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| Me at Brougham (aka Broom) Bridge, Dublin |
In ancient times, Archimedes had an "AHA moment" so astonishing that it caused him to leap out of his bath and run through the streets shouting, "EUREKA!" In 1843, William Rowan Hamilton had a similarly amazing "AHA moment," but instead of running naked, he carved his realization into the stones of Dublin's Broom Bridge. |
| Hamilton Memorials at Broom Bridge, Dublin |
Hamilton had long sought a means of extending the complex numbers to represent rotations in 3 dimensions. Even his young sons knew of his quest and would ask him when he came down to breakfast, "Well, Papa, can you multiply triplets?" |
| Hamilton Memorials at Broom Bridge, Dublin |
On October 16, 1843, while walking into Dublin with his wife from their home at Dunsink Observatory, the answer suddenly came to him. In his excitement, he took out his pen knife and carved the equations into the stone of the bridge: i
2 = j
2 = k
2 = ijk = -1
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| William Rowan Hamilton Plaque at Broom Bridge, Dublin |
Hamilton's discovery supported early work on light and quantum mechanics – and today relates also to virtual reality, spacecraft navigation, and even how your phone knows which way is up.Since 1990, there has been an annual walk where people retrace Hamilton’s steps. The group sometimes numbers 100 or more and includes everyone from school children to world-famous mathematicians, all here to honor Hamilton and his discovery of Quaternions.  |
| Dunsink Observatory, Dublin, former home of W. R. Hamilton |
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| Dunsink Observatory, Dublin, former home of W. R. Hamilton |
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| Dunsink Observatory, Dublin, former home of W. R. Hamilton |
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| Looking west from Broom Bridge, Dublin |
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| Looking east under Broom Bridge, Dublin |
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| Broom Bridge, Dublin |
Sadly, I missed this year's event by a mere 25 days, but I was glad for the opportunity to make my own pilgrimage to the bridge and see the plaque commemorating the discovery.
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| Me honoring the discovery of Quaternions at Broom Bridge, Dublin |
