On August 4, 1805, Irish physicist, astronomer, and mathematician William Rowan Hamilton was born. He made important contributions to classical mechanics, optics, and algebra, but is perhaps best known as the inventor of quaternions, a number system that extends the complex numbers.
H. Cao, and X. Zhu. (2006)cite arxiv:math/0612069Comment: This is a revised version of the article by the same authors that originally appeared in Asian J. Math., 10(2) (2006), 165--492.