The word pralaya is comprised of the prefix ‘pra’ attached to the verbal root, ‘lī’, meaning ‘destruction’. The prefix acts as an intensifier in this case, and the word pralaya consequently means, absolute destruction. In philosophy and in religious literature, the term Pralaya is attached to the concept of destruction that invariably follows a cycle of creation, and is viewed more as a necessary reprieve from the drudgery of existence. However, the nature of this destruction or pralaya is horrifying. Before delving into the nature of pralaya, pralaya is in itself categorized into two kinds, naimittika-pralaya and prākṛta-pralaya.
Naimittika-pralaya or elemental dissolution is the destruction of the three lower worlds of, Bhū, Bhuvaḥ and Suvaḥ, at the end of a thousand catruyugas. The Viṣṇu-Purāṇa states that at the end of a thousand caturyugas or at the end of Brahmā’s day, a complete dearth envelops the lower worlds, that lasts a hundred (mortal) years. As a consequence of famine, all created beings inhabiting these three worlds perish. The Supreme Being then assumes the nature of Rudra and enters the seven rays of the sun. He consumes all the water present in the three worlds and causes all the moisture to evaporate. Fed by the moisture, the seven rays of the sun manifest as seven mighty suns, radiating unimaginable heat. The burgeoning heat then sets the three worlds on fire, along with the nether world of Pātāla. This heat leaves the three worlds bereft of everything, and as dry as the shell of a tortoise. Rudra then becomes the scorching breath of Ādiśeṣa and reduces Pātāla and the three worlds to ashes. The eddying flames continue to blaze, heating up the Maharloka and causing the denizens of that world to resort to the higher world of Janaḥ. Rudra, after having thus consumed the lower worlds, heaves a sigh that is converted to enormous clouds that resemble elephants in size. Accompanied by strokes of lightning and claps of thunder, these cataclysmic clouds rain down showers in droplets the size of dice, until the fiery-wreath of cataclysm is put out. The shower accumulates to form a deluge, inundating Pātāla and the three worlds. The affected regions remain inundated and plunged in abysmal darkness for a hundred years, until the Supreme Being as Brahmā, awakens the next morning and creates the destroyed worlds all over again. In this naimittika-pralaya all of creation does not cease to exist. All of creation is reduced to non-existence in prākṛta-pralaya, and the phenomenon is explained as follows in the Viṣṇu-Purāṇa.
When famine and fire consume the three worlds and all seven nether worlds and when the will of the Supreme is to annihilate creation entirely, created beings and objects begin to disintegrate. All of creation is then broken down to the basic nature of the element of earth, which is smell. Smell is consumed in cataclysmic deluge. Water is reduced to its elemental nature, namely taste and is swallowed by cataclysmic fire. Form, the elemental nature of fire is put out by cataclysmic wind, which then is disintegrated to its elemental nature of touch. Touch is absorbed in ether and stands enveloping all that remains. Ether, the elemental property of which is sound, remains unembodied, until it is consumed by the great ‘I’ or ahaṅkāra. Ahaṅkāra which is essentially a combination of consciousness and darkness, is swallowed by mahat. Mahat, the innate nature of which is intelligence, is consumed in prakṛti. Prakṛti that is gross is sucked into its subtle form. The subtle form of prakṛti is then absorbed in the Supreme Spirit. All of creation, including the creator as Brahmā thus remain imperceptible until the cycle of creation is willed by the Supreme yet again. This prakṛti-pralaya or elemental dissolution takes place at the end of a time frame referred to as param, the lifespan of Brahmā. The Vedas state that after a period of abysmal darkness, the Supreme wills creation, and the process of creation that is the exact inverse of the process of pralaya described here, commences. The Viṣṇu-Purāṇa states that the period between prakṛti-pralaya and Śṛṣṭi (creation) is the time Śrīmannārāyaṇa closes his eyes in slumber. It is stated that creation is commenced and sustained during the waking hours of Nārāyaṇa and is stilled during his restful hours.
यदा जागर्ति विश्वात्मा तदा चेष्टते जगत्।
yadā jāgarti viśvātmā tadā ceṣṭate jagat|
When the Supreme Soul, the essence of creation, is awake, the universe functions. When Acyuta resorts to the (quietude) of mystic slumber, all of this (creation) is felled into stupor.
To get a better understanding of the time frame of a caturyuga, please refer to our article entitled, Kāla – The Eternal Fabric of Creation.