大劫

In this world, one development and one decline are called one Kalpa. When the human lifespan reaches its peak of 84,000 years, then every hundred years the average height decreases by one inch and the lifespan decreases by one year. This continues until the human lifespan reaches 10 years; then it begins to increase again. Once again, every hundred years, the lifespan increases by one year and the average height increases by one inch. When the lifespan reaches 84,000 years, it is called one Kalpa. A thousand Kalpas make one Small Kalpa ( 小劫 ), which is 16,800,000 years in this world. 20 Small Kalpas make one Middle Kalpa ( 中劫 ), which is 336,000,000 years in this world. 4 Middle Kalpas make one Great Kalpa ( 大劫 ), which is 1,344,000,000 years in this world. It takes 20 Small Kalpas for this world to come into being. It dwells for another 20 Small Kalpas. It then decays for 20 Small Kalpas, and is finally empty for 20 years. That is what is meant by production ( 成 ), dwelling ( 住 ), decaying ( 壞 )and emptiness ( 空 ). The 20 Small Kalpas of production make one Middle Kalpas, and so for dwelling, decaying and emptiness. Thus, the fourprocesses together make one Great Kalpa.

See also Kalpa.