Halley, Edmond

Halley, Edmond

Edmond Halley was born in Haggerston, Shoreditch, near London, on 8 November 1656 as son of a wealthy Derbyshire family. He started his education at St. Paul's School in London, and entered Queen's College at Oxford University in 1673 when he was seventeen years old. Here he studied the theories of Sir Isaac Newton, and learned of John Flamsteed's project at the Royal Greenwich Observatory using the telescope to compile an accurate catalog of stars visible in the Northern Hemisphere. Halley proposed to do the same thing for the Southern Hemisphere.

As astronomer and mathematician, Edmond Halley, who sometimes spelled his first name Edmund, was the first to calculate the orbit of a comet, which was later named after him. In addition he encouraged Sir Isaac Newton to write his Philosophiae Naturalis Principia Mathematica, which Halley published in 1687 at his own expense.

Leaving Oxford in 1676 without his degree, Halley sailed for the island of St. Helena in the South Atlantic. Financial support for this venture was obtained from his own father, and from King Charles II who provided a letter requesting the East India Company to take Halley and a colleague to the island (the southern-most territory under British rule). His results were published in a star catalog in 1678, establishing himself as a prominent astronomer. He married in 1682 and settled in Islington, where he spent most of his time on lunar observations. He was also interested in the problems of gravity.

He published the first meteorological chart in 1686 and the first magnetic charts of the Atlantic and Pacific areas, which were used in navigation long after his death. He was the pioneer for future generations to understand trade winds, tides, cartography, naval navigation, mortality tables, and stellar proper motions. Carrying on his work in observational astronomy, he published A Synopsis of the Astronomy of Comets in 1705. He began with the book in 1682. In it he described 24 comets, and also mathematically demonstrated that comets move in an elliptic orbits around the sun, and how over time they would pass the same point.

In 1703 Halley was appointed professor of geometry at Oxford, and in 1705 he accurately predicted the return, in 1758, of a bright comet, nowadays known as Halley's comet. The comet appeared as foreseen. Unfortunately Halley never saw his prediction come true. In the past it was observed in 1531, 1607, and 1682. In 1716 he suggested a high-precision measurement of the distance between the earth and sun by timing the transit of Venus across the face of the sun. In 1718 he discovered the proper motions of the fixed stars by comparing his astrometric measurements with those of the Greeks.

In 1721 he became Astronomer-Royal and commenced an 18-year study of the moon's complete revolution through its ascending and descending nodes. Halley died in Greenwich on 14 January 1742.