The //[['ikra]]// are an inquisitive and intelligent species, and over their millennia of history they have developed several models to make sense of [[Tagra]] and the greater universe.

===== The world =====
Despite the difference in their interpretations, all traditional cosmologies start from a common physical description of the world. Tagra is a roughly circular landmass surrounded by seawater and by the [[Wall of the Sea]], beyond which additional lands might or might not exist. Tagra may be believed to turn once a day around an axis, which passes through the "Heart of the World" (i.e., the South Pole). These lands and waters together form a flat disk, which is inserted in the middle of a sphere, cutting it precisely in half. The upper half of this sphere contains the heavens and celestial bodies, whereas the lower half is hidden and inaccessible.

There are three words in the [[Chaatai#Language|Chaatai language]] that might be translated as "world":
  * **//tagra//** primarily refers to the material, observable world: land, sea, and sky. In a narrow sense (the one used elsewhere in this wiki), it refers to the Antarctic continent and the surrounding waters, at least out to the Wall of the Sea. In the broadest sense, it refers to all physical existence, from the ground to the stars, as opposed to the realm of deities, spirits, and pure thought (compare the English terms "mundane" or "terrene").
  * **//dji//** (literally "egg", though it might be translated as "orb" or "globe") refers traditionally to the spherical shell in which the flat disk of Tagra is embedded. In modern scientific language, it refers primarily to planet Earth, as opposed to the specific continent of Tagra.
  * **//t'aakai'a//** (literally "all-around") is the closest to the English term "universe", referring to the totality of existence. It explicitly includes all that is not directly observable by the //'ikra//: the world of abstract concepts, the space below Tagra, hypothetical lands beyond the Wall of the Sea, and so on.

===== Mirror-world cosmology =====

===== Developmental cosmology =====
In the traditional [[Chaatai]] interpretation, the structure of the universe as described above is not fixed, but only a snapshot of an epoch-spanning history, based on a process of ordering of matter.

//Dji// was originally purely chaotic -- containing all the matter we see today, but without distinction, structure, orientation, sequence, or identity. At the beginning of history, a spark of order (usually identified as the breath of [[Chaatai#Philosophy and religion|'Au'a]]) manifested at the upper pole of the sphere //dji//, and proceeded down. This spark broadened as it descended, leaving behind a trail of increasingly ordered bodies in the upper regions. The physical world of Tagra is the front of this advance, always a circular section of the cosmic sphere. At the present Time, Tagra is halfway down the sphere, hence at its broadest point, and therefore sustaining the maximal diversity of things.

This circular interface between the expanding order and the contracting chaos is the only one in which life can exist, as it is both ordered enough to sustain distinct bodies and chaotic enough for these bodies to move and change. Above Tagra, one can see the already ordered regions of the cosmos: at the very top, the fixed stars, which do not move at all (it's the rotation of Tagra around its axis that produces their impression of movement); below, somewhat move chaotic, the planets, which do move but only along predictable paths; then the Sun and the Moon, which can not only move but change their nature (with eclipses, lunar phases, changes in color at dawn and sunset, etc.) Below Tagra, the primaeval chaos persists: while it cannot be directly seen, it erupts into the upper world with volcanoes and underground springs. The chaotic forces injected into the ground from below allow it to bear life, and impart Tagra its rotation.

At some point, as order spreads down //dji//, Tagra will start contracting, finally to vanish at the lower pole, leaving behind a perfectly ordered world, completely unsuitable for life -- a permanent crystal or constellation. There are different ideas on what will happen later. One is that the ordered state will last forever; after all, when no events are possible, time no longer exists. Another is that the ordered cosmos will slowly decay back into the chaotic state, possibly for the cycle to begin all over again. Yet another is that Tagra, having reached the lower pole, will "bounce" back and travel upward, this time converting order into chaos, and so on //ad infinitum//.

In modern times, scientific discoveries have made a strict interpretation of this discovery untenable. It is now accepted that Tagra is a continent at the pole of a spherical planet; for scientists, //dji// refers to this planet. It is also known that this planet revolves around the Sun, and that the "fixed" stars actually do move relatively to each other. Yet, one could argue that the ordering impulse of the cosmos exists, as demonstrated by biological evolution, by the growth of organisms, and by the formation of crystals. The 2-dimensional disk of Tagra moving through a 3-dimensional sphere of //dji// might be reinterpreted as a metaphor of a 3-dimensional universe moving through time, maybe expanding and contracting in an eternal cycle of "Big Bangs" and "Big Crunches".

This does not negate that the eventual fate of this iteration of the universe will be to become frozen and lifeless, though with the possibility of a very distant thawing. Which is, of course, exactly what happened eventually to Tagra, though for different reasons.
===== Cosmic-egg cosmology =====

In the [[Takrakaya]] tradition, the concept of //dji// or "egg" is taken more literally. The cosmic sphere is, in fact, the incubating egg of a transcendent Being (Takrakaya //khah//, Chaatai //kaya//) that will eventually hatch into a higher-order cosmos. All that exists in the universe takes part in the Being's development according to unfathomably complex rules, that may well seem arbitrary and senseless to //'ikra// observers.

This cosmology has important ethical applications. The respect of natural, social, and moral norms, as discovered through the millennia by prophets and philosophers, is necessary for the proper maturation of the Being. In the mildest interpretation of the cosmic-egg cosmology, those individuals who follow correctly rite and traditions will be incorporated into the Being itself to partake in Its existence. Those who do not, will be cast away as allantois (afterbirth); it's not clear what this fate entails exactly, but it can be assumed to be highly undesirable.

Some currents believe that sufficient disorder in the material world -- widespread vice and corruption, tyranny or rebellion, natural disasters -- will abort the Being, preventing Its hatching. The lineage of the [[Takrakaya#Divine Empress|Divine Empresses]] in Tsang-ha has the practical and ceremonial responsibility, among other things, to prevent this fate.

A yet darker interpretation of this model, found among discontented elements of Chaatai and Takrakaya society, holds that the Being //is already stillborn//, and the world is Its decaying corpse. This entails the necessity, depending on the subject, of either withdrawing from the material world and the greater society, or of deliberately destroying it as a final purification.
===== Many-world cosmology =====

===== Scientific cosmology =====