, also known as Ajima Manzō Chokuyen, was a Japanese
mathematician of the
Edo period.
[Smith, David. (1914). ]
His
Dharma name was (祖眞院智算量空居士).
Work
Ajima is credited with introducing
calculus into Japanese mathematics. The significance of this innovation is diminished by a likelihood that he had access to European writings on the subject. Ajima also posed the question of inscribing three mutually tangent circles in a triangle; these circles are now known as
Malfatti circles
In geometry, the Malfatti circles are three circles inside a given triangle such that each circle is tangent to the other two and to two sides of the triangle. They are named after Gian Francesco Malfatti, who made early studies of the problem o ...
after the later work of
Gian Francesco Malfatti
Giovanni Francesco Giuseppe Malfatti, also known as Gian Francesco or Gianfrancesco (26 September 1731 – 9 October 1807) was an Italian mathematician. He was born in Ala, Trentino, Italy and died in Ferrara.
Malfatti studied at the College of Sa ...
, but two
triangle centers derived from them, the Ajima–Malfatti points, are named after Ajima.
Ajima was an astronomer at the Shogun's Observatory (''Bakufu Temmongaki'').
[Jochi, Shigeru. (1997). ]
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
Lunar most commonly means "of or relating to the Moon".
Lunar may also refer to:
Arts and entertainment
* ''Lunar'' (series), a series of video games
* "Lunar" (song), by David Guetta
* "Lunar", a song by Priestess from the 2009 album ''Prior t ...
impact crater located on the eastern
Mare Fecunditatis, to the northwest of the prominent crater
Langrenus.
Selected works
In a statistical overview derived from writings by and about Ajima Naonobu,
OCLC
OCLC, Inc., doing business as OCLC, See also: is an American nonprofit cooperative organization "that provides shared technology services, original research, and community programs for its membership and the library community at large". It was ...
/
WorldCat encompasses roughly 20+ works in 30+ publications in two languages and 40+ library holdings.
*
OCLC 017232052 collected works
*
OCLC 057185881 algorithms considered
* (''Introduction of the 'Works and Days Calendar)
* (''Ajima's Studies for Western Calendars'')
* (''Methods of Professor Ajima's'' '')
* (''Introduction of Eclipses of the Sun and the Moon'')
* (''Methods of Three Diagonals and Three Circles'')
[Jochi, ]
* (''Periods of Decimal Fractions'')
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
Notes
References
* Endō Toshisada (1896). . Tōkyō: _____
OCLC 122770600* Oya, Shin'ichi. (1970). "Ajima Naonobu" in ''
Dictionary of Scientific Biography,'' Vol. 1. New York: Charles Scribner's Sons.
* Restivo, Sal P. (1992)
''Mathematics in Society and History: Sociological Inquiries.''Dordrecht: Kluwer Academic Publishers.
OCLC 25709270*
Selin, Helaine. (1997)
''Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures.''Dordrecht:
Kluwer/
Springer.
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
{{DEFAULTSORT:Ajima, Naonobu
1732 births
1798 deaths
18th-century Japanese mathematicians
Japanese writers of the Edo period
Japanese Buddhists