Kalpa is a Sanskrit word meaning a relatively long period of time in Hindu and Buddhist cosmology. In the Pali language of early Buddhism, the word takes the form kappa, and is mentioned in the assumed oldest scripture of Buddhism, the Sutta Nipata. This speaks of "Kappâtita: one who has gone beyond time, an Arahant". This part of the Buddhist manuscripts dates back to the middle part of the last millennium BCE. Generally speaking, a kalpa is the period of time between the creation and recreation of a world or universe. The definition of a kalpa equaling 4.32 billion years is found in the Puranas—specifically Vishnu Purana and Bhagavata Purana.
Buddhism
In one explanation, there are four different lengths of kalpas. A regular kalpa is approximately 16 million years long, and a small kalpa is 1000 regular kalpas, or about 16.8 billion years. Further, a medium kalpa is roughly 336 billion years, the equivalent of 20 small kalpas. A great kalpa is 4 medium kalpas, or around 1.344 trillion years. The Buddha did not give the exact length of the maha-kalpa in terms of years. However, he gave several astounding analogies to understand it.
Imagine a huge empty cube at the beginning of a kalpa, approximately 16 miles in each side. Once every 100 years, you insert a tiny mustard seed into the cube. According to the Buddha, the huge cube will be filled even before the kalpa ends.
Imagine a gigantic rocky mountain at the beginning of kalpa, approximately 16 x 16 x 16 miles. You take a small piece of silk and wipe the mountain once every 100 years. According to the Buddha, the mountain will be completely depleted even before the kalpa ends.
In one instance, when some monks wanted to know how many kalpas had elapsed so far, Buddha gave the below analogy:
If you count the total number of sand particles at the depths of the Ganges river, from where it begins to where it ends at the sea, even that number will be less than the number of passed kalpas.
Another definition of Kalpa is the world where Buddhas are born. There are generally 2 types of kalpa, Suñña-Kalpa and Asuñña-kalpa. The Suñña-Kalpa is the world where no Buddha is born. Asuñña-Kalpa is the world where at least one Buddha is born. There are 5 types of Asuñña-Kalpa:
In Hinduism, a Kalpa is equal to 4.32 billion years, a "day of Brahma" or one thousandmahayugas, measuring the duration of the world. Each kalpa is divided into 14 manvantara periods, each lasting 71 yuga cycles. Preceding the first and following each manvantara period is a juncture equal to the length of a Satya-yuga years. A kalpa is followed by a pralaya of equal length, which together constitute a day and night of Brahma. A "month of Brahma" is supposed to contain thirty such days, or 259.2 billion years. According to the Mahabharata, 12 months of Brahma constitute his year, and 100 such years the life cycle of the universe. Fifty years of Brahma are supposed to have elapsed, and we are now in the shvetavaraha kalpa or the fifty-first. At the end of a kalpa, the world is annihilated.
In Hinduism, a Kalpa is indicative for creation and dissolution of a universe. However, there are a few cycles of time mentioned in Hinduism, which consists of several iterations of such "Kalpa"-s. First one of them is referred as "One Month of Brahma", which consists of 30 Kalpas and successive dissolution phases. Each Kalpa in the series are distinctly identified by different names. Current "Kalpa" is referred to as "Sweta-Baraha", next one will be "Neel-Lohita". Combining 12 such "Months of Brahma", one year of Brahma is formed. 100 such years of "Brahma" is called as a "Maha-Kalpa". Length of a Maha-Kalpa is 311.04 trillion years. 8000 such "Maha-Kalpa"-s form one "Yuga of Brahma", whose length is 2.4 Quintillion years. There are other greater cycles whose lengths are 22.3 Sextillion years, 670 Sextillion years and 201 Septillion years respectively.
Other periods of time
Names
The previous kalpa was the Vyuhakalpa, the present kalpa is called the Bhadrakalpa, and the next kalpa will be the Nakshatrakalpa. The Matsya Purana lists the names of 30 kalpas, as follows:
Rathantara
Raurava
Deva
Kandarpa
Sadya
Tamah
Kaurma
Soma
Aghora
Vairaja
The Vayu Purana in chapter 21 gives yet anotherlist of 28 kalpas. It also lists five more kalpas in the next chapter.
In City at the End of Time, a science fiction novel by Greg Bear, Kalpa is a fortress city built on Earth by descendants of humans in the last period of the Universe to protect themselves from the Chaos that is devouring it.
