Astronomy and Cosmology

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

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single inconsistency arises, the whole structure has to be re-modelled, because of almost impossibility then to retain its originality while the constructive theories can be subjected to re-modelling without shattering the complete structure.
The author further discusses to which type of the above two categories, the ancient Jaina Astronomical Theory belong On one hand the abstraction method leads us to such small entity as the Samaya (44) and Pradeśa (sau) which are both regarded as indivisible just like the ultimate particle Paramāņu, while on the other hand there are such big quantities as the Rajju and Sāgara or Jagaśrěni and the periods like Pudgala or Bhāva Parāvartana, infinities in space and time. Most of the Jaina Astronomical principles have been found to be true but in some cases, for example, in the prediction of the time of eclipses, when the Jaina Principle Theory was found inadequate to explain and get consistent results of the processes and phenomena, it was replaced by the Constructive theories evolved all the world over. Lastly the author discusses the evolution of epicycles depicting the unified motion of the moon or the sun as described in Prakrit texts and comprising the two motions, (i) the rotation of the earth, which in turn relatively gives a kinetic view of them, and (ii) their motion along the fixed stars,
Due to the continuity of the motion in circles, for each day, with a radius varying from day to day, the geometrical figure of the path comes out to be a spiro-elliptic one, winding and unwinding represented by the equation
f+go * htk cos 8.
en The dynamical laws of Newton, Einstein etc. have been found from this equation,
In the end the author has given very useful and brief bibliographies of the source material, research articles and related books. Thus we see that the author has tried and tried very successfully, to give as much information and exposition as possible about the ancient Jaina Astronomical and Cosmological systems and other allied world systems, which is very praiseworthy and creditable.
Prof. L.C. Jain has got a keen interest not only in the study of the ancient Indian Mathematical and Astronomical works in general and the Jaina works in particular but also in the study of modern mathematics. He has got a vast experience of about three decades in this field and has himself brought out a large number of expository, survey and research articles on ancient Jaina mathematics, quite a good number of them dealing with the modern aspects inherent in the ancient Jaina principles.
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