CURIOSITIES:DESPITE THE ADMIRABLE and thought-provoking efforts of Banksy, and the recent emergence of his rather less talented Dublin counterpart, Maser, graffiti is generally considered a blight on the urban landscape.
In reality, graffiti has existed since early man developed the capability of scratching randomly on a cave wall. The first surviving example of "modern" graffiti is generally considered to be an advertisement for a brothel in the ancient Greek city of Ephesus.
The eruption of Vesuvius preserved myriad examples on the walls of Pompeii, and Renaissance artists Raphael and Michelangelo carved their names in the subterranean ruins of Nero's Domus Aurea, as did fellow tourists Casanova and the Marquis de Sade. Even Lord Byron blithely defaced one of the columns of the temple of Poseidon in Attica.
One illustrious graffiti artist who left his mark a little closer to home was acclaimed Irish mathematician Sir William Rowan Hamilton. On October 16th, 1843, while walking with his wife along the Royal Canal from Dunsink Observatory, where he lived and worked, to the Royal Irish Academy, he had a eureka moment equivalent to that experienced by Archimedes in his bath.
Having struggled for years with what he described as a "metaphysical stumbling block" - the establishment of rules for multiplication of imaginary numbers in three dimensions in a way consistent with the properties of abstract algebra - he decided to work in four dimensions instead (obvious, really). In a famous act of mathematical vandalism necessitated by the lack of a pen, he carved the necessary equations into the stone of Brougham (aka Broom) Bridge as follows: i2 = j2 = k2 = ijk = -1.
Naming these equations quaternions, he devoted the rest of his life to working on them. Nowadays they form the basis of developments including video gaming and computer-generated imagery. Whilst admittedly no trace of the original remains, a plaque erected in 1958 commemorates this momentous discovery and a mathematicians' pilgrimage from Dunsink observatory to the bridge has been organised by NUI Maynooth since 1989, attracting an illustrious international attendance.