Bode

NAME: Bode, Johann Elert

ACHIEVEMENT(S): Bode's rule.

NICKNAME/ALIAS: None

DATE/PLACE OF BIRTH: 19 January 1747, at Hamburg [Germany]

DATE/PLACE/AGE AT DEATH: 23 November 1826, in Berlin, Germany.  Aged 79

DISCIPLINE: Astronomer

FIELD: Astronomy

LANGUAGE: German

PARENTS: ?

SIBLINGS: ?

SPOUSE: Married three times

CHILDREN: ?

EDUCATION: ?

MAJOR WORK: 'Astronomisches Jahrbuch', 1776-1829

LIFE AND TIMES: In his early astronomical studies Bode was greatly encouraged by the poet Friedrich Klopstock,  who persuaded him to publish, in 1768,  his: ‘Instructions on the Study of the Stars.’

In 1772, at the age of 25, Bode was invited to join the astronomical observatory of the Berlin Academy as a mathematician,  to oversee the publication of the Academy's yearbook and to ensure the accuracy of its mathematical content.

The sale of astronomical almanacs was a major source of income for the Academy, but because they were often inaccurate,  sales were falling. During his early years at the Academy, Bode concentrated on developing improved mathematical methods to make the yearbook more accurate.

The new and much improved 1776 edition was compiled under Bode's direction and he continued to do the calculations for and publish each volume until the 1829 yearbook (published in 1826), a total of 53 volumes. Sales soon increased and, because of their accuracy, Bode's almanacs, which also included news on astronomical observations and discoveries from around the world, were held in high regard.

In 1772 Bode produced a rule which was had already been stated by Johann Daniel Titus of Wittenberg in 1766, but was so popularized by Bode that it was named after him. This law, also known as the (Titius-)Bode rule, was a mathematical formula which showed that there was a pattern to the distances of all the (then-known) planets from the Sun.

It accommodated the discovery in 1781 by Sir William Herschel* of the seventh planet, Uranus, (named by Bode) and of the asteroids found by Piazzi*, the orbit of which was calculated by Gauss* and confirmed by Olbers* in 1801.

The rule (or law) states that the distances between the large planets are in a nearly regular geometric progression. First take the sequence 0, 3, 6, 12, 24, etc.  To each number add 4. Divide each result by 10.  Of the first seven answers (0.4, 0.7, 1.0, 1.6, 2.8, 5.2, 10.0), six closely approximate the distances from the Sun, in astronomical units (1 AU is the distance between the Earth and the Sun), of the six planets known when Titius produced the rule: Mercury, Venus, Earth, Mars, Jupiter, and Saturn.

At about 2.8 AU from the Sun, between Mars and Jupiter, came the asteroids. The rule also holds for the seventh planet, Uranus,  at about 19 AU  The discovery of the eighth planet, Neptune, in 1846 by Urbain Le Verrier and John Couch Adams disrupted the series,  although Pluto, the ninth planet from the Sun, is at a distance (39 AU) roughly equal to that given by the rule for the eighth planet.

In 1776 Bode, almost the only writer then to support the relatively unknown ideas of  Kant*, Lambert and Herschel on the infinity of space, the infinite number of inhabited worlds, and the continuous birth and death of stars according to natural laws, put forward a theory of the Sun similar to that developed in 1795 by Herschel.

In 1784 Bode was appointed Royal Astronomer and elected as a member of the Berlin Academy, and two years later he was made Director of the Berlin Astronomical Observatory.  During the 1790’s Bode supervised its renovation.

Besides his tables, Bode worked on two sky atlases, which for a long time remained indispensable tools for all astronomers. The first was the 'Vorstellung der Gerstirne' (1782), with more than 5,000 stars, followed by the 'Uranographia' (1801), a collection of 20 star maps accompanied by a catalogue of 17,240 stars and nebulae, which contained, for the first time, the nebulae, star clusters and double stars discovered by William Herschel.

Bode retired as Director of the Observatory in 1825, after a long and distinguished career, a year before his death.

ASSESSMENT:  Bode's main contribution to astronomy  lay in the spreading of information about the subject to people from a wide range of backgrounds.

EXTRA CONNECTIONS:  His rule was used by Zach* to search for new planets

ONELINER: JE Bode, astronomer who mathematically sequenced the planets

BIBLIOGRAPHY:

EB, DSB