This month we celebrated Edmond Halley’s 354th birthday with a flyby of comet Hartley II. Most everybody knows of Halley’s Comet, but few know of his many other accomplishments some of which made the flyby of Hartley II possible.
Born the son of a soap maker, Halley was a contemporary of Isaac Newton, and perhaps the second greatest scientific mind of that era behind Newton. Few realize that without Halley one of the most important scientific publications of all time may have never been published. Halley edited and paid for the publication of Newton’s book on gravity, the Principia. This was the book that gave us Newton’s three laws of motion, and universal gravitation.
While at Oxford Halley set sail for St. Helena Island to chart and catalog stars in the southern hemisphere, the first to do so.
Halley was also a ship’s captain in the British Royal Navy. He commanded the HMS Paramore on two scientific voyages charting magnetic compass variations. He published maps showing magnetic compass corrections for true north, He also discovered the Antarctic Circumpolar Current and set the stage for Captain Cook’s journeys of exploration.
Halley was the first to discover stars are not fixed in the sky. Today we call it a star’s proper motion. He observed a transit of Mercury (when Mercury passes in front of the Sun) and proposed a precision measurement method for determining of the distance between the Earth and the Sun by timing the transit of Venus.
Among other things Halley made and dived in a diving bell staying under water for four hours, a pretty amazing accomplishment for the day. He published an article on life annuities setting the stage for the life insurance industry. He also discovered the relationship between air pressure and altitude, the principle used by the modern day altimeter.
Halley died in 1742 at the age of 85 seated in his chair at the Greenwich Observatory. He did not live long enough to see his comet return, nor did he know the comet would be named after him. As we know the comet did return as predicted and was first seen by Johann Georg Palitzsch, a German amateur astronomer, on Christmas Day, 1758.
Happy birthday Mr. Halley
Wishing you clear skies
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