The walk commemorates Hamilton’s famous creation of a strange new number system, called Quaternions, on the banks of the Royal Canal in Dublin on October 16, 1843. Hamilton was walking with his wife Helen from their home at Dunsink to a meeting of the Royal Irish Academy (at that time) in Grafton Street.
The walk retraces Hamilton’s steps from Dunsink Observatory to Broom Bridge in Cabra where he had his Eureka moment. He had ben for many years trying to create an algebra of three dimensional space, but had been unable to do so. His Eureka moment was to see that he could do this, but in four dimensions represented by quaternions. Hamilton performed a piece of mathematical graffiti by scratching his quaternion formulas on a stone in the canal bridge.