The realms of existence are customarily divided into three distinct "worlds" , listed here in descending order of refinement:

The Immaterial World : Consists of four realms that are accessible to those who pass away while meditating in the formless jhanas.

The Fine-Material World : Consists of sixteen realms whose inhabitants (the devas) experience extremely refined degrees of mental pleasure. These realms are accessible to those who have attained at least some level of jhana and who have thereby managed to (temporarily) suppress hatred and ill-will. They are said to possess extremely refined bodies of pure light. The highest of these realms, the Pure Abodes, are accessible only to those who have attained to "non-returning," the third stage of Awakening. The Fine-Material World and the Immaterial World together constitute the "heavens".

The Sensuous World : Consists of eleven realms in which experience — both pleasurable and not — is dominated by the five senses. Seven of these realms are favorable destinations, and include our own human realm as well as several realms occupied by devas. The lowest realms are the four "bad" destinations, which include the animal and hell realms.

The Immaterial World 

Realm 31: Neither-perception-nor-non-perception - Accessed by the fourth formless jhana. This was the sphere reached by Udraka Rāmaputra, the second of the Buddha's two teachers, who considered it equivalent to enlightenment. Total life span on this realm in human years - 84,000 Maha Kalpa (Maha Kalpa = 4 Asankya Kalpa). This is realm is place 5,580,000 Yodun ( 1 Yoduna = 16 Miles) above the Plane of Nothingness.
Realm 30: Nothingness - Accessed by the third formless jhana. In this sphere formless beings dwell contemplating upon the thought that "there is no thing". This is considered a form of perception, though a very subtle one. This was the sphere reached by Ārāḍa Kālāma, the first of the Buddha's two teachers; he considered it to be equivalent to enlightenment. Total life span on this realm in human years - 60,000 Maha Kalpa. This is realm is place 5,580,000 Yodun above the Plane of Infinite Consciousness.
Realm 29: Infinite Consciousness - Accessed by the second formless jhana. In this sphere formless beings dwell meditating on their consciousness as infinitely pervasive. Total life span on this realm in human years - 40,000 Maha Kalpa. This is realm is place 5,580,000 Yodun above the Plane of Infinite Space.
Realm 28: Infinite Space - Accessed by the first formless jhana. In this sphere formless beings dwell meditating upon space or extension as infinitely pervasive. Total life span on this realm in human years - 20,000 Maha Kalpa. This is realm is place 5,580,000 Yodun above the Akanita Brahma Loka — Highest plane of pure abodes.

Comments: The inhabitants of these realms are possessed entirely of mind. Having no physical body, they are unable to hear Dhamma teachings.


The Fine-Material World 

There are five Śuddhāvāsa worlds, or "Pure Abodes". They do not house beings who have been born there through ordinary merit or meditative attainments, but only those Anāgāmins ("Non-returners") who are already on the path to Arhat-hood and who will attain enlightenment directly from the Śuddhāvāsa worlds without being reborn in a lower plane. Because a Śuddhāvāsa deva will never be reborn outside the Śuddhāvāsa worlds, no Bodhisattva is ever born in these worlds, as a Bodhisattva must ultimately be reborn as a human being. Since these devas rise from lower planes only due to the teaching of a Buddha, they can remain empty for very long periods if no Buddha arises. However, unlike the lower worlds, the Śuddhāvāsa worlds are never destroyed by natural catastrophe. The Śuddhāvāsa devas predict the coming of a Buddha and, taking the guise of Brahmins, reveal to human beings the signs by which a Buddha can be recognized. They also ensure that a Bodhisattva in his last life will see the four signs that will lead to his renunciation.

Realm 27: Peerless devas - Accessed by the fourth jhana. World of devas "equal in rank" (literally: having no one as the youngest). The highest of all the Rūpadhātu worlds, it is often used to refer to the highest extreme of the universe. The current Śakra will eventually be born there. The duration of life in Akaniṣṭha is 16,000 kalpas (Vibhajyavāda tradition). Mahesvara (not to be confused with Hindu god Shiva) the ruler of the three realms of samsara is said to dwell here. The height of this world is 167,772,160 yojanas above the Earth (approximately the distance of Saturn from Earth)
Realm 26: Clear-sighted devas - Accessed by the fourth jhana. The "clear-seeing" devas live in a world similar to and friendly with the Akaniṣṭha world. The height of this world is 83,886,080 yojanas above the Earth. (approximately the distance of Jupiter from Earth)
Realm 25: Beautiful devas - Accessed by the fourth jhana. The world of the "beautiful" devas are said to be the place of rebirth for five kinds of anāgāmins. The height of this world is 41,943,040 yojanas above the Earth.
Realm 24: Untroubled devas - Accessed by the fourth jhana. The world of the "untroubled" devas, whose company those of lower realms wish for. The height of this world is 20,971,520 yojanas above the Earth.(approximately the distance of Sun from Earth)
Realm 23: Devas not Falling Away - Accessed by the fourth jhana. The world of the "not falling" devas, perhaps the most common destination for reborn Anāgāmins. Many achieve arhatship directly in this world, but some pass away and are reborn in sequentially higher worlds of the Pure Abodes until they are at last reborn in the Akaniṣṭha world. These are called in Pāli uddhaṃsotas, "those whose stream goes upward". The duration of life in Avṛha is 1,000 kalpas (Vibhajyavāda tradition). The height of this world is 10,485,760 yojanas above the Earth.(approximately the distance of Mars from Earth) 

The next realms are Bṛhatphala worlds. The mental state of the devas of the Bṛhatphala worlds corresponds to the fourth dhyāna, and is characterized by equanimity (upekṣā). The Bṛhatphala worlds form the upper limit to the destruction of the universe by wind at the end of a mahākalpa, that is, they are spared such destruction. 

Realm 22: Unconscious beings - Accessed by the fourth jhana. Only body is present, no mind. Devas who have attained a high dhyāna (similar to that of the Formless Realm), and, wishing to avoid the perils of perception, have achieved a state of non-perception in which they endure for a time. After a while, however, perception arises again and they fall into a lower state.
Realm 21: Very Fruitful devas - Accessed by the fourth jhana. Their lifespan is 500 mahākalpas. (Vibhajyavāda tradition). Some Anāgāmins are reborn here. The height of this world is 5,242,880 yojanas above the Earth.(approximately the distance of Venus from Earth) 

The following worlds are Śubhakṛtsna worlds. The mental state of the devas of the Śubhakṛtsna worlds corresponds to the third dhyāna, and is characterized by a quiet joy (sukha). These devas have bodies that radiate a steady light. The Śubhakṛtsna worlds form the upper limit to the destruction of the universe by water at the end of a mahākalpa, that is, the flood of water does not rise high enough to reach them. 

Realm 20: Devas of Refulgent Glory - Accessed by the third jhana (highest degree). The world of the devas who are the "offspring of merit". The height of this world is 2,621,440 yojanas above the Earth.
Realm 19: Devas of Unbounded Glory - Accessed by the third jhana (medium degree). Their lifespan is 32 mahākalpas (Vibhajyavāda tradition). They possess "faith, virtue, learning, munificence and wisdom". The height of this world is 327,680 yojanas above the Earth.
Realm 18: Devas of Limited Glory - Accessed by the third jhana (minor degree). Their lifespan is 16 mahākalpas. The height of this world is 163,840 yojanas above the Earth. 

The following realms are Ābhāsvara worlds. The mental state of the devas of the Ābhāsvara worlds corresponds to the second dhyāna, and is characterized by delight (prīti) as well as joy (sukha); the Ābhāsvara devas are said to shout aloud in their joy, crying aho sukham! ("Oh joy!"). These devas have bodies that emit flashing rays of light like lightning. They are said to have similar bodies (to each other) but diverse perceptions. The Ābhāsvara worlds form the upper limit to the destruction of the universe by fire at the end of a mahākalpa (see Temporal cosmology below), that is, the column of fire does not rise high enough to reach them. After the destruction of the world, at the beginning of the vivartakalpa, the worlds are first populated by beings reborn from the Ābhāsvara worlds. 

Realm 17: Devas of Streaming Radiance - Accessed by the second jhana (highest degree). The world of devas "possessing splendor". The lifespan of the Ābhāsvara devas is 8 mahākalpas (others: 2 mahākalpas). Eight mahākalpas is the interval between destructions of the universe by water, which includes the Ābhāsvara worlds. The height of this world is 81,920 yojanas above the Earth.
Realm 16: Devas of Unbounded Radiance - Accessed by the second jhana (medium degree). The world of devas of "limitless light", a concept on which they meditate. Their lifespan is 4 mahākalpas. The height of this world is 40,960 yojanas above the Earth.
Realm 15: Devas of Limited Radiance - Accessed by the second jhana (minor degree). The world of devas of "limited light". Their lifespan is 2 mahākalpas. The height of this world is 20,480 yojanas above the Earth.
The following realms are Brahmā worlds. The mental state of the devas of the Brahmā worlds corresponds to the first dhyāna, and is characterized by observation (vitarka) and reflection (vicāra) as well as delight (prīti) and joy (sukha). The Brahmā worlds, together with the other lower worlds of the universe, are destroyed by fire at the end of a mahākalpa.
Realm 14: Great Brahmas - Accessed by the first jhana (highest degree). The world of "Great Brahmā", believed by many to be the creator of the world, and having as his titles "Brahmā, Great Brahmā, the Conqueror, the Unconquered, the All-Seeing, All-Powerful, the Lord, the Maker and Creator, the Ruler, Appointer and Orderer, Father of All That Have Been and Shall Be." According to the Brahmajāla Sutta (DN.1), a Mahābrahmā is a being from the Ābhāsvara worlds who falls into a lower world through exhaustion of his merits and is reborn alone in the Brahma-world; forgetting his former existence, he imagines himself to have come into existence without cause. Note that even such a high-ranking deity has no intrinsic knowledge of the worlds above his own. Mahābrahmā is 1 1⁄2 yojanas tall. His lifespan variously said to be 1 kalpa (Vibhajyavāda tradition) or 1 1⁄2 kalpas long (Sarvāstivāda tradition), although it would seem that it could be no longer than 3⁄4 of a mahākalpa, i.e., all of the mahākalpa except for the Saṃvartasthāyikalpa, because that is the total length of time between the rebuilding of the lower world and its destruction. It is unclear what period of time "kalpa" refers to in this case. The height of this world is 10,240 yojanas above the Earth.
Realm 13: Ministers of Brahma - Accessed by the first jhana (medium degree). Beings in these planes enjoy varying degrees of jhanic bliss. The "Ministers of Brahmā" are beings, also originally from the Ābhāsvara worlds, that are born as companions to Mahābrahmā after he has spent some time alone. Since they arise subsequent to his thought of a desire for companions, he believes himself to be their creator, and they likewise believe him to be their creator and lord. They are 1 yojana in height and their lifespan is variously said to be 1⁄2 of a kalpa (Vibhajyavāda tradition) or a whole kalpa (Sarvāstivāda tradition). If they are later reborn in a lower world, and come to recall some part of their last existence, they teach the doctrine of Brahmā as creator as a revealed truth. The height of this world is 5,120 yojanas above the Earth.
Realm 12: Retinue of Brahma - Accessed by the first jhana (minor degree). Beings in these planes enjoy varying degrees of jhanic bliss. The "Councilors of Brahmā" or the devas "belonging to the assembly of Brahmā". They are also called Brahmakāyika, but this name can be used for any of the inhabitants of the Brahma-worlds. They are half a yojana in height and their lifespan is variously said to be 1⁄3 of a kalpa (Vibhajyavāda tradition) or 1⁄2 of a kalpa (Sarvāstivāda tradition). The height of this world is 2,560 yojanas above the Earth. 

The Sensuous Worlds 

The beings born in these worlds differ in degree of happiness, but they are all, other than Anāgāmi, Arhat and Buddhas, under the domination of Māra and are bound by sensual desire, which causes them suffering. The following four worlds are bounded planes, each 80,000 yojanas square, which float in the air above the top of Mount Sumeru. Although all of the worlds inhabited by devas (that is, all the worlds down to the Cāturmahārājikakāyika world and sometimes including the Asuras) are sometimes called "heavens", in the western sense of the word the term best applies to the four worlds listed below: 

Realm 11: Devas Wielding Power over the Creation of Others - Accessed by Ten wholesome actions, generosity, and the development of virtue and wisdom. These devas enjoy sense pleasures created by others for them. These devas do not create pleasing forms that they desire for themselves, but their desires are fulfilled by the acts of other devas who wish for their favor. The ruler of this world is called Vaśavartin (Pāli: Vasavatti), who has longer life, greater beauty, more power and happiness and more delightful sense-objects than the other devas of his world. This world is also the home of the devaputra (being of divine race) called Māra, who endeavors to keep all beings of the Kāmadhātu in the grip of sensual pleasures. Māra is also sometimes called Vaśavartin, but in general these two dwellers in this world are kept distinct. The beings of this world are 4,500 feet (1,400 m) tall and live for 9,216,000,000 years (Sarvāstivāda tradition). The height of this world is 1,280 yojanas above the Earth.
Realm 10: Devas Delighting in Creation - Accessed by Ten wholesome actions, generosity, and the development of virtue and wisdom. These devas delight in the sense objects of their own creation. The devas of this world are capable of making any appearance to please themselves. The lord of this world is called Sunirmita (Pāli Sunimmita); his wife is the rebirth of Visākhā, formerly the chief of the upāsikās (female lay devotees) of the Buddha. The beings of this world are 3,750 feet (1,140 m) tall and live for 2,304,000,000 years (Sarvāstivāda tradition). The height of this world is 640 yojanas above the Earth.
Realm 9: Contented devas - Accessed by Ten wholesome actions, generosity, and the development of virtue and wisdom. A realm of pure delight and gaiety. Bodhisattas abide here prior to their final human birth. This is where the bodhisatta Maitreya (Metteya), the next Buddha, is said to dwell. This world is best known for being the world in which a Bodhisattva lives before being reborn in the world of humans. Until a few thousand years ago, the Bodhisattva of this world was Śvetaketu (Pāli: Setaketu), who was reborn as Siddhārtha, who would become the BuddhaŚākyamuni; since then the Bodhisattva has been Nātha (or Nāthadeva) who will be reborn as Ajita and will become the Buddha Maitreya (Pāli Metteyya). While this Bodhisattva is the foremost of the dwellers in Tuṣita, the ruler of this world is another deva called Santuṣita (Pāli: Santusita). The beings of this world are 3,000 feet (910 m) tall and live for 576,000,000 years (Sarvāstivāda tradition). The height of this world is 320 yojanas above the Earth.
Realm 8: Yama Devas - Accessed by Ten wholesome actions, generosity, and the development of virtue and wisdom. These devas live in the air, free of all difficulties. Sometimes called the "heaven without fighting", because it is the lowest of the heavens to be physically separated from the tumults of the earthly world. These devas live in the air, free of all difficulties. Its ruler is the deva Suyāma; according to some, his wife is the rebirth of Sirimā, a courtesan of Rājagṛha in the Buddha's time who was generous to the monks. The beings of this world are 2,250 feet (690 m) tall and live for 144,000,000 years (Sarvāstivāda tradition). The height of this world is 160 yojanas above the Earth. 

The next three realms are the worlds of sumeru. The world-mountain of Sumeru is an immense, strangely shaped peak which arises in the center of the world, and around which the Sun and Moon revolve. Its base rests in a vast ocean, and it is surrounded by several rings of lesser mountain ranges and oceans. The three worlds listed below are all located on, or around, Sumeru: the Trāyastriṃśa devas live on its peak, the Cāturmahārājikakāyika devas live on its slopes, and the Asuras live in the ocean at its base. Sumeru and its surrounding oceans and mountains are the home not just of these deities, but also vast assemblies of beings of popular mythology who only rarely intrude on the human world.

Realm 7: The Thirty-three Gods - Accessed by Ten wholesome actions, generosity, and the development of virtue and wisdom. Sakka, a devotee of the Buddha, presides over this realm. Many devas dwelling here live in mansions in the air. The world "of the Thirty-three (devas)" is a wide flat space on the top of Mount Sumeru, filled with the gardens and palaces of the devas. Its ruler is Śakradevānām indra, "Śakra, lord of the devas". Besides the eponymous Thirty-three devas, many other devas and supernatural beings dwell here, including the attendants of the devas and many apsarases (nymphs). The beings of this world are 1,500 feet (460 m) tall and live for 36,000,000 years (Sarvāstivāda tradition) or 3/4 of a yojana tall and live for 30,000,000 years (Vibhajyavāda tradition). The height of this world is 80 yojanas above the Earth.
Realm 6: Devas of the Four Great Kings - Accessed by Ten wholesome actions, generosity, and the development of virtue and wisdom. Home of the gandhabbas, the celestial musicians, and the yakkhas, tree spirits of varying degrees of ethical purity. Its rulers are the four Great Kings of the name, Virūḍhaka, Dhṛtarāṣṭra, Virūpākṣa, and their leaderVaiśravaṇa. The devas who guide the Sun and Moon are also considered part of this world, as are the retinues of the four kings, composed of Kumbhāṇḍas (dwarfs), Gandharvas (fairies), Nāgas (dragons) and Yakṣas (goblins). The beings of this world are 750 feet (230 m) tall and live for 9,000,000 years (Sarvāstivāda tradition) or 90,000 years (Vibhajyavāda tradition). The height of this world is from sea level up to 40 yojanas above the Earth.
Realm 5: Human beings - Accessed by the development of virtue and wisdom. Rebirth as a human being is extraordinarily rare . It is also extraordinarily precious, as its unique balance of pleasure and pain facilitates the development of virtue and wisdom to the degree necessary to set one free from the entire cycle of rebirths. This is the world of humans and human-like beings who live on the surface of the earth. The mountain-rings that engird Sumeru are surrounded by a vast ocean, which fills most of the world. The ocean is in turn surrounded by a circular mountain wall called Cakravāḍa (Pāli: Cakkavāḷa) which marks the horizontal limit of the world. In this ocean there are four continents which are, relatively speaking, small islands in it. Because of the immenseness of the ocean, they cannot be reached from each other by ordinary sailing vessels, although in the past, when the cakravartin kings ruled, communication between the continents was possible by means of the treasure called the cakraratna (Pāli cakkaratana), which a cakravartin and his retinue could use to fly through the air between the continents. The four continents are:
1) Jambudvīpa or Jambudīpa is located in the south and is the dwelling of ordinary human beings. It is said to be shaped "like a cart", or rather a blunt-nosed triangle with the point facing south. (This description probably echoes the shape of the coastline of southern India.) It is 10,000 yojanas in extent (Vibhajyavāda tradition) or has a perimeter of 6,000 yojanas (Sarvāstivāda tradition) to which can be added the southern coast of only 3 1⁄2 yojanas' length. The continent takes its name from a giant Jambu tree (Syzygium cumini), 100 yojanas tall, which grows in the middle of the continent. Every continent has one of these giant trees. All Buddhas appear in Jambudvīpa. The people here are five to six feet tall and their length of life varies between 10 to power 140 years (Asankya Aayu) and 10 years.
2) Pūrvavideha or Pubbavideha is located in the east, and is shaped like a semicircle with the flat side pointing westward (i.e., towards Sumeru). It is 7,000 yojanas in extent (Vibhajyavāda tradition) or has a perimeter of 6,350 yojanas of which the flat side is 2,000 yojanas long (Sarvāstivāda tradition). Its tree is the acacia. The people here are about 12 feet (3.7 m) tall and they live for 250 years.
3) Aparagodānīya or Aparagoyāna is located in the west, and is shaped like a circle with a circumference of about 7,500 yojanas (Sarvāstivāda tradition). The tree of this continent is a giant Kadamba tree. The human inhabitants of this continent do not live in houses but sleep on the ground. They are about 24 feet (7.3 m) tall and they live for 500 years.
4) Uttarakuru is located in the north, and is shaped like a square. It has a perimter of 8,000 yojanas, being 2,000 yojanas on each side. This continent's tree is called a kalpavṛkṣa (Pāli: kapparukkha) or kalpa-tree, because it lasts for the entire kalpa. The inhabitants of Uttarakuru are said to be extraordinarily wealthy. They do not need to labor for a living, as their food grows by itself, and they have no private property. They have cities built in the air. They are about 48 feet (15 m) tall and live for 1,000 years, and they are under the protection of Vaiśravaṇa.
Realm 4: Asuras - Accessed by ten unwholesome actions. The demons — "titans" — that dwell here are engaged in relentless conflict with each other. The Asuras are always fighting to regain their lost kingdom on the top of Mount Sumeru, but are unable to break the guard of the Four Great Kings. The Asuras are divided into many groups, and have no single ruler, but among their leaders are Vemacitrin (Pāli: Vepacitti) and Rāhu.
Realm 3: Hungry Shades/Ghosts - Accessed by ten unwholesome actions and lack of virtue. The pretas, or "hungry ghosts", are mostly dwellers on earth, though due to their mental state they perceive it very differently from humans. They live for the most part in desert and waste places.
Realm 2: Animals - Accessed by ten unwholesome actions, lack of virtue, and behaving like an animal. This realm includes all the non-human forms of life that are visible to us under ordinary circumstances: animals, insects, fish, birds, worms, etc.If one is generous to monks and nuns, however, one may be reborn as an "ornamented" animal (i.e., a bird with bright plumage; a horse with attractive markings, etc.
Realm 1: Hell - Accessed by ten unwholesome actions, lack of virtue, and atrocities such as murdering your parents or causing a schism. These are realms of unimaginable suffering and anguish. Should not be confused with the eternal hell found in other religious traditions, since one's time here is — as it is in every realm — temporary. Physically, Hell (Naraka) is thought of as a series of layers extending below Jambudvīpa into the earth. There are several schemes for counting these Narakas and enumerating their torments. One of the more common is that of the Eight Cold Narakas and Eight Hot Narakas.
Each lifetime in these Narakas is twenty times the length of the one before it.
Cold Narakas:
Arbuda – the "blister" Naraka
Nirarbuda – the "burst blister" Naraka
Aṭaṭa – the Naraka of shivering
Hahava – the Naraka of lamentation
Huhuva – the Naraka of chattering teeth

Hot Narakas
Sañjīva – the "reviving" Naraka. Life in this Naraka is 162*1010 years long.
Kālasūtra – the "black thread" Naraka. Life in this Naraka is 1296*1010 years long.
Saṃghāta – the "crushing" Naraka. Life in this Naraka is 10,368*1010 years long.
Raurava – the "screaming" Naraka. Life in this Naraka is 82,944*1010 years long.
Mahāraurava – the "great screaming" Naraka. Life in this Naraka is 663,552*1010 years long.
Tapana – the "heating" Naraka. Life in this Naraka is 5,308,416*1010 years long.
Pratāpana – the "great heating" Naraka. Life in this Naraka is 42,467,328*1010 years long.
Avīci – the "uninterrupted" Naraka. Life in this Naraka is 339,738,624*1010 years long.

Below The Worlds
All of these worlds are supported initially upon the foundations of the earth. All of the structures of the earth, Sumeru and the rest, extend downward to a depth of 80,000 yojanas below sea level – the same as the height of Sumeru above sea level. Below this is a layer of "golden earth", a substance compact and firm enough to support the weight of Sumeru. It is 320,000 yojanas in depth and so extends to 400,000 yojanas below sea level. The layer of golden earth in turn rests upon a layer of water, which is 8,000,000 yojanas in depth, going down to 8,400,000 yojanas below sea level. Below the layer of water is a "circle of wind", which is 16,000,000 yojanas in depth and also much broader in extent, supporting 1,000 different worlds upon it. yojanas areequivalent to about 13 km (8 mi)

Maha Kalpa
The word kalpa, means 'moment'. A maha kalpa consists of four moments (kalpa), the first of which is creation. The creation moment consists of the creation of the "receptacle", and the descent of beings from higher realms into more coarse forms of existence. During the rest of the creation moment, the world is populated. Human beings who exist at this point have no limit on their lifespan. The second moment is the duration moment, the start of this moment is signified by the first sentient being to enter hell (niraya), the hells and nirayas not existing or being empty prior to this moment. The duration moment consists of twenty "intermediate" moments (antarakappas), which unfold in a drama of the human lifespan descending from 80,000 years to 10, and then back up to 80,000 again. The interval between 2 of these "intermediate" moments is the "seven day purge", in which a variety of humans will kill each other (not knowing or recognizing each other), some humans will go into hiding. At the end of this purge, they will emerge from hiding and repopulate the world. As of May 2015, it seems the lifespan of humans is 80 years, during the time of Gotama Buddha it was 100 years. After this purge, the lifespan will increase to 80,000, reach its peak and descend, at which point the purge will happen again.

Within the duration 'moment', this purge and repeat cycle seems to happen around 18 times, the first "intermediate" moment consisting only of the descent from 80,000—the second intermediate moment consisting of a rise and descent, and the last consisting only of an ascent.

After the duration 'moment' is the dissolution moment, the hells will gradually be emptied, as well as all coarser forms of existence. The beings will flock to the form realms (rupa dhatu), a destruction of fire occurs, sparing everything from the realms of the 'radiant' gods and above (abha deva).

After 7 of these destructions by 'fire', a destruction by water occurs, and everything from the realms of the 'pleasant' gods and above is spared (subha deva).

After 64 of these destructions by fire and water, that is—56 destructions by fire, and 7 by water—a destruction by wind occurs, this eliminates everything below the realms of the 'fruitful' devas (vehapphala devas, literally of "great fruit"). The pure abodes (suddhavasa, meaning something like pure, unmixed, similar to the connotation of "pure bred German shepherd"), are never destroyed. Although without the appearance of a Buddha, these realms may remain empty for a long time. It should be noted that the inhabitants of these realms have exceedingly long life spans.

The formless realms are never destroyed because they do not consist of form (rupa). The reason the world is destroyed by fire, water and wind, and not earth is because earth is the 'receptacle'.

After the dissolution moment, this particular world system remains dissolved for a long time, this is called the 'empty' moment, but the more accurate term would be "the state of being dissolved". The beings that inhabited this realm formerly will migrate to other world systems, and perhaps return if their journeys lead here again.

A mahākalpa is divided into four kalpas or "eons", each distinguished from the others by the stage of evolution of the universe during that kalpa. The four kalpas are:
Vivartakalpa "Eon of evolution" – during this kalpa the universe comes into existence.
Vivartasthāyikalpa "Eon of evolution-duration" – during this kalpa the universe remains in existence in a steady state.
Saṃvartakalpa "Eon of dissolution" – during this kalpa the universe dissolves.
Saṃvartasthāyikalpa "Eon of dissolution-duration" – during this kalpa the universe remains in a state of emptiness.
Each one of these kalpas is divided into twenty antarakalpas, "inside eons") each of about the same length. For the Saṃvartasthāyikalpa this division is merely nominal, as nothing changes from one antarakalpa to the next; but for the other three kalpas it marks an interior cycle within the kalpa.

Vivartakalpa

The Vivartakalpa begins with the arising of the primordial wind, which begins the process of building up the structures of the universe that had been destroyed at the end of the last mahākalpa. As the extent of the destruction can vary, the nature of this evolution can vary as well, but it always takes the form of beings from a higher world being born into a lower world. The example of a Mahābrahmā being the rebirth of a deceased Ābhāsvara deva is just one instance of this, which continues throughout the Vivartakalpa until all the worlds are filled from the Brahmaloka down to Naraka. During the Vivartakalpa the first humans appear; they are not like present-day humans, but are beings shining in their own light, capable of moving through the air without mechanical aid, living for a very long time, and not requiring sustenance; they are more like a type of lower deity than present-day humans are.

Over time, they acquire a taste for physical nutriment, and as they consume it, their bodies become heavier and more like human bodies; they lose their ability to shine, and begin to acquire differences in their appearance, and their length of life decreases. They differentiate into two sexes and begin to become sexually active. Then greed, theft and violence arise among them, and they establish social distinctions and government and elect a king to rule them, called Mahāsammata, "the great appointed one". Some of them begin to hunt and eat the flesh of animals, which have by now come into existence.

Vivartasthāyikalpa

First antarakalpa
The Vivartasthāyikalpa begins when the first being is born into Naraka, thus filling the entire universe with beings. During the first antarakalpa of this eon, human lives are declining from a vast but unspecified number of years (but at least several tens of thousands of years) toward the modern lifespan of less than 100 years. At the beginning of the antarakalpa, people are still generally happy. They live under the rule of a universal monarch or "wheel-turning king" (Sanskrit: cakravartin), who conquer[clarification needed]. The Mahāsudassana-sutta (DN.17) tells of the life of a cakravartin king, Mahāsudassana (Sanskrit: Mahāsudarśana) who lived for 336,000 years. The Cakkavatti-sīhanāda-sutta (DN.26) tells of a later dynasty of cakravartins, Daḷhanemi (Sanskrit: Dṛḍhanemi) and five of his descendants, who had a lifespan of over 80,000 years. The seventh of this line of cakravartins broke with the traditions of his forefathers, refusing to abdicate his position at a certain age, pass the throne on to his son, and enter the life of a śramaṇa. As a result of his subsequent misrule, poverty increased; as a result of poverty, theft began; as a result of theft, capital punishment was instituted; and as a result of this contempt for life, murders and other crimes became rampant.

The human lifespan now quickly decreased from 80,000 to 100 years, apparently decreasing by about half with each generation (this is perhaps not to be taken literally), while with each generation other crimes and evils increased: lying, greed, hatred, sexual misconduct, disrespect for elders. During this period, according to the Mahāpadāna-sutta (DN.14) three of the four Buddhas of this antarakalpa lived: Krakucchanda Buddha (Pāli: Kakusandha), at the time when the lifespan was 40,000 years; Kanakamuni Buddha (Pāli: Konāgamana) when the lifespan was 30,000 years; and Kāśyapa Buddha (Pāli: Kassapa) when the lifespan was 20,000 years.

Our present time is taken to be toward the end of the first antarakalpa of this Vivartasthāyikalpa, when the lifespan is less than 100 years, after the life of Śākyamuni Buddha (Pāli: Sakyamuni), who lived to the age of 80.

The remainder of the antarakalpa is prophesied to be miserable: lifespans will continue to decrease, and all the evil tendencies of the past will reach their ultimate in destructiveness. People will live no longer than ten years, and will marry at five; foods will be poor and tasteless; no form of morality will be acknowledged. The most contemptuous and hateful people will become the rulers. Incest will be rampant. Hatred between people, even members of the same family, will grow until people think of each other as hunters do of their prey.

Eventually a great war will ensue, in which the most hostile and aggressive will arm themselves and go out to kill each other. The less aggressive will hide in forests and other secret places while the war rages. This war marks the end of the first antarakalpa.

Second antarakalpa
At the end of the war, the survivors will emerge from their hiding places and repent their evil habits. As they begin to do good, their lifespan increases, and the health and welfare of the human race will also increase with it. After a long time, the descendants of those with a 10-year lifespan will live for 80,000 years, and at that time there will be a cakravartin king named Saṅkha. During his reign, the current bodhisattva in the Tuṣita heaven will descend and be reborn under the name of Ajita. He will enter the life of a śramaṇa and will gain perfect enlightenment as a Buddha; and he will then be known by the name of Maitreya (Pāli: Metteyya).

After Maitreya's time, the world will again worsen, and the lifespan will gradually decrease from 80,000 years to 10 years again, each antarakalpa being separated from the next by devastating war, with peaks of high civilization and morality in the middle. After the 19th antarakalpa, the lifespan will increase to 80,000 and then not decrease, because the Vivartasthāyikalpa will have come to an end.

Saṃvartakalpa

The Saṃvartakalpa begins when beings cease to be born in Naraka. This cessation of birth then proceeds in reverse order up the vertical cosmology, i.e., pretas then cease to be born, then animals, then humans, and so on up to the realms of the deities.

When these worlds as far as the Brahmaloka are devoid of inhabitants, a great fire consumes the entire physical structure of the world. It burns all the worlds below the Ābhāsvara worlds. When they are destroyed, the Saṃvartasthāyikalpa begins.

Saṃvartasthāyikalpa

There is nothing to say about the Saṃvartasthāyikalpa, since nothing happens in it below the Ābhāsvara worlds. It ends when the primordial wind begins to blow and build the structure of the worlds up again.

Other destructions

The destruction by fire is the normal type of destruction that occurs at the end of the Saṃvartakalpa. But every eighth mahākalpa, after seven destructions by fire, there is a destruction by water. This is more devastating, as it eliminates not just the Brahma worlds but also the Ābhāsvara worlds.

Every sixty-fourth mahākalpa, after 56 destructions by fire and 7 destructions by water, there is a destruction by wind. This is the most devastating of all, as it also destroys the Śubhakṛtsna worlds. The higher worlds are never destroyed.