Basic Information
Tachyons are a hypothetical subatomic particle that constantly moves at FTL speeds. They may not even exist, and even if they do, they're probably just tiny subatomic particles that we can't really interact with in any meaningful way. But, for the sake of an argument, let's say that somehow these tachyonic particles can coalesce to form tachyonic matter, and that matter can organize to form tachyonic life. Aliens composed of tachyons. What would this life be like?
It would be fast. By definition, tachyons zip around faster than the speed of light, and there's plenty of good arguments to suggest they just can't physically be slowed down to sub-luminal speeds. These creatures would be able to travel across the cosmos in extremely short periods of time. They could range across the universe as the whim struck them. The GM is probably free to decide whether they can just teleport wherever they want at will, or if they actually experience the passage of time and have to physically transit from place to place.
It would be impatient, at least by human standards. If your life is whizzing by that fast, you have to be able to process and react to stimulus at that speed. Humans, with our slow little brains and reliance on our eyes, would be painfully slow to them. Sci-fi often invokes the parallel of powerful aliens holding us in the same regard as which we hold ants. In this case, I think the analogy would be better with slugs. We just creep around at a snail's pace, and react to things that happened a lifetime ago. Given how fast their particles are moving, their chemical processes (if they have any) might burn out at a similar speed. They could have lifetimes expressed in microseconds. We might effectively be frozen in place from their perspective.
It would be alien, timeless and possibly non-euclidean. It would be in more than one place at a time, capable of what is effectively time-travel at will. They may experience events out of order, or understand an order that we would perceive as chaos (or temporal paradox). They may indeed have no sense of time at all, merely experiencing all things at once, with a complicated multilayered consciousness that perceives their own birth and death simultaneously. They may well be a fourth-dimensional lifeform as well, or be capable of doing some of the "tricks" mentioned on that page while still technically existing in only the same dimensions that we do. Groups of tachyonic lifeforms would be able to communicate in the eerie prescient way described on the tachyonic antitelephone page. They may find it trivially easy to generate (or navigate) stable time loops and other mind-bending phenomena.
It would pass us by. They'd think and move on compressed scales of time, but expanded scales of distance. You or I typically see just a single room at any given time, and rarely do we see more than a tiny fraction of our globe at any one moment. Tachyonic life, however, might well experience (and travel through) several arms of the galaxy all at once. They might not even be aware of us, because we're too tiny, stationary, and unimportant to notice us.
It might be blind. They constantly move faster than light. Eyes would likely be a waste of biological resources, since the data light might give them would be terribly out of date by the time they got there. I suppose there may be some sort of survival benefit to being able to sense light, as it might let you avoid crashing in to a star. However, the star would not actually be where they saw it at, since they're moving faster than the light. They'd also be able to constantly see their own visual echoes, a "map" or "script" of where they were going to go as well as a "recording" of where they'd been. (And if we were observing them, we'd see the same thing, though it would seem insanely fast to us.) So chances are they wouldn't evolve eyes. If they did, sight certainly wouldn't be their dominant sense (as it is with most humans) since the data from it would be so often out-of-date when they received it. They'd have to have some other way of knowing the shape and status of their environment.
If it's not blind, it might actually be all the more alien because of it. Imagine if you could see a constant visual record of everything you're ever going to do. There'd be few if any surprises, and you can imagine a Philosophy of Determinism would evolve from it. The very notion of free will might be unfamiliar to them. Cause and effect would be inverted or simultaneous to their eyes, which is bound to affect the way they think.
It may be massless. A million tachyonic lifeforms could dance on your head, and you'd never feel it. Alternately, it's possible they couldn't help but involuntarily push us away with a force that feels like wind or magentism. Tachyons could prove to be exotic matter, mirror matter, or something else that's alien on a subatomic level, being immaterial or exhibiting antigravity. They may well be able to travel through us, or stand inside us. They may fall away from the Warth at ever increasing speeds, or fall to its center (drawn in by gravity and unimpeded by conventional solid matter).
Of course, it's more dangerous if they do have mass. If they do, slowing them down to the speed of light or less would take infinite energy. Which means that if they got careless and bumped into us, it'd be worse than a thousand atom-bombs… or it would just tunnel through us destructively without losing any of its own momentum. Neither possibility is pleasant.
It would give us headaches. To our perceptions, the tachyonic organisms would seem to be in multiple places at once. A planet (or galaxy) occupied by tachyonic life would appear as a chaotic maelstrom. Each individual lifeform would appear to be in multiple places at once - at least two places, but potentially many more depending on how fast and how complicated their movement patterns were.
If a tachyonic creature moved in a straight line past you, you'd first see it at the closest point it passed. Then you'd see it seem to split in two, and both images would recede away at speeds you could scarcely comprehend. Your brain wouldn't know how to process it. It's clearly in two places at once, once version racing away faster than anything you can imagine, and the other version racing away just as fast, but in reverse. And that's just assuming it went parallel to you in a straight line.
If it zipped around randomly or in some complicated pattern, it might well appear to be in dozens of positions relative to you at any given time, with half the images moving backwards and the other half moving what you'd consider "normally".
If it moved towards you, and somehow managed to slow to sub-light speeds and wait for you to see it, it would still arrive suddenly without warning. Then it would split in two. One image would stand next to you while the other walked away backwards, speeding up as it got further away. Most people would stand there with their mouths open feeling dumbstruck as their brain tried to compute what just happened. Then, long before it actually left your side, you'd see it split and walk away again while it was still standing there. Then suddenly, the version next to you would be gone.
Sources
Game and Story Use
- First Contact scenarios with tachyonic life could be very interesting (but also a little frustrating, so be careful).
- A strange energy field appears at the edge of our solar system. Eventually, scientists identify that it's a cluster of tachyonic particles spinning in orbit around our sun thousands of times per second. The energy field coalesces into discrete pulses, waves or intersecting orbits, an amazingly these pulses are organized into clusters representing prime numbers. The particles are alive, and trying to talk to us!
- Because they appear to be in more than one place at once, we find it terribly difficult to understand them. They seem to be saying everything all at once.
- After several hours of trying to communicate with us, they suddenly disperse and leave our solar system entirely without warning. In the half a day we spent trying to figure out how to respond, a thousand generations of their lifetimes passed. Eventually, the new generations of aliens got sick and tired of waiting for our reply.
- A human spaceship arrives at a previously unexplored star, which exhibits strange properties. This faint (little brighter than a brown dwarf) star shifts colors (light frequencies) and experiences significant variation in shape (instead of being spherical and rounded by it's own gravity). As you approach, you discover that the star has far less gravity than expected, too. It turns out the star is actually just a pair of bio-luminescent tachyonic lifeforms conducting some sort of mating dance. They move around so frequently and erratically, that you see them as if they were in millions of places at once, and since they glow in the dark they trail of where they've been (and will be) looks like a star until you get up close.
- Pennies from heaven! There's a flash, and then two strange creatures appear and flee in opposite direction faster than the PCs can react. But in the spot where they first appeared, they leave an object. It's like the Voyager Golden Record, a device that (once decoded) explains in a nutshell everything the tachyonic aliens want us humans to know about them.
- A strange energy field appears at the edge of our solar system. Eventually, scientists identify that it's a cluster of tachyonic particles spinning in orbit around our sun thousands of times per second. The energy field coalesces into discrete pulses, waves or intersecting orbits, an amazingly these pulses are organized into clusters representing prime numbers. The particles are alive, and trying to talk to us!
- Tachyonic life would be so alien, it's probably best used as a plot device, interstellar terrain, navigational hazard, mystery or set dressing instead of being used as a creature, combat encounter, or NPC. You can't really talk to it or fight it. It's just a negative space wedgie to provide color and puzzle the PCs for a session.
- Ignoring that advice for a moment, these things would be insanely tough to face off against in a battle. A tachyonic raider would strike without warning and then flee in two directions. If armed with a laser (or non-tachyonic projectile weapon) it could shoot you an infinite number of times in the first combat round, employing time on target artillery tactics to deliver an overwhelming barrage all at once.
- PCs returning fire are just plain out of luck. You have to lead a moving target to hit it, but how do you lead something that moves faster than light? You can't possibly rely on your senses or reaction speed. Only a Jedi or a Psychic would even be allowed to make an attack roll against it, and that just based on their intuition. Remember, you won't see it until after it's already made its attack and left.
- Non-super-luminal life (slow things like us humans) can't practically ambush tachyonic life either. Once you try to attack it, it will zip away to safety, and it might even be able to warn itself before you attack. See tachyonic antitelephone for details.
- Improvising what a tachyonic lifeform does will be tricky, and a lot of work for the GM. Its actions will appear to be out of sequence, and it will be in more than one place at a time. Keep the interactions short, mysterious, and pre-scripted. Work out what its going to do on paper, and then present it to the players in an order that's "inside-out", starting with the closest / middle stuff and working out to both the beginning and the end of the encounter.
- Given the scales of speed and distance involved, the PCs probably won't be able to react in a meaningful way. While this is a boon to the GM (since you can plan the encounter without having to worry how the PCs will screw it up), it can also be boring or frustrating to players. Keep it short and fun. Play up the weirdness, blow your players minds with the trippy non-linear hijinks, and then move on to something they can interact with before they get tired of it.
- The eldritch abominations of the cthulhu mythos warp human brains all the time, and a few of them are capable of flying (or projecting) between worlds. Plus, most of the named ones are just automatic TPKs already (seriously, if you try to go mano-a-mano with Azathoth, no dice are needed, it's just time for a new character), so you could totally cast them as tachyonic entities. Not that they need to be rendered any weirder or more confusing than they already were, but it would certainly be a new twist to keep your players off balance.