Johann Daniel Titius (born Johann Daniel Tietz(e), 2 January 1729 – 16 December 1796) was a German

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

and a professor at

Wittenberg Wittenberg, officially Lutherstadt Wittenberg, is the fourth-largest town in the state of Saxony-Anhalt, in the Germany, Federal Republic of Germany. It is situated on the River Elbe, north of Leipzig and south-west of the reunified German ...

.sächsische Biografie
Titius was born in Konitz (Chojnice), Royal Prussia (a fief of the Crown of Poland) to Jakob Tietz, a merchant and council member from Konitz, and Maria Dorothea, née Hanow. His original name was Johann Tietz, but as was customary in the 18th century, when he became a university professor, he Latinized his surname to Titius. Tietz attended school in Danzig (Gdańsk) and studied at the

University of Leipzig Leipzig University (), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 December 1409 by Frederick I, Electo ...

(1749–1752). He died in

Electorate of Saxony The Electorate of Saxony, also known as Electoral Saxony ( or ), was a territory of the Holy Roman Empire from 1356 to 1806 initially centred on Wittenberg that came to include areas around the cities of Dresden, Leipzig and Chemnitz. It was a ...

Astronomy

He is best known for formulating the Titius–Bode law, and for using this rule to predict the existence of a celestial object at 2.8 AU from the sun which led to the 1801 discovery of what we now know as Ceres. He drew up the law in 1766, when he inserted his mathematical observation on planetary distances into a German translation of Charles Bonnet's book ''Contemplation de la Nature''. In part because of this law, the first four minor planets were at first labeled as full-fledged planets. After a fifteen-year hiatus, other minor planets started to be discovered at steadily increasing rates, and Ceres and company were eventually relabeled as

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...

s or

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

s. Because of its spherical shape, Ceres has had upgraded status as a

dwarf planet A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough to be hydrostatic equilibrium, gravitationally rounded, but insufficient to achieve clearing the neighbourhood, orbital dominance like the ...

since 2006. The asteroid

1998 Titius 1998 Titius, provisional designation , is a metallic–carbonaceous asteroid from the inner regions of the asteroid belt, approximately 14 kilometers in diameter. It was discovered on 24 February 1938, by German astronomer Alfred Bohrmann at He ...

and the crater Titius on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

are named in his honour.

Physics

Titius published a number of works on other areas in physics, such as a set of conditions and rules for performing experiments, and he was particularly focused in

thermometry Temperature measurement (also known as thermometry) describes the process of measuring a current temperature for immediate or later evaluation. Datasets consisting of repeated standardized measurements can be used to assess temperature trends. ...

. In 1765 he presented a survey of thermometry up to that date. He wrote about the metallic thermometer constructed by

Hanns Loeser Hanns is a given name. Notable people with the name include: *Hanns Blaschke (1896–1971), Austrian politician * Hanns Bolz (1885–1918), German expressionist and cubist painter * Hanns Brandstätter (born 1949), Austrian fencer * Hanns Braun (1 ...

. In his treatises on both theoretical and experimental physics, he incorporated the findings of other scientists, such as the descriptions of experiments written by

Georg Wolfgang Kraft Georg may refer to: * ''Georg'' (film), 1997 *Georg (musical), Estonian musical * Georg (given name) * Georg (surname) * , a Kriegsmarine coastal tanker * Spiders Georg "Spiders Georg" is an Internet meme that began circulating on the mic ...

in 1738.

Biology

Titius was also active in biology, particularly in classification of organisms and minerals. His biological work was influenced by

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

. ''Lehrbegriff der Naturgeschichte Zum ersten Unterrichte'', his most extensive publication in biology, was on systematic classification of plants, animals, and minerals, as well as the elemental substances ether, fire, air, water and earth.

References

External links

KDG Wittenberg: Prof. Dr. Joh. Daniel TitiusPlants and Planets: The Law of Titius-Bode explained
by H. J. R. Perdijk * {{DEFAULTSORT:Titius, Johann Daniel 1729 births 1796 deaths People from Chojnice 18th-century German astronomers People from Royal Prussia 18th-century German scientists