Love the thread - figured I'd seed some more ideas, see what sprouts. oneirotekt's post has a nice big variety of topics in it, so it's convenient for me to just reply to everything he said as a way of introducing my own ideas - I don't mean to attack them specifically, so I hope it doesn't come off that way. To the contrary, I picked that post to respond to cuz it has lots of good ideas for me to build on.
The Orz are from a dimension other than our own who have come here for an unknown (but, we can infer, vaguely sinister) purpose. They are comparable to our concept of living, sentient beings.
As you comment further on, most people seem to like the interpretation of the Orz as a single sentient being with multiple projections into this dimension. As such, Orz is a singular sentient being (rather than many sentient being
s), but whether there are other Orz's (i.e. other sentient organisms of the same 'species' as Orz), or whether Orz is a singular and unique phenomenon, is open to speculation. Also, I don't think Orz exactly 'came here', since I don't think it really 'left' wherever it was before - it seems more like it is now here in addition to wherever it was before, and may at any time be in lots and lots of places at once, spanning multiple dimensions. I agree, though, that Orz's agenda in this dimension seems vaguely sinister, and I like that phrasing.
But, there is ample room for variation just within this interpretation: for example, maybe the projections are like different fingers (i.e. they know they're all parts of one organism and work together), or maybe they're more like different echos/reflections (i.e. something about the nature of interdimensionality causes the single Orz entity to be 'reflected' multiple times in this reality), in that each individual 'finger' doesn't think of the other 'fingers' as separate from itself - it is aware of the fact that its presence is fractured and echoed in this dimension, but it relates to itself the way we would relate to all our reflections in a house of mirrors. We can see what look like lots of copies of us, but we know the other ones are all false. Orz's speech (such as using 'we') doesn't really support either of these interpretations, but then again, Orz speech can't be taken literally anyway.
There are many dimensions other than our own, each with their own independent rules for time and space. We (humans and our neighbors) are unique in that we do not move between the dimensions.
I don't think there's any reason to conclude that the races in our dimension are 'unique' in our inability to travel between dimensions - it seems just as likely that the races in our dimension (that we know about, who knows what's in other galaxies) are all too young to have figured that out yet. What's more, some of our neighbors (to use the term slightly more broadly, time-wise) - specifically, the Androsynth and the Taalo - DO seem to have figured out how to move between dimensions, and this advancement then led to the ultimate fate of both of these races (whatever that may have been).
Both the Arilou (who are a much younger, shorter lived race compared to the ancient Orz) and Orz are from two different dimensions...
Who says the Orz are older than the Arilou? For that matter, who says it even makes sense to talk about the 'age' of an interdimensional species? As you've already commented, each dimension could easily have completely different rules of physics and temporality - the idea of 'age' almost definitely doesn't translate very direactly between dimensions.
... the Arilou from a "higher order" dimension (presumably what we call Quasi-Space) directly above our own (if you visualize the multitude of dimensions as the floors of an office building) and the Orz from another directly beneath our own.
*The Middle* might be another way of referring to our dimension, ie the one between *above* (the Arilou home dimension) and *below* (the Orz home dimension).
I think this is the topic on which I disagree most with that seems to be the dominant interpretation of multidimensionality that I've seen expressed in this thread, so forgive me if I get a little longwinded here. Although the best-fit terms (*above*, *below*, *middle*) seem to suggest it, I think visualizing the dimensions as a linear 'stack' like an office building is not the right way to think about it. Multidimensionality doesn't necessarily just mean adding an axis to everything, such that any given location in spacetime (3 spacial coordinates, 1 temporal coordinate) in our dimension has a counterpart in all the other dimensions (by adding a dimension coordinate) - that implies way too much linearity (i.e. the idea of one dimension having exactly two neighbors, one in each direction). I think it's much more interesting and plausible to think of multiple dimensions as far, far more complex phenomenon; linkages between the dimensions are not a simple matter of finding a way to change your dimensional coordinate, but rather involve a very convoluted process of translating what passes for matter and energy in our dimensions into an equivalent sort of 'existence' in another dimension, and this is why natural portals are so rare and interdimensional travel seems to be one of the last things a sentient race ever figures out. To anticipate a counterpoint, it is true that Hyperspace and Quasispace seem to have very similar laws of physics (i.e. the fact that you ship can 'go' there and look pretty much the same, the fact that you can fly around in those places the way we fly around in truespace, etc) doesn't mean that other dimensions are also similar: maybe the reason we use those dimensions as clever means of travel is because they happen to be two of the few that _are_ similar enough to serve that purpose. As such, sentient races figure out Hyperspace pretty quickly, and probably figure out Quasispace not too long after that, but figuring out how to interact with 'less similar' dimensions, as the Taalo and Androsynth presumably did, takes more work.
This has some interesting implications for a lot of other topics in this thread. For example, the idea of interdimensional beings *smell*ing eachother becomes more complex - if the dimensions were all stacked up neatly one on top of the other, it seems like a relatively simple matter to just travel from one to the next looking for life forms. Also, under such an interpretation, why would *They* need to *smell* a life form in order to get to it, and having *smell*ed it, why would *They* be able to access it so immediately? Getting from wherever *They* are to our dimension would have to involve traveling through all the dimensions in between, and if they were that close to us in the stack, wouldn't they have found us already anyway?
I think it's better to think of interdimensionality involving several axes, maybe a huge or even infinite number: you can go 'up' and 'down' through dimensions, but maybe you could also go sideways, forward, backward, inside, outside, around,
ana and
kata (for anyone who's read the scifi book I'm taking that from but can't remember tha name of), etc etc. In that case, finding something in interdimensional space is like finding something in single dimensional space: we would never have found the Slylandro if nobody had told us where to look. The Ur-Quan would never have found any of its victims if they hadn't traced their hyperwave broadcasts back to them. Similarly, *They* can only really find a race in interdimensional space if that race does something that penetrates interdimensional space, like start opening portals (which might create some kind of interdimensional reverberation that could be detected and pinpointed).
Then, the Arilou's efforts with humans becomes something like putting up a hyperwave shield around a planet: if the hyperwave transmissions, which are detectable, are blocked, nobody has any reason to look at that planet so nobody ever does, and the inhabitants become basically 'invisible' to someone like the Ur-Quan. Similarly, if the Arilou tampered with humans to dampen or eliminate anything in our existence which might have 'reverberated' interdimensionally, that prevents *Them* from pinpointing us.
In fact, multidimensionality probably isn't even as simple as thinking of more axes along which to travel between dimensions: if getting from another dimension to this one was the hard part, and getting around within one dimension was the easy part, then why haven't *They* devoured everything in this dimension? They clearly know this dimension exists and even know how to find it, since *They* either came here to eat the Androsynth or else caused the Androsynth to move to *Them* - but if *They* could do that, why wouldn't they do it to everyone else in this dimension, too? Why would they need to *smell* each race separately in order to get to them, even if they're all in the same dimension?
As the Orz bodies are only material projections, their destruction does not actually harm the Orz entity. They view human death as "dissolving" because our souls are tied inextricably to our material bodies, and once the body dies the soul "dissolves".
I don't necessarily agree. People seem to like this interpretation because it allows them to take the next step and point out that Orz might not realize that destroying our ships actually does hurt (and in fact permenantly destroys) sentient beings. I don't like this interpretation, first of all because we never specified what kind of 'projection' of Orz it is that we see; if they're literally like 'fingers' that 'poke through' into our dimension but share some kind of connection to the 'true' Orz, then wouldn't it hurt a little to cut those fingers off? It is possible that the projections are more like holograms - something that we can perceive and allows us to interact with the Orz, but which is not 'real' and does not have any impact on the 'true' Orz. But even if this is the case, it seems plausible (from other things Orz says) that Orz understands that *dancing* in *heavy space* is actually bad for, and hurts, the people who live in *heavy space*. If it didn't think that, why would it threaten to *dance* with us in order to get us to stop doing something it doesn't like, such as ask about the Androsynth?
Some other random comments:
I agree with a previous poster that the Taalo probably met Orz in another dimension, after the Taalo figured out IDF. But has anyone in the SC2 universe ever expressed concern that the Taalo might have fallen prey to *Them*? If the Taalo have been galavanting around between dimensions, it seems that they would have almost definitely encountered *Them*, since the Androsynth had only just begin to poke a few holes when *They* immediately came and wiped them out. So if the Taalo were somehow not vulnerable to *Them*, how come? Maybe it has something to do with the Taalo's other precularity - their psionic ability. If the Taalo were a species whose consciousness was such that psionic ability was second nature, maybe that also protects them from *Them*? (That sounds convoluted, I know) Maybe *They* 'eat' species not in a physical or literal way, but in a psychic way - like 'eat'ing their souls, and it only works if the prey can't protect itself psionically. On the other hand, if that were true, it seems like the Arilou would have encouraged psionic ability in Humans to enable us to protect ourselves, and that doesn't seem to be the case. On the other other hand, maybe the Taalo were, in fact, devoured by *Them*, and we just never heard about it. Or maybe we did and I'm just forgetting it.
Why do the Rainbow Worlds point to the Galactic Core? A random idea here, and in a way similar to and derived from the explanation in SC3, but maybe the Precursors were also trying to protect the future inhabitants of this galaxy from *Them*. Modern physics suggests that there are probably supermassive black holes at the center of most galaxies, maybe even lots of them; singularities of that magnitude might be the sort of thing that would cause natural interdimensional weaknesses, and maybe that is a point of 'close contact' to other dimensions, where *They* are. In that case, the galactic core would be one of the places where *They* could 'see' into this dimension and possibly *smell* if anyone interesting lived here - what if the Rainbow Worlds were made to shield us from that 'sight'? If the Precursors found some inanimate material (like the hyper-radioactive whateveritis that the RWs are made of) which was capable of masking our presence - our *smell* - from *Them*, it would make sense to orient that shield toward the place where *They* would be looking from, which would be the galactic core.
Along those lines, maybe the Precursors ultimate destination wasn't another dimension, but rather extinction: maybe the Precursors attracted the attention of *Them* and were just as vulnerable as the Androsynth. Knowing that *They* were coming, and not wanting to put other life in this galaxy at risk, maybe the Precursors set up the Rainbow Worlds to mask our *smell* and then went somewhere else in order to draw *Them* away from us; when *They* caught up to the Precursors and devoured them, at least *They* didn't also catch wind of the other life in this galaxy in the process. It would seem in line with the Precursor's noble image to sacrifice themselves to protect fledgling life.
If you actually read this whole post, I admire you. Sorry to be so longwinded, I talk alot when I get excited.