The Book of Walls: Dimensions
The dimensions of time and space within the Illusion work as absolutes. Humans understand space to be the distance between themselves and things or persons outside themselves, and they believe this distance to be absolute in the case of immobile things: the distance between New Delhi and New York is immutable. You can move from one or the other, but you have to spend time to do it and you have to transverse every point in space that is supposed to be between those two cities. It is generally believed that the closest connection between two things is a straight line; no matter what other way you choose you can never find a quicker route than the straight one.
Time is also perceived as absolute. Even though you may feel that this hour flies or that hour crawls your watch will always insist that exactly the same amount of time has passed. There is always a moment of 'now': there is a future and there is a past, but neither can be directly experienced. All you will ever really experience is 'now'.
Of course all of this is wrong. Space and time are means to categorize the illusory reality, and the human senses are equipped to perceive some parts of illusory reality as space, and other aspects of it as time. Let's look at a hypothetical example:
Let the world be n-dimensional. Within this world of unknown dimensions exists a single mathematical dot (with no spatial extension, therefore 0-dimensional). Let's further say this dot has a sense of self; as there are no reference points within its 0-dimensional world outside of itself it does not have a sense of location, even though it moves through the n-dimensional continuum. But let's say it may perceive different n-dimensional locations it passes by different flavours. Every single point in the n-dimensional continuum that it passes has a different taste. The dot perceives a sequence of different tastes, and this sequence it calls time. All of these individual points are elements of a single line. Were we to perceive all stations of the path of the dot at once, we would see this line. Lets say this one-dimensional line is also aware of itself moving through the n-dimensional continuum. The line perceives all of its length at once and calls the individual dots which constitute the line 'space' because their relation to each other is spatial. But all of these dots move through the n-dimensional continuum, and the different stages of this movement will again be perceived as time. Yet they also constitute, if perceived at once, a two-dimensional construct, and its movement creates a three-dimensional construct in turn. In all cases, spatial information is that which is perceived at once, while temporal information is that which is perceived in sequence. But in all cases, only the sensory equipment determines which dimensional information is spatial, and which is temporal. In Reality there may be a way to perceive four dimensions as space and a fifth as time, and so on. But we will get to that later.
It has been determined that 'space' is dimensional information we can take in at once: look around you, and you will find a wealth of information, your distance to certain objects or other people, the size of things etc. You can take all of this in at a glance, and if you turn around you can soak up all the spatial information available to you at your current position. But you can, try as you might otherwise, only perceive one moment at a time.
Now consider a movie. The movie consists of thousands of images. They all have the same width and breadth (space) and they are shown to us in sequence (time). They make sense only if shown in sequence; though they could be projected into the same space all at once we could not take any meaning out them. Time helps us to categorize sequences of events which, if perceived simultaneously or in the wrong order, would not make any sense to us.
And here lies the lie: space and time are not absolute. In Reality, distances are mutable; events can be perceived differently than in the order the dictate of time imposes on them.
Lets first take a look at Real space. An Awakened being ('subject') perceives spatial relations of objects to itself. All spatial information is dependent on the relation of the subject to the object perceived; as with the other domains, time and space do not determine the relation of subject and object, but the subject's stance towards the object determines its temporal and spatial relation to the subject.
Kether perceives certain areas of Metropolis to be his domain. Within these areas, his majestic influence can be felt, and his citadel can quickly be reached. Areas Kether is not interested in lie further away. If Kether's interest in, say, a specific part of the Machine City were aroused, this area would instantly be closer to his citadel, and his influence would extend itself there; if Kether's interest wanes, the distance between this area and his citadel increases. There is no movement involved; Reality simply adjusts itself to the different status quo.
All Awakened beings have this control (or rather, attitude) towards space. If an Awakened being were to live in a flat in New Delhi, and its closest (but unawakened) friend lived in New York, then the Awakened one need only stroll across the hall to visit its friend, while the unawakened one, trapped as he is in the Illusion, would have to travel all the way to India. If the Illusion breaks down, distance becomes as relative to those within the breach as it is to the Awakened, but usually they cannot control the effect without sound instruction in the domain of time and space.
Real time is also dependent on the attitude of the Awakened. There is no absolute time which can be measured by clocks, but there is still a sequence of events. Such events are called Cataclysms, and the periods before and after the Cataclysm are called Aeons.
Every Awakened being is able to create Cataclysms. In fact they do so all the time (no pun intended), but only important Cataclysms are noticed. Were Shiva Nataraja to destroy a certain aspect of Reality with his dance, this would constitute a Cataclysm and there would be an Aeon before and an Aeon after the destruction. Cataclysms of noticeable importance are usually only created by very powerful beings; the more powerful a being, the greater its capacity for world-shaking Cataclysms.
The biggest Cataclysm of all is of course the disappearance of the Demiurge. With the Cataclysmic decision to do whatever the Demiurge decided to do (die, walk away, be a normal human, whatever) everything that went before became part of the Aeon of the Demiurge's Reign, while everything that came after became part of the Aeon of the Demiurge's Disappearance. The latter Aeon is further subdivided by the Cataclysm of Astaroth's Search; by the Cataclysms of the Destructions of Hod, Yesod, Chesed and Chokmah; and so on.
It is important to note that Cataclysms and Aeons are not necessarily related in any way to the passing of time within the Illusion. One could say they often are at right angles to Illusory time. Therefore the Disappearance can be linked to a certain time; this Cataclysm just happens to be related to a certain period of time (the 19th / 20th century) and the Illusory time before is quite close to the Aeon of the Demiurge's Reign, while the time after that, such as the present, is close to the Aeon of the Demiurge's Disappearance. However, within an Aeon there is no time; therefore for instance, angels falling from the disintegrating Elysium (see the Elysium sourcebook also on this site) can drop into the Illusion at any time after the Cataclysm, even though they feel the Demiurge has just left the building a minute ago.
Other Cataclysms may influence the Illusion as a whole: for instance, when the powers that control the Illusion allowed the main philosophical mindset within the Illusion to change from mythical to scientific, the nature of the world as perceived within the Illusion changed along with it. Before the Cataclysm, tales of creation were true, even different tales told by different people; but increasing contact between peoples made a single truth more desirable, and the scientific mindset (although slow to evolve) finally changed the Illusion so far as to accomodate evolution, a prehistory without humans and a physical, rational, and logical explanation of existence (refer to the chapter about Madness for additional insights into reason and logic). Now, all of the Illusion, no matter how far back in time you might travel using your abilities in the domain of time and space, will be aligned to the Aeon of Science. The Aeon of Myth is completely lost to us. Magicians starting in the Aeon of Myth and traveling into the future will never reach the Aeon of Science; they will, however, reach futures of Myth that never existed in our time frame.
The most important source of Cataclysms which change all of the Illusion can even change all of Reality. There is only one such source: it is the abyss of Achlys. If anything is thrown into this abyss it disappears from existence and thus from Reality. It will not only cease to exist, it will never have existed. Both Reality and the Illusion will accomodate themselves so as to never have contained that which is thrown into Achlys. If for instance a group of people who are linked to each other only by some obscure heirloom were to travel there and throw that heirloom into Achlys, they would all immediately return into the Illusion where they were before the heirloom entered their lives, they would not meet (or have met) and they would have no memories of their journey to Achlys and what they did there. No-one who throws anything into Achlys returns to tell of the experience because they never made it in the first place! Now imagine what would happen if the Demiurge decided to jump right in...
There is yet another secret to time and space in the Illusion: everyone carries their own perception of time and space with them, and thus their own world.
If someone manages to perceive time and space differently, if they manage to travel through time and / or space, they create some sort of Cataclysm which they cannot control. Therefore it may be possible to travel backwards in time and kill one's parents before they even meet. This should create a paradox (if you approach this with reason and logic, but you should know better by now): the killer should not be born, therefore should not be able to ever travel back in time to kill his parents, therefore they will stay alive and eventually meet and give birth to their later killer, who travels back in time... etc. etc. ad nauseam. But it doesn't work this way. If you manage to travel back in time you do so. If you kill your parents you do so. They are dead. You live in a time which does not have an explanation for your existence. If you return to the time when you started the persons you call your parents will have died before your birth and there still is no explanation for your existence. The Illusion simply does not care.
If you return back in time after you made a wrong decision and meet your other self and tell your other self to decide differently, your other self might do so. Yet that doesn't change your history. You don't remember having met yourself and having been told to decide differently. If you stay in that past time frame you exist twice, though at different physical ages. People you may have made enemies by your decision may not be your enemies anymore because your other self decided differently - but your memory doesn't change, you just become an anachronism. It may even be possible to travel forward in time again, but you will still remember having made your decision and your other self will still exist (if nothing untoward happened). You could even return to kill your other self and come back to your present and visit your own grave. And it gets worse: a friend could go back in time and keep you from killing your other self; he could then return and you could still meet him at your grave because your present doesn't change; yet in a sense he would also return into a present in which he has succeeded, you hadn't killed yourself, and you existed twice. This is the stuff of insanity.
How does this work? Think of any irrational time-travelling event as a Cataclysm which splinters Reality into myriad personal options. Within the new version of the Illusion time travel and subsequent paradoxes are allowed. Logic and reason end, cause and effect become disjointed - everything becomes possible. But the Cataclysm is personal and does not extend to others - people who entered that state will be perceived as completely insane by others.
In the light of this, let's return to the initial example of n-dimensional space: the Illusion is a system with three distinct spatial dimensions (experienced at once) and one temporal dimension (experienced in sequence). Keeping our movie analogy, if you made a still photograph of each increment of time and projected all of those images onto the same screen at once you could see the formerly sequential, temporal information all at once. Reduced to one object, you could see the car as its parts, the assembled brand new state and the wrecked state after the final crash all at once. Somehow, eqipped with proper sensory organs, this information, taken in at once, would become a fourth spatial dimension. But what is the fifth dimension which consists of the movement through the n-dimensional continuum? The answer is, possibility. The spatial information regarding the car contains its measurements and its life cycle, the latter of which our human perception cannot understand as spatial; the new sequential (that is, temporal) information consists of the different possible fates of the car. To a being knowing four spatial and one temporal dimension, time is a sequence of different fates. This is where what we have to perceive as temporal paradoxes comes in. Reality is multi-faceted and contains any number of alternative fates. And that's not the end yet: if possibilities are merely a fifth dimension of space to a six-dimensional being, what is the sixth dimension, perceived as time by this being? Impossibilities? And what then? The mind boggles - I for sure can't follow there, so maybe that is where the Demiurge has gone.
So, let's review: within the Illusion, time and space are absolute as perceived by our senses and we cannot change them. In Reality, time and space are relative to the attitude the Awakened being takes to them. Space is an expression of emotional or intellectual closeness, and time moves in wild, Cataclysmic jumps from static state to static state - these are called Aeons. Time travel is possible even to the partly enlightened (or victims of accidents); but paradoxes simply refuse to solve themselves and happily go about destroying your mind. In essence, whatever you as game master feel you should introduce in the context of time / space perception inside or outside the Illusion, go with it. Don't fear that you might contradict yourself, pay no mind to continuity, gleefully embrace paradoxes. Done with confidence, there is more horror to be gained from that than from the slow and painstakingly described disembowelment of player characters at the hands of Nepharites...