# Reactionless Drives

Technically, this is a trope-a-day from much later in the cycle, but seeing as (a) I just wrote it up having been thinking about it recently, (b) I’m sure at least some of my readers have been wondering about the very common use of reaction drives in the Eldraeverse ever since I first mentioned vector control, and (c) among those are the ones wondering how (and if) I avert running smack into Burnside’s Advice in the worst possible way. So:

The important thing to remember about a reactionless drive is that it’s not reactionless.

A vector control drive is a member of the entire family of vector-control technologies, and like all the other members of said family, it obeys Newton’s Third Law. Vector control used for artificial gravity transfers the reaction to the action it’s applying to the stuff between the gravity rotors to the structural framework it’s bolted to. Vector control used in tractor/pressor beams pushes the party of the first part every bit as much as it pulls the party of the second part, and on the precisely opposite vector. And a vector control drive, while it utilizes extremely fancy ontotechnological trickery to spread the reaction to the action out across all the ambient mass in appropriately vast volumes (if not the entirety of, but that’s real hard to measure) of the local universe, is absolutely no different in this respect.

What you get from a vector control drive is not needing to haul all those vast quantities of reaction mass around with you. Note: only the remass. Vector control drives still need fuel, and since there are certain inevitable inefficiencies in coupling the action to the reaction quite so indirectly, they need significantly more fuel than an equivalent reaction drive. You aren’t getting away from having those huge spherical tanks of D and He3 strapped to the back of your starship that easily.

Another thing you might get is a degree of, um, stealth, inasmuch as you don’t have the huge bright drive flare that most reaction drives tend to produce. Of course, as we all know, there ain’t no Stealth In Space, because apart from your life support’s comfortable temperature alone making you stand out like a lighthouse against the 3K sky background, you’re also running a bloody great reactor (and radiating its heat) to power your vector control drive.

In short: the existence of vector control permits you to build something damned close to a classic SFnal reactionless drive. It provides you with rather fewer reasons as to why you might want to, outside a few highly specialized edge cases.

(Side note: the mad scientists out at Resplendent Exponential Vector have also been experimenting along the lines of the Alcubierre drive to get reactionlessness and a working fittler in one package. After their prototype vaporized a fortunately-spare dwarf planet and exploded first time out, their tort insurers have been reluctant to cover further development at a price they can afford.)

# What is Ontotechnology?

Well, let me say right up front that ontotechnology as I describe it is pure-quill handwavium. Its connection to contemporary, real-world physics is that I endeavor to avoid coming right out and stabbing said contemporary, real-world physics in the face; after all, anything discovered in the future has to be consistent with the present. Rather, it is my speculation as to what the physics of the future as expanded by posthuman intellects running on hardware the size of small moons would look like – and as pure speculation, that means I don’t want to see any “but I read in this book that it was possible” arguments made anywhere, ‘kay?

Disclaimer over with, I stole the term from Eliezer S. Yudkowsky, who coined it as a neologism for “technology that permits manipulation of the fundamental rules of reality”. Which is exactly what ontotechnology does.

(How does it do it? Well, I postulate that the fundamental realization behind ontotechnology – by any of the three theories you care to use – is that at a very basic level, the map is the territory. Information and mass-energy are essentially equivalent. Mathematics doesn’t just represent the fundamental structure of reality; it is the fundamental structure of reality. Think of the universe, if you will, as a computer program, database, and processor all of which are also each other; ontotechnology, in those terms, is the skillful application of the root password and a debugger to it to make it work differently.)

You want to change the laws of physics? It does that. Treat space and time as building material? It does that, too. Set the speed of light to 60 mph, abolish the weak nuclear force, make gravity attract in proportion to the cube of the distance instead of the square, invent an entire new universal force that affects particles based on their heretofore-unknown qualities of shiny, fluffy, and matte? Sure, no problem. Can do. A fully mature ontotechnology would let you invent your very own personal version of physics that works exactly the way you want it to and impose it on whatever bit of the universe you want to work that way – or, hell, just reach outside, take hold of the brane, and make a new universe that runs according to your principles.

The problem, of course, is that even for weakly godlike moon-brains, programming universes is very, very complicated. The set of self-consistent/self-sustaining physical laws is a very, very tiny subset of the set of expressible physical laws, and the set of physical laws that are compatible with the existence of mass-energy as we know it is an even tinier subset of that subset, and the set of physical laws that are compatible with the existence of complex informational structures like, well, us is… you get the picture – and that’s without taking into account whatever laws control ontotechnology itself. (And, to further extend that debugging analogy, when you crash the universe tryin’, you don’t get a nice friendly exception message, or even a blue screen of death.)

All of which is why no-one, in the present time of the Eldraeverse, has a fully mature ontotechnology, and probably won’t for millions if not billions of years to come.

But they have been able to figure out a few applications that can be made to work safely and reliably, and that’s where technologies like the controllable wormhole, and the tangle channel, and vector control (which lets you do interesting things to gravity and the linkage between inertial and gravitational mass, starting with breaking mass into those two distinct concepts) come from – and where any future breakthroughs along those lines (say, if I decide at some point to let dimensional transcendence be invented) and/or mysterious rule-breaking alien artifacts dug up will draw from.

# The Perils of Memetic Contamination

I have, so far, sat down on at least three to five occasions to attempt to wrap some firm-SF details around the group of technologies in my universe which go under the general name of ‘vector control’.

Thus far, I have devised three to five different versions of the mass effect.

Well, not quite, but almost the mass effect.

Grumblesmurf.

# Trope-a-Day: Floating Continent

Floating Continent: Actually, there are quite a lot of these, whether you call them skyhomes, sky cities, or sky islands (in roughly increasing order of size).  They are divided into the ones which hover over terrestrial worlds (which exist mostly because people think they’re cool, and why not?), the ones which float at a more people-friendly level in the atmospheres of planets of more Venerian temperament, and the ones which float around in the atmospheres of actual gas giants.  (The distinction there between “hover” and “float” is whether they’re actively powered and maintained by vector control, or whether good old aerostat principles are good enough to keep them up there.)

Not to be confused with orbital cities, which don’t float, but rather fall in endless circles.

# Trope-a-Day: Energy Weapons

Energy Weapons: Present, even if by and large Kinetic Weapons Are Just Better and therefore much more used.  Lasers and grasers exist, despite their limitations, primarily as heat-pumping weapons, knife-fight range point defense, and as blinding lasers, as do electrolaser stunners/anti-machine weapons, with all their limitations of atmospheric composition and humidity.  Plasma lances exist too, although they only work at point-blank range, even in space, due to dissipation.  (And regular flamethrowers, of course.)  There are microwave heaters and other kinds of algetics.  And there are limited-use, short-range, vector-control based gravitic weapons (based off the tractor-pressor principle, either to yank, slam, or vibrate).

But for all that existing, it’s still the slugthrowers that see the most use.

# Trope-a-Day: Casual Interstellar Travel / Casual Interplanetary Travel

Casual Interstellar Travel / Casual Interplanetary Travel: It’s a little complicated.  Technically, yes, you can travel interstellarly fairly casually, since while you have to drag one end of your wormhole at subluminal speed to wherever you want it, interstellar travel to places where you have one already is pretty damn casual.  Step through and you’re there.  Ping.

Of course, wormholes and their associated stargates are Really Damn Expensive, and so is interstellar travel to anywhere that isn’t on the stargate networks involving as it does the many years relativity demands of you even in lighthugger starships, the great expense of said lighthugger, and for that matter, the even greater expense of the thousands or tens of thousands or even, for the largest luggers, hundreds of thousands of tons of antimatter you need to fuel the thing.

Further, and to subvert this slightly, while there’s casual interstellar travel, what there isn’t is casual interplanetary travel (speed-wise; it’s much more casual cost-wise).  No-one’s invented a convenient magical gravity drive that lets you whip up nigh-instantaneous thousands of gravities of acceleration (while there are vector-control drives, neither acceleration nor delta-v are any better, and indeed usually worse, than equivalent reaction drives; blame conservation of mass-energy), so getting anywhere in-system, including out to the stargate, still takes days or weeks, and for interstellar travel, that means on both ends of the wormhole.

This is resubverted for those with the right metaphysical attitude, because if you don’t go into quivering neo-Luddite theofear at the thought of having your mind separated from your body and transmitted elsewhere to be reinstalled in a different one at the far end (and granted, that’s not exactly most people outside the rampaging postsophontist neophile civilizations), then you can just mindcast where you want to go (assuming of course they have the right receiving equipment, which is by no means guaranteed outside the aforementioned civilizations).  Which is substantially quicker and counts as fully casual interplanetary/interstellar travel, because photons and (especially) tangle move a lot faster than your own personal meat/rock can be transported.

# Trope-a-Day: Can Breathe In Space

Can Breathe In Space: Technically, you can do this by using a vector-control “envelope” to hold air in around you (although you will still need some means of replenishing it if you plan to do this for long, special provisions like oxygen-carrying hemocules aside).  While useful to avoid ebullism and other pressure/temperature syndromes if you should find yourself in a decompressing compartment, needing to leap from airlock to airlock, etc., and it’s a lovely showy party piece… most people still prefer actual vacuum suits if they plan on stepping outside.