November 8th marks the 356th anniversary of the birth of Edmond Halley (1656 — 1742), the English astronomer best known for tracking the orbit of what came to be known after his death as Halley's Comet. But like many scientists of his day he was not just an astronomer, but branched out into several fields, advancing knowledge in such diverse areas as terrestrial magnetism and actuarial science.
While still an undergraduate at The Queen's College at Oxford, Halley published papers on the solar system and on sunspots. He left Oxford before graduating and traveled to the island of Saint Helena in the south Atlantic where he catalogued 341 stars of the southern hemisphere and observed the full transit of Mercury.
He published the first meteorological chart—a global map of the trade winds—and published a work on the monsoons. Halley built a diving bell which allowed him to stay underwater for up to four hours, and built a rudimentary magnetic compass. A man of many layers, he even translated scientific works from Arabic, Greek and Latin.
Halley was instrumental in publishing Isaac Newton's groundbreaking masterpiece, Principia Mathematica. In 1682, Halley visited Newton to discuss his own theories on gravity, only to find that Newton's work far exceeded his own. Halley urged Newton to write Principia Mathematica, and when the Royal Society declined to pay the cost of publishing, Halley paid for it out of his own pocket.
Halley laid the foundation for actuarial science by publishing an article on life annuities, based on the demographic data available at the time, the mortality tables for the city of Breslau. His work was very influential in the later development of actuarial tables.
In 1698 he was given command of a ship, and embarked on the first purely scientific voyage in English history, to study magnetism and compass variations in the southern hemisphere. He published General Chart of the Variation of the Compass (1701), a chart of magnetic variations shown by isogonic or "Halleyan lines" (lines of equal declination from true north) from 52 degrees north to 52 degrees south.
Along with William Stukely, Halley attempted to scientifically date Stonehenge using magnetic records, basing their assumption that the monument was laid out magnetically. Although they came up with the year 460 BC, which was off by thousands of years, they established the first use of scientific methods for dating ancient monuments.
In 1705, Halley published a paper stating his belief that the comet seen in the years 1456, 1531, 1607, and 1682 were the same comet, which he predicted would return in 1758. He died sixteen years before the comet's return, but it did return when he predicted. After that, the comet became known as Halley's Comet.
The comet last appeared in 1986, and will appear again in 2061. Being a comet that is visible to the naked eye, it is the only such comet that might appear twice in a lifetime. Halley's Comet was the first to be observed and photographed up close by spacecraft.
In 1720 Halley was named Astronomer Royal, a position he held until his death at age 85 in 1742.
In honor of Halley's many contributions to the advancement of science, in addition to the comet, both a lunar and Martian crater are named for him, as well as the Halley Research Station on Antarctica.