Ajima Naonobu
Ajima Naonobu (安島 直円, 1732 – May 20, 1798), also known as Ajima Manzō Chokuyen, was a Japanese mathematician of the Edo period.[1]
Work
Ajima is credited with introducing calculus into Japanese mathematics. This significance of this innovation 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]
Legacy
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]
- 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]
- Fujin Isshũ (Periods of Decimal Fractions)[1]
See also
- Sangaku, the custom of presenting mathematical problems, carved in wood tablets, to the public in shinto shrines
- Soroban, a Japanese abacus
- Japanese mathematics (wasan)
Notes
- 1 2 Smith, David. (1914). A History of Japanese Mathematics, pp. 195-205., p. 195, at Google Books
- ↑ Restivo, Sal P. (1992). Mathematics in Society and History: Sociological Inquiries, p. 58. , p. 58, at Google Books
- ↑ Fukagawa, Hidetoshi; Rothman, Tony (2008), Sacred mathematics: Japanese temple geometry, Princeton University Press, p. 79, ISBN 978-0-691-12745-3.
- ↑ Weisstein, Eric W. "Ajima-Malfatti Points". MathWorld. .
- ↑ C. Kimberling, Encyclopedia of Triangle Centers, X(179) and X(180).
- 1 2 3 4 Jochi, Shigeru. (1997). "Ajima Naonobu," Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures, p. 38., 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., p. 38, at Google Books
- ↑ Jochi, p. 39., p. 39, at Google Books
References
- Endō Toshisada (1896). History of mathematics in Japan (日本數學史史 Dai Nihon sūgakush). Tōkyō: _____. OCLC 122770600
- Oya, Shin'ichi. (1970). "Ajima Naonobu" in Dictionary of Scientific Biography, Vol. 1. New York: Charles Scribner's Sons. ISBN 0-684-10114-9
- Restivo, Sal P. (1992). Mathematics in Society and History: Sociological Inquiries. Dordrecht: Kluwer Academic Publishers. ISBN 978-0-7923-1765-4; OCLC 25709270
- Selin, Helaine. (1997). Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures. Dordrecht: Kluwer/Springer. ISBN 978-0-7923-4066-9; OCLC 186451909
- David Eugene Smith and Yoshio Mikami. (1914). A History of Japanese Mathematics. Chicago: Open Court Publishing. OCLC 1515528 -- note alternate online, full-text copy at archive.org