Al-Sijzi

Abu Sa'id Ahmed ibn Mohammed ibn Abd al-Jalil al-Sijzi (c. 945 - c. 1020, also known as al-Sinjari and al-Sijazi; Persian: ابوسعید سجزی‎; Al-Sijzi is short for "Al-Sijistani") was an Iranian[3] Muslim astronomer, mathematician, and astrologer. He is notable for his correspondence with al-Biruni and for proposing that the Earth rotates around its axis in the 10th century.[4][5]

For other people named Al-Sijistani, see Al-Sijistani.
Abu Sa'id al-Sijzi
Born945 CE
Sijistan, Saffarid dynasty (modern-day Afghanistan)[1]
Died1020 CE
Main interests
Mathematics, Astronomy, Astrology
A page from Al Sijzi's geometrical treatise.
Model of the solar system and earth movement ("planetarium") according to al-Sijz[2]i

He dedicated work to 'Adud al-Daula, who was probably his patron, and to the prince of Balkh. He also worked in Shiraz making astronomical observations from 969 to 970.

Mathematics

Al-Sijzi studied intersections of conic sections and circles. He replaced the old kinematical trisection of an angle by a purely geometric solution (intersection of a circle and an equilateral hyperbola.)

Earth's rotation

Al-Biruni tells us that Al-Sijzi invented an astrolabe, called "al-zūraqī", whose design was based on the idea that the Earth rotates:[6]

I have seen the astrolabe called Zuraqi invented by Abu Sa'id Sijzi. I liked it very much and praised him a great deal, as it is based on the idea entertained by some to the effect that the motion we see is due to the Earth's movement and not to that of the sky. By my life, it is a problem difficult of solution and refutation. [...] For it is the same whether you take it that the Earth is in motion or the sky. For, in both cases, it does not affect the Astronomical Science. It is just for the physicist to see if it is possible to refute it.

Al-Biruni also referred to Al-Sijzi as a prominent astronomer who defended the theory that the earth rotates in al-Qānūn al-Masʿūdī.[4][7]

The fact that some people did believe that the earth is moving on its own axis is further confirmed by a reference from the 13th century which states:

"According to the geometers [or engineers] (muhandisīn), the earth is in constant circular motion, and what appears to be the motion of the heavens is actually due to the motion of the earth and not the stars."[5]

Notes
  1. Helaine Selin (12 March 2008). Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures. Springer Science & Business Media. pp. 159–. ISBN 978-1-4020-4559-2.
  2. "Modell des Sonnensystems und der Erdbewegung ("Planetarium") nach as-Siǧzî". Museum des Institutes für Geschichte der Arabisch-Islamischen Wissenschaften. 2010.
  3. Kheirandish, Elaheh (1 April 2006). "The "Fluctuating Fortunes of Scholarship": A Very Late Review Occasioned by a Fallen Book". Early Science and Medicine. 11 (2): 214. doi:10.1163/157338206776908882.
  4. Bausani, Alessandro (1973). "Cosmology and Religion in Islam". Scientia/Rivista di Scienza. 108 (67): 762.
  5. Young, M. J. L., ed. (2006-11-02). Religion, Learning and Science in the 'Abbasid Period. Cambridge University Press. p. 413. ISBN 9780521028875.
  6. Seyyed Hossein Nasr (1993), An Introduction to Islamic Cosmological Doctrines, pp. 135–136. State University of New York Press, ISBN 0-7914-1516-3.
  7. "ʾaḥad al-mubrazīn fī ʿilm al-hayʾa"
gollark: It's always good to have plenty of spare alts. I may or may not have some in this very server, for purposes.
gollark: California's power grid is known for its reliability so desalination would work well there.
gollark: Maybe use specific train keywords in your search query too.
gollark: If you found an exploit in one of the games you could probably load your own stuff (until they notice).
gollark: That's probably all it's good for.

References


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.