Edmond Halley

• Born: 8 November 1656
• Birthplace: Haggerston, England
• Died: 14 January 1742 (natural causes)
• Best Known As: Discoverer of Halley's Comet

Edmond Halley was the first man to recognize the recurring astronomical visitor now known as Halley's Comet. Halley was already interested in the stars when he entered Queen's College, Oxford at the age of 16. He later left Oxford without a degree and became a protege of the Astronomer Royal, John Flamsteed. Halley and Flamsteed had a falling out, but by age 22 Halley had already been elected to the prestigious Royal Society. In 1705 he published Synopsis on Cometary Astronomy, in which he argued that prominent comets observed in 1531, 1607 and 1682 had all been the same comet, returning to pass Earth on a cycle of about 76 years. He was proven correct when the comet returned on Christmas Day of 1758 (though Halley himself had died in 1742), and the comet has since been known as Halley's Comet. Halley became a professor at Oxford in 1704 and succeeded Flamsteed as Astronomer Royal in 1720. Multitalented and exceedingly brainy, Halley also contributed to other scientific fields during his long career; he is especially known for inventing the diving bell.

In scientific circles, Halley's Comet is more properly known as Comet Halley... Halley was a friend and staunch supporter of Sir Isaac Newton; he paid for the initial printing of Newton's Principia Mathematica... Halley's name is sometimes spelled Edmund... Halley's Comet last passed Earth in 1986, and is due to return in 2061... Writer Mark Twain was born and died in Halley's Comet years: 1835 and 1910... Halley inspired the punning name of the rock band Bill Haley and the Comets, which recorded "Rock Around the Clock" in 1954.

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Edmond Halley, detail of an oil painting by Richard Phillips, 1720; in the National … (credit: Courtesy of the National Portrait Gallery, London)

(born Nov. 8, 1656, Haggerston, Shoreditch, near London — died Jan. 14, 1742, Greenwich, near London) English astronomer and mathematician. He studied at the University of Oxford. In 1676 he set sail for the South Atlantic with the intention of compiling an accurate catalog of the stars of the Southern Hemisphere. His star catalogue (1678) recorded the position of 341 stars. In 1684 he met Isaac Newton at Cambridge, which led to his prominent role (with Robert Hooke and Christopher Wren) in the development of Newton's law of gravitation. Halley edited Newton's Philosophiae Naturalis Principia Mathematica, bringing it to print in 1687. He produced the first meteorological chart (1686, showing the distribution of prevailing winds in the world's oceans) and magnetic charts of the Atlantic and Pacific (1701). In astronomy, he described the parabolic orbits of 24 comets observed in the years 1337 – 1698. He showed that three of these were so similar that they must have been the same comet, and he accurately predicted its return in 1758 (see Halley's Comet).

For more information on Edmond Halley, visit Britannica.com.

Edmond Halley

Library of Congress

[b. Haggerston, England, November 8, 1656, d. Greenwich, England, January 14, 1742]

Halley's contributions to science began as an astronomer, starting in 1676 when he traveled to Saint Helena to catalog the then unmapped stars of the Southern Hemisphere. In 1705 Halley wrote that comets travel in orbits that periodically bring them back to Earth's vicinity and correctly proposed that the comet of 1682 would return in 1758. In 1710, after comparing current positions of stars with those listed in Claudius Ptolemy's star catalog, Halley was the first astronomer to recognize that stars have motions of their own and that the Moon gradually changes its orbit.

Halley also studied Earth's magnetic field and weather, explaining the cause of monsoon winds and the relation between weather and barometric pressure. He invented the diving bell. Perhaps his greatest contribution to science, however, was persuading Newton to write the Principia.

The English astronomer Edmund Halley (1656-1742) studied the orbital movements of the moon and of comets and discovered the proper motion of the fixed stars.

The son of a prosperous London soap-boiler, Edmund Halley was born on Nov. 8, 1656, in Haggerston near London. He attended St. Paul's School, where he excelled in classics and mathematics and early developed an interest in astronomy. At the age of 16, when he entered Queen's College, Oxford, he was already an accomplished astronomical observer. He continued his observations at Oxford and, before he was 20, had sent to the Royal Society an explanation of an improved means of calculating planetary orbits.

Recognizing the need for more accurate star charts, Halley, while still an undergraduate, proposed a plan for surveying the stars of the southern hemisphere as a supplement to the surveys then being made of the northern hemisphere by John Flamsteed and Johannes Hevelius. He left Oxford without a degree and in 1676 journeyed to the island of St. Helena in the South Atlantic. St. Helena's frequent cloud cover made it poorly suited for astronomical observations, although in 18 months on the island Halley managed to determine the position of approximately 350 stars. In addition, he made one of the first complete observations of a transit of Mercury; it occurred to him that similar transits might be used to accurately calculate the sun's distance from the earth. He returned to England in 1678, published his results, and was dubbed by Flamsteed "the Southern Tycho, " a reference to the famous Danish astronomer Tycho Brahe.

Publication of Newton's "Principia"

Upon his return Halley received, by royal mandate, his Oxford degree and, at the age of 22, was elected a fellow of the Royal Society. After 2 years of traveling on the Continent, he returned to London, where he married and, in 1682, began a lengthy series of lunar observations. Designed to last for 18 years, these observations were to correct tables of the moon's position in an effort to solve the problem of accurately determining longitude. Such a lengthy project was not, however, well suited to Halley's temperament, and he was soon diverted to other concerns.

Intensely interested in the problem of gravitation, Halley had obtained by 1684 an inverse-square relationship, but since he was unable to deduce from it the planetary motions, in August that year he traveled to Cambridge to seek the assistance of Newton. What would be the orbit of a planetary body subjected to such a force? An ellipse, Newton replied. He had earlier proved that this was so and shortly thereafter sent Halley a copy of his demonstration. Realizing the significance of what Newton had done, Halley, utilizing great skill and tact, persuaded the reluctant Newton to develop and publish his ideas on celestial mechanics. Newton's Principia was published in 1687. Halley read the manuscript, corrected the proofs, and paid the publication costs out of his own pocket. A lasting friendship ensued, and in 1696, through Newton's influence, Halley was appointed deputy comptroller of the Mint at Chester.

Astronomical and Physical Observations

Halley maintained a lifelong interest in the declination of the magnetic compass, and he published two significant papers (1683 and 1692) discussing the causes of this variation and its change with time. Between 1698 and 1702 he undertook a series of government-sponsored expeditions to make extensive measurements of terrestrial magnetism in the South Atlantic and to study in detail the tides and coast of the English Channel. He correlated the data from his South Atlantic voyages with other measurements he had been collecting and in 1702 published for the first time a map showing lines of equal declination. Of great navigational value, these lines (known today as isogonics) were for years called "Halleyan lines."

Halley's calculation of the periodic nature of comets was perhaps his most significant contribution to astronomy. In his Synopsis of the Astronomy of Comets (1705) he collected and analyzed all known observations of comets and computed the parabolic orbits of 24 comets dating from 1337 to 1698. The orbital elements of three (1531, 1607, and 1682) were so similar as to suggest that they were in fact the successive returns of a single body whose orbit was an enormous elongated ellipse, rather than a parabola, and whose period of revolution was approximately 76 years. Halley successfully predicted the return of this comet in 1758 and suggested that other comets might also have elliptical orbits. Halley's comet, as it is known today, returned on schedule in 1835, 1910, and 1986.

Before Halley's discovery of the "proper motion" of fixed stars, it was believed that they (unlike the planets) never moved in relation to each other. In 1718, however, Halley pointed out that three of the brightest stars (Sirius, Procyon, and Arcturus) had apparently changed their relative positions markedly since having been observed by the Greeks. In fact, Sirius appeared to have moved perceptibly since observed by Tycho Brahe only a century and a half earlier. After carefully comparing the positions of other stars and establishing that this apparent movement could not be accounted for by any motion of the earth, Halley concluded that the three had actually shifted their relative positions and suggested that, if observed over sufficiently long periods, this proper motion might also be detected in other stars as well.

Halley's knowledge and interests were extensive. He pursued such varied topics as the magnetic origin of the aurora borealis, the design and construction of diving bells, and the establishment of quantitatively accurate mortality tables. He continued his astronomical observations until a few months before his death on Jan. 14, 1742.

Further Reading

Selections from Halley's correspondence and unpublished papers, together with two 18th-century biographical memoirs, are in Eugene Fairfield MacPike, ed., Correspondence and Papers of Edmund Halley (1932). The best biography of Halley is Angus Armitage, Edmund Halley (1966). Also useful is Colin A. Ronan, Edmund Halley:Genius in Eclipse (1969). For Halley's relations with contemporary astronomers see Eugene Fairfield MacPike, Hevelius, Flamsteed and Halley (1937).

Additional Sources

Standing on the shoulders of giants:a longer view of Newton and Halley, Berkeley:University of California Press, 1990.

Halley, Edmond (1656-1742). Astronomer, remembered because his name is attached to a comet. Leaving Queen's College, Oxford, without a degree in 1676, he went to St Helena to map the southern stars. After a famous meeting with Wren and Hooke, he visited Newton in Cambridge, and hearing about his work on gravitation, persuaded him to publish it. In 1703 he became professor of astronomy at Oxford, and in 1720 astronomer-royal. He computed the orbits of several comets, and deduced that those of 1456, 1531, 1607, and 1682 were periodic returns of the same body.

Edmond Halley
Portraiture by Thomas Murray, ca. 1687
Born	8 November 1656(1656-11-08) Haggerston, Shoreditch, London, England
Died	14 January 1742 (aged 85) Greenwich, London, England
Nationality	British
Fields	Astronomy, geophysics, mathematics, meteorology, physics
Institutions	University of Oxford Royal Observatory, Greenwich
Alma mater	University of Oxford
Known for	Halley's comet

Edmond Halley FRS (pronounced /ˈɛdmənd ˈhɔːliː/; 8 November 1656 – 14 January 1742) was an English astronomer, geophysicist, mathematician, meteorologist, and physicist, who is best known for computing the orbit of Halley's comet, which is named for him.

Contents 1 Biography and career 2 See also 3 Named after Halley 4 Notes and references 5 Further reading 6 External links

Biography and career

Halley was born in Haggerston, Shoreditch, England, the son of a wealthy soapboiler. As a child, Halley was very interested in mathematics. He studied at St Paul's School, and then, from 1673, at The Queen's College, Oxford. While an undergraduate, Halley published papers on the solar system and sunspots.

On leaving Oxford, in 1676, Halley visited the south Atlantic island of St. Helena and set up an observatory with a 24 foot long aerial telescope with the intention of studying stars from the Southern Hemisphere^[1]. He returned to England in November 1678. In the following year he went to Danzig (Gdańsk) on behalf of the Royal Society to help resolve a dispute. Because astronomer Johannes Hevelius did not use a telescope, his observations had been questioned by Robert Hooke. Halley stayed with Hevelius and he observed and verified the quality of Hevelius' observations. The same year, Halley published Catalogus Stellarum Australium which included details of 341 southern stars. These additions to present-day star maps earned him comparison with Tycho Brahe. Halley was awarded his M.A. degree at Oxford and elected as a Fellow of the Royal Society.

In 1686 Halley published the second part of the results from his St. Helena expedition, being a paper and chart on trade winds and monsoons. In this 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 visualization.

Halley married Mary Tooke in 1682 and settled in Islington. The couple had three children. He spent most of his time on lunar observations, but was also interested in the problems of gravity. One problem that attracted his attention was the proof of Kepler's laws of planetary motion. In August 1684 he went to Cambridge to discuss this with Sir Isaac Newton, only to find that Newton had solved the problem, but published nothing. Halley convinced him to write the Principia Mathematica Philosophiae Naturalis (1687), which was published at Halley's expense.

In 1690, Halley built a diving bell, a device in which the atmosphere was replenished by way of weighted barrels of air sent down from the surface.^[2] In a demonstration, Halley and five companions dived to 60 feet in the River Thames, and remained there for over an hour and a half. Halley's bell was of little use for practical salvage work, as it was very heavy, but he made improvements to it over time, later extending his underwater exposure time to over 4 hours.^[3] Halley suffered one of the earliest recorded cases of middle ear barotrauma.^[2] That same year, at a meeting of the Royal Society, Halley introduced a rudimentary working model of a magnetic compass using a liquid-filled housing to damp the swing and wobble of the magnetized needle.^[4]

In 1691 Halley sought the post of Savilian Professor of Astronomy at Oxford, but, due to his well-known atheism, was opposed by the Archbishop of Canterbury, John Tillotson and Bishop Stillingfleet. The post went instead to David Gregory, who had the support of Isaac Newton.^[5]

A 1702 printing of Halley's chart

In 1692, Halley put forth the idea of a hollow Earth consisting of a shell about 500 miles (800 km) thick, two inner concentric shells and an innermost core, about the diameters of the planets Venus, Mars, and Mercury.^[6] He suggested that atmospheres separated these shells, and that each shell had its own magnetic poles, with each sphere rotating at a different speed. Halley proposed this scheme in order to explain anomalous compass readings. He envisaged each inner region as having an atmosphere and being luminous (and possibly inhabited), and speculated that escaping gas caused the Aurora Borealis.^[7]

In 1693 Halley published an article on life annuities, which featured an analysis of age-at-death on the basis of the Breslau statistics Caspar Neumann had been able to provide. This article allowed the British government to sell life annuities at an appropriate price based on the age of the purchaser. Halley's work strongly influenced the development of actuarial science. The construction of the life-table for Breslau, which followed more primitive work by John Graunt, is now seen as a major event in the history of demography.

In 1698, Halley was given the command of the Paramour, a 52-foot pink, so that he could carry out investigations in the South Atlantic into the laws governing the variation of the compass. 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, allegedly by officers resentful of being under a civilian's command. The Paramour returned to England in July 1699. Halley thereupon received a commission as a temporary 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.

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, and received an honorary degree of doctor of laws in 1710. In 1705, applying historical astronomy methods, he published Synopsis Astronomia Cometicae, which stated his belief that the comet sightings of 1456, 1531, 1607, and 1682 related to the same comet, which he predicted 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.

Grave of Edmond Halley

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^{[citation needed]}. It is not to Halley's credit that he failed to acknowledge Gregory's priority in this matter. In 1718 he discovered the proper motion of the "fixed" stars 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.^[8]

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 (AD 920, AD 220 and 460 BC), 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.^[9]

Halley succeeded John Flamsteed in 1720 as Astronomer Royal, a position Halley held until his death in 1742 at the age of 85. Halley was buried in the graveyard of the old church of St. Margaret, Lee (now ruined). In the same vault is Astronomer Royal John Pond; the unmarked grave of Astronomer Royal Nathaniel Bliss is nearby.^[10]

See also

• Scientific revolution

Named after Halley

Plaque in South Cloister of Westminster Abbey

• 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

These are generally either pronounced /ˈhæli/, rhyming with valley, or /ˈheɪli/ "Hailey", though some people will use Halley's supposed pronunciation of his own name, /ˈhɔːli/ "Hawley". The "Hailey" pronunciation led rock and roll singer Bill Haley to punningly call his backing band his "Comets" after Halley's Comet^{[citation needed]}.

Notes and references

Bust of Halley (Royal Observatory, Greenwich)

1. ^ Gazetteer - p. 7. MONUMENTS IN FRANCE - page 338
2. ^ ^{a b} Edmonds, Carl; Lowry, C; Pennefather, John. "History of diving.". South Pacific Underwater Medicine Society Journal 5 (2). http://archive.rubicon-foundation.org/5894. Retrieved 2009-03-17. 
3. ^ "History: Edmond Halley". London Diving Chamber. http://www.londondivingchamber.co.uk/index.php?id=history&page=4. Retrieved 2006-12-06. 
4. ^ Gubbins, David, Encyclopedia of Geomagnetism and Paleomagnetism, Springer Press (2007), ISBN 1402039921, 9781402039928, p. 67
5. ^ Derek Gjertsen, The Newton Handbook, ISBN 0710202792, pg 250
6. ^ Halley, E. (1692). "An account of the cause of the change of the variation of the magnetic needle; with an hyphothesis of the structure of the internal parts of the earth". Philosophical Transactions of Royal Society of London 16: 563 – 578. doi:10.1098/rstl.1686.0107. http://www.archive.org/details/philosophicaltra03royarich. 
7. ^ Carroll, Robert Todd (2006-02-13). "hollow Earth". The Skeptic's Dictionary. http://skepdic.com/hollowearth.html. Retrieved 2006-07-23. 
8. ^ Holberg, JB (2007). Sirius:Brightest Diamond in the Night Sky. Chichester, UK: Praxis Publishing. pp. 41–42. ISBN 0-387-48941-X. 
9. ^ Johnson, Anthony, Solving Stonehenge, The New Key to an Ancient Enigma(Thames & Hudson 2008) ISBN 978-0-500-05155-9
10. ^ Halley's gravesite is in a cemetery at the junction of Lee Terrace and Brandram Road, across from the Victorian Parish Church of St. Margaret. The cemetery is a 30-minute walk from the Greenwich Observatory.

Further reading

• Armitage, Angus (1966). Edmond Halley. London: Nelson. 

• Coley, Noel (1986). "Halley and Post-Restoration Science". History Today 36 (September): 10 – 16. http://www.historytoday.com/MainArticle.aspx?m=12983&amid=12983. 

• Cook, Alan H. (1998). Edmond Halley: Charting the Heavens and the Seas. Oxford: Clarendon Press. 

• Ronan, Colin A. (1969). Edmond Halley, Genius in Eclipse. Garden City, New York: Doubleday and Company. 

• Seyour, Ian (1996). "Edmond Halley - explorer". History Today 46 (June): 39 – 44. http://www.questia.com/googleScholar.qst?docId=5000361197. 

External links

Wikimedia Commons has media related to: Edmond Halley

• Online catalogue of Halley's working papers (part of the Royal Greenwich Observatory Archives held at Cambridge University Library)
• A Halley Odyssey
• Halley, Edmund, An Estimate of the Degrees of the Mortality of Mankind (1693).
• Halley, Edmund, Considerations on the Changes of the Latitudes of Some of the Principal Fixed Stars (1718) - Reprinted in R. G. Aitken, Edmund Halley and Stellar Proper Motions (1942)
• O'Connor, John J.; Robertson, Edmund F., "Edmond Halley", MacTutor History of Mathematics archive, http://www-history.mcs.st-andrews.ac.uk/Biographies/Halley.html .
• There is material on Halley's life table for Breslau on the Life and Work of Statisticians website: Halley, Edmond
• The National Portrait Gallery (London) has several portraits of Edmond Halley: Search the collection
• Edmond Halley Biography (SEDS)

v • d • e Savilian Professors of Geometry Henry Briggs (1619) · Peter Turner (1631) · John Wallis (1649) · David Gregory (1691) · Edmond Halley (1704) · Nathaniel Bliss (1742) · Joseph Betts (1765) · John Smith (1766) · Abraham Robertson (1797) · Stephen Peter Rigaud (1810) · Baden Powell (1827) · Henry John Stephen Smith (1861) · James Joseph Sylvester (1883) · William Esson (1897) · Godfrey Harold Hardy (1920) · Edward Charles Titchmarsh (1932) · Michael Atiyah (1963) · Ioan James (1969) · Richard Taylor (1995) · Nigel Hitchin (1997)

v • d • e Astronomers Royal John Flamsteed (1675) · Edmond Halley (1720) · James Bradley (1742) · Nathaniel Bliss (1762) · Nevil Maskelyne (1765) · John Pond (1811) · George Biddell Airy (1835) · William Christie (1881) · Frank Watson Dyson (1910) · Harold Spencer Jones (1933) · Richard van der Riet Woolley (1956) · Martin Ryle (1972) · Francis Graham-Smith (1982) · Arnold Wolfendale (1991) · Martin Rees (1995)

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