Astronomy and Cosmology

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

Page 67

to the sun being 62 celestial parts in oth day, it covers the stretch of 54900 celestial parts in 29 or 29.516 days, where as the modern value for lunar synodic month is 29-5305 days. This is the data for a mean motion of the moon. 105
743 The motion of the stu rähu with respect to the moon is -18 celestial parts less in a muhūrta, hence the moon covers 54900 celestial parts ahead of it in 29 13 or 29.555 days, which represents lunar fictitious synodic month. The mean of true and fictitious being 29.535, it differs from modern value by .005 only. 106
The motion of the moon is also in spiral orbits, its zodiac being the stretch of $1158 yojanas. The roads or the orbits of the moon are defined
to be 15, with an interval of 35 497 yojanas cach, in the Jambūdvipa and Lavaṇasamudra. 107 The motion of the moon in yojanas per muhūrta for different paths is detailed. 108 This is a very important record in linear
105. Cf. T. P., 7.508. Cf. Neugebauer, pp. 118, 121, 162 and Needham and
Ling, pp. 392-401, vol. III. 106. Cf. T. S., 4.402 and 4.405. For comparison with Babylonian lunar
velocity, cf. Neugebauer, pp. 118, 119, 121, the mean velocity being 13; 10.350 per day. The mean synodic month was close to 29, 31, 54
days. Cf. ibid., p. 122. 107. Cf. T. P., II, 7:125, 7.120 & T. S., 4.396, 4.377. The eccentric circle
theory of sun's motion was recognized in China after about +570. Akin to three types of nakşatres in Jaina School, in China, the planispheres consisted of 'three roads' each marked with twelve stars, one for each of the months corresponding to their heliacal risings. The central road was called Anu, the outer road as Ea, and inner road as
Enlil. Cf. Needham and Ling, vol. III, p. 256. 108. Cf. T. P. 7.186 to 7.200. These details are not available in T. S., nor
in C. P.
48