I. Nature of Reality
I.a. Illusory Universe
Virtual Universe hypotheses:
I.a-1.) Holographic Universe
The 4-dimensional (3 spacial dimensions plus 1 time dimension) universe we feel like we live in could in fact be a projection of some 3-dimensional (2 spacial dimensions plus 1 time dimension) goings-on upon the event horizon of some singularity, or at the edge of the universe (upon the inside surface of what seems from our perspective to be an inverse quantum singularity - or big bang).
I.a-2.) Imaginary Universe
If life on Earth, which seems so perfectly adapted to living and interacting in a 4-dimensional (3 spacial dimensions plus 1 time dimension) realm could actually just be 4-D projection or representation of some 3-dimensional (2 spacial dimensions plus 1 time dimension) goings-on in some realm removed from that which we feel we indwell, then it stands to reason that the holographic universe might not even be objectively real at all, but may be a subjective experience generated by the animal brain. We animals feel like we inhabit a common 4-dimensional universe because we all share common ancestors and need to communicate with one another (interspecies signaling such as threat displays) and are thus constrained by natural selection to generate roughly compatible imaginary 4-dimensional realities (language/communication constrains thought; Sapir-Whorf hypothesis), but we're really all just interacting in some 3-dimensional (2 spacial dimensions plus 1 time dimension) realm á la the holographic universe model, or in some other way occupy a reality meaningfully different from the reality we animals feel we commonly inhabit.
This would go a long way toward explaining why humans take so easily to imaginary realities not only in the forms of government, laws, borders, fiat currency, credit, account statements, and the like, but also our indulgence in fantasy and fiction; our animal brain naturally impells us to create imaginate realities anyway, so we're already neurologically geared for it.
I.a-3.) Simulated Universe
It has been suggested that the universe might actually be a simulation.
Probability argument: If simulated universes can be created with as much detail as our universe, then simulated universes will eventually outnumber "actual" universes. Thus, there is a greater chance that our universe is a simulated universe than there is that out universe is a "natural" universe.
The universe has traditionally been conceived of as 3-dimensional.
Duration/time added as 4th dimension at least as early as H. G. Wells (The Time Machine).
I.c. The Multiverse
I.c-1.) The Bubbleverse
Inflationary Multiverse; multiverse of bubble-universes created each in its own period of inflation subsequent to a common singularity.
Dark Energy. Expansion is speeding up. Vacuum activity at the quantum level contributes energy to "empty space".
The universe we live in appears to have a very small but non-zero cosmological constant; 120 orders of magnitude smaller than the predicted value (Albrecht et al., 1:01:40)
I.c-2.) The Treeverse
Self-replicating universe. The universe might be hospitable to life because the universe is itself alive.
I.c-3.) A Bubbleverse of Treeverses, or a Treeverse of Bubbleverses?
Which is the omniverse and which is just one of many multiverses? Does each bubble-universe or pocket-universe in the bubbleverse (omniverse) produce its own treeverse (multiverse) of furcating quantum timelines? or does each quantum event for which there exists more than one possible outcome split the entire bubbleverse (multiverse) into multiple bubbleverses to create a treeverse (omniverse)?
I.c-4.) Parallel Universes
The question of which type of multiverse subsumes the other may be moot. It may be, for example, that there is only a bubbleverse, and that each pocket-universe contains particles that are quantumly entangled with particles in other pocket-universes, so that if Schrödinger’s Cat dies in one universe it must live in another, not because of one universe splitting into two in a fractal or tree-like pattern, but because of some kind of causal relationship between two thitherto identical pocket-universes that had always been separate. In other words, "quantum universes", or alternate timelines, or whatever one wishes to term the different versions of our universe, do not converge as we follow them backward through time, as in the furcating-lineage version of the many worlds interpretation, but instead run parallel to one another, each from its own distinct big-bang.
I.d. Cyclic Universe
I.d-1.) The Duoverse
Inspired by String Theory. Two parallel universes / branes repeatedly collide due to vacuum energy, and this collision is the big bang (Albrecht et al., 1:08:17)
II. Nature of the Self
II.a. The Ego, or Homuncle (Homunculus)
II.b. Illusory Self
II.b-1.) Materialistic-Deterministic Illusory Self
II.b-2.) Spiritually Illusory Self
Bibliography & Works Cited
Andreas Albrecht, Alan Guth, Andrei Linde, Neil Turok. Multiverse: One Universe or Many? World Science Festival
Does the Multiverse Really Exist? Space Science Documentary
The Whispering Mind: The Enduring Conundrum of Consciousness. Youtube (Jan 24, 2014)