Handwavium: Paragravity

Okay, let’s talk about paragravity.

First up, a note on nomenclature. Paragravity is one of the two things that an Imperial habtech might be referring to when they talk about artificial gravity, the other being spin gravity. Unlike spin gravity, which is “powered” by good old centrifugal force, paragravity is produced by ontotechnological space magic that does wonderfully complex things involving information physics and grand unified theories and other such things to poke the universe in exactly the right way – basically, one branch of the mass-inertia-and-momentum manipulating vector control.

Which is to say that it is produced by gravity rotors, suitcase-sized boxes with a power connector, a ‘weave connector, and a thermal management connector on the outside, filled with solid-state hardware that is a proprietary product of Mariseth Gravitics, ICC. And into whose internal workings we shall thus respectfully avoid going.

What we’re talking about here is how they work on the outside.

The field of paragravity (the gravity envelope) can only be created between two gravity rotors of opposed polarity. That gets you a straight field (with perhaps some convex distortion at the edges) between the two, which imposes a force functionally identical to mass-generated gravity (i.e., affecting all atoms, etc., equally) on everything with mass inside it.  This creates a consistent down direction towards what, for the sake of designation, we shall call the “positive” rotors.

(You have to have a closed envelope, and can’t operate an unpaired gravity rotor even if you wanted to: since the universe is functionally infinite in whatever direction you’re pointing it, energy requirements for the half-field head asymptotically for infinity, at which point the circuit breakers save you from a messy ‘splosion.)

Both momentum and energy are conserved, as they would have to be.

The former is the reason that you gravity rotors should be bolted firmly to the structure of the hab; whatever force they exert is, per Callaneth’s Lemma (or Newton’s Third Law, whatever name you prefer), reciprocally exerted too, half to each rotor in the pair.

While difficult to arrange even deliberately, this does imply that if you can get enough mass in one spot and move it just right, you can get the gravity rotors to tear themselves free and leap in the appropriate reciprocal direction.

With regard to the latter: it takes energy to establish the gravity envelope, but once it’s up and running, maintaining it takes only minimal energy physically speaking. (I.e., it still consumes quite a bit of energy in the rotor while it’s up and going, because rooting the universe ain’t cheap; that energy just doesn’t go into the envelope.  It’s this waste that makes paragravity a real expensive thing to run.)

That, however, is only true so long as nothing is moving within it. Falling objects, moving in the down direction of the envelope, take energy from the envelope as they gain kinetic energy.  (Likewise, when you lift an object within the envelope against its downforce, that pushes energy into the envelope, which is a surge effect that the hardware has to cope with. Alas, it’s not something that can be harvested in the majority of applications.)  You could call this paragravitational potential energy if you like, since it sits in essentially the same place in the relevant equations.

While it takes the rotors a little while to initialize from a cold start (although some of this time is self-diagnostics and the like), once up and running, though, you can change the parameters of the gravity envelope very quickly; and you can generate pretty much any amount of gravity you want up to their capacity so long as you’re willing to spend the energy (which varies proportionately) needed to do it.

This is what lets you use the exact same technology for inertial damping; you just have appropriately oriented gravity rotors cancel out your engine thrust inside the starship – while bearing in mind that this will have certain effects on your structural load. (Likewise, you can use them when grounded – but since they don’t block planetary gravity, if you want 1G in the cabin when landed on a 3G world, you will actually be running the paragravity system at -2G.)

The drawback, however, is that the same lack of “inertia” in operation that lets you change your gravity quickly means that they fail equally quickly – and shut down essentially instantly if the power fails, just like an electromagnet’s field collapses – so failing to keep up maintenance schedules may mean being abruptly smashed to the deck with a force of twelve gravities! Caveat engineer.