However, the shape of the universe depends on its density. If the density is more than the critical density, the universe is closed and curves like a sphere; if less, it will curve like a saddle. But if the actual density of the universe is equal to the critical density, as scientists think it is, then it will extend forever like a flat piece of paper. However, Jainism also describes the curvatures in the Loka. We find flat, closed, and open structure in Jain cosmological model. Our Agams cite that the universe is not same everywhere, it is expanded at some places while contracted at other places. The regions, where the universe expands, or contracts are recognized as curvatures and technically known as Vigraha in Jainism. Comparing the density model, we may infer that the Urdhva Loka is similar to closed universe, the Madhya Loka like the flat universe and the Adho Loka as the open universe. Because of varying density, we observe the curvatures. These curvatures are inbuilt and everlasting due to continuous action of the two elements or quantum fields/ forces i.e., Dharmāstikāya and Adharmāstikāya, causing uneven structures in response to local modifications.
Jainism describes building blocks of the universe quantitatively and in greater details. The Loka consists of six everlasting and imperishable substances such as: Jivastikaya (soul), Pudgalastikaya (matter), Dharmastikaya (force for motion), Adharmastikaya (force for rest), akashstikaya (space/ loka) and kal (time). These substances, through their modifications and the relation in which they stand towards one another, produce the multifarious world-processes. In fact, the jiva has continuous interaction with pudgal as a function of space and time throughout the universe, and that governed by two quantum fields/ forces dharmastikaya and adharmastikaya. However, all these six elements exist only in the Loka and not in the Aloka. Jain canonical texts cite that the boundaries between Loka and Aloka as well as the three layers are monitored by the aforesaid two forces.
In order to understand the Jain cosmos in the perspective of modern science the Madhya Loka is most important and interesting. Madhya Loka consists of 900 yojans above and 900 yojans below the reference land surface. It is inhabited by
1). Jyotishka Devas i.e., celestial objects (planets, stars, galaxies etc.) at a height between – 790 to 900 yojans above the reference land surface.
2). Humans and Tiryanch (Animals, birds, plants) on the reference land surface.
3). Vyantar Devas (Intermediary gods) – 100 yojan below the reference land surface.
The Madhya loka is densely populated by continents and oceans. However, these continents and oceans mean that each continent itself might be either a universe, separated from the other by an ocean/ gaseous media or it might be a large galaxy system and separated from the others by a large volumetric area of water or other gaseous molecules. In this context, the most common question that frequently being asked “where the Mount Meru is located”? The Jain texts cite that the Mount Meru is at the center of the world surrounded by Jambūdvīpa in the form of a circle forming a diameter of 100,000 yojans. Texts also cite that there are two sets of sun, moon and stars revolving around Mount Meru: while one set works, the other set rests behind the Mount Meru. This philosophy is difficult to explain in reference to modern science. However, significance of this concept might be that the Sun, Moon, planets, and stars etc. are reference points in each plane of the celestial sphere of a given galaxy in the Jambūdvīpa, which itself may be one independent universe including our own Milky-way galaxy, likely to be “Bharat Kshetra”. Thus, the Jambūdvīpa appears to be a set of galaxies and the center of the same would be Mount Meru, and, perhaps, Jambu plus other two continents (Dhatki and half Pushkar) may be a small part of the visible universe of modern cosmology. This argument may be further endorsed in context to the total number of galaxies possible in the whole Madhya Loka would be >1012, which is first order estimate by modern cosmology (https://nineplanets.org/questions/). This also suggests that the observed red shift in the universe, suggesting that the galaxies moving away from each other, is in fact, within the middle loka. Further, the remaining continents and oceans are likely to be other universes within the middle loka in consistence to theory of multi-universe/ parallel universe of modern astronomers.
In view of above scenario, it is but natural to ask, “where is our home in the middle loka?” In order to address this question, we have to learn more about Jambūdvīpa. Jain texts describe that the Jambūdvīpa continent has 6 mighty mountains, dividing the continent into 7 zones (Kshetra) viz.
- Bharat Kshetra.
- Mahavideh Kshetra.
- Airavat Kshetra.
- Ramyak Kshetra.
- Hiranya vant Kshetra.
- Hemvant Kshetra.
- Hari Varsh Kshetra.
In view of the preceding discussions, Jambūdvīpa appears to be a set of ~108 galaxies, we may conjecture that these seven kshetras (zones) appear to be sub-set of galaxies and our Milky way is a part of the Bharat Kshetra. This may also be endorsed in context to Jain texts which cite that the three zones i.e., Bharat Kshetra, Mahavideh Kshetra and Airavat Kshetra are also known as Karma Bhoomi because practice of austerities and liberation is possible and the Tirthankaras preach the Jain doctrine, and the other four zones, Ramyak, Hairanyvat Kshetra, Haimava Kshetra and Hari Kshetra are known as Akarmabhoomi or Bhogbhumi as humans live a sinless life of pleasure and no religion or liberation is possible. The Mount Meru is in the center of Jambūdvīpa i.e., in the center of the Mahavideh Kshetra, which is belt of galaxies in equatorial plane of the Jambūdvīpa. It is further widely established that Shri Simandhar Swamy is currently renouncing and meditating in the Mahavideh Kshetra in accordance with its time cycle (Kal Chakra) to become next Tirthankar of that Kshetra. Similarly, the Bharat Kshetra and Airawat Kshetra are also a subset of galaxies in the southern and northern hemisphere of the Jambūdvīpa respectively. These two in addition to Mahavideh Kshetra are Kaumbhoomi and therefore Jainism is being worshipped and Tirthankars take birth, however, as per their respective time cycle. Our home is in a land known as the Earth, a suitable planet of the solar system of one of the galaxies of the Bharat Kshetra known as Milky-way (Akash-ganga), where the time cycle is spanning in the Fifth Ara.
We discussed the universe/Loka in the perspectives of Jainism and the modern science. According to Jain texts the universe is comprised of Loka (cosmos) and Aloka (trans-cosmos), and the Loka is of finite size, while Aloka is empty and of infinite size. On the contrary, according to the science the universe is infinite, full of matter, energy, and radiation. The Loka of Jain texts is comprised of six eternal elements. However, the important conclusion of our investigation in the current article is the universe of science is restricted in the middle part of the Loka and even that also has not been explored by all big telescopes or space missions. The multi-universe theory is also likely to be possible in the middle Loka as it has several continents and oceans with each one is comprised of billions of galaxies. However, according to Jain canonical texts, the habitable zone planets are possible only in two and half continents as discussed in the article. Each continent has different time cycle and accordingly the temporal sequence of events of Jain tradition take place including the birth of Tirthankaras.