Jaganmohanlal Pandita Sadhuwad Granth

Author(s): Sudarshanlal Jain
Publisher: Jaganmohanlal Shastri Sadhuwad Samiti Jabalpur

Page 444

Similarities Between Jaina Astronomy and Vedanga Jyotisa
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4. According to both Vedanga Jyotisa and Jaina astronomy, maximum and minimum lengths of daylight are eighteen and twelve muhurtas (one muhurta = 48 minutes) respectively. The length of daylight increases or decreases by 2/61 muhurta a day.
5. Atharva Veda Jyotisa records some shadow-lengths of a gnomonic experiment that was devised for standardisation of muhurta (= 48 minutes) as the fundamental unit of time. We find gnomonic data in Jaina canonical texts also. Jainas had used gnomonic shadow-lengths for the determination of the time of the day and of the seasons as well. It is worthy of note that Atharva Veda Jyotisa records shadow-lengths as a function of time whereas Jainas had measured time as a function of shadow-length.
6. Vedanga Jyotisa employs a linear zigzag function to determine the length of any day in the year. In addition to it, Jaina astronomy employs linear zigzag functions at several other places also, e. g., to determine the declination of the sun and that of the moon, to determine the rate of change of moon-shadow-length at the end of a month in connection with determination of seasons etc.
7. The Vedic trandition of observation of celestial phenomena was also preserved by exponents of Jaina School of astronomy. According to Aittareya Brahmana, solstices were determined upto a span of three days but Jainas had determined summer solstice upto thirty muhurtas a day only. Jainas had also made several observations regarding some other celestial phenomena like lunar occultations, chatratichatra yoga (lunar occultation with chitra, je alpha Virginis), heliacal motion of venus, and the phenomena of eclipse formation. Besides Jains had classified Jyotisikas (astral bodies) and developed the concept of taraka grahas (star planets) etc.
8. Arithmatical treatment was employed in both Vedanga Jyotisa and Jaina astronomy. A similar practice was also continued down to the period of development of Siddhantic astronomy.
9. Both Vedanga Jyotisa and Jaina astronomy are interwoven with the systems of twentyseven and twentyeight naksatras (lunar mansions of the Hindus) respectively. Any diect use of rasis (signs) has not so far been unearthed therein.
These are the few aspects which exhibit similarities between Vedanga Jyotisa and Jaina astronomy. However need it be emphasized that Vedanga Jyotisa traditions have not only been continued by the exponents of Jaina School of astronomy, but they have also been advanced ahead and some of them reached more perfection or the higher stage of learning in Siddhantic astronomy. Jaina texts, as O. P. Jaggi (Scientists of Ancient India and their Achievements, p. 144, 1966) also opines, have rather helped to elucidate certain passages in Jyotisa Vedanga. Evidently Jaina astronomy holds an intermediary stage in between Vedanga Jyotisa and Siddhantic astronomy. However it is worthy of note that Jaina School of astronomy played a vehement role in the development of Siddhantic astronomy as the present author Dr. S. S. Lishk (Role of Pre-Aryabhata I Jain School of