A Bright Thought on Dark Matter
Humans are designed to hate any hindrances and seek for the ways to reach the unreachable. As soon as there is an impenetrable barrier, we get extremely curious of what could be found behind it, and our fantasy would readily compensate for temporary lack of evidence. Of course, we cannot fancy anything beyond the already experienced, and the true nature of "transcendental" things escapes vision, substituted by some anthropomorphic concoctions. Such naiveties serve the only purpose of instigation, a moral encouragement and a promise. Indeed, if we can at least think about what is hidden behind the wall, the wall is no longer entirely blind; even if there is nobody out there, we are free to populate it with the creatures of our own, starting with vague ideas and finishing with a regular industry.
So, given the Universe as a whole, our cosmological thought would instantly switch to the issue of multiple worlds, and the apparent consistence of our knowledge about ordinary matter would provoke claims of something not so ordinary yet to be discovered. Well, there are heaps of things we can see and play with; this does not makes us quite happy unless we dream up an impalpable mystery, some dark matter that cannot yet be grasped, thus giving us enough room to theorize and measure. Surprisingly, the majority of the world's behavior is found to be due to that unknown substance, and the inquisitive humanity is imperatively obliged to bring light to that new and promising domain of experience.
For a philosopher this does not make any great surprise. The world is qualitatively infinite, and the same thing can be approached from quite different angles. Science means knowledge. Wisdom means the appreciation of how little we really know. It is always better to know; ignorance may be a disaster, but it is no shame. It is only stubborn adherence to the already learned and refusal to learn more that is to shun.
Today, when dark matter has become as banal in astrophysical discourse as big bang or black holes, and as experimentally justified, it may merely seem a matter of time for it to be eventually detected and included in the mathematics of the physical world. We are certain to soon invent an appropriate instrumentation to gloriously observe the truth of our conjectures. Meanwhile, everybody is free to guess what it all will really look like.
Well, why not? Probably, my personal preferences are far from the academic mainstream, but they could bring an innocent amusement to me, and probably to those who happen to read these lines before dark matter gets drawn out of the dark.
The majority of popular accounts picture dark matter as a special kind of matter interacting in a peculiar way, in addition to the already available fundamental particles and interactions as described by the standard model. However, when it comes to philosophical amusement, this approach does not inspire much enthusiasm, since mere discovery of yet another physical force is too dull, too habitual nowadays. I don't mean that there is nothing to add to the standard model; moreover, it is bound to expand in that way or another. It is quite admissible that some kinds of dark matter could fit in that extensive line. But I am as sure that our old acquaintances may sometimes show up in unexpected turns, as the observation point shifts a little bit away. The standard model is humanity-centered; it is perfect to speak of the world as we see it here and now, but it may, too, be useful to look at ourselves with somebody else's eyes, to give life an intensive coloring.
For instance, let us meditate over the possible effects of relative motion of material bodies. Please don't tell me that the issue has long since been exhausted in this era of ubiquitous relativism. Going without saying for many decades has nothing to do with standing to reason. One might reason that the outcome of our efforts to construct a covariant Universe does not well agree with its underlying ideas, and primarily, with the idea of a frame of reference. First, we admit that an observer may have a universal scale for the whole space-time; later, we find that some portions of space-time are utterly inaccessible to the observer, whose observations can never go beyond the light cone. An inherent logical fallacy is obvious. However successful in applications, such a theory can hardly be taken for serious as a model of the entire Universe.
As it often happens, the humanity grew accustomed to relativistic physics, and people just don't care to grasp the meaning of their own words. Even forgetting for a while, that any formal singularity can only be an indication of conceptual insufficiency and the necessity of a more elaborate model, one should be more attentive to the consequences of the commonly adopted theory (quite useful within the limits of its applicability). Indeed, all Einsteinian relativity tells us is that, as long as we use light for a communication standard, there is no way to compare the observations of two observers moving relative to each other faster than light. Isn't it obvious from the very beginning? Of course, such observers will have to seek for a different information carrier, to get in touch. However, this does not prohibit neither the possibility of such relative motion, nor the ability of physical interaction. Thus, two observers may exchange light signals with each other, as their relative velocity is low enough, but the both will remain invisible for a third observer, for whom they move too fast; this latter may find companions within the same light cone, who would be as incapable of communicating with the above faster-than-light couple. In this model, the whole space-time acquires a kind of cellular (or lattice) topology, with the creatures within each cell believing that their limited world is all that mother nature can afford, just like modern physicists do.
Here comes dark matter. There is an infinity of relativistically separated worlds, so that, for light-cone prisoners, the bulk of dark matter will always be overwhelmingly bigger than all the visible matter of their single-cell world. Some dare to estimate the quantity of dark matter in up to 99% of the mass of the Universe; in view of the out-there infinity, they are not brave enough.
So what? Are we doomed to eternal solitude, with no hope to talk to our faster (or slower) colleagues? Not at all. Within its light cone, faster-than-light (dark) matter is just ordinary matter, and the same standard model could explain its structure and interactions in exactly the same manner. Being of essentially the same nature, material bodies of different relativistic cells can interact with each other, and all we have to do is to guess how a faster-than-light electron should behave in the presence of a slow electron (and the same for the other inhabitants of the standard model). It may well happen, that some of the intruders would take the guise of the ordinary particles and fields; some others may look like apparent singularities or, at least, apparently causeless events, like spontaneous symmetry violation or certain phase transitions. There is no reason for nature to stick to the only possibility.
Just for illustration, consider a very fast material body moving in a limited volume. Viewed by an earthly observer, it will seem to fill the whole volume as a kind of field. Inner (faster-than-light) motion is perfectly hidden, and all we get is an overall effect of virtual interactions upon our "macroscopic" world, a kind of spectrum. The well-known quantum paradigm. The brethren-physicists may sit within an electron, and, to communicate with us, they will need to work hard modifying its outer behavior to the extent that we could not ascribe it to mere physical force. In our world, similar activity might look like rearranging matter on a scale comparable to the whole visible Universe.
But let's be optimistic and seek for universal signal carriers other than light, to make relativistic barriers transparent. This would allow cross-barrier interactions and the existence of material bodies combining the phenomena of many levels. Still, admit that the hierarchical organization of nature in general (and physical nature in particular) is not much of a news.