ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

ĀRYABHAṬA & BRAHMAGUPTA CONTROVERSY 85 commentary on the Brāhmasphuṭasiddhānta we have the privilege of presenting to the public, it is clear that in certain respects Bhāskara and others may be wrong but the Āryabhaṭa's authenticity cannot be questioned. Pṛthūdakasvāmin while commenting on the Brāhmasphuṭasiddhānta, XI. 26 writes: Such a mistake may have been made by Bhāskara and others; they have not understood his (Āryabhaṭa's) intention. The passage in the Mahābhāskarīya giving constants of the ardharātrika system runs as follows (we are giving the translation from Kripa Shankar Shukla's edition on the Mahābhāskarīya) : The astronomical processes which have been set forth above come under the sunrise day - reckoning (audayika system). In the midnight day-reckoning (ardharātrika system) too, all this is found to occur: the difference that exists is being stated (below). ¹ The next fourteen stanzas relate to the midnight day- reckoning of Āryabhaṭa I. (i) Civil days and omitted lunar days in a yuga and revolution numbers of Mercury and Jupiter are thus given : (To get the corresponding elements of the midnight day-reckoning) add 300 to the number of civil days (in a yuga) and subtract the same (number) from the number of omitted lunar days (in a yuga); and from the revolution numbers of (the śīghrocca of) Mercury and Jupiter subtract 20 and 4 respectively. ² Thus according to the midnight day-reckoning, we get civil days in a yuga = 1,577,917,800 omitted lunar days in a yuga = 25,082,280 revolution number of the śīghrocca of Mercury = 17,937,000 revolution number of Jupiter = 364,220

1. निबन्धः कर्मणां प्रोक्तो योऽसावौदयिको विधिः । अर्धरात्रे त्वयं सर्वो यो विशेषः स कथ्यते ॥ —MBh. VII. 21
2. त्रिशती भूर्दिने क्षेप्या ह्यवमेभ्यो विशोध्यते । ज्ञ गुर्वोर्भगणेभ्योऽपि विंशतिश्च ततोऽब्धयः ॥ —MBh. VII. 22