Sometimes one can even see one's own past or future in several places. Going to those places just means coming back to the same point but at the different moments in time.
Sometimes space functions like time and time like space, sometimes one or the other does not exist at all. Sometimes they function in completely weird ways. Sometimes there are many more dimensions of one or the other or both.
As the Imaginarium has no time or can have multiply time dimensions in the same place, all passing at different speeds, it is not possible to know how much time as passed while inside it. A second can become a million years or the other way around.
Mental dangers
The entire experience tends to cause extreme emotions of helplessness, confusion, many types of fears like claustrophobia, fear of open spaces, fear of heights, fear of people in general, different unnerving sensations like a feeling of being followed or observed, all of these eventually leading to some form of madness.
Even those entering it in their minds alone, not physically, are subjected to these effects. They might not be as dependent on a physical reality to move around and to deal with their environment as one who is there physically but their minds are still used to interact with the environment around them in a sort of physical way.
Corrupting
Its ultimate danger though is that it slowly consumes the existence of anything inside it, corroding it like an acid that leaves nothing unburned.
Real things slowly become less real, more subjective, less focused, less defined, eventually having their nature change into that of the Imaginarium itself, being turned into fantasy, subjectivity, imagination, becoming non-real.
You are slowly unmade!
Those affected by this tend not to notice as it is a slow process and there is nothing inside the Imaginarium that can serve as a point of comparison to remember oneself of what is real and what is not. Only when one tries to leave it again can this change become apparent as the contrast between the reality, even if only that of a stable Imaginata, and what one have become in whatever amount of time has passed. At that time it is already too late and nothing more can be done about it.
Resisting the dangers
The only way to resist these effects to some extent is by being able to focus one's thoughts enough but even this is a temporary measure for there is only so much time one can maintain a focused and continuous thought without being distracted by anything and if there is anything that the inside of the Imaginarium is is distracting.
Entering it
Entering it requires leaving reality itself, going through the Great Barrier into the land of fantasy. This sentence alone should give an idea of how hard it is to achieve.
Mentally
The easiest way to do it though, is through the mind. Any usage of the imagination in any way is already a form of entering it just slightly, like wetting one's toes on the beach.
The exact same thing that gives it shape is what allows us to reach into it. We do this all the time without even knowing it or thinking about it. We are able to explore large parts of it as well as many of the Imaginatas that exist in there. We are also able to remember our past which lives there through the use of our memory and to plan for the future by using our ability to predict it through expectations and reasoning that also allow us to cross the Great Barrier into it.
Sleeping and dreaming penetrates it much deeper, as does day dreaming.
Going inside your own unconscious!
Lucid dreaming is an even more powerful way of doing it. Its the form at which the potential of the Imaginarium to be molded by one's desires really becomes apparent. But it is also deceiving in that it hides the chaos that lies beneath it all and the difficulty in controlling it, for the unconscious mind keeps it stable for the entire process.
Meditation is similar but it allows one to reach as deep while remaining conscious.
Many hallucinogenic drugs also send one's mind into it, possibly providing some degree of stabilization around it, possibly not. The dangers inherent to the usage of such drugs are, many times, not actually directly derived from their usage but a consequence of being inside the Imaginarium.
Astral projection is probably the more advanced form of having one's mind leave the body and it also allows for easy entering into the Imaginarium, if one is aware of it and how to do it. It can become so easy as to the point of being trivial.
Physically
Entering it physically is much harder. One's body is part of one's reality and what needs to be made is to separate that part of reality that is one's body from the rest of it.
How does one get into the land of imagination? The story of a book, the setting of a TV show or a movie? How does one enter into the realm of all that is not real, the sea of the elements of imagination? This is probably impossible so, in order to do it one must achieve the impossible.
Magic is one way, the more obvious one, if it exists in one's reality at all. But some kind of super-science can also allow to achieve this result. It just needs to understand the nature of reality and be able to poke holes through it. How it can be done and how easy it is depends on the nature of the Imaginata one is trying to exit from.
It also crosses back into reality
More strange than being able to enter it is to have it or its contents, to have fantasy, cross back into reality and affect it.
Sometimes the Imaginarium itself or some Imaginata is able to cross the Great Barrier into the Realium at some level. This can be witnessed as we are affected by it happening, we have our feelings affected in this or that way because of it, we become convinced of something or get a new idea that just appeared out of no where, we get inspired, motivated, unmotivated, etc. All those things are examples of the Imaginarium reaching out to us, into the Realium.
Things physically entering reality from outside probably do not happen in the Realium itself but they can happen all the time in several Imaginatas. It all depends on the nature and permeability of the Great Barrier around them.
Reasons to enter it
There are many reasons that lead those crazy enough to do so. The first and most obvious one is because it is in our nature. It is there so it causes a need to explore it to appear. It is the last and larger frontier.
Some explorations are purely scientific in nature, driven by the search for knowledge, an attempt to understand the nature of this new frontier and what it can say about the nature of their own reality. Others are purely driven by greed in an attempt to collect as much of its endless resources and treasures as possible.
Becoming something more!
Attempts at contacting the realities of other Imaginatas are also typical. Some are simply motivated by curiosity, a desire for cultural exchange or exploration. Others by attempting to establish trading relations with them. But many are also motivated by a desire for conquest and exploitation of their resources.
Another common reason is a desire to escape one's own reality, to find something better or to create a new one shaped by one's desires. The idea that anyone can create and shape their own personal reality according to their whims and live like a king there or even become a god inside it can be very tempting.
It is even possible to change oneself by imagining something different, possibly something more but the risk is even higher.
Activities inside of it
Many civilizations from different Imaginatas are aware of the existence of the Imaginarium and some are able to enter it with more or less difficulty using different methods and processes.
Exploration
There is some exploration of it, analogous to our own exploration of space.
Researchers study its apparent patterns and behaviors from the safety of an Imaginata, using special machines akin to telescopes that allow looking into it. They study other Imaginatas in the same way we study other stars or planets. They also study the brain and the process of imagination and relate those two disciplines for that is the nature of the Imaginarium. Some research stations have been establish inside it for scientific purposes.
The areas immediately surrounding an Imaginata have the properties of both that Imaginata and the Imaginarium. They are very stable and very similar to the Imaginata itself but not fully so. It becomes more unstable as one reaches farther away into the Imaginarium. These are the most explored areas, the places where most structures are built and where most activity exists. They are sometimes referred to as beachheads.
Contact
As different civilizations explore it and venture into it several end up contacting each other and forming different types of relationships.
Any contact with other Imaginatas usually tends to be mostly limited to the closest ones. They tend to have somewhat similar or, at least, familiar inner realities for they usually originate from each others imaginations and exist as derivations of each other. Because of this or as a reason for this they also tend to have people with similar ways of thinking or believing and imagining.
Politics of every kind ensue as the result of different civilizations meeting each other. They trade and learn with each other, form larger groups based on common interests, etc.
As it usually happens whenever different civilizations meet each other, there are also military incursions into it, prisons, military bases, fleets, war!
Built structures
Many civilizations have built or attempted to build many types of lasting structures directly inside the Imaginarium, unattached to any Imaginata.
These structures serve many possible usages from exploratory and research stations, military outposts, mining facilities, etc. If some area of interest is found inside it, usually some type of structure will be built in order to try to claim and maintain control over it. Any found resource that one intends to collect also requires the necessary machines and structures to do so effectively. Industrial complexes that take advantage of some property of the Imaginarium in order to work more efficiently. Artificial habitats help dealing with over-population problems inside of Imaginatas that suffer from it. On places where the Imaginarium is sufficiently understood and explored, even tourist places can be found.
Due to the inherent orientation difficulties inside the Imaginarium another common type of structure is a navigational beacon, similar to a light house but adapted to the specific conditions of this much more hostile environment. They are intended to help ships reach their destinations much more consistently and faster. Without them any type of movement through the Imaginarium is much more uncertain and a large percentage of ships used to get lost. Even with their presence, disappearances are still not a rare occurrence.
Paths of many kind crisscross through its space!
Another structure intended to make movement more constant and safer is the establishment of routes of some type. These can vary from simple guiding lasers to the construction of actual physical road like structures. Due to their size and because, by their very nature, they are usually not entirely inside well stabilized and controlled areas. They are usually very hard to follow correctly unless one is very familiar with them and knows how to do so safely. It is not unheard of for them to change in unpredictable ways under the effects of the environment around them. Because of this they require regular maintenance and the ruins of ancient paths that fell into disuse can be found floating around sometimes. Even then, with all those flaws and limitations, they still make the paths along them much safer than without them. Despite these requirements they are very commonly used to establish trade routes between Imaginatas or as umbilical cords to the artificial structures constructed in no man's land.
All these artificial structures will require a form of maintaining their stability in face of the corrosive nature of the Imaginarium. The more they are, the larger they are, the closer they are to Imaginatas and the more people they have on them the more stable they become. Unless these structures exist in an area very close to several Imaginatas that provide it stability, these effects tend to not be enough for them to be entirely dependable. Because of this there have been many attempts at artificial stabilization technologies.
Lost and abandoned structures are not uncommon and are probably much more numerous than those in use and properly stabilized. Usually they are warped by their environment, having lost all or part of their stability. The most primitive ones didn't even have a stability generation mechanism, which is probably what caused their eventual collapse in the first place. Some can be in their current state due to past accidents that lead to their destruction. Many can be very dangerous and unpredictable.
Tunneling through it
Tunnels have been digged through the Imaginarium to link multiple Imaginatas together. The creation of portals between the realities of different Imaginatas usually manifests physically as tunnels crossing the Imaginarium space between them.
They allow for communication and movement between them without having to enter and be exposed to the Imaginarium directly. They are similar to roads except that they are closed to the Imaginarium environment outside of them, providing a much higher measure of protection.
Its their construction and maintenance that is the hard part but once they are in position things become a lot easier. They are much harder to build than simple roads for they require actually isolating the environment of the Imaginarium from entering them over their entire distance which is not easy. It is not simply possible to first build the open tunnel and then siphon out the Imaginarium from the inside of it. Not for such larger structures.
Some areas have very large and complex networks of those tunnels inside them linking hundreds, thousands, millions and, sometimes, even higher numbers of Imaginatas. The larger the network, the more tunnels there are and the more Imaginatas they connect to, the stabler is the area between those Imaginatas and the safer and less maintenance the tunnels require. This happens because so many closely related Imaginatas have a much stronger effect on the area around them and each one reinforces the others, all contributing together to stabilizing it. The closer and more related two Imaginatas become the more common, similar and related their imaginations tend to be as well. If a network becomes strong enough in the space between several Imaginatas, the entire grid becomes a huge common beachhead. In the extreme the close Imaginatas can even join together into a single larger one, covering the entire space between them all.
Other structures existing directly in the Imaginarium can also be linked to those tunnel networks.
The Domain of Divine Art is a realm found in Abstraction, where the Meanings of Artworks reside alongside the Essence of Divine Art. The span of this realm, the ascendent space it takes up within abstraction, is determined by its inhabitants, that is to say, the domain of works of art results from the engagement of a self-consciousness on an intent (author), and the will of a self-consciousness to provide interpretation (audience). While fiction is co-created by these two, its meaning is divine, is searched for, and its coordinates are approximated, but never reached, as it resides within the Domain of Divine Art. The projection of coordinates (given by the intersecting intents and interpretations) onto Abstraction represents the Domain of Divine Art. The border of the Domain can be thought of as constituted by the outer-most meanings. It can be thought of as a sort of a paradisiacal space, a garden of earthly delights.
Art
The notion of art is a dialectical one, and a one impossible to conclusively define, because the very definition gives it a boundary that is destined to be surpassed. – Surrealist art, for instance, breached the definition of what art was considered to be, hence widening the notion, and setting the stage for another disturbance to this new definition, as presented by suprematism. Each movement of the notion incorporates within the renewed definition the inadequacies of its previous iteration. – Art is art only insofar as it ceases to be itself. Many have pondered meaning of an art piece, trying to uravel the complex web of relations of authors (writers, composers, etc.), executing entities (players, performers, etc.), and recipients (audiences, viewers, etc.) with theories of art interpretation postulating that meaning cannot reside with any one of them alone. Within the Rollebon cosmology cosmology, meaning is not made. It exists already within the framework of the universe. It is found. And it is all of the above mentioned parties that discover this meaning together. Only ever approximating it, but never discovering it. Art is divine, it is godly, and as such, it is an antecedent to all the universes that developed self-consciousnesses.
Realium is just another name for Reality, although put in the context of ThisWriter's Top Cosmology.
"Reality is that which, when you stop believing in it, doesn't go away."
Philip K. Dick
Position on the Omniumverse
The Realium is one of the two essential parts of the Omniumverse, the other one being the Imaginarium which stands in opposition to it. The Great Barrier ensures the separation between both.
It contains everything else
Both the Omniumverse and the Imaginarium are real in some sense of the word, therefore part of the Realium.
The proof of that is that we truly imagine things that are not real, therefore imagination is real. As the Imaginarium is just another name for imagination, this shows that it is also real, even if not in a concrete material way.
The same thing can be said of the Omniumverse. Its essence is that of whatever difference exists between what is actually real from what is imagined. It is an obvious truth that there is some difference between what is really real and what is fantasy therefore the Omniumverse as defined must also be real.
Reality is also in the Imaginarium
Anyone can theorize about the internal organization of the Realium but, until those theories can be verified or proved, they just describe one more Imaginata inside the Imaginarium.
Even if they turn out to be truth, they also already exist as Imaginatas as by the previous statement and knowledge also exists in the Imaginarium so they would continue to exist as Imaginatas anyway. This implies that there exists an infinite number of copies of the Realium in the Imaginarium. Or, more than just copies, that the Realium actually exists an infinite number of times inside the Imaginarium.
Internal Organization
Both the Realium and most Imaginatas, but not the Imaginarium, have some type of internal organization. This internal organization is called a Cosmology, no matter how or what it is, which corresponds to their inner reality. The closer a specific Imaginata is to the Realium, the more based on it it is, the more similar its internal organization will be to that of the Realium.
For now, all that we believe to know is that there is one universe, our own, possibly more if at least one of the multiverse theories is true.
If, instead of a single reality, there exist multiple parallel (or not) realities, they do not, each, correspond to one Realium out of many. Instead the Realium is the collection of all true realities, no matter how different or "far apart" they are from each other in whatever way.
Point of View Hypothesis
If one ignores the fact that one is real and the others are not, there is a similitude between the Realium and the Imaginatas. It is possible, even likely, that from their inside, many of the Imaginatas look to be the Realium instead and that the Realium is, for them, just another Imaginata.
So, what is the Realium and what is an Imaginata can just be a matter of a point of view. This is not a certainty but it is a possibility. This can make one wonder if there is actually any difference at all. Or is it just not another case of we putting ourselves at the center of reality or in an otherwise special position like putting Earth at the center of the Universe? Is our reality special and different because ours is the real Realium and others are just Imaginatas? Is "real Realium" just a pleonasm, exactly like it sounds or is Realium just another word for "my Imaginata"?
If it is the case that the Realium is just another Imaginata then the Omniumverse would just be the Imaginarium and nothing more, instead of being something larger that contains it, with the Great Barrier being just the border between each Imaginata and the rest of the Imaginarium. If that is the case there is no way to be sure of it while staying inside of either the Realium or any other Imaginata and it is not possible to know if there will be a way to be sure even if standing directly in the pure Imaginarium.
With The Box being synonymous to the Imaginarium in all likelihood, that would mean that it also turns out to be everything after all.
Comparisons with other structures
There have been some attempts at comparing the Realium with other structures that are also about defining or placing reality in relation to the rest of a cosmology. For that purpose, it can be said that any structure that corresponds to all reality and only to reality alone, that is real only and always, from any and all points of view, no matter what, is the Realium.
If there is no such structure that corresponds to reality from any and all points of view then, as explained above on the Point of View Hypothesis section, there would be no Realium. All possible realities would have a point of view from which they would be fictional instead. There would be no absolute reality, therefore, no Realium.
Creator God Hypothesis
If there exists a creator god of reality, one could identify its act of creating reality with the act of anyone else creating an Imaginata through the use of imagination. This would allow us to say that the reality itself, the Realium, or even the Omniumverse is just the creator god's Imaginata. Such creator god would be reality's Demiurge.
Realium in Practice
What this all means in practice is that the Realium, by definition, is off-limits to any and all fiction or fantasy.
Everyone is free to write, believe or imagine whatever they want about the real world, any story, any speculation, etc. But the thing is, that as soon as they do so, they are actually writing about a fictional version of reality, not about reality itself. They are writing about just another Imaginata, no matter how similar it is to the Realium, it no longer is the actual Realium. It no longer is the actual reality, it is a fictional or fictionalized reality.