Bernhard Walther (1430June 19, 1504) was a German merchant,

humanist Humanism is a philosophical stance that emphasizes the individual and social potential, and agency of human beings, whom it considers the starting point for serious moral and philosophical inquiry. The meaning of the term "humanism" ha ...

and astronomer based in

Nuremberg Nuremberg (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...

, Germany. Walther was born in

Memmingen Memmingen (; Swabian German, Swabian: ''Memmenge'') is a town in Swabia (Bavaria), Swabia, Bavaria, Germany. It is the economic, educational and administrative centre of the Danube-Iller region. To the west the town is flanked by the Iller, the ...

, and was a man of large means, which he devoted to scientific pursuits. When

Regiomontanus Johannes Müller von Königsberg (6 June 1436 – 6 July 1476), better known as Regiomontanus (), was a mathematician, astrologer and astronomer of the German Renaissance, active in Vienna, Buda and Nuremberg. His contributions were instrument ...

settled in Nuremberg in 1471, they worked in collaboration to build an

observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Th ...

and a

printing press A printing press is a mechanical device for applying pressure to an inked surface resting upon a printing, print medium (such as paper or cloth), thereby transferring the ink. It marked a dramatic improvement on earlier printing methods in whi ...

. After the death of Regiomontanus in 1476 at

Rome Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...

, Walther bought his instruments, after Hans von Dorn, commissioned by the Hungarian king, had failed to come to an agreement with the council of Nuremberg. Walther continued to observe the

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

s until his death in Nuremberg. His house, purchased in 1509 by

Albrecht Dürer Albrecht Dürer ( , ;; 21 May 1471 – 6 April 1528),Müller, Peter O. (1993) ''Substantiv-Derivation in Den Schriften Albrecht Dürers'', Walter de Gruyter. . sometimes spelled in English as Durer or Duerer, was a German painter, Old master prin ...

, is today a museum.

Astronomy

Walther amplified on the effects of

refraction In physics, refraction is the redirection of a wave as it passes from one transmission medium, medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commo ...

in altering the apparent location of the heavenly bodies, and substituted

Venus Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" planet for having almost the same size and mass, and the closest orbit to Earth's. While both are rocky planets, Venus has an atmosphere much thicker ...

for 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 ...

as a connecting-link between observations of the Sun and stars. As a result, his observations are the most precise prior to those of

Tycho Brahe Tycho Brahe ( ; ; born Tyge Ottesen Brahe, ; 14 December 154624 October 1601), generally called Tycho for short, was a Danish astronomer of the Renaissance, known for his comprehensive and unprecedentedly accurate astronomical observations. He ...

. His pupil Johannes Schöner made unpublished data of Walther's observations of Mercury available to

Nicolaus Copernicus Nicolaus Copernicus (19 February 1473 – 24 May 1543) was a Renaissance polymath who formulated a mathematical model, model of Celestial spheres#Renaissance, the universe that placed heliocentrism, the Sun rather than Earth at its cen ...

. There were 45 observations in total, 14 of them with longitude and latitude. Copernicus used three of them in "

De revolutionibus ''De revolutionibus orbium coelestium'' (English translation: ''On the Revolutions of the Heavenly Spheres'') is the seminal work on the heliocentric theory of the astronomer Nicolaus Copernicus (1473–1543) of the Polish Renaissance. The book ...

", giving only longitudes, and erroneously attributed them to Schöner.Copernicus refers in Book V
p.169a: ''Primum à Bernardo Vualthero ..'
p.169b: '' ..latitudine Borea part. I. medietate & tertia ..'
p.169b: ''Secundus ..Ioanne Schonero ..Borea fcrup.XLV.''
These values differed slightly from the ones published by Schöner in 1544 in ''Observationes XXX annorum a I. Regiomontano et B. Walthero Norimbergae habitae, °, Norimb. 1544'', a collection of the astronomical observations of

and Walther, as well as manuscripts of Regiomontanus, which had been in the possession of Walther. In 1618,

Willebrord Snell Willebrord Snellius (born Willebrord Snel van Royen) (13 June 158030 October 1626) was a Dutch astronomer and mathematician, commonly known as Snell. His name is usually associated with the law of refraction of light known as Snell's law. The ...

noted them as an appendix to his ''Observationes Hassiaceae''.

Equipment

In 1484 Walther introduced clocks driven by weights, their first use in astronomical determinations. His printing press was used to produce some of the earliest astronomical publications.

Legacy

Walther is the

eponym An eponym is a noun after which or for which someone or something is, or is believed to be, named. Adjectives derived from the word ''eponym'' include ''eponymous'' and ''eponymic''. Eponyms are commonly used for time periods, places, innovati ...

of lunar crater

Walther Walther () is a masculine given name and a surname. It is a German form of Walter, which is derived from the Old High German '' Walthari'', containing the elements ''wald'' -"power", "brightness" or "forest" and ''hari'' -"warrior". The name was ...

Works

*Regiomontanus, Johannes: Opera Collectanea. Osnabrück: Otto Zeller 1972 (includes Observations by Bernhard Walther)

References

* This work in turn cites: ** J. G. Doppelmayr, ''Hist. Nachricht von den nürnbergischen Mathematicis'', p. 23 (1730) ** G. A. Will, ''Nürnbergisches Gelehrten-Lexikon'', vii. 381 (1806) ** J. E. Montucla, ''Hist. des mathematiques'', i. 546 ** J. S. Bailly, ''Hist. de Paste. moderne'', i. 319 ** E. F. Apelt, ''Die Reformation der Sternkunde'', p. 54 ** J. P. von Wurzelbaur, ''Uranies Noricae basis astronomica'' (1719) ** J. F. Weidler, ''Hist. astronomiae'', p. 322 ** A. G. Kästner, ''Geschichte der Mathematik'', ii. 324 **H. Petz, ed., ''Mitteilungen des Vereins für die Geschichte der Stadt Nürnberger'', vii. 237 (1888) ** R. Wolf, ''Gesch. der Astr.'' pp. 92ff. **Ralf Kern, ''Wissenschaftliche Instrumente in ihrer Zeit''. Vol. 1: ''Vom Astrolab zum mathematischen Besteck''. Cologne, 2010. p. 112.

-Hauses. Norica 3 (Juli 2007), pp. 69–77 *Kremer, Richard L.: Bernhard Walther's Astronomical Observations. Journal for the History of Astronomy 11 (3/1980), pp. 174–191 *Kremer, Richard L.: The Use of Bernhard Walther's Astronomical Observations: Theory and Observation in Early Modern Astronomy. Journal for the History of Astronomy 12 (2/1981), pp. 124–132 *Kremer, Richard L.: Walther's Solar Observations: A reply to R. R. Newton. Quarterly Journal of the Royal Astronomical Society 24 (1983), pp. 36–47 *Newton, Robert R.: An analysis of the solar observations of Regiomontanus and Walther. Quarterly Journal of the Royal Astronomical Society 23 (1982), pp. 67–93 *Pilz, Kurt: Bernhard Walther und seine astronomischen Beobachtungsstände. Mitteilungen des Vereins für Geschichte der Stadt Nürnberg 57 (1970), pp. 176–188 *Steele, John Michael; Stephenson, Francis Richard: Eclipse Observations by Regiomontanus and Walther. Journal for the history of astronomy 29 (4/1998), pp. 331–344 *Zinner, Ernst: Leben und Wirken des Joh. Müller von Königsberg genannt Regiomontanus. 2te verb. Aufl. Osnabrück: Otto Zeller 1968 *

Johann Christian Poggendorff Johann Christian Poggendorff (29 December 1796 – 24 January 1877) was a German physicist born in Hamburg. By far the greater and more important part of his work related to electricity and magnetism. Poggendorff is known for his electrostatic mo ...

: ''Biographisch-literarisches Handwörterbuch der exakten Naturwissenschaften.'' *Ernst Zinner: ''Entstehung und Ausbreitung der coppernicanischen Lehre.'' 2. Aufl. München 1988, *Hans Gaab: ''Die große Nürnbergische Uhr.'' In: ''Beiträge zur Astronomiegeschichte.'' 8 (2006), pp. 43–90; Acta Historica Astronomiae, Vol. 28,

External links