In the Dark

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:

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 preparing my tax return.

Although it is quite easy to reach Broombridge from Maynooth, I have never managed to attend the walk nor any of the other celebratory events because I’ve either been away or teaching. Perhaps one of these years, after I’ve retired, I’ll be able join the walk or attend one of the various ectures.

P.S. Maynooth University is also home to the Hamilton Institute which promotes and facilitates research links between mathematics and other fields.

This entry was posted on October 16, 2026 at 1:35 pm and is filed under Euclid, History, mathematics with tags Broom Bridge, Broombridge, Dublin, ESA Euclid, Quaternions, William Rowan Hamilton. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.