The Day Sir Edmund Halley Spied His Comet
It was September 4, 1682, when Edmund Halley first set his eyes on the comet that would later bear his name. For anyone who lived through the 1985 comet passing, it’s the reason most people remember Halley.
It’s a poor association. What Sir Edmund Halley was to modern science was so much more than a glowing ball of rock and ice.
He was an influential colleague of Isaac Newton. He was an inventor of something called a diving bell. He was a cartographer and a decent sailor by that account.
Halley made many contributions to science, but what many don’t know is that without him, students may never have heard the story of the apple striking Newton’s head. It was Halley who encouraged the aging Newton to write down his gravitational theories, now the laws of science.
Like the chicken and the egg, it would be hard to define who made who, the comet or the man. Unarguably, Halley’s comet became the vehicle for so much more than the reputation of one man.
The official discovery year for Halley’s Comet is 1758. The man passed in 1742, but history grants Edmund Halley posthumous credit for the discovery, as it was he who predicted its return in back in 1705.
Halley wasn’t the first to observe the comet he saw in 1682. In fact, it was the observations of previous astronomers, mixed with a little Newtonian gravitational theory, upon which he constructed his prediction.
An astronomer by the name of Apianus witnessed a comet in 1531, and Kepler saw one in 1607. By Halley’s math, they’d witnessed the same comet, that it was on an ellipse around the sun, lasting some 75 years or so.
Prior to Halley, the prevailing theory about comets was that they traveled straight lines.
In his 1705 document, Halley said this:
”Many considerations incline me to believe the Comet of 1531 observed by Apianus to have been the same as that described by Kepler and Longomontanus in 1607 and which I again observed when it returned in 1682. All the elements agree. Whence I would venture confidently to predict its return, namely in the year 1758.”
It turned out he was right.
The man’s name rhymes with the word tally, not the name Bailey. Say it out loud, “Hal-E.”
Born in 1656, London, young Edmund grew up in a comfortable home. His father, a wealthy soap-maker, recognized that boy had a forward thinking mind so he made sure that young Edmund had access to the learning materials warranted a prodigy.
He studied science at Oxford, admitted age 17, where he quickly developed a reputation in astronomical circles. Halley was so good, he didn’t finish his studies at Oxford, never took the degree exams, but still earned his degree by command of King Charles II.
By age 20, Halley joined an expedition to the South Atlantic, where he catalogs the stars as would any good astronomer.
While Halley’s first effort to predict the path of a comet he observed in 1680 failed, it was the existing beliefs about comets that bucked his efforts.
By the time the 1682 comet appeared, he’d steeled his resolve to make a better prediction. He made detailed observations, then put them away to ponder for later.
While Halley stewed on his ideas about the 1682 comet, he pursued other passions.
In 1686, he created an early meteorological chart. He commanded sailing expeditions and developed new methods of cartography, which changed navigation methods at the time. Randomly, he invented a diving bell.
When he wasn’t doing those things or writing poetry, he was engineering new harbor fortifications or making scientific observations about the world around him.
Most importantly, from time to time, Halley often revisited the data he collected on the 1682 comet. He considered the ideas of his contemporary, Isaac Newton, who theorized that comets move parabolically to the sun like planets.
Working with Newton, he determined a prediction about the 1682 comet’s return, factoring in gravitational anomalies. It would return after his death, but he hoped science would respect his prediction.
Sir Edmund Halley lived to a ripe age of 86 before passing, which he did sitting in his chair at the Greenwich Observatory.
Science did not forget Halley. When the 1682 comet returned in 1758 as predicted, they named it after him.
For the would be observers today, we’ll wait until 2061 to see it, just as predicted by Halley.