Shou-Shi calendar was produced by Kuo Shoujing (郭守敬) in 1281 in the Yun
Dynasty (元) and was introduced into Japan around 1670. Kuo Shoujing applied
Arabian astronomy based on spherical trigonometry to the Chinese calendar. In
Japan, Seki Takakazu (関孝和,1642–1708) introduced Kuo’s mathematics into
Japanese mathematics.
Hirose’s second topic (1970) was the determinations of the days of the winter
solstice in the Shou-Shi calendar and other old calendars in China. He found that the
days of the solstice in old calendars are different when compared to the values
calculated from the modern calendar.
In the 1970s, Hirose turned his attention to the translation of some astronomical
classics from the Tokugawa period into modern Japanese with some critical notes.
These translations were presented in the Series on Japanese Thought, Volumes
63 and 65 (日本思想大系) in 1971–1972.
3.9 History of Astronomy in Postwar Period
Studies of the history of astronomy in Tokyo area started with Kanda Shigeru and
Hirose Hideo. This section discusses the works of Kanda and of the generations
following him (Miyajima 2008).
Kanda Shigeru (神田茂, 1894–1974) of the TAO collected records of astronomical phenomena, such as solar and lunar eclipses, arrangements of planets, occultation, comets, guest stars, and meteorological phenomena, observed in the years up to
1600 (Kanda 1935). This collection was extended by Osaki Shoji (大崎正次) to the
modern age between 1600 and 1867 (Osaki 1994). Osaki also collected the names of
historical constellations in China (Osaki 1986). In the early Zhou period (around
1000 BC), the numbers of constellations are limited to the ecliptic, north polar
region, and regions of bright stars like Orion. Over time, the constellations were
expanded to the whole sky and gradually introduced to Japan. Osaki identified their
names and compared them with Western constellations. Uchida Masao (内田正男),
who was working in the same section with Kanda in the TAO, edited an encyclopedia on the calendar and time in Japanese history (Uchida 1986).
Saito Kuniji (斎藤国治, 1913–2003) worked on solar physics at the TAO and,
following his retirement in 1974, started studying the history of ancient astronomy.
He was interested in various appearances of unusual stars and their effects on social
events. He summarized astronomical phenomena in the Asuka period (seventh
century, age of Prince Shotoku) (Saito 1982) and in ancient China (Saito and
Ozawa 1992). Saito also proposed the “ancient astronomy” as a new science field.
This field treats the studies on the reliability of ancient records and on the accurate
determination of the ages of historical events (Saito 1982). This new field yields
close connection of humanistic science (literature and history) and natural
science (astronomy). For example, Fig. 3.20 illustrates the paths of a total eclipse
(July 3, 1742) and a total ring eclipse (January 30, 1786). These eclipses were
observed in Hirosaki (弘前), Sendai (仙台), Kyoto (京都), and other locations,
3.9 History of Astronomy in Postwar Period
75
Dynasty (元) and was introduced into Japan around 1670. Kuo Shoujing applied
Arabian astronomy based on spherical trigonometry to the Chinese calendar. In
Japan, Seki Takakazu (関孝和,1642–1708) introduced Kuo’s mathematics into
Japanese mathematics.
Hirose’s second topic (1970) was the determinations of the days of the winter
solstice in the Shou-Shi calendar and other old calendars in China. He found that the
days of the solstice in old calendars are different when compared to the values
calculated from the modern calendar.
In the 1970s, Hirose turned his attention to the translation of some astronomical
classics from the Tokugawa period into modern Japanese with some critical notes.
These translations were presented in the Series on Japanese Thought, Volumes
63 and 65 (日本思想大系) in 1971–1972.
3.9 History of Astronomy in Postwar Period
Studies of the history of astronomy in Tokyo area started with Kanda Shigeru and
Hirose Hideo. This section discusses the works of Kanda and of the generations
following him (Miyajima 2008).
Kanda Shigeru (神田茂, 1894–1974) of the TAO collected records of astronomical phenomena, such as solar and lunar eclipses, arrangements of planets, occultation, comets, guest stars, and meteorological phenomena, observed in the years up to
1600 (Kanda 1935). This collection was extended by Osaki Shoji (大崎正次) to the
modern age between 1600 and 1867 (Osaki 1994). Osaki also collected the names of
historical constellations in China (Osaki 1986). In the early Zhou period (around
1000 BC), the numbers of constellations are limited to the ecliptic, north polar
region, and regions of bright stars like Orion. Over time, the constellations were
expanded to the whole sky and gradually introduced to Japan. Osaki identified their
names and compared them with Western constellations. Uchida Masao (内田正男),
who was working in the same section with Kanda in the TAO, edited an encyclopedia on the calendar and time in Japanese history (Uchida 1986).
Saito Kuniji (斎藤国治, 1913–2003) worked on solar physics at the TAO and,
following his retirement in 1974, started studying the history of ancient astronomy.
He was interested in various appearances of unusual stars and their effects on social
events. He summarized astronomical phenomena in the Asuka period (seventh
century, age of Prince Shotoku) (Saito 1982) and in ancient China (Saito and
Ozawa 1992). Saito also proposed the “ancient astronomy” as a new science field.
This field treats the studies on the reliability of ancient records and on the accurate
determination of the ages of historical events (Saito 1982). This new field yields
close connection of humanistic science (literature and history) and natural
science (astronomy). For example, Fig. 3.20 illustrates the paths of a total eclipse
(July 3, 1742) and a total ring eclipse (January 30, 1786). These eclipses were
observed in Hirosaki (弘前), Sendai (仙台), Kyoto (京都), and other locations,
3.9 History of Astronomy in Postwar Period
75