The Indian cyclic model assumes the existence of countless island universes, which go through their own periods of development and destruction. The conception of cyclicity is taken to be recursive. For an early exposition of these astronomical and cosmological ideas, one may read al-Bīrūnī's classic history of Indian science, composed in 1030 AD, and for an even earlier, popular, view of Indian ideas, one may consult the Vedantic text called the Yoga Vāsiṣṭha (YV), which at 32,000 shlokas is one of the longest books in world literature.