Hamilton Day
Hamilton Day commemorates a ground-breaking discovery by one of Ireland’s most famous scientists, William Rowan Hamilton (1805–65).
Hamilton Day (16 October)
On 16 October 1843, Irish mathematician William Rowan Hamilton MRIA and his wife Helen were walking along the banks of the Royal Canal from Dunsink Observatory on their way to the Royal Irish Academy.
At Broome Bridge, William had a eureka moment and came up with a new algebra he called quaternions. So excited was he by his discovery, he scratched the fundamental formula i² = j² = k² = ijk = −1 onto the bridge with his penknife. His quaternions revolutionised algebra and would later help to put a man on the moon and be used for CGI in movies.
Hamilton Day on 16 October is commemorated annually by the Academy through an award ceremony that recognises the most gifted third level mathematics students in Ireland. An internationally renowned speaker is invited each year and gives the Hamilton Lecture and also a masterclass for the prize winners.
Hamilton Day is supported by 
Who is Hamilton?
William Rowan Hamilton (1805–65) is universally recognised as the greatest mathematician, and arguably the greatest scientist, that Ireland has produced to date.
Latest Hamilton Day updates
Hamilton Prize in Mathematics
Each year on Hamilton Day, the Academy recognises the top final year mathematics undergraduate students from across the island of Ireland. An internationally renowned speaker hosts a masterclass for the winners and the day concludes with the publicly focused Hamilton Lecture.
Hamilton Did It
In 2018, the RIA, Transport Infrastructure Ireland and TU Dublin ran a curated competition open to staff, alumni and students of the TU Dublin School of Creative Arts at Grangegorman. Applications were invited for artworks to commemorate that Eureka moment which Hamilton had on 16 October 1843. The winner of this publicly funded commission was former Fine Art student, Emma Ray, who designed an artwork commemorating Hamilton’s groundbreaking graffiti at Broombridge Luas stop. The artwork was officially launched in 2019.
‘Hamilton Did It’ was an artwork project that commemorated William Rowan Hamilton’s Eureka moment at Broombridge. This was the result of a collaboration between the RIA and students and staff on the BA Visual Communication at TU Dublin School of Creative Arts. A recent Visual Communication graduate, Lily Gaertner drew from our rich local heritage of scientific discovery at Dunsink and Broombridge to produce a set of illustrations for a poster and digital campaign to promote the legacy of Irish mathematician William Rowan Hamilton and its impact on current technological innovation. The poster headline ‘Hamilton Did It’ was generated by a final year Visual Communication student, Jake Skelly.
