Tangents (QD)

Underlying this story is the assumption that parallel universes are real, something that both quantum wave theory and the theory of relativity predict the possibility of.  Endless possibilities for alternate Earths exist, all contained within a structure known as superspace. It is composed of every possible parallel universe, all coexisting side by side.  Each of these individual realities will be referred to as a paraverse (contracted form for parallel universe) or a tangent.  Each tangent is a timeline, an alternate version of history.
Each separate tangent is like a thread, and the entire network of threads make up superspace. Timelines branch apart from each other at various points in their history, but threads also remain braided together in rough groupings of similar tangents, forming clusters across superspace.  It's generally accepted that only truly significant events result in the creation of new timelines, and truly massive events or catastrophes (such as the Second Impact from Evangelion) serve as massive bifurcations of the threads and can produce entirely new clusters.
There is also a theory (the one I am following in this story) that every action produces multiple tangents, but that almost all of those tangents merge back together into a single thread. Only a few of these tangents created cross over the minimum temporal energy threshold that will allow them to sustain themselves as separate from another tangent, but it is left to the reader to imagine how significant an event would have to be to do this.  Time travel is an example of one of the ways that this might be done, but the change done in the past would still have to be large enough to split off a new tangent that would not simply fade back into one of the others.
Tangents are 'grouped' together into clusters, all of the paraverses within a cluster sharing many basic characteristics with each other, and they are all wound and braided around each other much like threads forming a rope.  Each individual cluster may hold anywhere from dozens to thousands of tangents, maybe even more. 
Generally, the tangents within a cluster bifurcated from each other relatively recently (anywhere from a few moments to thousands of years ago), as they share many historical similarities, but it is also possible for a tangent within a given cluster to have originated within a completely different cluster and 'migrated' to its new location. For the purposes of this story, it can be assumed that different tangents tend to be attracted to others of
similar attributes. An example of this is what could be called the 'Nuclear Armageddon cluster,' which contains tangents where terrible wars were fought between the Empire of Japan and the United States, or even between high-tech versions of the Aztecs and the Babylonians, to name a couple of random examples.
As another example of this, consider a tangent where the biology of the Earth favored a sentient species of cats to arise to dominance over the world instead of humanity.  Events and even individuals could have parallel happenings in this timeline thread that is represented by the manga or anime story of 'Ranma 1/2', complete with the entire cast being represented by catlike sentients who even bear both the same names and general attitudes as their human counterparts.  Such a timeline could be pulled into the 'Ranma 1/2 cluster' of tangents, and the reader can then imagine how events would be similar and different to that other timeline thread.  The dreaded Nekoken could be a tapping into the primal drives and abilities of the race in that timeline, and might not require as mind-warping a training method. Other possible, similar (yet different) events are left up to the imagination of the reader.
Moving away from the cluster of the baseline tangent used in this story, the tangents will grow more and more unusual, and I will classify them into four 'divisions' of timeline clusters: Historical, Biological, Cosmological, and Fantastic. Looking at these divisions in cross-section, the picture would be roughly a series of concentric rings, radiating out from the center much like a bullseye.  However, as was previously mentioned above, the
divisions are not rigidly fixed, and tangents originally from the Biological division could become part of a cluster in the Historical division (such as the tangent with the catlike versions of Ranma 1/2 characters mentioned above).  These divisions are also relative to each other, as an inhabitant of different tangents will define the tangents that surround them differently. For example, the 'Slayers' tangent would be in the Fantastic division as seen from our own Earth, but we would also be in the Fantastic division to theirs, since they would see us as a timeline with greatly different physical laws from their own.
The Baseline cluster is the one that immediately surrounds the tangent of Imperial Earth, the so-called Baseline tangent.  It is the reference point from which all other tangents in this story will be looked at.
The Historical division generally indicates the millions of tangents where the presence of humanity is the defining characteristic. The many differences in worlds will be determined by the numerous potential divergent events and changes in human history. Different cultures may reign supreme, unusual governments may rule, and even the course of technology may be radically different, but humans are still humans.  Most of the trips taken in this story will be to tangents in the Historical division.
The Biological division of clusters has seen evolution playing games.  In some, humanity exists, but is subtly changed. In others, humanity shares the Earth with other sentient lifeforms.  And in still others, the species called man never arose (or perhaps not even mammals), and nature filled the void with sentient apes, cats, or dinosaurs.
The Cosmological division represents timeline threads where the solar system itself developed differently. For example, billions of years ago, Earth itself never formed in some timelines.  In others, Earth formed a little closer or a little farther from the sun, and the whole biosphere may be radically different, if life even took hold at all.
Lastly, the Fantastic division represents tangents where the very laws of nature have taken on sometimes bizarre variations. For example, on some of these tangents, humans exist but possess strange abilities such as magic or superpowers, while in others, the Elves still rule a pristine and verdant Earth that is vibrant with magic. However, also possible are worlds where various forms of undead rule supreme over a blasted and dead Earth as the least powerful of the nightmarish servants of the elder gods of madness and darkest evil.
There might also be divisions that lie outside the Fantastic, but the incredible superspacial distances make it difficult to determine what they might be.
To make it easier on the readers to catalogue the different parallel worlds, I will be using a simple two-dimensional grid to establish a coordinate system for each tangent, using the home tangent of Imperial Earth as the Baseline tangent, and it will be designated 0.000,0.000 for its coordinates. The further a coordinate is from the Baseline, the more radically different it will be from Imperial Earth.  For the purposes of this story, the divisions previously given (Historical, Biological, etc) will each be roughly ten full spaces apart (for example, 0.000 to 10.000 along the x-axis is the radius for the Historical division). With a grid of ten thousand tangents by ten thousand tangents, that gives just the Historical division alone over three hundred and fourteen million paraverses, more than sufficient for my needs as an author.
Here are some sample worlds and also their coordinates relative to
Imperial Earth:
*Earth  0.000,0.000 - The world of Scholar-Ranma (Baseline cluster)
*Earth  +0.001,-0.001 - The world of Scholar-Ranko (Baseline cluster)
*Earth  +4.612,+4.509 - The world of Shampoo 1/2 (Ranma 1/2 cluster)
*Earth  +4.614,+4.496 - The world of Nabiki 1/2 (Ranma 1/2 cluster)
*Earth  +4.614,+4.502 - The world of Ranma 1/2 (Ranma 1/2 cluster)
==Notes==
This section is inspired by the information presented in TSR's excellent role-playing sourcebook "Tangents."
It also seems to inspire time/dimensional travel for the entire Altered Destinies Multiverse. Or at the very least each author uses something similar.
Category:Quantum Destinies
Category:Universes