Английская Википедия:Abu-Mahmud Khujandi
Шаблон:Short description Abu Mahmud Hamid ibn al-Khidr al-Khujandi[1] (known as Abu Mahmood Khujandi, al-khujandi or Khujandi, Persian: ابومحمود خجندی, Шаблон:Circa - 1000) was a Muslim Transoxanian astronomer and mathematician born in Khujand (now part of Tajikistan) who lived in the late 10th century and helped build an observatory, near the city of Ray (near today's Tehran), in Iran.
Astronomy
Шаблон:See Khujandi worked under the patronage of the Buwayhid Amirs at the observatory near Ray, Iran, where he is known to have constructed the first huge mural sextant in 994 AD, intended to determine the Earth's axial tilt ("obliquity of the ecliptic") to high precision.
He determined the axial tilt to be 23°32'19" for the year 994 AD. He noted that measurements by earlier astronomers had found higher values (Indians: 24°; Ptolemy 23° 51') and thus discovered that the axial tilt is not constant but is in fact (currently) decreasing. His measurement of the axial tilt was however about 2 minutes too small, probably due to his heavy instrument settling over the course of the observations.[2][3]
Mathematics
Khujandi stated a special case of Fermat's Last Theorem for n = 3, but his attempted proof of the theorem was incorrect. The spherical law of sines may have also been discovered by Khujandi, but it is uncertain whether he discovered it first, or whether Abu Nasr Mansur, Abul Wafa or Nasir al-Din al-Tusi discovered it first.[4][5]
Notes
References
External links
Шаблон:Islamic astronomy Шаблон:Islamic mathematics Шаблон:People of Khorasan Шаблон:Authority control
- ↑ Шаблон:MacTutor
- ↑ Al-Khujandī, Abū Maḥmūd Ḥāmid Ibn Al-Khiḍr, Complete Dictionary of Scientific Biography, 2008
- ↑ Шаблон:MacTutor
- ↑ Also the 'sine law' (of geometry and trigonometry, applicable to spherical trigonometry) is attributed, among others, to khujandi. (The three others are Abul Wafa Bozjani, Nasiruddin Tusi and Abu Nasr Mansur). Razvi, Syed Abbas Hasan (1991) A history of science, technology, and culture in Central Asia, Volume 1 University of Peshawar, Peshawar, Pakistan, page 358, Шаблон:OCLC
- ↑ Bijli suggests that three mathematicians are in contention for the honor, khujandi, Abdul-Wafa and Mansur, leaving out Nasiruddin Tusi. Bijli, Shah Muhammad and Delli, Idarah-i Adabiyāt-i (2004) Early Muslims and their contribution to science: ninth to fourteenth century Idarah-i Adabiyat-i Delli, Delhi, India, page 44, Шаблон:OCLC
- Английская Википедия
- 940s births
- 1000 deaths
- 10th-century Iranian astronomers
- Astronomers of the medieval Islamic world
- Inventors of the medieval Islamic world
- Scientific instrument makers
- Scholars under the Buyid dynasty
- 10th-century inventors
- 10th-century Iranian mathematicians
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