Everything about Edmond Halley totally explained
Edmond Halley FRS (
November 8,
1656 –
January 14,
1742) was an
English astronomer,
geophysicist,
mathematician,
meteorologist, and
physicist.
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 with the intention of studying
stars from the Southern Hemisphere. 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 didn't 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 and 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. 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 did make improvements to it over time, later extending his underwater exposure time to over 4 hours.
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 52 foot
pink,
Paramour (a pink was a form of small unrated vessel, akin to a sloop), 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 vessel 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
Oxford University, 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. When it did it became generally known as
Halley's Comet.
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 isn't 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.
In 1720, Halley succeeded
John Flamsteed as
Astronomer Royal, a position which Halley held until his death in
Greenwich, at the age of 85. He was buried in the graveyard of the old church of St. Margaret, Lee, (now ruined), which sits at the junction of Lee Terrace and Brandram Road, across from the Victorian Parish Church of St. Margaret which replaced it, in the same vault as Astronomer Royal
John Pond; the unmarked grave of Astronomer Royal
Nathaniel Bliss is nearby. It is about 30 minutes walk from the Greenwich Observatory.
Hollow Earth
In 1692 (
Philosophical Transactions of Royal Society of London), 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. Atmospheres separate these shells, and each shell has its own magnetic poles. The spheres rotate at different speeds. Halley proposed this scheme in order to explain anomalous compass readings. He envisaged the
atmosphere inside as
luminous (and possibly inhabited) and speculated that escaping gas caused the
Aurora Borealis.
Named after Halley
These are generally either, rhyming with
valley, or /ˈheɪli/
"Hailey", though some people will use Halley's 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.
Notes and References
Bibliography
Armitage, Angus, Edmond Halley (Nelson, 1966)
Cook, Alan H., Edmond Halley: Charting the Heavens and the Seas (Oxford: Clarendon Press, 1998)
Ronan, Colin A., Edmond Halley, Genius in Eclipse (Garden City, NY: Doubleday and Company, 1969)Further Information
Get more info on 'Edmond Halley'.
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