I’ve mentioned some aspects of physics in my science-fiction setting before, but now I feel like taking the opportunity to add some more thoughts. The most characteristic extension of our real-life understanding of physics in my space-opera setting is an infinity of naturally-occurring wormholes at the quantum level, connecting all points in space and time, popping in and out of existence like suds on the sea’s surface, which can be plucked out of that foam and greatly enlarged into a stable wormhole, enabling effective faster-than-light communication and travel. In addition, this infinity of quantum-scale wormholes is one and the same as quantum entanglement, per the (real-life!) conjecture ER=EPR, the aggregation of this infinitude determining the large-scale structure of space and time.

I’m sure I’m butchering not just ER=EPR here but also quantum foam, the latter of which, surprisingly enough considering how weird it is, is basically proven! Nevertheless it’s close enough to real science and science-based speculation that the broader idea may well describe the universe we actually live in, close enough to reality for hard science fiction purposes. And certainly a cool enough idea for softer science fiction, even if it is disproven someday as a description of real life!

The upside of harnessing naturally-occurring wormholes from the quantum foam is that it’s a connection across great distances that already exists; therefore to open up a wormhole to a billion light-years away one need not make a pair of wormholes and then send one mouth out on a billion-year trip before you can reach that destination at effective faster-than-light speeds. That’s perhaps the biggest limitation of wormholes as they exist in the Orion’s Arm worldbuilding project. Which opens up interesting possibilities for them, but it’s not what I wanted for my setting; wormholes in my setting function as a pure jump drive (which I discuss here). I wanted any place in the universe to be accessible more-or-less instantaneously.

Another important use of wormholes in my setting is creating a tangle of non-orientable space, meaning any matter fed into one mouth will come out the other side as antimatter! In my universe I posit that the energy invested into creating the wormhole is far less than the energy return from feeding antimatter through it, thus turning antimatter into a primary energy source, instead of an energy storage medium, like it would be with the antimatter-making techniques known to us today.

## Including Preons in my World

Another way to manufacture antimatter in my setting might be breaking matter down into its elementary constituents, sometimes known as preons. “Preon models” posit that quarks and the like are composites of still-more-elementary particles, known as “preons”; physicists tend to rule out such particles, since to have remained undetected they’d have to be very heavy, with some other force canceling out all that extra mass to yield the energies we observe in the Standard Model’s particles. As such, it seems unnecessarily superfluous.

But there’s one compelling feature of a preon model: the “rishon model” of preons, among many other ideas, supposes that equal amounts of matter and antimatter do indeed exist in nature, it’s just that the antimatter is almost all confined in preon-scale structures. Honestly, it’s the most elegant and beautiful solution for the baryon asymmetry problem I’ve heard so far, and I’ve mentally penciled in its truth in my space-opera setting: in my universe, preons are real, and are comprised of equal parts matter and antimatter.

As such, it’s possible to break matter down into the preons and reassemble it into antimatter, but unlike the wormhole method this is not a positive energy-return-on-energy-invested process, so would tend to be disfavored for practical use.

## String Theory and Beyond

The most fundamental set of particles are these preons, which in turn are vibrations of strings, as real-life string theory predicts for Standard Model particles. Apparently string theory is consistent with the idea of preons (in real life that’s actually one of its problems: it’s consistent with pretty much anything!), and M-theory and its brane cosmology is just too cool an idea to not include as a description of reality in my space-opera setting.

The bulk our universe (a “brane”) is in, coexisting with an infinitude of others, is an eleven-dimensional space. This possibly is where civilizations wink out to when they ascend to a higher plane of existence in my setting, but we’d be naïve to think the series of planes ends there, at just eleven dimensions. Who’s to say the bulk of M-theory isn’t itself a subset of an even larger-dimensional structure, and so on and so on to infinity? Literally! There are mathematical structures based on an infinite number of dimensions, and Max Tegmark speculates that all mathematical structures really exist somewhere…

Personally I’d speculate that Gödel’s incompleteness theorems mean that mathematics itself is a subset of non-mathematical thought, a mathematical universe a subset of an ultimately spiritual reality. For purposes of my worldbuilding I’ll propose that this is very remote from the world we inhabit today in real life, but would be relevant to a sufficiently advanced civilization, such as humans eons into the future.

## The Dark Side of the Cosmos

One big unsolved problem in physics is the nature of dark energy and dark matter, which together make up like 95% of the universe’s mass-energy content. The leading theory for dark matter is that it consists of weakly interacting massive particles, possibly the very same particles predicted by supersymmetry theory, but many other candidates have been offered. Dark energy is even more mysterious, generally thought to consist of either a cosmological constant inherent to space (which, as its name suggests, is constant) or a quintessence field that varies with time. One compelling feature of the latter is that such a field can also account for cosmic inflation.

I’m most interested, though, in the dark fluid theory, which proposes that both dark matter and dark energy can be accounted for as a single fluid whose effects on the universe change depending on the local matter density; effectively, galaxies are bubbles suspended in the dark fluid, accounting for dark matter’s effects (even its observed clumpiness!), and the smoother dark fluid in deep intergalactic space has a repulsive effect on matter and energy, accounting for dark energy and the observed acceleration of the universe’s expansion. It’s worth noting that dark fluid shares similarities with quintessence, and may well have similar properties and abilities, i.e. varying with time.

In my universe I think I’ll go with the dark fluid approach; perhaps in this setting it’s called quintessence, or the quintessence fluid. This also implies that there are no juicy new dark-matter particles, at least not in any great abundance. Eh, whatever; every approach has its downsides.

## Black Holes, or Fuzzballs?

Another unsolved problem in physics is what exactly is inside a black hole. String theory predicts that black holes are “fuzzballs”, their interiors filled with stretched-out strings from one side of the event horizon to the other, with no singularities actually existing. Nevertheless, it’s possible that the effects would be similar to a classic black hole: if you penetrate the event horizon, you just go into a realm of blackness with nothing amiss, the only difference being there isn’t a singularity at the center, just an ever-more-tangled thicket of strings, sort of like a string analogue of a neutron star. It’s consistent with the depiction of black holes in my stories, what I want my world’s black holes to be, and one of the leading current theories, so I’ll roll with it I think.

## Conclusion

That’s about all I can think of for now. When I think of more physical aspects of my world to include, you, dear readers, will be among the first to know.