Bernhard Walther

Bernhard Walther ( 1430 in Memmingen *, † June 19, 1504 in Nuremberg) was an astronomer, humanist and merchant. The students, patrons and followers of Regiomontanus, citizens of Nuremberg since 1467, is considered the most accurate astronomical observer of his time.

Life

Walther was the first factor of the Memminger Vöhlin company in Nuremberg and as such very successful and equipped with special powers. He played a remarkable role in Nuremberg. As a patron and supporter of the Regiomontanus he allowed this building the first observatory in Germany. Later he had to Albert Dürer relationships, and perhaps also to Veit Stoss, the figures of Adam and Eve probably passed through the Welser- Vöhlin Society at the Lisbon court. He was inducted into the larger Council of the City of Nuremberg in 1501. His marriage with Christiane Amman (? -1498 ) Was childless, and the heir squandered his library and instruments. His house was purchased in 1509 by Albrecht Dürer and now houses a museum.

Contribution to astronomy

Walther made ​​it possible in 1471 Regiomontanus to set up an observatory in Nuremberg and printing shop, which he continued after his death in 1476. He acquired the library and the astronomical instruments of his teacher and friend, after Hans had in vain tried by thorn on behalf of the Hungarian king to the city council of Nuremberg about it. In particular, he sat with an astrolabe ( measured armillary sphere ) begun by Regiomontanus systematic observations of the planet for over 30 years until his death continues. The observation time was usually determined on classic Star heights. He also related the first one ( quite inaccurate ) mechanical clock. Those watches have had no minute hand, so he read the minutes from the position of the gears. He was the first astronomer who took into account the refraction of light in the earth's atmosphere. This is the first "modern" series of observations. Regiomontanus intended so to be able to establish better planetary tables in order to obtain more precise data for the creation of horoscopes. Overall, they found 746 Sun heights to determine annual points and the length of the year. In addition, they measured 615 planetary positions with length and width. Unfortunately, no one was found in 1500, which systematically compared these measurements with the traditional planetary tables. Only Tycho Brahe took the systematic observations on back, which he partly conscious leaning on measurements of Walther in order to possibly find temporal changes in the orbital parameters can.

Nicolaus Copernicus Related Merkur observations, but she wrote to Nice, which they had told him before publication. There were 45 observations, 14 with length and width. In Copernicus' major work three Mercury observations are given, but only the lengths. But they did not agree with the values ​​published in 1544. In 1618 they were re-issued by Willibrord Snell as an appendix to Coeli et siderum in eo errantium Observaciones hassiacae.

Walther and Regiomontanus measurements were not published until 1544 by his pupil Johannes Schöner ( 1477-1547 ): Observationes XXX annorum a Regiomontano I. et B. Walt Hero Norimbergae habitae.

Meteorology

Also weather forecasts were then derived from horoscopes. To test the predictions Regiomontanus and Walther recorded on meteorological observations. Walthers treatise canons de judiciis aurae was published by his astrology appended students Johannes Schoner.

Timekeeping

Also, and especially by his astronomical work, he gained high reputation in Nuremberg. Thus, the Council commissioned him to the calculations of the course of the day lengths, which were the basis of the 1489 reform of the so-called Great Nürnbergischen clock. A change in his data was not until 1700 with the introduction of the kingdom Improved calendar ( vulgo Gregorian calendar ) in the Protestant states of Germany needed. The 1502 installed sundial on the east choir of St. Lorenz church, indicating the Nürnbergischen hours was calculated by Johannes Stabius with the help of Walther's work. Walther had the conic teaching of Apollonius of Perga translated from Greek into Latin, and wrote a treatise on the manufacture of sundials by means of conic sections. Both works are lost.

Honors

Johannes Hevelius honors him by Firmamentum puts him on the frontispiece of his celestial atlas Sobiescianum in a number of astronomers like Tycho Brahe, Hipparchus, Ptolemy and Copernicus. The crater on Earth's Moon Walther bears his name.

Works (selection)

  • Johannes Regiomontanus: Opera Collectanea. Otto Zeller, Osnabrück 1972 ( contains the traditional observations of Bernhard Walther )

Literature (selection )

  • Raimund Eirich: Bernhard Walther (1430-1504) and his family. In: Communications of the Association for the History of the City of Nuremberg 74 (1987 ), pp. 77-128
  • Hans Gaab: A contemporary of Martin Behaim: The merchant Bernhard Walther (1430-1504), astronomer lover and previous owner of the Albrecht- Dürer -Haus. Norica 3 (July 2007 ), pp. 69-77
  • Richard L. Kremer: Bernhard Walther 's Astronomical Observations. In: Journal for the History of Astronomy 11 (3/1980) pp. 174-191
  • Richard L. Kremer: The Use of Bernhard Walther 's Astronomical Observations: Theory and Observation in Early Modern Astronomy. In: Journal for the History of Astronomy 12 (2/1981), pp. 124-132
  • Robert R. Newton: An analysis of the solar observations of Regiomontanus and Walther. In: Quarterly Journal of the Royal Astronomical Society 23 (1982 ), pp. 67-93
  • Richard L. Kremer: Walther 's Solar Observations: A reply to RR Newton. In: Quarterly Journal of the Royal Astronomical Society 24 (1983 ), pp. 36-47
  • Kurt Pilz: Bernhard Walther and his astronomical observatories. In: Communications of the Association for the History of the City of Nuremberg 57 ( 1970), pp. 176-188
  • John Michael Steele, Francis Richard Stephenson: Eclipse Observations by Regiomontanus and Walther. In: Journal for the history of astronomy 29 (4/1998), pp. 331-344
  • Ernst Zinner: life and work of John Mueller of Königsberg called Regiomontanus. 2 verb. Ed Otto Zeller, Osnabrück 1968
  • Johann Christian Poggendorff: Biographic- Literary Dictionary of the Exact Sciences.
  • Ernst Zinner: emergence and spread of coppernicanischen teaching. 2nd edition, Munich 1988, ISBN 3-406-32049- X
  • Hans Gaab: The Great Nürnbergische clock. In: Contributions to the History of Astronomy. 8 (2006 ), pp. 43-90; Acta Historica Astronomiae, vol 28, ISBN 3-8171-1771- X
  • Siegmund Günther: Walther, Bernard. In: General German Biography (ADB ). Volume 41, Duncker & Humblot, Leipzig 1896, pp. 97-99.
  • Walther, Bernard, a Astronomus. In: Johann Heinrich Zedler: Large full Universal Lexicon Aller managed knowledge and skills. Volume 52, Leipzig 1747, column 1829 to 1831.
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