The expanding metaverse is an Etherite version of the concept behind the Sphere of Time, known mainly to the Masters and Arch-Magi of the Tradition. While it is probable that the Oracles themselves have transcended this idea, it remains a useful way of explaining how one can travel into the past and/or to alternate universes.

According to this concept, it is inadequate to say there is one universe or many; rather, the whole Tellurian exists as a probability continuum extending through a fifth dimension, neither of space nor time proper. In theory, each point in this dimension represents a universe--an infinitesimal slice of probability. In practice, however, all known beings and objects occupy a finite "distance" along this dimension. This is the result of the "quantum floor" to reality. Below a minimal change, differences between versions of a given particle are indetectible; the minimum probability difference is the change of an energy state of a single particle by one quantum level. Since this tiny difference is usually indistinguishable, the practical "width" of a single object on a macroscopic scale is generally much greater.

The consequence of the quantum floor is that there seem to be a number of distinguishable universes, each with its own probability width which represents the likelihood of that universe existing. Each object has a number of counterparts--actually, parts of itself that vary slightly--across the many different distinguishable universes. The width of any universe as regards an observer is its narrowest observable entity; from the observers' point of view, there are at least two universes, one containing the object and the other not. (In practice, observable entities usually extend through more than two universes, since they consist of a large number of particles, of which there are many different arrangements.) It is possible to view these alternate universes, or even travel to them, via Entropy and Spirit, or with the advanced Time magick of the Oracles of Time.

The precise manner of these alternate universes' existence is very much in debate. Is only one of them "real"? Are there a finite number of "real" universes, with the others not "real"? Or are all possible universes "real"? The problem involved is that each being consists of an innumerable array of counterparts in this fifth dimension, each of which is slightly different. Can a single being actually make all choices at once? The alternate possibilities are just as philosophically problematic, however. If there is only one being, choosing only one path, what privileges his reality above the others? And if a being splits in two each time she makes a choice, is one the original and the others copies? Supposedly in ancient times the Oracles claimed that all realities truly existed, side by side, and that the difference between the first and third options was illusory. There is, however, no sure way of verifying whether the documents in question are correct. Even if this is so there remains the question of why it matters what anyone does, since there is always an alternate universe in which they did something else.

How does this "metaverse" relate to the Sphere of Time? Two things occur in the metaverse as time passes. One is that, from the point of view of an observer moving through time, the probability width of each universe is changing. As they do so, a possible state of affairs becomes harder or easier to reach, with or without magick; we simply say that an event becomes less or more likely to occur. As the time when an event can happen passes the observer's present, the probability approaches either one (the event happens) or zero (it doesn't happen); once the present moment is passed, the alternate universe is no longer reachable except by magick (or possibly magic).

The other is that, as time passes, the number of possible states the universe can be in increases. A person who wakes up can move only a relatively short distance from his bed in one minute; an hour later, there are a great many more locations he can be in. Mages therefore refer to the metaverse as expanding, as more and more universes become possible. (This is not the same as the expansion of the three-dimensional universe, though the two are obviously related.) The problem with this expansion is that "meaningless" universes in which nothing truly exists because all particles are randomly distributed increase faster than "meaningful" universes. Likewise, each universe splits off many more universes less "meaningful" than itself than it does universes as "meaningful" as itself or more. This tendency is called entropy; the actual "meaning" which groups together particles into identifiable realities is called quintessence. At least, so the Time mages argue; Entropy and Prime mages have been known to strongly disagree!

It should be noted that the probability of an event is partly a matter of perspective. From our point of view, it is extremely unlikely that the Confederacy could have won the Civil War, but this is so because of any number of events that had already happened. There would be alternate universes in which the South occupied a different strategic position, so that it could reasonably or even certainly be expected to win. However, these universes would be farther from our own, diverging at earlier points in time, and thus would _appear_ to be approximately as unlikely as the universe in which the South wins by an improbable freak occurrence. The mage traveling to such universes therefore has about an equal chance of reaching any of them.

While the Oracles of Time may still argue various theories regarding the metaverse, they are known to be beyond the relatively petty squabbles about whether people move through time, time passes by people, or only consciousness moves along through an essentially static universe. So far as can be told, the Oracles dismiss these as inconsequential differences about words that really mean the same thing.

Disciples of Time are capable of causing events to happen at a faster or slower rate, but even a Master is incapable of reversing time so that an event _unhappens_. The beginning Archmagi of Time learn that art, discovering how to cause an event to occur in reverse. Of course, they can only do so to single occurrences. At the sixth level, a mage is able to make a shattered cup come together, rise from the floor, and settle back on the table, but she cannot rewind time for all of New York, let alone for the entire universe.

Of course, it is then possible to alter the circumstances surrounding the event so that it never occurs, or occurs differently. In some cases, such as the above example, this is all but inevitable if only the single event is rewound; whatever caused the cup to fall the first time is already gone, so once back on the table it won't fall again without another disturbance. Of course, if the cup only rises part of the way before being released, it will certainly fall right back. Tampering with an object still in reverse time is risky, because its interactions with normal matter are reversed. For instance, the aforementioned cup rises, in one sense, because gravity now repels it, and settles back on the table because the electromagnetic forces that once kept it from falling through now attract it to its prior spot. Placing one's hand in the cup's way would cause it to settle on the hand's underside, and it would remain there as the hand moved, unless it toppled off (in which case it would continue to fall upward until it landed somewhere else) or was placed back in proper temporal sync with reality. Moreover, stationary objects in reversed time may do things without apparent cause; the cup might suddenly rise from the table if somewhere else for it to land is available, since it might have fallen from that spot in normal time.

With difficulty, the Archmage is able to reverse her own time frame for very short periods; from her point of view, the rest of time is reversed so that things happen backwards, and she is, in a sense, traveling back in time. Such a state can be maintained for about half an hour, at most. Alternatively, the mage can reverse her time in such a way as to seem to be doing things backward; this erases her memories as she "rewinds," and from her perspective she has traveled forward in time. Other people, however, may point out to her what she has been doing.

At this level, the Archmage discovers how to fully travel into the past much as Time Masters travel into the future, vanishing from one point in time and reappearing in another. As explained in _Horizon: Stronghold of Hope_, this is a vulgar activity, especially if the mage changes history. The rules stated in that volume regarding Paradox are applicable, and so I won't repeat them here.

One is left with the question of why Paradox "knows" that history has been changed. There are two non-exclusive reasons why this is so. The first answer deals with the alteration of causality. This is the classic "time paradox" from which the basic idea of Paradox was probably taken. Due to the mage's actions in the past, his present is changed in some way. The result is that the mage's current reality is transformed (by a Paradox backlash): for instance, he may be altered by a Paradox flaw (was born a different gender; didn't go to college; etc.); he takes physical damage and may "die" because he never existed or was previously injured or killed; he vanishes into a Paradox realm because he no longer was born in "true reality"; and so on.

The second answer is that, in Mage terms, the past, present, and future are not really different. In some sense, an actual change occurs, rather than something different simply "having happened." Even though the Sleepers are not consciously aware that history has changed, their Avatars know; moreover, mages may well know via Awareness or their own time perceptions and in situations like this may count as witnesses to vulgar magick. Furthermore, in some cases, the mage may well have revealed his presence to history; that someone materialized in the path of Lee Harvey Oswald's bullet would certainly go down in the history books.

When she reaches this state, the Oracle becomes capable of viewing alternate existences with Time magick alone. This may at first seem like a rather small step, but there are several reasons this is not so.

First, the mage is now able to examine alternate existences for whatever learning she might glean from them. With other Spheres, she may learn information she could never have gained in this universe alone. She might also learn of talisman and magickal practices that never existed in this universe, or never became prominent.

Second, the Oracle is also making a big step in understanding. Learning that, in some sense, one's actions are not as important as she thought, and in another may be even more important as she sees how she determined the destiny of other people may well be a large movement toward Ascension.

Third, on a practical level, the Oracle is now able, by studying the various possible ways history might have gone in detail, to change history and incur only the amount of Paradox she would receive from an ordinary feat of magick. By tampering with small events, the mage might be able, for instance, to bring about Hitler's death in such a way that no one could tell there was any interference at all; such an action would be purely coincidental. Merely disguising herself properly could allow her to slay Hitler and still have the action merely be vulgar in the ordinary manner.

With this understanding of Time, the Oracle is capable of changing history without even entering it. He can alter the flow of time while remaining in his sanctum in the present day. However, he is limited to doing so by changing a specific event; he could cause John Wilkes Booth's gun to misfire, but he could not cause the South to win the Civil War without specifying the means by which it happened (and he would have no guarantee that it would work).

There are two ways in which this can be done, or two alternate things that he can do. The first is an actual change in history; the mage is now in an alternate timeline in which things proceeded differently, he fits into it perfectly, and no one can tell the difference consciously. The second is a transfer between extant worlds; the mage proceeds across the dimensional barriers to a world where history is different, where he will probably be out of place and will presumably have a counterpart.

In the first case, the mage will suffer Paradox in the normal fashion. If the event seems to be the natural proceeding of events, the effect is coincidental; if something appears wildly out of place, it's vulgar. The Oracle is not capable of producing a magickal effect in the past unless he has the Spheres to produce it in the present, _even by changing history so that another mage did it._ Obviously, producing the effect with no apparent cause is vulgar. Forcing another mage to produce a vulgar effect produces Paradox not only for the past mage, but like Paradox for the present mage as well; if the past mage's effect is coincidental, he gains no Paradox although the present mage may accumulate it if others recognize that something odd has happened. Tampering with the past may also alert other mages, especially those who know something of Time themselves. Finally, directly changing someone's decision allows them to resist as usual, even though they're not consciously aware that anything is happening.

In the second case, the Oracle is not affected by Paradox merely by changing worlds, so long as he doesn't vanish or appear in clear view of Sleepers without a good explanation. (One might well find a world where such things are commonplace!) However, if his counterpart in that realm is not significantly different from him, meeting that other version of himself produces the same sort of effect as meeting himself in another time would. Since no one is actually being changed, there is no chance to resist the effect; someone else he shifted with him could resist, though.

The ultimate power over time is the ability to change history in any way the Oracle chooses. At this level, she can pick any event, however complex, and alter its outcome, although the more complex the harder it is to change. Likewise, the Oracle can travel to any alternate world, no matter how different it is from her own. One thing the Oracle still cannot do (at least, not with this Sphere alone) is create a history in which the paradigm of reality is radically different; doing so would generate enough Paradox to tear her asunder.

Paradox affects the mage just as it would at the previous level; changing history in this way may mask the effect or generate extra attention, depending on the precise nature of what occurs. The Oracle can also encounter alternate versions of herself, however alike, without danger of Paradox.

The Mirror Zone, in the opinion of many mages who are aware of the metaverse concept, is one way in which mages and others sometimes find themselves in contact with alternate histories. Unfortunately, the uncontrollable nature of the usual way one encounters the Zone makes it rare that anyone finds their way to a cosmos of use to them. It may, however, work to enlighten them regarding alternate worlds.