Astronomy and Cosmology

Author(s): L C Jain
Publisher: Rajasthan Prakrit Bharti Sansthan Jaipur

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Now with respect to the nakşatras, the sun moves 5 celestial parts less per muhūrta. Thus it traverses 150 celestial parts in a day and 54900 parts or 3600 in 366 days, which is in relation to fixed stars. The average solar month is thus of 30 days.
Similarly the moon covers 67 celestial parts less with respect to the nakgatras, per muhūrta, covering the strip of 54900 celestrial parts in 27 31 solar days or 27.313 days, where as the modern value for a lunar side real month is 27:32166 days.
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The stu rāhu moves 1829 16 celestial parts per 48 minutes, and
describes the strip of 54900 celestial parts in a 1990 solar day. Relative to nakşatras the stu rāhu moves celestial parts in a muhūrta. Hence it covers the strip of 54900 celestial parts or 3600 in 360 solar days. This is
22259 a stu year. The mean solar day is thus equal to solar day is thus equal to 210601
- The modern value of this is 24 hours, 3 minutes, 56-5 seconds. It appears that this rāhu was perhaps responsible for division of year and the strip into twelve equal parts, for it gives 12 stations as well, and consequently led to the invention of 12 rāśis, or 12 zodiacal signs. No where in the history of astronomy, one comes across with such a rāhu as in the Trilokasāra, described above. Here one degree has been set in equivalence with one day, 91 as in China.
The motion of the stars has been mentioned to be greater than that of the nakşatras, showing that the school was aware of the proper motion
91. For such a description of the sun, Needham and Ling quote, “The
uniform and apparently circular rotation of the heavenly bodies is mentioned many times in texts which are probably much older than Chang Hệng or even Lohsia Hung, for example the Chi Ni Tzut book e and the Wên Tzu5 book. The former (perhaps of —3rd or -4th century) speaks of the sun's path as a turning ring (hsün huan) with limits but no starting-point (wei shih yu chi7) ever rotating (chou huis) and never still, the sun moving 10 each day.' (The extremely early appearence of this graduation system, which led to 36570 instead of 3600 in the Chinese circle, should be noted.] Cf. pp. 218, 219.
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