Dr. N.L. Kachhara
Because the structure of the middle loka is of special interest, I will describe it first. This part of the loka contains innumerable (asamkhyat) ring-shaped circular islands (dweepas) separated by as many ring-shaped circular oceans (samudras) arranged in a circumscribing fashion one after another. The middle circular island is called Jambudweepa, which, according to some scholars, is supposed to be our planet Earth. Such island structures are not found in nature and require proper interpretation. This description is symbolic, with the oceans representing large spaces between the islands and the rings representing the orbits of the moving islands. The islands could be astronomical objects, such as planets. There are also innumerable celestial objects like stars, suns, moons, and planets orbiting the mountain called Mount Meru, which is situated at the center of Jambudweepa. These celestial objects, called Jyotishka Deva, stars and moons, are found in circular orbits all over the middle loka starting at some distance from Mount Meru and continuing until the last island. The orbital paths of all celestial objects lie in a small axial space of 110 yojana starting at height of 790 yojanas above Jambudweepa. Yojana is a measure of distance used in astronomical applications and is equal to 8000 miles (4000 miles in the Digambara tradition). This means that the middle loka contains stars, planets, galaxies, etc., separated by large distances and moving in orbits. According to present scientific knowledge, there are about 100-140 billion galaxies containing a total of about 7x1022 stars.
Figure 2. The Mobile Zone (Trasanadi) of the loka. Distances are in rajju. The heavens and hells are represented by flat lines. The space between the heavens and hells are regions in which the souls and subtle bodies of mobile beings move from the middle loka to the heavens and hells at superluminal speeds during migration on the change of modes. Immobile beings of the subtle type are present all over the loka. Liberated souls move from the middle loka to the Siddhashila almost instantaneously.
According to Jainism, there are innumerable islands, stars and other orbiting astronomical objects in the middle loka. The value of "innumerable," according to Acharya Kanakanandhi, is estimated to be about 10140. Even if we account for all the planets, satellites, meteorites, inter-stellar and inter-galactic moving objects, the number of islands, planets and stars in the Jain system appears to be many orders of magnitude greater than the expected number of astronomical objects in the scientific universe. Further, scientific observations show that the observable universe is almost flat and is estimated to be nearly 200 billion light-years across, approximately 2x1022 kilometers wide. According to one estimate, one rajju, the diameter of the middle loka, is about 1.85x1021 kilometers; other estimates give much higher values. It is therefore reasonable to assume that the universe that science is exploring is actually the middle loka of Jainism, which is also flat and of comparable size. This is a very important inference because it means that science knows only about a part of the total universe, while Jainism describes the whole universe that exists.
There could be an alternative way of describing the middle loka. In this description, the orbiting celestial objects, including all stars, suns, moons, planets, etc., form one part that is a flat disc. Since all planets do not support the life of mobile beings, the planets supporting such life, i.e. islands, are projected into another plane to highlight their presence. This collection of planets, called islands, forms the second part, which in fact is a constituent of the first part. Jain philosophy particularly emphasizes that these island planets are where animals and human beings live. The other celestial objects have only one-sense beings. Animals are found on all islands, but human beings are supposed to exist only on the two and half islands of Jambudweepa, Dhatakikhand, and half of Pushkaravaradweepa. It has not been possible to correctly identify these three islands in the context of the universe known to science, but the message is clear that intelligent life like human beings exists on only a few planets. Some scholars think that our planet Earth is Jambudweepa. If the other two islands are assumed to be somewhere in the Milky Way galaxy, then it would mean that no other galaxy contains planets where human beings could be found. Of course, planets in other galaxies would have animals. However, this kind of assumption must be regarded as highly speculative and there is need for further thinking and research. If Earth is Jambudweepa, where is Mount Meru? This, like many others, is a puzzling question. It appears that Mount Meru has been conceived to represent the central idea that all astronomical objects in the middle loka have an orbital motion. In the human body, "meru" means spine. The spine forms the central axis around which the body is made. Similarly, Mount Meru forms the central axis around which the structures of the middle loka and Trasanadi are formed. Is Mount Meru an imaginary concept that may not in fact have any physical existence?
According to Jain philosophy, the loka is beginningless but matter follows the basic rule of origination-cessation-permanence. This means that any aggregate, like a star or a planet, can disintegrate into particles and paramanus and such particles and paramanus can reassemble and aggregate to form new stars or planets. In the same way, islands are also not permanent; they may disintegrate and lose their identity. Astronomical observations confirm that this is a regular process in space: old stars and galaxies are destroyed, and new stars and galaxies are formed. This may be one reason that the number of islands and stars in the middle loka is said to be countless, since their number is not fixed and keeps changing over time. But the overall structure of the middle loka remains of the same kind.
There are two other important features of the middle lokaas described in Jain texts: human beings are only found in a small part of the middle loka; and that the Jyotishkadeva outside this part are stationary, according to the Bhagwati Sutra. The human zone of the two and half islands is also known as samayaksetra or the time zone (considering vyavaharakala). We know that day and night on Earth is defined by the rotation of the Earth on its axis, and the year is defined by the orbital time of the Earth around the Sun. The question is, what should we understand by the statement that Jyotishkadeva are stationary? We know that all astronomical objects have an orbital motion. Therefore, the only possibility is that these objects do not rotate about their axes. Whether such a structure would be stable is to be examined, but it appears that the day and night system is essential for human existence. Animals with one to five senses, however, can survive in the absence of such a system. The vyavaharakala is measured by human beings only and has no meaning to animals, and therefore it can be assumed to be absent in the middle loka beyond the human zone.
