World Library  
Flag as Inappropriate
Email this Article
 

Nur ad-Din al-Bitruji

Nur ad-Din al-Bitruji
Born 12th century
Al-Andalus
Died 1204 AD
Era Islamic Golden Age
Region Caliphate
Main interests
Astronomy
Notable ideas
First non‐Ptolemaic astronomical system; physical cause of celestial motions

Nur ad-Din al-Bitruji (also spelled Nur al-Din Ibn Ishaq Al-Betrugi and Abu Ishâk ibn al-Bitrogi; another spelling is al Bidrudschi) (known in the West by the Latinized name of Alpetragius) (died ca. 1204 AD) was an astronomer and a Qadi from Al-Andalus.[1] Despite his limited knowledge of Ptolemy's Almagest, al-Biṭrūjī was the first astronomer after Ptolemy to present a non-Ptolemaic astronomical system as an alternative to Ptolemy's models. Another original aspect of his system was that he proposed a physical cause of celestial motions.[1]

The crater Alpetragius on the Moon is named after him.

Contents

  • Life 1
  • Planetary model 2
  • Works 3
  • Notes 4
  • References 5
  • Further reading 6

Life

Almost nothing about his life is known, except that his name probably derives from Los Pedroches (al-Biṭrawsh), a region near Cordoba.[1] He was a disciple of Ibn Tufail (Abubacer) and was a contemporary of Averroes.

Planetary model

Al-Bitruji proposed a theory on planetary motion in which he wished to avoid both epicycles and eccentrics,[2] and to account for the phenomena peculiar to the wandering stars, by compounding rotations of homocentric spheres. This was a modification of the system of planetary motion proposed by his predecessors, Ibn Bajjah (Avempace) and Ibn Tufail (Abubacer). He was unsuccessful in replacing Ptolemy's planetary model, as the numerical predictions of the planetary positions in his configuration were less accurate than those of the Ptolemaic model,[3] because of the difficulty of mapping Ptolemy's epicyclic model onto Aristotle's concentric spheres.

It was suggested based on the Latin translations that his system is an update and reformulation of that of Eudoxus of Cnidus combined with the motion of fixed stars developed by al-Zarqālī. However, it is not known whether the Andalusian cosmologists had access or knowledge of Eudoxus works.[1]

One original aspects of al-Biṭrūjī's system is his proposal of a physical cause of celestial motions. He combines the idea of "impetus" (first proposed by John Philoponus) and the concept of shawq ("desire"), of Abū al‐Barakāt al‐Baghdādī, to explain how energy is transferred from a first mover placed in the 9th sphere to other spheres, explaining the other spheres' variable speeds and different motions. He contradicts the Aristotelian idea that there is a specific kind of dynamics for each world, applying instead the same dynamics to the sublunar and the celestial worlds.[1]

Works

Al-Bitruji wrote Kitāb al-Hayʾah (The book of theoretical astronomy/cosmology, Arabic, كتاب الهيئة), which presented criticism of Ptolomy's Almagest from a physical point of view. It was well known in Europe between the 13th and the 16th centuries, and was regarded as a valid alternative to Ptolemy's Almagest in scholastic circles.[1]

This work was translated into Latin by Michael Scot in 1217 as De motibus celorum [4] (first printed in Vienna in 1531). A Hebrew translation by Moses ibn Tibbon was done in 1259.[1]

There is also an anonymous treatise on tides (Escorial MS 1636, dated 1192) which contains material seemingly borrowed from al-Bitruji.[1]

Notes

  1. ^ a b c d e f g h Samsó 2007.
  2. ^ Bernard R. Goldstein (March 1972). "Theory and Observation in Medieval Astronomy", Isis 63 (1), p. 39-47 [41].
  3. ^ Ptolemaic Astronomy, Islamic Planetary Theory, and Copernicus's Debt to the Maragha School, Science and Its Times, Thomson Gale.(inaccessible document)
  4. ^ Pederson, Olaf. (1978) Science in the Middle Ages. ed. by David Lindberg. Chicago: Chicago University Press. p. 321

References

  • Samsó, Julio (2007). "Biṭrūjī: Nūr al‐Dīn Abū Isḥāq [Abū Jaʿfar] Ibrāhīm ibn Yūsuf al‐Biṭrūjī". In Thomas Hockey; et al. The Biographical Encyclopedia of Astronomers. New York: Springer. pp. 133–4. (PDF version)  
  • Samsó, Julio (1970–80). "Al-Bitruji Al-Ishbili, Abu Ishaq".  

Further reading

  • Helaine Selin, Encyclopaedia of the history of science, technology, and medicine in non western cultures, p. 160
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.