Buddhism has an extremely complex and detailed cosmology that is both spatial (different worlds or realms) and temporal (how the universe comes into being and is then dissolved).
We can look at Buddhist cosmology in this way: they are teachings of impermanence, dependent origination, and karma, among other things.
As sentient beings, we are metaphorically like “hitchhikers” going from place to place in this vast Buddhist “universe”. As we hitchhike, our “merits” determine if we find a Bodhisattva or Buddha who pulls off to the side of the road to give us a ride, or if we have to continue walking a very long time until we get to the next town.
Before we begin, let’s give thanks to the dolphins who tried to explain the Buddhist teachings to us “Buddhist universe hitchhikers” all these years and just gave up with us because we thought they were cute and only wanted fish 😉
Table of Contents
Beings and Realms of Rebirth
A major component of Buddhism is rebirth. This is a foundational teaching that explains we are “suffering” due to our constant arising in forms (such as a human) in an endless cycle of rebirth (Saṃsāra).
Buddhists actively practice (such as the generation of merit) for future existences to arise in the human realm (for reasons described below) with conditions that bring them closer to enlightenment.
These are six literal realms of rebirth. Buddhists aspire to always have their mind in the right ‘realm,’ and work towards having a good rebirth in the right realm in the future so they can continue on the path. All these realms are considered Dukkha, however, and the goal of Buddhists is to end rebirth in all of them.
- Devas or gods realm: While many aspire to be reborn in this pleasure-filled realm due to wholesome karma, where existence can last for eons, it is still temporary.
- Human realm: This is a fortunate realm because it is the only one that provides the right balance to understand the Dharma, practice it, attain Nirvana, and end Saṃsāra.
- Demigod realm: An ‘evil’ realm where they often fight with those in the ‘gods realm.’
- Animal realm: A very ‘hellish’ realm due to acting upon ‘impulse and instinct.’
- Hungry ghosts realm: Suffering caused by a constant craving for attachments they cannot fulfill.
- Hell realm: Those who have created evil karma enter this realm (violation of the Five Precepts).
An important component of all these realms is that existence in any of them is impermanent, even though in some of the realms one can have a long lifespan. When karma has been exhausted in a realm, one is reborn in another realm.
What does this have to do with you? The Buddha said that the Human realm was desirable because it has the right conditions for enlightenment. However, the human realm is also a very rare existence for rebirth, so one should use this opportunity to devote themselves to the path!
Heavenly realms may be pleasurable, and in some instances conducive to future awakening, but it is right in the “mud” of the human realm where one can fully bloom into enlightenment. For example, before he was the Buddha, the Bodhisattva Svetaketu existed in Tuṣita heaven and decided when the time was right for their rebirth in the human realm…as Siddhartha Gotama, the man who would become the Buddha of our era (Shakyamuni Buddha [referred to as Gotama Buddha in Theravada Buddhism]).
Tuṣita heaven is of course found in the ‘heavenly realm’, but it’s one that is reachable through advanced meditative states. It features prominently in both branches of Buddhism because the future Buddha, Maitreya, exists there as a Bodhisattva. However, in Mahayana Buddhism, it is recognized as a place where Bodhisattvas dwell who are destined to become enlightened in their next life.
Sahā World & Realms of Existence

The Sahā World is used in Mahayana Buddhism to refer to the mundane existence we all find ourselves in. Essentially, it is a world where one hasn’t realized Nirvana yet.
This Sahā World is made up of Three Realms that one traverses through in the cycle of rebirth (Samsara) commonly associated with the attainment of certain meditative states (Pali: jhāna, Sanskrit: dhyana).
- The desire realm (kāmadhātu) where one is bound by sensual desire and encompasses the six realms of rebirth described above (such as humans).
- The form realm (rupadhātu) is where one ascends through the five worlds within it.
- And finally, the formless realm (Ārūpyadhātu) where those inhabitants have no shape or form and have attained higher levels of ‘formless’ meditative skills known as Arūpadhyānas.
Typically one finds devas, gods, and Bodhisattvas residing in the form and formless realms. While the formless realm which seems desirable, existence in any form there is impermanent. One will eventually take on a new existence, such as a return to a lower state of existence when their merit or karma is exhausted.
Devas, gods, Bodhisattvas, and even Buddhas take the imagination of humans to new levels. Because of their long lifespans in these existences, supernatural powers, etc., one can initially assume they have godlike powers. This isn’t the case. Devas, for instance, can’t create or control the world and are not omniscient or omnipotent.
These realms are important for laypersons because they encourage one to strive harder on the Buddhist path through the Threefold Training. As they develop wisdom, morality, and concentration, they are able to achieve higher states of awareness and start creating more wholesome karma (merits) rather than unwholesome.
As they generate merit, they are working to ensure the next existence finds itself in a realm that is conducive to the continuous goal of reaching enlightenment. And in the case of Mahayana Buddhists, the goal of becoming a Buddha.
But what about Buddha “Pure Lands” that encompasses an entire practice and even some schools in Mahayana Buddhism? What are those, and are they some sort of “super Buddha”? Let’s find out next…
Buddha Fields

There are “Pure Lands” in Mahayana Buddhism where one can be reborn in to be under the guidance of a celestial Buddha to achieve enlightenment and become a Buddha.
The most popular is Amitābha Buddha and his Western Pure Land known as Sukhāvatī.
But what is this?
- A Pure Land is something created due to a Buddha’s “reward body” (more on this at the end of the article).
- Due to their desire and vow to help sentient beings, a Pure Land (also called a Buddha Field) is generated around them. This “world” is similar to a refuge or safe haven for those who desire to be reborn there.
- Why be reborn there? Because one can more easily achieve enlightenment under the guidance of a living Buddha, and Bodhisattvas. Due to the ‘age of decline of the Dharma’ which is considered by both branches of Buddhism as the time after a Buddha’s death where enlightenment by sentient beings becomes less likely (since one is no longer able to “hear” them and be under their guidance). Simply reading the sermons is not the same as having a living Buddha, as Shakyamuni Buddha taught us.
- This age of decline can result in some looking for the next Buddha of an era, such as Maitreya, to come into the world where liberation (enlightenment/nirvana) would become easier. Yet, Maitreya won’t come for a very, very, very long time after Shakyamuni’s teachings are gone (and right now, they are not gone).
- In Mahayana Buddhism, there is no need to wait for Maitreya, as one can experience rebirth in a Buddha’s pure land so they can progress on the Mahayana path, which is the “Bodhisattva Path”, towards becoming a Buddha themselves.
While this sounds great, it’s not a snap of your fingers “you’re enlightened” deal. It’s very similar to going to school, and everyone is at different levels. Regardless, anyone who gets to a pure land is able to progress (even if it takes a long time) since they are uninhibited by the Sahā World which can be very distracting. Think of it as going to the college library to study as you sit right next to your professor who is helping you, and not to a college fraternity party to study where studying takes a back seat!
Pure Lands take on two realities for Buddhists:
- Literal: These are literal places you will be reborn in if you follow the practices to achieve that. This isn’t like a heaven where you stay there forever. Again, it’s like a school where you are there to achieve a goal and then get back into the ‘world’. The Mahayana path is to become a Buddha, and one can’t do that blissfully staying in just one place.
- Mental: While not all Pure Land Buddhists recognize this part, it is very much part of the teaching of Buddhists in China, Taiwan, and Vietnam where Pure Land and Meditation (Ch’an/Zen/Thien/Seon) is often complimentarily practiced. In this interpretation, the literal pure land isn’t negated, instead one can achieve the pure land right here, right now, through their own efforts. This is immensely difficult but is the ultimate pure land teaching in this view. Amitābha Buddha is your own inner Buddhanature, and the pure land known as Sukhāvatī is your own pure land of your mind. If you think of it as Nirvana being Sukhāvatī, and your awakened state as Amitābha, you’ll get the idea here. In general, there are three levels of Pure Land practice, and most of us are on the first level trying to get to the literal pure land (due to the challenges the Saha world places on us at advancing any higher on our own).
Periods of Time

You will often hear the word “Kalpa” which is a unit of time (around 16 million years to hundreds of billions of years).
It is recognized that “we” have been trapped in Saṃsāra for countless kalpas and may be for more until we finally attain Nirvana.
For Mahāyānists, it is understood that the Bodhisattva path towards Buddhahood will take many kalpas (in much the same way Shakyamuni Buddha did).
A Kalpa is an extremely long period of time.
- A Kalpa is an expression of the creation and recreation of a world (we have had several Kalpas, and Buddhas, before Shakyamuni Buddha, and more will come).
- There are four different lengths for Kalpas (regular or traditional expression of this is about 16 million years long, a small expression is about 16 billion years long, a medium expression is 320 billion years long, and a great Kalpa is about 1.28 trillion years long). Kalpa’s can have up to 1,000 Buddhas who come one by one in them. Some Kalpa’s have no Buddhas.
- We are currently living in the “Bhadra Kalpa”, known as the “Fortune Aeon” which is one of the most favorable aeons to occur.
- We are using a regular expression for this current Kalpa, meaning it lasts about 16 million years.
- There have already been four Buddhas in this Kalpa, including Shakyamuni Buddha, of whom we currently follow and know his teachings. There are 29 named Buddhas, including Shakyamuni and Maitreya. Maitreya Buddha will be the fifth, and last, Buddha in this Kalpa when the teachings of Shakyamuni Buddha become unknown.
Speaking of hidden knowledge, I was quite overwhelmed to learn about what a “Kalpa” is. This is both a Hindu and Buddhist term used to describe extreme periods of time. This is an important thing to learn, as it relates to when we will see Maitreya Buddha in our world.
- A Kalpa is an expression of the creation and recreation of a world (we have had several Kalpas, and Buddhas, before Shakyamuni Buddha, and more will come). There are four different lengths for Kalpas (regular or traditional expression of this is about 16 million years long, a small expression is about 16 billion years long, a medium expression is 320 billion years long, and a great Kalpa is about 1.28 trillion years long). Kalpa’s can have up to 1,000 Buddha’s who come one-by-one in them. Some Kalpa’s have no Buddha’s.
- Asamkhya Kalpa: This is known as a “Great eon/aeon”. Compared to trying to describe a regular kapa, getting to explaining how long an Asamkhya Kalpa is becomes a fruitless endeavor. To explain how long this kalpa is, two smaller units of kalpas are used to explain it (because many of these would be needed and are considered “minor” kalpas):
- Mustard Seed Kalpa: The analogy here is to imagine a huge container that is 10 kilometers (~6 miles) on each side. Then, every 100 years, we remove only a single seed! Now, just imagine how long it would take to remove all those seeds if we only remove one every 100 years. And this is a much smaller unit of measurement than an Asamkhya Kalpa.
- Boulder Kalpa: Another analogy is if you have a huge boulder with the same dimensions as we explained in the Mustard Seed Kalpa. Now, every 100 years, rub the boulder just once with sandpaper (or another analogy is a feather), imagine how long it will take for the boulder to be completely broken down.
- We are currently living in the “Bhadra Kalpa”, known as the “Fortune Aeon” which is one of the most favorable aeons to occur. We are using a regular expression for this current Kalpa, meaning it lasts about 16 million years. There have already been four Buddha’s in this Kalpa, including Shakyamuni Buddha, of whom we currently follow and know his teachings. There are 29 named Buddhas, including Shakyamuni and Maitreya. Maitreya Buddha will be the fifth, and last, Buddha in this Kalpa when the teachings of Shakyamuni Buddha become unknown (Yes, that means the teachings of Shakyamuni Buddha…the Buddha we all know right now…will become unknown. Thus, we are obviously not at this point yet).
Time also takes on a different meaning in the realms of rebirth, most prominently in the heavenly realms.
- A month to a deva or other being in this realm would be equivalent to 12,000 years in our human realm, and one year for them would be 144,000 years for us!
- The lifespan of a deva in this realm would be a mind-boggling 576,000,000 years
- Ksana: this is the “briefest” moment or measurable unit of time. According to Ven. Master Hsing Yung, it is approximately one seventy-fifth of a second! To give some context, a single thought in your head is about 90 ksanas. And in a single ksana, he says there are 900 instances of arising and ceasing. This is certainly amazing to comprehend!
Now, us humans who would be glad to just get a few decades on this earth can’t fathom living past a century in our own realm, let alone the countless ones in the heavenly realm.
Yet, our comprehension of time and space is very much controlled by our own ignorance, delusion, and confusion about the reality of the existence we find ourselves in and surrounded by.
For laypersons, getting to a heavenly realm or staying in the human realm in order to progress on the path towards enlightenment is the goal. They do this primarily through meritorious deeds (“merit”) such as helping others, which is the hallmark of Buddhist laypersons around the world, and even Buddhist monastics.
Bodies of a Buddha

In Mahāyāna Buddhism, rebirth takes on a slightly different meaning for fully enlightened beings such as a Buddha, known as dharmadhātu.
- This dharmadhātu is the enlightened being’s mindstream that is of pure essence and free of all attachments.
- Upon parinirvāṇa (final Nirvāṇa or death of the body/five aggregates), their mindstream is not only liberated from Saṃsāra but also the illusionary nature of both Saṃsāra and Nirvāṇa.
- Mahāyānists teach that a Buddha has “three bodies” known as Dharmakāya.
- Even though they do not arise in a new physical existence after parinirvāṇa, they exist in an expansive state (a Buddha’s Reward Body) where they may be realized during deep meditative states or by other means (for example, Amitabha Buddha’s Western Pure Land is due to his Reward Body). Shakyamuni Buddha continues to have both a Reward Body and Dharma Body.
- A Dharma Body is essentially pure truth (Dharma) and awakening itself, which is the goal of all Buddhists.
To give an example of this, Shakyamuni Buddha had a Pure Land around him on this earth due to his Reward Body but also had a Manifested Body that allowed ordinary beings to see and interact with him as a form of skillful means towards their awakening.
Why is this so important? It’s because it means that birth and death are just mere notions that we humans have about existence. A Buddha continues to exist through their Dharma Body, which takes things to a whole other level.
A Manifested Body is important for a Buddha in order to teach sentient beings, it’s impermanent but still an important aspect of getting the “wheel of dharma” rolling again to help liberate sentient beings.
With the Reward and Dharma bodies, a Buddha is not really “gone”, and can be realized through advanced meditative states. While in his Manifested Body, the Buddha said there were certain teachings he wasn’t going to explain [here on earth] because they were too advanced and not the right time. He was very much in an “emergency” situation with sentient beings at the time and this was the right choice.
In the Mahayana traditions, these advanced teachings were said to be revealed centuries later at the right time for them to be understood (thanks to the Reward/Dharma bodies which allowed Shakyamuni and Bodhisattvas to reveal them).
An important footnote is that just because Shakyamuni has a Reward and Dharma body doesn’t mean he has some sort of godlike power. These bodies are there to aid one in understanding and realizing the Dharma as the primary purpose.
Conclusion

This was only a small ‘taste’ of Buddhist cosmology, and I hope to update this article in the future with more information!
While I wanted to introduce you to just a few of the concepts and teachings, the most important piece is this:
You are in the rarest and most advantageous existence right now – a human being. You have the capacity to become enlightened, realize nirvana, progress on the path, hear the Buddha’s teachings, and most importantly your own power to transform your karma from unwholesome to wholesome! The merits you generate are a vital part of advancing towards the goal of enlightenment.
While our mundane world can be very challenging (Dukkha), this is the “mud” that provides us the “nutrients” in order to grow. The reason lotus flowers are always used in Buddhism is due to their illustrative example of the Buddhist path: they exist in murky and muddy water unseen to the eye which nourishes them, eventually breaking the top of the water, and blooming beautifully with no dirt or mud on the flower.
That blooming is enlightenment and Nirvana, and it’s within you. It’s your true natural state. But without the nutrients of the saha world, you aren’t able to grow your flower ‘stalk’ long enough to break the surface of the water, nor bloom into a beautiful flower. This takes time, patience, continued effort and determination, and practice.
While you personally may not experience the results of your practice in this extremely short ‘human’ existence you are in right now, the merits you generate now have long-lasting consequences. Do good. And practice like this is a rare opportunity…because it is.