(Hello! Near as I can manage, every Wednesday will have a post outlining some feature of the Parhelionverse, and as always I invite questions about the world, story, characters, etc. on the Tumblr blog. These posts aren’t necessary to understand the comic, but they might be handy for summarizing context. All of the posts can be found on the About page.)
Excerpted from the Encyclopedia Xenobiologica, v43.981.4a, slightly abridged, Ponoma Publishing House, a Yima subsidiary
This is solely a reference volume, and the information is necessarily incomplete. If you or someone you know suffers from a condition described, seek formal medical attention.
Returning from a voyage to find one’s peers years older is psychologically taxing, even with experience and therapeutic support. Many large ports are equipped to re-acclimate people, offering personal counseling and summaries of cultural shifts. Career pilots often build up a culture within their own ships to stave off the isolation, but this further impedes socialization with terrestrial culture.
Sustained relativistic travel has deeper effects. The overall sense of time erodes: career pilots may completely misjudge durations of time, perceiving an hour as a day or vice-versa. There is no known cure for this, but with adequate social support they can live functional lives.
Those who refuse to be temporally adrift will turn to other travel methods, with their own sets of risks.
Dimensional slicing was discovered through a series of accidents, now trade secrets of the highest severity. The monopolizers refuse to collaborate with medical science, so the risks are as dire as they are poorly-understood.
The most visible side effect is burns or scarring, in roughly .03% of pilots. They can pierce through vital organs without consequence, yet patients with scars of any size and otherwise good health have been known to spontaneously die.
The scars often appear as a starfield (43%) or a crystalline gash (26%), but have also been observed as clustered eyes, bismuth-like fractal forms, absolute darkness, or more. There are no credible reports of one patient having multiple types of scarring.
(The leading theory is that these scars are overlaid slivers of higher dimensions. This makes a number of spurious leaps, and has little practical application, but it is the least-unlikely explanation to date.)
Some pilots describe a presence pressing into their mind, and develop all manner of mnemonics and superstitions to ward it off. Rarely, pilots claim that they continue to share a mind with the intruder after the flight. There is no “normal” profile of a pilot overtaken- erratic, serene, hyperfocused, bloodthirsty. Some pilots and religious traditions welcome the intrusion, ascribing significance for any number of reasons. No test finds any sign of this, but the changes are too dire to merely be placebo.
“Kill-and-replace” teleportation, though limited to light speed, has a risk profile similar to FTL travel. Internal bleeding and organ failure are the most severe side effects (~.0027% of uses). Dizziness and nausea (31%) are the most common, but typically lessen with experience. (If they get noticeably worse with each trip, seek help immediately.)
Periodically, a trip can completely alter the user’s personality. Many such cases turned out to be mere placebo, or insurance scams, but a growing body of evidence suggests that brain chemistry can be irreversibly altered with each trip. The effects are poorly-understood, largely due to ethical limits on testing and the sparse, unreliable data.
Most other methods of teleportation are strictly limited to inanimate cargo. There are doubtless many living passengers, but they remain understudied. Until more data is gathered, the interim conclusion is “immensely inadvisable.”