William Rowan Hamilton
William Rowan Hamilton (August 4, 1805 – September 2, 1865) was an Irish mathematician, physicist and astronomer. He made important contributions to the development of optics, dynamics, mathematics, geometry and algebra. His discovery of quaternions is the most famous work. His work was important in the development of quantum mechanics. Hamilton's talent was discovered very early by the astronomer John Brinkley. In 1823, when Hamilton was eighteen, John Brinkley said: "I don't say he would be but now he is the leading mathematician of his age". Hamilton was the first to introduce the term "vector", "association law".