In traditional Buddhist (as well as Hindu) cosmology, kalpas are unfathomably long periods of time. Though they come in different sizes, even a “regular” kalpa is beyond huge: 16,000,000 years. A “great kalpa” is almost 1,300,000,000,000 years.
Sometimes these enormous lengths of time are described in colorful metaphors, such as:
- longer than the time it would take to fill a cube that is 16 miles wide and 16 miles high with mustard seeds, at the rate of one mustard seed every 100 years;
- longer than it would take, at the same once-a-century frequency, for the brushing of an eagle’s wing against a mountain to wear that mountain away;
- longer than it would take for a turtle (one who appears, again, once every 100 years) to randomly poke its head through a ring floating on the ocean’s surface.
Kalpas relate to the nature of the universe itself, describing immeasurably long cycles of creation and destruction. Like modern science, ancient Buddhist cosmology described a universe of almost infinite size, variety, and duration.
The kalpa is often evoked as an encouragement to spiritual practice, reminding us how rare it is to be born human and to hear the Buddhist teachings. “The dharma,” as one Zen chant puts it, “is rarely encountered, even in hundreds of thousands of millions of kalpas.”