William Rowan Hamilton was an Irish mathematician and astronomer of the 19th century, considered by some to be near in intellect to Isaac Newton. He created a novel system of algebra for operating on complex numbers, coined the term "vector," founded vector analysis, developed icosian calculus, and made important contributions to the understanding of light and optics.

Born in Dublin at the stroke of midnight, between the 3rd and 4th of August 1805, Hamilton was the only son of Archibald Hamilton and Sarah Hutton. In 1808, possibly because of his family's difficult financial condition, Hamilton was sent to live with his uncle, the Reverend James Hamilton, head of a diocesan school in the village of Trim, 40 miles northwest of Dublin. Hamilton had little contact with his parents during childhood, but his four sisters lived with him intermittently, continuing into adulthood. His mother died in 1817 and his father in 1819. Hamilton began...