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. It considers human beings the starting point for serious moral and philosophical inquiry. The meaning of the term "human ...

and astronomer based in

Nuremberg Nuremberg ( ; german: link=no, Nürnberg ; in the local East Franconian dialect: ''Nämberch'' ) is the second-largest city of the German state of Bavaria after its capital Munich, and its 518,370 (2019) inhabitants make it the 14th-largest ...

, Germany. Walther was born in

Memmingen Memmingen (; Swabian: ''Memmenge'') is a town in 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 river that marks the Baden-W� ...

, 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 and a

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

. After the death of Regiomontanus in 1476 at

Rome , established_title = Founded , established_date = 753 BC , founder = King Romulus (legendary) , image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg , map_caption ...

, 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, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a you ...

s until his death in Nuremberg. His house, purchased in 1509 by Albrecht Dürer, 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 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 commonly observed phenome ...

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

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

for the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

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; generally called Tycho (14 December 154624 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was ...

. His pupil

Johannes Schöner Johannes Schöner (16 January 1477, in Karlstadt am Main – 16 January 1547, in the Free Imperial City of Nuremberg) (aka, Johann Schönner, Johann Schoener, Jean Schönner, Joan Schoenerus) was a renowned and respected German polymath. It is ...

made unpublished data of Walther's observations of Mercury available to

Nicolaus Copernicus Nicolaus Copernicus (; pl, Mikołaj Kopernik; gml, Niklas Koppernigk, german: Nikolaus Kopernikus; 19 February 1473 – 24 May 1543) was a Renaissance polymath, active as a mathematician, astronomer, and Catholic canon, who formulated ...

. 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, Snell. His name is usually associated with the law of refraction of light known as Snell's law. The lunar crater Sne ...

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 person, a place, or a thing after whom or which someone or something is, or is believed to be, named. The adjectives which are derived from the word eponym include ''eponymous'' and ''eponymic''. Usage of the word The term ''epon ...

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 fir ...

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.

*Eirich, Raimund: Bernhard Walther (1430–1504) und seine Familie. Mitteilungen des Vereins für Geschichte der Stadt Nürnberg 74 (1987), pp. 77–128 *Gaab, Hans: Ein Zeitgenosse Martin Behaims: Der Kaufmann Bernhard Walther (1430–1504), Liebhaberastronom und Vorbesitzer des Albrecht Dürer-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 ...

: ''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