Yugas (World Ages)

The yugas are the four world-ages of Hindu cosmology, Satya (or Krita), Treta, Dvapara and Kali, which run in sequence, each shorter and more degenerate than the last, before the cycle begins again. Satya Yuga is an age of truth and virtue; each following age sees dharma decline, until Kali Yuga, the present age, the shortest and darkest, after which the cycle renews.

The lengths given in the Puranas are enormous and vary between texts, reaching into hundreds of thousands of years, with the four together making a mahayuga and a thousand mahayugas making a kalpa, a day of Brahma.

The scheme frames history as a long decline from an original perfection, with the present understood as Kali Yuga, and it carries a strong moral and religious charge: the erosion of virtue across the ages, and the promise of renewal when the cycle turns. Similar four-age schemes of decline appear in other traditions, notably the Greek and Roman ages of gold, silver, bronze and iron.

The atlas gives each yuga its character, its traditional length, and its place in the cycle. The yugas are the largest of the temporal cycles gathered under Cosmic Cycles.