Edmond (or Edmund) Halley (; 8 November [O.S. 29 October] 1656 – 25 January 1742 [O.S. 14 January 1741]) was an English astronomer, mathematician and physicist. He was the second Astronomer Royal in Britain, succeeding John Flamsteed in 1720.
From an observatory he constructed on Saint Helena in 1676–77, Halley catalogued the southern celestial hemisphere and recorded a transit of Mercury across the Sun. He realised that a similar transit of Venus the help of King Charles II, was granted a master's degree from Oxford.
Halley encouraged and helped fund the publication of Isaac Newton's influential Philosophiæ Naturalis Principia Mathematica (1687). From observations Halley made in September 1682, he used Newton's law of universal gravitation to compute the periodicity of Halley's Comet in his 1705 Synopsis of the Astronomy of Comets. It was named after him upon its predicted return in 1758, which he did not live to see.
Beginning in 1698, Halley made sailing expeditions and made observations on the conditions of terrestrial magnetism. In 1718, he discovered the proper motion of the "fixed stars".
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Early life
Halley was born in Haggerston in Middlesex. His father, Edmond Halley Sr., came from a Derbyshire family and was a wealthy soap-maker in London. Halley showed an early interest in mathematics. He studied at St Paul's School, where he developed an interest in astronomy and was elected captain of the school in 1671. The following year, his mother, Anne (probably née Robinson) died. In July 1673, Halley entered The Queen's College, Oxford. He took a twenty-four-foot (7.3 m) long telescope with him, apparently paid for by his father. While still an undergraduate, Halley published papers on the Solar System and sunspots. In March 1675, he wrote to John Flamsteed, the first Astronomer Royal, telling him that the leading published tables on the positions of Jupiter and Saturn were erroneous, as were some of Tycho Brahe's star positions. His association with Flamsteed soon led to Halley's first publication and to his expedition to Saint Helena.
Career
Publications and inventions
In 1676, Flamsteed helped Halley publish his first paper, titled "A Direct and Geometrical Method of Finding the Aphelia, Eccentricities, and Proportions of the Primary Planets, Without Supposing Equality in Angular Motion", on planetary orbits, in Philosophical Transactions of the Royal Society. Influenced by Flamsteed's project to compile a catalogue of stars of the northern celestial hemisphere, Halley proposed to do the same for the southern sky. He left Oxford to undertake the project, choosing the South Atlantic island of Saint Helena, from which he could observe southern stars as well as some northern stars for comparison. King Charles II supported the expedition.
Halley sailed to Saint Helena in late 1676 and established an observatory with a large sextant with telescopic sights. Over the following year, he made observations for what became the first telescopic catalogue of the southern sky, and observed a transit of Mercury across the Sun. Focusing the Mercury transit, Halley recognised that observations of planetary solar parallax, especially during a transit of Venus, could be used to determine trigonometrically the distances between Earth, Venus and the Sun.
Halley returned to England in May 1678, and used his data to produce a map of the southern stars. Oxford would not allow Halley to return because he had violated his residency requirements when he left for Saint Helena. He appealed to Charles II, who signed a letter requesting that Halley be unconditionally awarded his Master of Arts degree, which the college granted on 3 December 1678. Just a few days before, Halley had been elected as a fellow of the Royal Society, at the age of 22. In 1679, he published Catalogus Stellarum Australium ('A catalogue of the stars of the South'), which includes his map and descriptions of 341 stars. Robert Hooke presented the catalogue to the Royal Society. In mid-1679, Halley went to Danzig (Gdańsk) on behalf of the society to help resolve a dispute: because astronomer Johannes Hevelius' observing instruments were not equipped with telescopic sights, Flamsteed and Hooke had questioned the accuracy of his observations; Halley stayed with Hevelius and checked his observations, finding that they were quite precise.
By 1681, Giovanni Domenico Cassini had told Halley of his theory that comets were objects in orbit. In September 1682, Halley carried out a series of observations of what became known as Halley's Comet; his name became associated with it because of his work on its orbit and predicting its return in 1758 (which he did not live to see). In early 1686, Halley was elected to the Royal Society's new position of secretary, requiring him to give up his fellowship and manage correspondence and meetings, as well as edit the Philosophical Transactions. Also in 1686, Halley published the second part of the results from his Helenian expedition, being a paper and chart on trade winds and monsoons. The symbols he used to represent trailing winds still exist in most modern day weather chart representations. In this article he identified solar heating as the cause of atmospheric motions. He also established the relationship between barometric pressure and height above sea level. His charts were an important contribution to the emerging field of information visualisation.
Exploration years
In 1698, at the behest of King William III, Halley was given command of the Paramour, a 52 feet (16 m) pink, so that he could carry out investigations in the South Atlantic into the laws governing the variation of the compass, as well as to refine the coordinates of the English colonies in the Americas. On 19 August 1698, he took command of the ship and, in November 1698, sailed on what was the first purely scientific voyage by an English naval vessel. Unfortunately problems of insubordination arose over questions of Halley's competence to command a vessel. Halley returned the ship to England to proceed against officers in July 1699. The result was a mild rebuke for his men, and dissatisfaction for Halley, who felt the court had been too lenient. Halley thereafter received a temporary commission as a captain in the Royal Navy, recommissioned the Paramour on 24 August 1699 and sailed again in September 1699 to make extensive observations on the conditions of terrestrial magnetism. This task he accomplished in a second Atlantic voyage which lasted until 6 September 1700, and extended from 52 degrees north to 52 degrees south. The results were published in General Chart of the Variation of the Compass (1701). This was the first such chart to be published and the first on which isogonic, or Halleyan, lines appeared. The use of such lines inspired later ideas such as those of isotherms by Alexander von Humboldt in his maps. In 1701, Halley made a third and final voyage on the Paramour to study the tides of the English Channel. In 1702, he was dispatched by Queen Anne on diplomatic missions to other European leaders.
The preface to Awnsham and John Churchill's collection of voyages and travels (1704), supposedly written by John Locke or by Halley, valourised expeditions such as these as part of a grand expansion of European knowledge of the world:
What was cosmography before these discoveries, but an imperfect fragment of a science, scarce deserving so good a name? When all the known world was only Europe, a small part of Africk, and the lesser portion of Asia; so that of this terraqueous globe not one sixth part had ever been seen or heard of. Nay so great was the ignorance of man in this particular, that learned persons made a doubt of its being round; others no less knowing imagin'd all they were not acquainted with, desart and uninhabitable. But now geography and hydrography have receiv'd some perfection by the pains of so many mariners and travelers, who to evince the rotundity of the earth and water, have sail'd and travell'd round it, as has been here made appear; to show there is no part uninhabitable, unless the frozen polar regions, have visited all other countries, tho never so remote, which they have found well peopl'd, and most of them rich and delightful….
Life as an academic
In November 1703, Halley was appointed Savilian Professor of Geometry at the University of Oxford, his theological enemies, John Tillotson and Bishop Stillingfleet having died. In 1705, applying historical astronomy methods, he published the paper Astronomiae cometicae synopsis (A Synopsis of the Astronomy of Comets); in this, he stated his belief that the comet sightings of 1456, 1531, 1607, and 1682 were of the same comet, and that it would return in 1758. Halley did not live to witness the comet's return, but when it did, the comet became generally known as Halley's Comet.
By 1706 Halley had learned Arabic and completed the translation started by Edward Bernard of Books V–VII of Apollonius's Conics from copies found at Leiden and the Bodleian Library at Oxford. He also completed a new translation of the first four books from the original Greek that had been started by the late David Gregory. He published these along with his own reconstruction of Book VIII in the first complete Latin edition in 1710. The same year, he received an honorary degree of doctor of laws from Oxford.
In 1716, Halley suggested a high-precision measurement of the distance between the Earth and the Sun by timing the transit of Venus. In doing so, he was following the method described by James Gregory in Optica Promota (in which the design of the Gregorian telescope is also described). It is reasonable to assume Halley possessed and had read this book given that the Gregorian design was the principal telescope design used in astronomy in Halley's day. It is not to Halley's credit that he failed to acknowledge Gregory's priority in this matter. In 1717–18 he discovered the proper motion of the "fixed" stars (publishing this in 1718) by comparing his astrometric measurements with those given in Ptolemy's Almagest. Arcturus and Sirius were two noted to have moved significantly, the latter having progressed 30 arc minutes (about the diameter of the moon) southwards in 1800 years.
In 1720, together with his friend the antiquarian William Stukeley, Halley participated in the first attempt to scientifically date Stonehenge. Assuming that the monument had been laid out using a magnetic compass, Stukeley and Halley attempted to calculate the perceived deviation introducing corrections from existing magnetic records, and suggested three dates (460 BC, AD 220 and AD 920), the earliest being the one accepted. These dates were wrong by thousands of years, but the idea that scientific methods could be used to date ancient monuments was revolutionary in its day.
Personal life
Halley married Mary Tooke in 1682 and settled in Islington. The couple had three children.
Named after Edmond Halley
Halley's Comet (orbital period (approximately) 75 years)
Halley (lunar crater)
Halley (Martian crater)
Halley Research Station, Antarctica
Halley's method, for the numerical solution of equations
Halley Street, in Blackburn, Victoria, Australia
Edmund Halley Road, Oxford Science Park, Oxford, OX4 4DQ UK
Edmund Halley Drive, Reston, Virginia, United States
Edmund Halley Way, Greenwich Peninsula, London
Halley's Mount, Saint Helena (680m high)
Halley Drive, Hackensack, New Jersey, intersects with Comet Way on the campus of Hackensack High School, home of the Comets
Rue Edmund Halley, Avignon, France
The Halley Academy, a school in London, England
Halley House School, Hackney London (2015)
Halley Gardens, Blackheath, London.
Pronunciation and spelling
There are three pronunciations of the surname Halley. These are , , and .
As a personal surname, the most common pronunciation in the 21st century, both in Great Britain and in the United States, is (rhymes with "valley"). This is the personal pronunciation used by most Halleys living in London today. The alternative is much more common when referring to the comet than it is when used as a modern surname.
Colin Ronan, one of Halley's biographers, preferred . Contemporary accounts spell his name Hailey, Hayley, Haley, Haly, Halley, Hawley and Hawly, and presumably pronunciations varied similarly.
As for his given name, although the spelling "Edmund" is quite common, "Edmond" is what Halley himself used, according to a 1902 article, though a 2007 International Comet Quarterly article disputes this, commenting that in his published works, he used "Edmund" 22 times and "Edmond" only 3 times, with several other variations used as well, such as the Latinised "Edmundus". Much of the debate stems from the fact that, in Halley's own time, English spelling conventions were not yet standardised, and so he himself used multiple spellings.
In popular media
Halley is voiced by Cary Elwes in the 2014 documentary series Cosmos: A Spacetime Odyssey.
A fictional version of Halley appears in The Magnus Archives, a horror podcast, where he tried to extinguish the sun.
Fritz Weaver portrayed a fictional version of Halley in Comet Watch, a second-season episode of the anthology series Tales from the Darkside.
Actor John Wood was cast as Edmond Halley in the TV series, Longitude in 2000.
Halley is a major figure in David Williamson's play Nearer the Gods, about Sir Isaac Newton
The pronunciation was used by rock and roll singer Bill Haley, who called his backing band his "Comets" after the common pronunciation of Halley's Comet in the United States at the time.
Halley is one of the side characters in novels Taivaanpallo (The Celestial Sphere, Otava 2018) and Merenpeitto (The Art of Living under Water, Otava 2019) by the Finnish writer Olli Jalonen.