It’s Hamilton Day!

Sir William Rowan Hamilton (1805-1865) Today, October 16th, is Hamilton day! It was on this day 183 years ago, in 1843, that William Rowan Hamilton first wrote down the fundamental result of quaternions. Apparently he was walking from his residence at Dunsink Observatory into Dublin when he had a sudden flash of inspiration, and wrote the result down on the spot, now marked by a plaque: Picture Credit: Brian Dolan This event is commemorated by an annual Hamilton Walk. Broombridge railway station (Droichead Broome), near the bridge (Broom Bridge), where Hamilton had his Eureka moment, is not far from Maynooth University the main commuter line from Maynooth into Dublin. This is ironic because Quaternion algebra does not commute. (Geddit?) You may be interested that quaternions form the core mathematical framework used in the Euclid satellite’s telemetry system to represent and control its attitude (pointing direction and orientation). I also make extensive use of quaternions in…