Astronomy and Cosmology

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

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etc. belonging to human beings while utsedhārgula is used to measure the heights of sub-human and hellish objects and the cities and residences of four types of gods. In Svetāmbara School, 1000 utsedhārgulas while in Digambara tradition, 500 utsedhāngulas are taken equal to one pramāņāigula. Thus according to the Svetāmbara tradition, the pramāņa yojana is equal to modern 8000 miles while the Digambara pramāņa yojana comes out to be equal to 4000 miles and is used to measure the regions, the islands, the oceans, the high mountains, rivers etc., described in the Jaina cosmology. The Buddhist School takes its own angūli-parva equal to two argūlas of the Jainās. The Chinese generally take one yojana equal to 30 li or equal to 6.12 miles, they also take a yojana equal to 40 li or even equal to 16 li only. The concept of yojana occurs in Süryasiddhānta also and according to Vācaspati and Sabdārņava košas, a yojana may be taken equal to 5 miles as pointed out by Dixit. Fleet and Cunningham have estimated one yojana equal to 9.4 miles and 6.7 miles respectively, the former value being accepted by L. C. Jain, the author of the present text while the latter value being accepted by Lishk and Sharma. Thus we find that a yojana is taken equal to different measures, by different texts and scholars, generally also depending upon its use.
Based on the concepts of the Jaina School, Lishk and Sharma have calculated the obliquity of the eclipitic as 23° 5' (in structure of the mathematical model of Meru) very close to the modern value. They have also calculated the maximum north polar distance of the moon from the sun or eclipitic as 7.7° which may however approximate to the modern value 5° 8' 40" if a yojana is taken equal to 5 miles.
In Chapter VIII, the author mentions about the calendrical yuga system. As stated by him, the various Indian Schools including the Jaina School accepted the quinquennial yuga or cycle but as pointed out by the author, this yuga (or cycle) began with the nakşatra, Abhijit, a concept found in the Jaina School. This cycle was found to be of 780 solar years or 285480 days (one solar year=366 days).
In the last Chapter on Astronomical Theory, the author discusses many important modern concepts in the light of the concepts given in the Jaina literature. He quotes Albert Einstein as distinguishing between the various types of theories in Physics, specially the Principle Theories and the Constructive Theories. The Principle Theories, which are based on analytic methods, are logically perfect and have a secured foundation while the Constructive Theories follow the synthetic methods and could be made complete, clear and adaptable. However, if a singie principle fails or if a
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