[8] Ernest Barker, a classmate of Whittaker's at the Grammar School with whom he shared the office of prefect, later recalled his personality: "He had a gay, lively, bubbling spirit: he was ready for every prank: he survives in my memory as a natural actor; and I think he could also, on occasion, produce a merry poem.

[8] Whittaker struggled with the poetry and drama which was required by the upper school, and expressed gratitude for being allowed to leave these studies behind and specialise in mathematics.

[11] Whittaker was the pupil of Andrew Russell Forsyth and George Howard Darwin while at Trinity College and received tutoring throughout his first two years.

[13] In 1902, Whittaker found a general solution to Laplace's equation, which received popular news coverage as a "remarkable discovery", though the mathematician Horace Lamb noted that it did not offer any new features.

[16] He also wrote several celebrated books in his early career, publishing A Course of Modern Analysis in 1902 and following it up with A Treatise on the Analytical Dynamics of Particles and Rigid Bodies just two years later in 1904.

[2] In 1906, Whittaker was appointed Andrews Professor of Astronomy at Trinity College Dublin, which came with the title Royal Astronomer of Ireland.

[18] Ball's recommendation, which was published in a collection of his letters in 1915, stated that Whittaker was the only person he knew who could "properly succeed Joly" and that the role would "suit him in every way".

[19][18] The Royal Astronomers acted as directors for the Dunsink Observatory, which used outdated astronomy equipment; it was understood that the primary responsibility of the role was to teach mathematical physics at Trinity College.

[2][20] During this time, the relative leisure of his post allowed him to complete the reading required to write his third major book A History of the Theories of Aether and Electricity, from the age of Descartes to the close of the nineteenth century.

[20] He was elected as a Fellow of the Royal Society of Edinburgh in 1912, after being nominated by Cargill Gilston Knott, Ralph Allan Sampson, James Gordon MacGregor and Sir William Turner.

[22] He was said to be a great lecturer by one of his previous attendees, who stated that his "clear diction, his felicity of language and his enthusiasm could not fail to evoke a response" and that he was very good with illustrations.

[23][24] Freeman Dyson commented on Whittaker's lecture style by saying that students were "warmed, not only by the physical presence of a big crowd packed together, but by the mental vigour and enthusiasm of the old man".

[26] The laboratory was the first attempt of a systematic treatment of numerical analysis in Great Britain and friends of Whittaker have said he believes it his most notable contribution to the education of mathematics.

[22] The laboratory program was so successful, it resulted in many requests for an extra summer course to allow others to attend who previously were unable, ultimately leading to the establishment of a colloquium through the Edinburgh Mathematical Society.

James Robert McConnell noted that Whittaker's research in the connection between physics and philosophy spanned nearly forty publications written over his last 15 years.

[35] During the three years prior to the publication of second volume of his History, Whittaker had already determined that he was going to give priority for the discovery of special relativity to Henri Poincaré and Hendrik Lorentz in the new book.

[2] He received published obituaries from Alexander Aitken,[38] Herbert Dingle,[39] Gerald James Whitrow,[32] and William Hunter McCrea,[40] among others.

In June 1958, two years after his death, an entire issue of the Proceedings of the Edinburgh Mathematical Society was dedicated to his life and works.

[6][49] Funded by a donation from his family in 1958, the Edinburgh Mathematical Society promotes an outstanding young Scottish mathematician once every four years with the Sir Edmund Whittaker Memorial Prize, also given in his honour.

[55] Whittaker wrote three scientific treatises which were highly influential, A Course of Modern Analysis, Analytical Dynamics of Particles and Rigid Bodies, and The Calculus of Observations.

[56] In 1956, Gerald James Whitrow stated that two of them not only were required reading for British mathematicians, but were regarded as fundamental components of their personal libraries.

[32] Despite the success of these books and his other researchers and their influence in mathematics and physics, the second edition of Whittaker's A History of the Theories of Aether and Electricity has been called his "magnum opus".

[5][32][20] In reference to the title's popularity, William Hunter McCrea predicted that future readers would have a hard time acknowledging it was the result of just "a few years at both ends of a career of the highest distinction in other pursuits.

"[57] Whittaker also wrote The theory of optical instruments during his time as Royal Astronomer of Ireland as well as several books on philosophy and theism.

[56] The book was an edited set of lecture notes from the Cambridge Tripos courses Whittaker taught and contained results from mathematicians such as Augustin-Louis Cauchy and Karl Weierstrass which were relatively unknown to English speaking countries.

[61] The book represented the forefront of development at the time of publication, where many reviewers noted it contained material otherwise non-existent in the English language.

[61] The book was a landmark textbook, providing the first systematic treatment in English for the theory of Hamiltonian dynamics, which played a fundamental role in the development of quantum mechanics.

[72] Though the dispute has lasted decades, most scholars have rejected Whittaker's arguments and scientific consensus has continued to hold that special relativity was Einstein's development.

[74] Whittaker's worldview was classified as neo-Cartesianism in the volume, a philosophy described as being "founded on the principle that the search for a universal science should be modelled on the procedure of physicomathematicians.

He stated that "If the transitions from mathematics to moral values are not firmly established, Whittaker's attempt does not succeed in remedying the defects of Descartes' solution.