H is for Hotel

A hotel in Paris is where I spent last week. I couldn't get internet access on my laptop so I've to catch up on letters again! The hotel was undergoing renovations so getting into/out of my room was an adventure. The drain backed up one day and flooded the room, unfortunately the day I desperately needed a nap. More on this in later post. Then the water went entirely. Bit of a disaster hotel really. That said I had a great conference in Paris: my presentation went very well, I had lots of time with my colleagues and met mathematicians from around the world.

Hamilton is one of the most well known Irish mathematicians. Famed for his work on mechanics, differential equations and the invention of the quaternions. The quaternions are described by this equation



and are one of only four finite dimensional normed division algebras over the real numbers. There is an annual pilgrimage in Ireland from Dunsink Observatory where he worked to Broom Bridge where it is believed the idea for the quaternions struck him. Apparently he engraved the idea into the bridge and there is a plaque there now to commemorate him. Each October the RIA hold the Hamilton Lecture given by the best of mathematicians.

2005 was the 200th anniversary of his birth and a commemorative 10 Euro coin was minted in Ireland. I received one as a 21st birthday present and treasured it until giving it to my husband as part of our marriage ceremony. One side looked like this:


Finally a note on 'h' in the Irish Language. It is the third most frequently used letter as it is the most common representation of the 'séimhiú' since Irish switched to the roman alphabet about the 1950s. Previous to then a dot above the consonant to be leniated was used.