Ajima Naonobu
Ajima Naonobu (安島 直円?, 1732 – May 20, 1798), also known as Ajima Chokuyen, was a Japanese mathematician of the Edo period.[1]
Ajima is credited with introducing calculus into Japanese mathematics. This significance of this innovaction is not diminished by a likelihood that he had access to European writings on the subject.[2] Ajima also posed the question of inscribing three mutually tangent circles in a triangle;[3] these circles are now known as Malfatti circles after the later work of Gian Francesco Malfatti, but two triangle centers derived from them, the Ajima–Malfatti points, are named after Ajima.[4][5]
Ajima was an astronomer at the Shogun's Observatory (Bakufu Temmongaki).[6]
In 1976, the International Astronomical Union (IAU) honored Ajima by identifying a crater on the moon with his name. Naonobu is a small lunar impact crater located on the eastern Mare Fecunditatis, to the northwest of the prominent crater Langrenus.[7]
Selected works
In a statistical overview derived from writings by and about Ajima Naonobu, OCLC/WorldCat encompasses roughly 20+ works in 30+ publications in 2 languages and 40+ library holdings.[8]
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- Ajima Naonobu zenshū (安島直円全集?) "017232052" OCLC 017232052, collected works
- Sanpō kosō (算法考艸?) OCLC 22057185881, algorithms considered
- Jujireki bimmo (Introduction of the 'Works and Days Calendar')[6]
- Anshi seiyo-reki koso (Ajima's Studies for Western Calendars)[6]
- Ajima sensei bimmo do jutsu (Methods of Professor Ajima's 'bimmo' )[6]
- Koshoku mokyu zokkai (Introduction of Eclipses of the Sun and the Moon)[9]
- Sansha San'en Jutsu (Methods of Three Diagonals and Three Circles)[10]
See also
Notes
- ^ Smith, David. (1914). A History of Japanese Mathematics, pp. 195-205. at Google Books
- ^ Restivo, Sal P. (1992). Mathematics in Society and History: Sociological Inquiries, p. 58. at Google Books
- ^ Fukagawa, Hidetoshi; Rothman, Tony (2008), Sacred mathematics: Japanese temple geometry, Princeton University Press, p. 79, ISBN 9780691127453, http://books.google.com/books?id=OxKKDCmGDlEC&pg=PA79 .
- ^ Weisstein, Eric W., "Ajima-Malfatti Points" from MathWorld..
- ^ C. Kimberling, Encyclopedia of Triangle Centers, X(179) and X(180).
- ^ a b c d Jochi, Shigeru. (1997). "Ajima Naonobu," Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures, p. 38. at Google Books
- ^ United States Geological Survey: Planetary names, Naonobu; Naonobu lunar crater (in Japanese)
- ^ WorldCat Identities: 安島直円 1739-1798
- ^ Jochi, pp. 38-39. at Google Books
- ^ Jochi, p. 39. at Google Books
References
| Persondata |
| Name |
Ajima, Naonobu |
| Alternative names |
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| Short description |
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| Date of birth |
1732 |
| Place of birth |
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| Date of death |
1798 |
| Place of death |
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