Brahmagupta (II, 467) remarks that according to Aryabhata all the planets were not at the first point of Meṣa at the beginning of the yuga. I do not know on what evidence this criticism is based.[1]
Brahmagupta (XI, 8) remarks that according to the Arydstasata the nodes move while according to the Dasagitika the nodes (excepting that of the Moon) are fixed :
āryāṣṭaśate pātā bhramanti daśagītike sthirāḥ pātāḥ ।
muktvendupātam apamaṇḍale bhramanti sthirā nātaḥ. ॥
This refers to I, 2 and IV, 2. Aryabhata (I, 7) gives the location, at the time his work was composed, of the apsides and nodes of all the planets, and (I, 7 and IV, 2) implies a knowledge of their motion. But he gives figures only for the apsis and node of the Moon. This may be due to the fact that the numbers are so small that he thought them negligible for his purpose.
Brahmagupta (XI, 5) quotes stanza 1 of our text:
yugaravibhagaṇāḥ khyughriti yat proktam tat tayor yugaṁ spaśṭaṁ ।
triśatī ravyudāyānaṁ tadantaraṁ hetunā kena. ॥[2]
- ↑ See Sūryasiddhānta, pp. 27-28, and JRAS, 1911, p. 494.
- ↑ Cf. JRAS, 1865, p. 401. This implies, as Sudhakara says, that Brahmagupta knew two works by Aryabhata each giving the revolutions of the Sun as 4,320,000 but one reckoning 300 savana days more than the other. Cf. Kharegat (op. cit., XIX, 130). Is the reference to another book by the author of our treatise or was there another earlier Aryabhata? Brahmagupta (XI, 13-14) further implies that he knew two works by an author named Aryabhata in one of which the yuga began at sunrise, in the other at midnight (see JRAS, 1863, p. 384 ; JBBRAS, XIX, 130-31 ; JRAS, 1911, p. 494 ; IHQ, IV, 506). At any rate, Brahmagupta does not imply knowledge of a second Aryabhata. For the whole problem of the two or three Aryabhatas see Kaye (Bibl. math., X, 289) and Bibhutibhusan Datta
