Al-Nayrizi

Abū’l-‘Abbās al-Faḍl ibn Ḥātim al-Nairīzī (Arabic: أبو العباس الفضل بن حاتم النيريزي‎‎, Latin: Anaritius, Nazirius, 865–922) was a 9th-10th century Persian mathematician and astronomer from Nayriz, Fars Province, Iran.

He flourished under al-Mu'tadid, Caliph from 892 to 902, and compiled astronomical tables, writing a book for al-Mu'tadid on atmospheric phenomena.

Nayrizi wrote commentaries on Ptolemy and Euclid. The latter were translated by Gerard of Cremona. Nairizi used the so-called umbra (versa), the equivalent to the tangent, as a genuine trigonometric line (but he was anticipated in this by al-Marwazi).

He wrote a treatise on the spherical astrolabe, which is very elaborate and seems to be the best Persian work on the subject. It is divided into four books:

1. Historical and critical introduction.
2. Description of the spherical astrolabe; its superiority over plane astrolabes and all other astronomical instruments.
3. Applications.
4. Applications.

He gave a proof of the Pythagorean theorem using the Pythagorean tiling.^[1]

Ibn al-Nadim mentions Nayrizi as a distinguished astronomer with eight works by him listed in his book al-Fihrist.

Notes

1. Nelsen, Roger B. (November 2003), "Paintings, plane tilings, and proofs" (PDF), Math Horizons: 5–8. Reprinted in Haunsperger, Deanna; Kennedy, Stephen (2007), The Edge of the Universe: Celebrating Ten Years of Math Horizons, Spectrum Series, Mathematical Association of America, pp. 295–298, ISBN 978-0-88385-555-3. See also Alsina, Claudi; Nelsen, Roger B. (2010), Charming proofs: a journey into elegant mathematics, Dolciani mathematical expositions, 42, Mathematical Association of America, pp. 168–169, ISBN 978-0-88385-348-1. Nelsen uses the "Annairizi" form of his name; for the identification of it with Anaritius, see Isis, vol. 6, p. 515.

References

• H. Suter: Die Mathematiker und Astronomen der Araber (45, 1900)
• Nachtrage (164, 1902).
• O'Connor, John J.; Robertson, Edmund F., "Abu'l Abbas al-Fadl ibn Hatim Al-Nayrizi", MacTutor History of Mathematics archive, University of St Andrews.

Primary sources

• The (fragmentary) text of Nairizi's commentary on Euclid I. PDF scans from the edition of Codex Leidensis 399 (Classical Arabic)

External links

• Sabra, A. I. (2008) [1970-80]. "Al-Nayrīzī, Abu'l-'Abbās Al-Faḍl Ibn Ḥātim". Complete Dictionary of Scientific Biography. Encyclopedia.com.
• DeYoung, Gregg (2007). "Nayrīzī: Abū al‐ʿAbbās al‐Faḍl ibn Ḥātim al‐Nayrīzī". In Thomas Hockey; et al. The Biographical Encyclopedia of Astronomers. New York: Springer. p. 823. ISBN 978-0-387-31022-0. (PDF version)