There are relatively few phenomena that can entirely annihilate a person - especially in ways which violate basic physical laws about the conservation of mass and energy.
When used in medical science - as it primarily is - the word ‘idiopathic’ describes an illness or a disorder with no known cause. Nonetheless, and despite its obvious and frequent applicability, it is seldom found in either the nomenclature or the writings of more esoteric maladies (although perhaps this absence is itself a preventative measure to avoid an inevitable ubiquity that would cost the term its definitive value). There is, however, a notable exception in Nihil Idiopathica (lit. idiopathic nothingness); a phenomenon whose nature is so uniquely defiant of interrogation - whose very existence defies the belief of even those who have witnessed it first-hand - that the label has been used to bring it within the bounds of conventional and conceivable ignorance.
Absent an understanding of how the condition is contracted, its incubation period is inherently unknowable. Still, it is often referred to as acute because by the time there is any sign of it at all it has already progressed to completion. In spite of its dramatic name, it could be said that calling it Nihil Idiopathica still manages to understate quite how abrupt and final it is. More - and worse - than fatal, perhaps it is better to consider the sickness (only classified as such because its effects are contained to discrete individuals) as obliterative: The victims of Nihil Idiopathica are hollowed out, their physical bodies literally replaced by a distant and profound nothingness more absolute than even that word can imply.
The symptoms begin, always, whilst the affected person is asleep. A fiery itch runs down the chest from neck to navel, its maddening urgency intruding upon their dreams and quickly becoming enough to awaken even the soundest of sleepers. Even if there were some way to halt the development of Nihil Idiopathica, at this point it would already be too late. Roused from their rest too suddenly, groggy and vexed, the urge to scratch at the itch is as irresistible as the desire to know what has caused it. They tease and needle at it, but any relief this brings is momentary and jarring against the shock of what comes next: The skin splits and peels dryly, revealing the blackest depths of space within.
It would, of course, be a paradox for something that is finite to be able to hold an infinity within itself - especially one that might encompass its own vessel - so it is generally assumed that Nihil Idiopathica creates a window onto another location (rather than being the nothingness itself). Stars and nebulae glimmer and shine at distances that defy intuitive understanding (the aperture opening into a physical void vast enough to contain the psychological multitudes we are all said to contain) beyond the ragged edges of skin that flap gently into the nothingness. The experience is both surreal and uncanny, a complete violation of bodily integrity which, nonetheless, compromises neither the affect nor the appearance of normal biological functions.
In fact, the process is almost upsettingly bloodless; the meat and marrow of a person consumed by the metamorphosis from person to nothingness, from physical to conceptual. This lack of pain, the absence of the warnings and the caution which pain imparts - along with their understandable disbelief about what is happening to them - can induce a dissociative shock that leads people to think (or to assume) that they are dreaming. As a result of this psychological distance from what is happening to them, they end up acting with an uncharacteristic abandon. Fascination replaces fear and they will pick and pull at the opening, oftentimes standing before a mirror to observe their own dissolution, teasing and tearing away strips of skin and revealing more of the void inside of them.
Even as they recklessly destroy the husk of their own body, the void holds - inviolable to anything but their own grasping fingers - to the confines of its former corporeal dimensions; the consciousness of the victim remembering the bounds that were once, briefly, able to contain it. Still, even the strongest will is not enough to preserve the delicate balance of a state that is fundamentally unsustainable. When the shell becomes too damaged the consciousness dissipates - spread too thin across the infinity it now inhabits - and the portal shatters into tiny fragments, each of which collapses in on itself. The only trace left behind is any thin tatters of skin that didn’t fall into the void as they were shorn free; peeled thin like the remnants and remains of a bad sunburn.
Efforts to explain how such a thing could occur run a futile gamut between pure guesswork and wild speculation. No theory that has been proposed in earnest has had more weight or merit than the deliberate absurdities that are posited - in mocking opposition - in order to expose the former’s reliance on purely inductive reasoning. Attempts to define possible first principles from which such a thing might follow fall apart; contradictions and incongruities straining beyond even the fluid ontologies that incorporate and allow for an understanding of so many other impossible things. Inasmuch as there is an accord of any kind around Nihil Idiopathica, it seems that more people than not attribute its existence to some unknowable magic rather than to an unknown science.
A few people have been able to resist the continued and desperate urge to pick themselves apart entirely - at least for a time - and left notes and drawings, even some photographs, which have been used to study Nihil Idiopathica. Using these scant but remarkable records, people have attempted to employ stellar cartography to calculate the points in space onto which these windows have opened. Although these labours have been largely fruitless, this frustration has itself led to several intriguing possibilities. These windows might open not only to points at a distant remove from us in space, but perhaps also in time: Both the past and the future could, albeit in a limited fashion, be observable through them.
If a subject with Nihil Idiopathica could restrain themselves (or otherwise be restrained) to keep from passing beyond the critical point of their self-destructive compulsion and into complete dissolution, we might be able to gather more comprehensive data. By examining the proper motion and radial velocity of stellar drift - and accounting for other differences due to parallax - it might be possible to determine exactly when and where the other side of these windows exist. Then, even allowing for the random and uncontrollable nature of what we would be able to observe, we could gain incredible insights into the farthest reaches and extremities of a universe, into things that we could never otherwise hope to observe.