric function, which by now has a very considerable literature. His second book, Analytical Dynamics, published in 1904 summed up in elegant chapters the classical dynamics from Lagrange through Hamilton to Poincaré. It was translated into German and other languages.
In 1906 Whittaker was appointed Royal Astronomer of Ireland, and Professor of Astronomy in the University of Dublin. One of the pupils attending his courses of advanced lectures in mathematical physics was Mr De Valéra; each of master and pupil was in later life occasionally mistaken for the other. His chief work of those years, probably his magnum opus and one that certainly entailed more reading and historical research than any other, was his History of the Theories of Aether and Electricity, from the age of Descartes to the Close of the Nineteenth Century, published in Dublin in 1910. In 1951 he revised and amplified this work; in 1953 (his eightieth year) a second volume brought the history to 1926, the beginning of the Born- Heisenberg-Jordan-Dirac-Schrödinger epoch. He expressed the hope of writing a third volume on the later developments up to 1950; but it is very doubtful whether this was a feasible project, even if physical strength had remained to undertake it.
George Chrystal, professor of mathematics in the University of Edinburgh since 1879, died in 1911. Whittaker, appointed to succeed him, entered on his duties in January 1912. Retiring in 1946, he held this, his most important post, for thirty-five years. He founded a school of research and a mathematical laboratory, at that time quite an innovation in British universities. This led to a further textbook with the collaboration of G Robinson, The Calculus of Observations. In this connection one must mention his contact and friendship with many members of the actuarial profession in Edinburgh, in particular with that very distinguished actuary, the late G J Lidstone, LL.D. The introduction of a curriculum in actuarial mathematics in the University of Edinburgh may be ascribed to these contacts.
Many thousands of his students (he made a point of lecturing to classes at all levels) will chiefly remember his flawless delivery and his art of exposition; his colleagues in the University will remember the unsparing conscientiousness with which he took a full share in administration and in membership of extraneous educational bodies. Further afield he was well known at mathematical congresses and was on terms of correspondence with many of the leading mathematicians of the world. He received knighthood in 1945.
From 1930 onward, following his reception into the Roman Catholic Church, his interests turned to natural theology and to the reconciliation of modern science and cosmogony with revealed religion. This is the theme of several essays and books of this period, notably of Space and Spirit. In conclusion we must note the quite unusual lucidity and rapidity of his mind and his equally remarkable capacity for industry; also the ever-present impulse to do justice by the work of another, as when he edited the posthumous manuscript of Eddington and published the latter's Fundamental Theory. In manner he combined the courteous manner of the last century with an entirely sympathetic and friendly accessibility.
He is survived by Lady Whittaker, daughter of the Rev. Thomas Boyd, of Edinburgh, and by three sons and two daughters. His second son, Dr J M Whittaker, formerly professor of mathematics in the University of Liverpool, is now vice-chancellor of the University of Sheffield.