Bode, Johann Elert

views updated Jun 11 2018

Bode, Johann Elert

(b. Hamburg, Germany, 19 January 1747; d. Berlin, Germany, 23 November 1826)

astronomy.

Bode, the son of a commercial accounting teacher and the nephew of the well-known writing master and mathematic master Jürgen Elert Kruse of Hamburg, had a great love for practical calculations throughout his life. This, with his pedagogical abilities, made him an excellent teacher of astronomy. He studied astronomy by himself and was strongly stimulated in his studies by the Hamburg scholars J. A. Reimarus and J.G. Büsch, as well as by the poet Friedrich Klopstock. They encouraged the nineteen-year-old to publish his famous Anleitung zur Kenntnis des gestirnten Himmels (1768), which was in print for nearly a hundred years and won innumerable adherents to astronomy.

In 1772 Johann Lambert summoned Bode to the astronomical observatory of the Berlin Academy as an arithmetician, to help in the publication of accurate ephemerides. The sale of astronomical almanacs was one of the chief sources of income for the Academy; because of their low degree of accuracy, however, the almanacs were not selling well. The new Astronomisches Jahrbuch für 1776 was compiled under Bode’s direction and published in 1774. He continued to do the calculations for and publish each successive annual volume until that of 1829 (published in 1826). Bode’s almanacs were soon greatly esteemed. Aside from the ephemerides, the Jahrbücher also contained scientific news on observations and discoveries around the world.

In 1786 Bode was appointed royal astronomer, director of the astronomical observatory, and member of the Berlin Academy. He was active in these positions for nearly forty years, until his retirement in 1825. In spite of the renovations which he arranged, the observatory, situated on the roof of a five-story tower of the Academy building, could not compete with those of Paris and London; it was equipped only for modest investigations of comets, planets, double stars, and so forth.

Bode’s literary activity more than made up for the observatory’s deficiencies. Besides his tables, his two sky atlases were for a long time indispensable tools for astronomers: the Vorstellung der Gestirne, which, according to the example set by John Flamsteed’s atlas, contained more than 5,000 stars; and the Uranographia, which surpassed all its predecessors by listing over 17,000 stars and containing, for the first time, the nebulae, star clusters, and double stars discovered by William Herschel.

Bode was almost the only writer to support the then not widely known ideas of Kant, Lambert, and Herschel on the infinity of space, the infinite number of inhabited worlds, and the continuous birth and passing away of stars according to natural laws. He also made public in 1772 the relation first established by the Wittenberg professor Johann Daniel Titius, the Titius-Bode series, according to which the distances between the large planets are in a nearly regular geometric progression. The minor planets, unknown at that time, and the planet discovered in 1781 by Herschel fit well into this series. (If one substitutes for Venus, Earth, Mars, Jupiter, and Saturn the numbers n = 0, 1, 2, 4, 5, then the distance is obtained from the relation A = 0.4 + 2n • 0.3 [astronomical units]. For Mercury the last member is zero, for the minor planets n =3, for Uranus n = 6.) Bode gave the name Uranus to Herschel’s newly discovered planet.

Bode married three times: his first two wives were nieces of the Berlin astronomer Christine Kirch; the third was the niece of the chemist Andreas Marggraf. He was a member of the Royal Society of London, as well as of the academies of Berlin, St. Petersburg, Stockholm, Copenhagen, and Göttingen.

BIBLIOGRAPHY

I. Original Works. Bode’s writings include Anleitung zur Kenntnis des gestirnten Himmels (Hamburg, 1768; 11th ed., Berlin, 1858); Sammlung astronomischer Tafeln (Berlin, 1776); Kurzgefasste Erläuterung der Sternkunde (Berlin, 1778; 3rd ed., Berlin, 1808); Dialogen über die Mehrheit der Welten (Berlin, 1780; 3rd ed., Berlin, 1798), a translation of Fontenelle’s Entretiens sur la pluralité des mondes; Vorstellung der Gestirne auf 34 Kupfertafeln nebst Fixstern verzeichnis (Berlin-Stralsund, 1782; 2nd ed., Berlin, 1805); Allgemeine Betrachtungen über das Weltgebäude (Berlin, 1801; 3rd ed., Berlin, 1807); and Uranographia sive astrorum descriptio (Berlin, 1801), 20 folios with the catalog Allgemeine Beschreibung und Nachweisung der Gestirne.

II. Secondary Literature. Biographical material on Bode is in Encke, an obituary speech, in Abhandlungen of the Berlin Academy (1827); Poggendorff, I; Allgemeine deutsche Biographie, III, 1; and Schroeder, Lexikon der hamburgischen Schrifisteller, I (Hamburg, 1851), 282 ff., with an extensive list of his works.

Bernhard Stricker

Bode, Johann Elert

views updated May 08 2018

Bode, Johann Elert (1747–1826) A German astronomer who popularized the theory, known later as Bode's law, that there is a simple arithmetical relationship between the distances from the Sun to the planets of the solar system. After the discovery of Neptune, which did not conform with the ‘law’, the idea fell into disrepute.

More From encyclopedia.com