There are about twenty portraits of many of these professors hanging in the School of Physics, together with a portrait of Erasmus Smith (1611-1691) himself.  Smith was wealthy, and during his lifetime the Erasmus Smith’s trust was formed for the purpose of advancing education in Ireland.  After Smith’s death the trust made an endowment enabling the Trinity physics professorship to be created and funded.

The first Erasmus Smith’s professor was Richard Helsham.  He was an able polymath who was best known for the posthumous publication of his course of lectures in natural philosophy.  This widely used book was one of the earliest undergraduate texts on Newtonian physics.  Helsham also pursued a career in medicine.  He was physician to Jonathan Swift, writer and the dean of Dublin’s St Patrick’s Cathedral.

Through the years, other distinguished academics succeeded Helsham to the professorship.  In the 18th century, when many academics in Trinity and elsewhere published little or nothing, Hugh Hamilton FRS wrote a book on conic sections that was said to have been well received by the Swiss mathematician, Leonhard Euler, among others.  Matthew Young, a popular figure in Trinity, also published widely, and, like Hamilton, was a founder member of the Royal Irish Academy.

In the 19th century Humphrey Lloyd FRS observed conical refraction in a biaxial crystal, thus providing further evidence for the newly proposed wave theory of light.  He also worked extensively on terrestrial magnetism.  James McCullagh FRS produced the standard mathematical analysis prior to Maxwell’s work of how light waves behave in crystalline materials.  McCullagh also devised what became known as the curl of a vector.  Joseph Allen Galbraith extended Foucault’s work on his pendulum and the effect of the earth’s rotation.  The highly talented and charismatic George Francis Fitzgerald FRS proposed, among his many other achievements, that objects moving near the speed of light appeared to contract in length.  This was later also shown by Lorentz and then by Einstein in his theory of relativity.

 In the 20th century, despite Trinity and Ireland’s poverty at the time, Robert Ditchburn FRS worked widely on optical spectroscopy, including light absorption in caesium vapour.  Ernest Walton split the atomic nucleus by artificial means, thus demonstrating quantitatively Einstein’s energy-mass equivalence E = mc2 and ushering in the era of accelerator-based nuclear physics.  Walton and his co-worker John Cockcroft shared the Nobel prize in physics for this Cambridge-based work.  The wide research interests of Denis Weaire FRS include soft condensed matter and the discovery in foams of the Weaire-Phelan structure, and the history of physics in general.  He has received many awards for his work.  Michael Coey FRS has produced books and at least 800 articles on magnetism, magnetic materials and spintronics.  He, too, has received many international awards, and with an h-index of over 100 he is said to be Ireland’s most highly cited scientist.

Michael Coey retired from the Erasmus Smith’s professorship in 2012, and thus a decade has elapsed between then and the appointment of Johnny Coleman to the chair.  His research into nanomaterials and their structures includes work on liquid suspensions of two-dimensional materials like graphene.  Such structures are valuable in the production of a wide range of new materials.  Like his predecessor he has an h-index of over 100.  From 2011 until his 2022 appointment he was Trinity’s professor of chemical physics.   His appointment (by ‘translation’) is particularly welcome, as it comes in time for the tercentenary in 2024 of the Erasmus Smith’s professorship.