What is flux? Given the intentionally ambiguous lore typically used by the game I doubt we will get a hard answer - at least I've not found one. Most of the speculation I've seen online describes it as a sort of abstraction of a bevy of loosely related mundane energy management limitations. Heat, ballistics feed system status, electrical supply stability, the sort of stuff that is mostly familiar to us. Applied in a different context perhaps, but ultimately nothing too unusual.
I really don't like that answer. It's boring.
We have what seem to be high throughput atomic printers being installed on everything from fighters to forge worlds, spatial manipulation that would give Einstein either a heart attack, a moment of holy inspiration, or both, and
Spoiler
demons from beyond the realm of space and time.
Flux being heat management would be disappointing in that context. From a personal perspective, I've always seen that ubiquitous flux bar and been struck by a silent wonder as to the nature of such an unusual and ubiquitous type of motive energy. We see
using the same system of energy as the Invictus, a ship that predates even the Mk 1. Yes, that system could simply be an abstraction of more mundane mechanics, but that would be a waste, a dereliction of the style of mundane magic seen in stuff like nanoforges and hyperdrives. Any type of mundane reactor, even one running on antimatter, fails to live up to the rest of the setting.
So I gave it some thought and came up with a speculative nature of flux that fits the game better, and is way cooler. Let's start with the name. Flux can mean many things, but I want to hone in on a specific type: magnetic flux. It is, essentially, a measurement of the strength of a magnetic field passing through a plane. While our three spatial dimensions are not quite a plane, in the context of however many extra dimensions are utilized by Domain tech, 3d might be close in some contexts. A context such as energy, perhaps exotic, passing through our space from higher dimensions on the way to lower dimensions. So I propose that flux systems basically poke holes in higher dimensions and let the energy within drain through the ship's systems and out into lower dimensions. If we want to wax poetic (or Luddic), a cosmic water wheel siphoning heaven's nectar, stealing energy as it falls to hell.
And of course, like any setting with perfectly ambiguous underlying laws, there is plenty to support this idea. Let's start with antimatter fuel. It exists, and is obviously absolutely vital, given the stellar-political shenanigans Sindria caused. But in normal space, no mater how hard you drive your ship and its systems, it never touches a drop of fuel. The only place that fuel is ever expended is in hyperspace travel, activating gates, or performing hyperspace jumps. So it seems hyperspace requires some alternative source of energy, either as a catalyst to assist the flux network, or as a flat out replacement. I lean towards a catalyst personally, given the unchanged combat flux mechanics in hyperspace. The gate hauler, a gargantuan construct that brute-force warps space to achieve FTL, requires only some transplutonics to reactivate. It would be impossible to move the thing with a fission reaction, so it has to have some other power source simply reactivated by the transplutonics: flux. Maybe a tiny bit of antimatter would also work in principle, but given the autonomous nature of the thing and lack of access to antimatter the choice of transplutonics might fill the gap as an in-situ failsafe. The gates require antimatter to activate, but if we assume that antimatter is used as a catalyst to restart and assist a flux network, it makes sense. Jumping to hyperspace also requires antimatter, so perhaps we can say that most activities involving higher dimensional manipulation are unsuitable for pure flux systems to manage. We can chalk that up to not being able to use dimension juice to manipulate dimensions. A gap in the theory, sure, but not a huge one. It might be that rousing a ship from a cold start without any available external power also requires a negligible amount of antimatter to poke the hole to the flux dimension, but either so little it is mechanically insignificant or something that can be substituted using external power. To go even further, what if antimatter is not, strictly speaking, even used as an energy source? Maybe it is used as a source of exotic particles, or maybe its charge symmetry is useful?
Now, if we have a dead simple source of effectively infinite power, why is flux management still important in combat? Well, even if we have some infinite source of exotic energy raining down from higher dimensions, it still needs to go somewhere after you utilize it. If you don't dump it into its destination lower dimension it will eventually build up and overwhelm your systems - an overload. It might be that the bright flash from a destroyed ship is not a reactor going critical, but flux gushing forth uncontrolled before the hole in space closes. Now, the following is getting specific to the point I feel it gets less interesting, but let's talk about the details of flux management. Why is there a distinction between hard and soft flux? Soft flux seems to be fairly tame; you draw energy from somewhere, you use it, and then it trickles down to a lower dimension through the spatial volume occupied by the flux circuit and any additional flux vents. Venting is interesting, but it could be easily explained as increasing the volume of space for flux to dissipate through by projecting it outside the volume of the hull. Hard flux is more difficult. It builds up primarily through shield activity and phase immersion, and for the most part will not vent until those systems are disengaged. It gets even messier because beams result in soft flux buildup on shields, and some skills allow for limited though-shield venting of hard flux. This is getting even more speculative, but maybe discrete shield hits (not beams) result in the formation of a standing wave or knot in the flux supporting the shield, which cannot be smoothed or untied until the shield is disabled, unless you have specific expertise in managing that sort of thing. Phase gets even stranger. Perhaps the nature of phase immersion has inherently harsh harmonics or sharp peaks? Honestly by this point the idea is becoming less interesting and more tedious. Which is probably why most tech lore in the game is intentionally vague. In any case, my hyperfixation for the past few days is sated, so thanks to anyone who managed to read my ramblings to this point, and adieu.
