Edmond Halley

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Edmond Halley around 1687 on a painting by Thomas Murray (1663–1735)

Edmond Halley (also: Edmund Halley; * 29 October July / 8 November  1656 greg. In Haggerston near London ; † 14 January 1741 jul. / 25 January  1742 greg. In Greenwich ) was an English astronomer , mathematician , Cartographer , geophysicist and meteorologist .

Life

Halley studied mathematics and astronomy at Oxford and at the age of 21 was able to publish a method for determining the aphelias and eccentricities of planets. He traveled to St. Helena in 1677 . On November 7, 1677, he was the first astronomer to observe a transit of Mercury from beginning to end. He then suggested that Mercury and Venus transits be measured to determine the astronomical unit in order to determine the size of the solar system. James Gregory had made this suggestion earlier in his book Optica promota , which Halley was most likely familiar with. He also measured the positions of 341 stars in the southern sky. In 1686 he published the observations of the Passat and monsoon winds that he had collected on this trip. Commissioned by the Royal Society , whose secretary he later became, Halley traveled to Danzig to settle the scientific dispute between Robert Hooke and Johannes Hevelius .

In the years 1680 to 1681 Halley toured France and Italy and initiated the scientific collaboration between the observatories of Greenwich and Paris . Between Calais and Paris, Halley first observed the comet that was later named after him. From 1677 he always pointed out the importance of the Venus passages for the determination of the solar parallax through his calculations .

In 1684 he discussed evidence for Kepler's laws in a London coffee house with Christopher Wren and Robert Hooke . Since no solution was found, it was decided to turn to Isaac Newton . In August 1684, Halley visited Newton in Cambridge, who had the solution to the problem in the drawer. Halley convinced him to finish the job. He also advanced the printing costs for the Principia . This brought him into considerable financial difficulties, especially since the Royal Society not only contributed nothing, but also paid his salary as its secretary not in cash but in the form of books ( De Historia Piscium ).

Between 1698 and 1700, Halley traveled as commander of the warship HMS Paramore in the South and North Atlantic to determine the direction of the magnetic needle at various points on the earth's surface. As a result of these trips he was able to publish the first major map of magnetic declination in 1701 . In further voyages he measured the English Channel and visited the Adriatic ports .

Halley's grave in London

In 1703 Oxford University appointed Halley to the Savili Chair of Geometry . There he worked on the theory of the moon in order to perfect it for use in determining the length of the sea . In 1705 he was able to calculate the orbital elements of the comets (the years 1531, 1607 and 1682) using this new method . These calculations led to the suspicion that these appearances were always the same comet that would return around the beginning of 1759. Since the prediction was confirmed, this comet has since been referred to as Halley's Comet .

When the royal astronomer ( Astronomer Royal ) John Flamsteed died in 1719 , Halley was appointed his successor in Greenwich that same year. With effect from taking office in Greenwich, Halley resigned as Secretary of the Academy of Sciences . As an astronomer in Greenwich, he revised Ptolemy's list of stars and published it in Geographiae veteris scriptores graeci minores . In 1729 he became a foreign member ( associé étranger ) of the Académie des sciences in Paris.

plant

In addition to his calculations of comet orbits (e.g. Halley's Comet ), Halley also researched terrestrial magnetism and the monsoons and discovered the proper motion of stars.

But he also made an effort to improve the diving bell . In 1690 he and five colleagues dived 20 m deep in the Thames for an hour and a half . He connected this bell with weighted barrels anchored below the bell with air so that it could flow upwards. He later improved the system so that he could stay underwater for four hours.

He also improved the mirror octant , an instrument for astronomical observations (for navigation) at sea. As a math advisor to Amicable and Perpetual Assurance , Halley created the mathematical foundations of life insurance mathematics .

Halley also dealt with questions of the chronology of classical antiquity. In his treatise on inscriptions in Palmyra, however, contrary to almost all related websites, no astronomical observations to determine the slowing down of the earth's rotation are dealt with. Halley only says in the last paragraph that to determine the secular acceleration of the moon (the moon's movement apparently accelerated by the slowed rotation of the earth) one has to find ancient inscriptions.

Halley also translated classical mathematical treatises like the conic teaching of Apollonius of Perga from Arabic.

Solving the problem of length occupied him all his life. It is against this background that his mapping of the earth's magnetic field and his theory of the hollow earth given below must be seen. He also supported the proposal made by William Whiston and Humphry Ditton in 1714 that the British Parliament should offer a large monetary prize for solving the problem.

He made important findings in meteorology, for example the barometric altitude formula .

Hollow earth

Halley with a diagram of the hollow earth

In 1691 he proposed the first scientifically based hollow earth theory. Isaac Newton calculated that the moon was denser than the earth. Based on the general view that all matter in planets and moons is of the same density, Halley concluded that part of the earth must be hollow. He had also observed that the earth's magnetic field has four poles and changes over time. He assumed that the earth consists of a central sphere and three concentrically surrounding hollow spheres, roughly the size of the celestial bodies Moon, Mercury and Venus. Each of these bodies has its own magnetic field, and since they rotate at different speeds, there is a changing overall magnetic field on the surface of the earth. Since it was assumed at the time that all celestial bodies were inhabited, he also colonized the inner planets. This hollow earth theory is the first conclusion from Newton's new theory of gravity in the Principia , even before Halley's prediction of a comet of 1695. On March 6, 1716, very bright aurora borealis were observed again for the first time after the Maunder minimum in Great Britain and large parts of Europe , even on Days visible. The Royal Society asked Halley to explain these phenomena. He attributed it to the fact that the earth's crust is thinner in northern latitudes, which means that the light shines through from the cavities. When the 80-year-old Halley was portrayed as the Astronomer Royal , he was depicted with a diagram of the hollow earth.

Aftermath

From November 21 to 22, 1956, an exhibition was held in the rooms of the Royal Society on the occasion of Halley's 300th birthday. Parts of this exhibition were then on view from December 31, 1956 to January 20, 1957 in the British Museum .

After Edmond Halley the asteroid (2688) Halley , the comet 1P / Halley , the lunar crater Halley , the Martian crater Halley as well as the Halley station in Antarctica and the Halley method for determining zeros were named.

Fonts (selection)

  • Methodus Directa & Geometrica, Cujus Ope Investigantur Aphelia, Eccentricitates, Proportionesque Orbium Planetarum Primariorum, Absque Supposita Aequalitate Anguli Motus, ad Alterum Ellipsews Focum, from Astronomis Hactenus Usurpati . In: Philosophical Transactions . Volume 11, London 1676, pp. 683-686, DOI: 10.1098 / rstl.1676.0031 .
  • Catalogus Stellarum Australium sive Supplementum Catalogi Tychonici . London 1679 (online) .
  • An Account of the Cause of the Change of the Variation of the Magnetical Needle; With an Hypothesis of the Structure of the Internal Parts of the Earth: As It Was Proposed to the Royal Society in One of Their Late Meetings . In: Philosophical Transactions . Volume 16, London 1692, pp. 563-578, DOI: 10.1098 / rstl.1686.0107 .
  • Some Account of the Ancient State of the City of Palmyra, with Short Remarks upon the Inscriptions Found there . In: Philosophical Transactions . Volume 19, London 1695, pp. 160-175, DOI: 10.1098 / rstl.1695.0023 .
  • A new and correct sea chart of the whole world shewing the variations of the compass as they were found in the year MDCC. Mount & Page, London 1702 (online) .
  • Astronomiae Cometicae Synopsis . In: Philosophical Transactions . Volume 24, London 1705, pp. 1882-1899, DOI: 10.1098 / rstl.1704.0064 .
    • A Synopsis of the Astronomy of the Comets . In: Miscellanea Curiosa: Being a Collection of some of the Principal Phaenomena in Nature . Volume 2, London 1706, pp. 321-344 (online) .
  • Apollonii Pergaei de Sectione Rationis Libri Duo ex Arabico MS latine versi. Accedunt ejusdem de Sectione Spatii Libri Duo restituti . Oxford 1706.
  • Apollonii Pergaei Conicorum Libri Octo et Sereni. Antissensis de Sectione Cylindri et Coni Libri Duo . Oxford 1710.
  • An Account of the Late Surprizing Appearance of the Lights Seen in the Air, on the Sixth of March Last; With an Attempt to Explain the Principal Phenomena thereof . In: Philosophical Transactions . Volume 29, 1714, pp. 406-428, DOI: 10.1098 / rstl.1714.0050 .
  • Methodus Singularis Qua Solis Parallaxis Sive Distantia a Terra, ope Veneris intra Solem Conspiciendoe . In: Philosophical Transactions of the Royal Society . Volume 29, number 348, 1716, pp. 454-464 ( doi: 10.1098 / rstl.1714.0056 ).
Posthumously
  • Edmundi Halleii Astronomi dum viveret Regii tabulae astronomicae accedunt de usu tabularum praecepta . J. Brevis, London, 1749.

literature

  • Angus Armitage: Edmond Halley . Nelson, London 1966.
  • S. Chapman: Edmond Halley, FRS 1656-1742 . In: Notes and Records of the Royal Society of London . Volume 12, Number 2, 1957, pp. 168-174 (JSTOR) .
  • Alan Cook: Edmond Halley: Charting the heavens and the seas . Clarendon, Oxford 1998, ISBN 0-19-850031-9 .
  • David W. Hughes, Daniel WE Green: Halley's First Name: Edmond or Edmund . In: International Comet Quarterl . Volume 29, 2007, pp. 7-14 (PDF; 961 kB)
  • Harold Spencer Jones: Halley as an Astronomer . In: Notes and Records of the Royal Society of London . Volume 12, Number 2, 1957, pp. 175-192 (JSTOR) .
  • Colin A. Roman: Edmond Halley: Genius in eclipse . Macdonald, London 1970

Web links

Commons : Edmond Halley  - Album with pictures, videos and audio files

Individual evidence

  1. ^ Meyer's Large Conversational Lexicon . 6th edition. Bibliographisches Institut, Leipzig / Vienna 1909 ( zeno.org [accessed on June 18, 2019] Lexicon entry "Halley").
  2. ↑ The source of the birth and death dates is a biography of Edmond Halley written shortly after his death: Biographia Britannica , Volume 4, 1757, pages 2494-2520. On his tombstone in Lee near Greenwich, his birth and death years were indicated by the following inscription: Natus est AC MDCLVI. Mortuus est AC MDCCXLI. Before 1752 the Julian calendar was used in England . In addition, the year began on March 25th July. .
  3. ^ List of members since 1666: Letter H. Académie des sciences, accessed on November 22, 2019 (French).
  4. ^ Edward Bullard, Colin A. Ronan: The Exhibition to Commemorate Edmond Halley, 1656-1742 . In: Notes and Records of the Royal Society of London . Volume 12, Number 2, 1957, pp. 166-167 (JSTOR) .
personal data
SURNAME Halley, Edmond
BRIEF DESCRIPTION English astronomer
DATE OF BIRTH November 8, 1656
PLACE OF BIRTH Haggerston near London
DATE OF DEATH January 25, 1742
Place of death Greenwich