Imagine a world that works mostly like our own: it's built of atoms and quantum particles, there's gravity and conservation of energy, etc. Perhaps the physical laws aren't exactly the same as our universe, for sci-fi purposes, but overall the world looks, feels, and operates just like our own--with one, massive exception.

In this world, there is a Handwavium of sorts that just doesn't play by the rules. It isn't made of recognizable particles, doesn't follow conservation of energy or momentum, and resists all attempts of scientific investigation. It's widely believed to follow its own set of laws completely separate from ordinary matter, but no one has been able to figure them out. Maybe it's made of a new class of particles; maybe it's some completely new kind of "stuff" unlike anything in our universe. Nobody knows for certain.

The problem is that this Handwavium isn't floating out in space or in some sort of shadow dimension: it's a very common substance in this world and forms large portions of the ground. It's visible, heavy, touchable, and behaves a lot like rock most of the time (except for when the story needs it to do something more interesting, of course).

At least, that's what I want it to be like, but I'm starting to feel that this is logically inconsistent. If my substance doesn't obey quantum mechanics, then how can it interact with photons to be visible, or electrons to be tangible? If I disregard real world physics entirely, I don't think I can satisfactorily justify why it superficially behaves so much like ordinary matter, especially since the rest of the universe is supposed to be relatively hard-ish sci-fi.

So, my thinking goes, even if it isn't made of electrons and quarks and gluons and whatnot, maybe it can superficially act enough like them to explain its appearance. For example, it doesn't have electrons, but some of its structure is negatively charged, and is "electron-like" enough to repel ordinary electrons and become solid. In programming terms, I want it to "implement the physics interface" while being completely different under the hood.

Preliminary sub-question _{(probably too opinion-based)}: is this a plausible explanation for my Handwavium's properties?

I myself have drilled users here in the past for asking about the "plausibility" of systems that knowingly invoke alternate laws of physics, but remember, I'm staying rooted in real-world physics here, and then tacking on something "other". Based on the real physics that I'm mostly sticking to, is it possible to postulate anything about whether not nor my idea makes sense? If not, move along, that is not the main thing I'm here to ask.

Main question (assuming the first part is positive or unanswerable): what is the minimum behavior my Handwavium has to express in order to "act like" ordinary matter?

Extrapolating on the electron/tangibility example I gave earlier, what would this substance have to do in order to:

• Be solid to the touch. Negative charge seems like the answer.

• Be visible to the human eye. Other radiation doesn't matter.

• Have mass and be affected (perhaps inconsistently) by gravity. This is probably unanswerable considering that we lack a theory of quantum gravity.

• Be movable by force (transfer kinetic energy). Like with gravity, it's a bit lazy in this regard, seems to follow intuitive mechanics but isn't consistent with the amount of force needed to move it.

• Have temperature.

• Optional challenge question: give it a taste and smell, explaining how it triggers the receptors and what it tastes and smells like.

BUT:

• No conservation of energy/momentum.

• None of Newton's laws:

  • It can start moving with no force acting upon it.
  • Acceleration is unpredictable.
  • A force can be exerted with no opposing force.

• None of the laws of thermodynamics:

  • Heat can flow from cold to hot.
  • Entropy can decrease without expending energy -- MAYBE. I know this is probably the most fundamental law I'm breaking here and it's not a big deal if this can't be accommodated.

I haven't thought about relativity, could go either way.

All of this applies only to the Handwavium itself, not to regular objects interacting with it. So for example, regarding Newton's law, if you punch a block of it with 20N of force you will have 20N of force applied back to your hand, but if it reaches out and punches you with 20N equivalent of "force", there's no saying what the force applied back on it will be, if any.

Hopefully this makes sense. If not, please explain why.

Note: I really don't know how to tag this, I refrained from using "science-based" or "reality-check" but I'm not sure if there's something more appropriate. Thanks.