I’m especially curious in the case of fantasy settings. I’m admittedly not super well read in the genre, I know about the Ways from the Wheel of Time series[1] , and I’m sure D&D has its fair share of fast travel mechanics.
Anyway, in my case I use mass routers. Rather than a dry lore dump here’s a slightly less dry lore dump in story form!
spoiler
He glanced nadirward through the observation window at the green and blue surface of the planet. A river, coruscating in Focus’s rays, wound through the verdant jungle passing below. It was THE river, the measure to which all other rivers were compared. It was so old that it didn’t even have a name. Every other river on Yih, and every watercourse wrought on other celestial bodies by pioneers in the intervening millennia, was, after peeling away one hundred thousand years of sound changes and semantic drift, named after this river.
But he had seen this sight countless times, and it failed to put his mind at ease. He spun the metal prayer ring on his writing claw, feeling each of the twelve teeth pass under the pad of his outer thumb. The ring had belonged to one of his sires, who had often handed the shiny trinket to him to amuse himself with when he was barely a pup. It had been years since he had prayed it, not until this morning just before being shriven. It had been years since he was last shriven, too. He’d be the first to say he wasn’t the most pious Wayfarer, but there was a real possibility, however infinitesimal, that today his life would come to a messy end, and he wanted to have a clean conscience if it came to that.
He turned to face the cause of his anxiety. Attached to a bulkhead opposite the window was a cylindrical machine barely larger than a suspension capsule, with a bore just large enough to fit a single yinrih, and maybe a satchel if the yinrih in question was particularly svelte. He floated over and looked through the bore. It was like he was staring down the business end of a railgun.
«You’re going to be fine, Hearthfire.» He tried to reassure himself. «Nothing’s going to happen. We did gross upon gross of tests. Equator to pole, Low orbit to surface, surface to moon, even interplanetary hops, all the way from Hearthside to Moonlitter. Inert object tests, live tests, and all the tree-dwellers we sent came out perfect.»
«Except Moonbeam.» nagged a tiny voice in the back of his brain.
«Poor Moonbeam. I know you’re not supposed to name them. Makes it harder when… That happens.» The little tree-dweller went in fine, but the impulse buffer on the egress router failed as she dropped back into realspace on the surface, retaining all the momentum from the ingress router in orbit. In the span of a temporal quantum she ceased to be biology and turned into physics, ending up impacting the opposite wall at 20 times the speed of sound. The barrier was built to take it, but her poor body wasn’t. She ended up a maroon smear on the wall.
«Time to get strapped in.» said a sandy-furred engineer floating next to the mass router.
He took a deep breath and floated into the bore, slipping his forelegs into the harness, then his hind legs, then his tail, and finally his head.
A voice came through the earpiece around his left ear. «Hearthfire, this is Morningstar. Everything’s up and up down here.» It was the same cleric that had given him absolution this morning. «Just for review, you’re being routed through an intermediate router on the surface before egressing at the antipodes. The impulse buffer is good on both the intermediate and the egress, in case a packet gets dropped along the way.»
«Ingress and egress buffers are synced.» Said the sandy-furred engineer.
«Acolyte, begin the countdown. May The Light illuminate your way, Hearthfire.» Said Morningstar.
«Twelve…» The sandy-furred engineer began solemnly sounding off the numbers.
«Eleven…» In a matter of seconds, a thin sheath of realspace containing Hearthfire’s body would be shunted into the Underlay.
«Ten…» This realspace bubble would be encapsulated into billions of discrete packets.
«Nine…» From the perspective of a hypothetical observer embedded in the Underlay, these packets would appear discontiguous, and could take separate paths to reach the same destination.
«Eight…» But from the perspective of an observer contained within one of these packets, the entire space would still be contiguous.
«Seven…» Blood would still flow, and nerve impulses would still travel uninterrupted.
«Six…» Or they would if the traversal through the Underlay weren’t instantaneous.
«Five…» Hearthfire’s stream of consciousness would not be broken.
«Four…» There would be no ontological question that what emerged from the egress router was the same Hearthfire that entered the ingress router.
«Three…» These packets would hop instantaneously through an intermediate router directly below at the surface.
«Two…» This router would, in mere nanoseconds, direct the flow of packets to an egress router at the antipodes.
«One…» The egress router would absorb all the momentum that Hearthfire had while in orbit before shunting him back into realspace. Should the intermediate router drop a single packet, the whole flow containing Hearthfire’s mass would be shunted harmlessly back into realspace at that router, provided it, too, absorbed his momentum correctly.
«Zero.» Hearthfire felt a tingling sensation, as though his whole body had fallen asleep. The feeling lasted but a fraction of a second, then he felt the weight of his body pulling him down. He had made it. In less than the blink of an eye, he had gone from a space station in low orbit over Yih to a lab on the surface on the opposite side of the planet. Hearthfire was the first yinrih to traverse a mass router network, and he had done it without a hitch.
This was going to change everything.
fun fact: the Ways inspired the Nether from Minecraft insofar as one step in one dimension is multiplied in the overworld ↩︎
From the sci-fi setting, it’s your pretty standard “bend space until both destination and departure points are actually nominally close to each other” kind of drive.
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Time between jumps usually bottoms out at around 15-20 minutes for most drives, but increases exponentially as a function of distance traveled and desired accuracy of your destination point.
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This is because the pre-calculation to compute a successful bend in space-time grows massively more complex the more gravity fields are involved. Extremely long-distance jumps can take hours or days to calculate, but inter-system jumps can be carried out rapidly.
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Intersecting the event horizon of a fold in progress is bad. “You’re reduced to a fine relativistic spray” bad. So far accidents have been “minor”, as in they didn’t kill thousands.
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The exotic matter required for drives is stupendously expensive. As a result, almost no ships have internal drives, but require a “drive barge” or “FTL barge” to exploit FTL. Despite this, barges are common enough that most families can afford to take an FTL trip if needed.
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In UNHA operations, all drives are legally owned by the government and crewed by a detachment of naval personnel, with explicit orders to scuttle a drive rather than allow it to be misused.
In the fantasy setting, it’s a little bit different. For one thing, no two fast travel castings work entirely alike. This is because it is a key tenet that magic is a deeply and intrinsically personal thing, and while casters than study concepts to gain inspiration, there’s no such thing as a “standardized” casting which can be moved between casters.
For instance, some casters port you through an alternate dimension, and some bend space. Some open a gateway, some transmute you into photons then back, and some encapsulate you in a bubble which moves rapidly.
Even within a broad category, there are subsets: For instance, if they use an alternate dimension, is it one in which points are simply “closer together”, or where time flows differently?
It’s important to know these things, because different species or other casters being brought along can have… unexpected reactions to different methods.
The exotic matter required for drives is stupendously expensive. As a result, almost no ships have internal drives, but require a “drive barge” or “FTL barge” to exploit FTL. Despite this, barges are common enough that most families can afford to take an FTL trip if needed.
Like a tugboat or tow plane with a glider. Unique.
In UNHA operations, all drives are legally owned by the government and crewed by a detachment of naval personnel, with explicit orders to scuttle a drive rather than allow it to be misused.
What constitutes “misuse”?
Another thing about mass routers, really more about the Underlay, is that you need tailstone for FTL communication, which the mass routing protocol needs to form neighbor relationships with adjacent routers. Tailstone is manufactured by growing monocrystals and fractioning them into wafers. A tailstone wafer can only communicate with other wafers shaved from the same monocrystal, so Underlay tunnel interface cards are sold in sets (usually pairs) that are hard-linked to one another, containing matching wafers. The ansible links between nodes are therefor much more like hard wire runs in that they can’t be easily changed to different endpoints.
This manufacturing process has a lot of cybersecurity implications. A bad actor planted within a tailstone fab could grow larger crystals than a downstream client ordered, then break the crystals up to form multiple normal sized ones, giving the client the expected quantity and keeping the other half. That bad actor could then perform MITM attacks on ansibles or routers using those crystals.
One such attack is route poisoning, which is where a malicious router injects false routes into the system, telling other routers that a particular endpoint is somewhere it isn’t, redirecting travelers to a destination of the attacker’s choosing.
Refreshing that the defining characteristic of your magic system seems to be that it isn’t a system.
It’s important to know these things, because different species or other casters being brought along can have… unexpected reactions to different methods.
I love the trope of fast travel being inherently scary. One idea I had was an inversion of the typical hyperspace is hell concept whereby FTL shunted you through Heaven, the risk wasn’t demonic possession but having your face melted off by overwhelming holiness Raiders of the Lost Ark style, meaning special precautions had to be taken to keep people from perceiving the environment outside the ship, even conceptually (via sensor readings, for example).
As for the Lonely Galaxy, there are rumors among the superstitious that the Underlay is in fact the Void (the Claravian version of hell), and that the reason why the Bright Way discourages even negative discussion of demons is that it would make them look bad if the network they invented was routed through the realm of the damned.
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So this is more SciFi but the fundementals work for fantasy.
Gates, and gates only so the first time someone has to slowboat it which is either an epic lifetime journey or a sacrifice of your place in time to relativistic travel depending on the genre in order to set up a gate at the destination. The gates then function as a classic folding of space between them, not to zero but such that a multi-lightyear trip is reduced down to an internal length of just a few miles.
This is all fine when everything works, though if the gate shuts off mid transit you can end up with a whole fleet trapped in the intervening void until its turned back on, or worse a nefarious actor who gains control of a pair of gates may even expand the intervening space rather than shrinking it, trapping their victims not just in deep space, but in an ever expanding volume that can’t be escaped even with near light-speed travel.
Has anybody looked at using automated transport and power-up ships to set up the gates? Or is it a process that is sufficiently complex that it can’t be carried out by an automated system?
…conversely, if your explorer ship is bringing a gate with it, can you turn on the gate mid-trip and rotate crews in and out by passing them back through the gate?
I like settings where FTL doesn’t exist, and interstellar travel times are dealt with by simply making humans biologically immortal. If you think about it, curing aging is actually much less of a stretch than FTL, scientifically speaking.
Not currently running anything sci-fi, but have been tossing around this idea. Humans die and they lose a tiny amount of weight when they do. Turns out that it is a soul and that soul can be converted into an immense amount of energy for a very short period of time. Destroying the soul in the process. That energy is used to generate a temporary wormhole between space points. However, the soul has influence on the destination so you need someone who wants to die for you. Or you risk your destination not being correct, or worse getting lost in terrible outer dimensions.
As most fantasy plays out on a single planet, magical fast travel like portals or teleportation could not care less if it is FTL or not. Whether you walk through a portal or cast a teleport spell, both actions are slow enough to easily mask any concept of a universal speed limit like c.
Hence the “or fast travel” part of the title.
In his book about writing sci-fi and fantasy, Orson Scott Card posits this is the first thing you should think about when mai ng your sci-fi setting: FTL (star wars) or Cryogenization (alien). This directly impacts how societies evolve: do you say goodbye to your loved ones when hopping on the starship, knowing you’ll never see them again, or can you zap from one side of the galaxy to the other and still be back for breakfast?
Interesting. Some relevant tidbits my story didn’t mention:
The yinrih are capable of STL interstellar travel, but because they can’t lose consciousness without dying, they can’t resort to hypersleep. Instead, they use a technique called metabolic suspension which halts metabolism but uses Science™ to keep the brain and nervous system active. The device that does this is called a suspension capsule (referenced in the story above). The traveler is completely submerged in a fluid matrix called neurogel that acts as a non-invasive brain-computer interface, a liquid ventilation medium (for when your metabolism starts up again but your lungs are still paralyzed), and a shock absorbent.
Since the person is still conscious but their sensory systems don’t work, the suspension capsule presents a simulacrum to the traveler in order to keep them from going insane due to lack of sensory input. It also speeds up their subjective time perception to make the trip pass more quickly. The problem with the simulacrum (sim for short) is that the more realistic it is, the more the person is tempted to dissociate, thinking the sim is reality and forgetting their life outside. In order to stave off this madness, Claravian missionaries (the only group to engage in interstellar travel) undertake a rigorous routine of prayer and meditation to keep their minds anchored in reality.
I needn’t tell you that the ability to present an arbitrarily realistic simulation to a person is subject to flagrant abuse, and so-called gel-head parlors offer recreational suspension for a price. This abuse prompts Claravian research monasteries to start looking into safer modes of interstellar travel, which is what results in the invention of the mass router.
As for the router itself, there are strict mass and volume limits to what can be sent through the underlay, meaning individual flows are limited to a single person and maybe a small carry-on. Because the mass router is discovered while a team of missionaries is living among humans on Earth, a mass router trunk is able to be established between Sol and Focus immediately. The missionaries construct a working mass router using their ship’s fabricator and materials found on Earth.
…gross upon gross…
Does this yinrih culture use a duodecimal number base? That’s a neat detail.
I don’t know much about travel that fast in my world. It’s mostly low fantasy (i like fantasy but can’t write magic) so there’s no teleportation or portals. Some routes are particularly fast if they pass through an area of hyperbolic space, but that’s as close as i get to any sci-fi fast travel. I have considered saying the speed of light is infinite, but i’m not sure yet what implications that could have.
Yes. The countdown also started at 12. Commonthroat uses base 12 but base 24 is also seen in other yinrih languages. Yinrih are six-toed arboreal quadrupeds, meaning they use all four paws for both grasping and movement, and they have 24 digits to count with.
Traveller has a very good fully fleshed out system that invokes “jump space” - effectively hyperspace. You leave the primary universe, enter a pocket space, then “precipitate” back into regular space. The duration of the jump is fixed at 1 week no matter the distance. During the week, there is no interaction with regular space. The ship is isolated. It makes for excellent plot mechanics.
