#1 reblog = 1 nanometer out!!!!!

[songfawn]

[random-thought-depository]

Continuing from my last post about science fictional “hyperspaces” (wow, I think that might be the most viral original post I ever wrote; it’s amazing what being reblogged by @argumate can do for a post!):

As a science fiction writer, these are the features I find attractive about “hyperspace” that incline me to favor it over other explanations for “fast” interstellar communication and travel:

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Hyperspace lets space still feel big. Wormholes/portals and instantaneous “jump drives” tend to make space feel small (though wormholes lend themselves nicely to space outside the wormhole network feeling big and to a feeling of sharp discontinuity between “known” or “civilized” space within the network and “unknown” or “wild” space where the network doesn’t reach). Start-anywhere go-anywhere jump drives without serious limitations have the additional issue that they’re more-or-less equivalent to teleporters, so they create the ultimate MAD setting where defending multiple fixed locations from a peer adversary is very difficult, and they minimize the strategic advantages of sustainable stationary banditry over unsustainable hyper-exploitive mobile banditry, and since the likely implications of that are very depressing I prefer to avoid it (except maybe if I was deliberately setting out to write a dystopia or explore the idea).

I want space to feel big in my writing, to give the reader some feeling of the vastness, grandeur, and inhuman scale of the universe. For my main science fiction setting, I think I’ll give hyperspace travel an effective “speed” of something like 5-10 c in Sol’s local neighborhood. That way interstellar journeys are more manageable than they’d be with journeys through our space, but journeys to other inhabited solar systems usually take at least a year or two (Sol to Alpha Centauri may be less than a year in hyperspace, but add in travel time to and from the Sol and Alpha Centauri hyper-limits, which is probably going to be at least a couple of months for each leg, and it’s probably about a year).

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Hyperspace feels more like the sort of thing that might plausibly be useable to almost hairless apes with near-future-ish technology. With warp drives and wormholes and jump drives and so on I get the niggling feeling that’s the sort of thing you should probably have to be on approximately the level of an Orion’s Arm Archialect to do. Real theoretical warp drive and wormhole proposals tend to involve stuff like exotic forms of matter and energy and very large amounts of energy. Hyperspace would be a natural phenomenon, so it’s easier to explain it in terms of people exploiting natural phenomena we just don’t know about now, no weirder than being able to travel faster than rowing would allow by building a sail to catch the wind.

You can say that there are some rare atoms that naturally have a structure that extends into hyperspace. With human senses and 2020s technology they just look like ordinary atoms of silicon, iron, etc., but with the right kind of machinery you can detect them, sift them out of the surrounding 3D atoms, and concentrate them. Once you’ve got enough of them, you can make them the core of a pair of transmitters that you can use to send and receive radio messages through hyperspace. With more energy, you can “push” on these structures and “push” those atoms into hyperspace, and then if those atoms are part of a larger solid object the rest of the object and anything touching it gets dragged along with them (with a certain size limit, perhaps related to mass being “pushed” and energy used, so you don’t have to worry about accidentally sending the whole Earth into hyperspace the first time you try this - that’d be one heck of an oops; maybe a later disproven small theoretical possibility of that happening would go down into the history books along with “before they exploded Trinity they were worried it might ignite the atmosphere”); thus you can send a whole ship into hyperspace instead of just information. When you want to leave hyperspace you can reverse the operation and “push” the ship back into our space.

That gives you a nice highly valuable “handwavium” that can be a hook for various plot and worldbuilding points, e.g. there’s not much obvious economic reason to colonize Mars IRL except maybe tourism (anything you could mine there you get more easily from near-Earth asteroids, and it’s too inhospitable to make much sense as a settler colony), but maybe there’s a huge mother lode of these hyperspace-touching atoms somewhere on Mars. These hyperspace-touching atoms would be especially valuable if the process of using them for communication or in hyperdrives “strained” these structures and at some predictable rate caused some of them to “snap,” causing the atoms to become ordinary 3D atoms of silicon or iron or uranium or whatever. Then there’d be a continuous need for (relatively) large amounts of new ones even in a steady-state economy; you couldn’t just keep recycling them and recycling them and just do a little mining to make up for recycling inefficiencies. This would also be an interesting limit on use of hyperspace; using hyperspace radio or doing a hyperjump involves destroying a small amount of a precious resource, so people wouldn’t want to do it frivolously. This might augment that sphere analogy limitation on hyperspace communication I talked about in my other post; even if a hyperspace radio message from Saturn to Earth got there a little ahead of a radio message through our space, you’d probably send a radio message through our space for anything that isn’t time-critical, because the message arriving ten minutes sooner usually just isn’t worth the predictable cost in “snapped” hyperspace-touching atoms.

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Hyperspace would be an environment, so you can do interesting things with it.

Since hyperspace offers a short-cut because it’s more compact than our space, I like to pull on the idea that it’s like our space but in a more compact state, so it’s similar to what our space looked like when the universe was younger and smaller. Going to hyperspace might be a little like time travelling back to a few tens or hundreds of millions of years after the Big Bang, before the first stars formed. The environment of hyperspace might be a little like the inside of a giant molecular cloud, but “warmer” and extremely impoverished in heavy elements. The gas density might be a few thousand to a few billion atoms per cubic centimeter (by comparison, sea level air is about 10^19 molecules per cubic centimeter while the interstellar medium averages around 1 atom per cubic centimeter). The gasses and plasmas in hyperspace would be almost pure hydrogen and helium. The cosmic microwave background temperature in hyperspace might be around 50 K; that’s warm in comparison to what it is in our space (around 3 K), and warm enough to probably be a big part of the reason hyperspace has no stars (present day star-forming giant molecular cloud regions have gas temperatures around 10-20 K), but by human standards it’s deeply cold; it’s upper atmosphere of Uranus temperature. With no stars, I’d guess hyperspace would be a place of more-or-less total darkness outside the range of any lights humans passing through might bring with them.

Alternately, if I want hyperspace to have a murky and mysterious quality and be a place where visibility isn’t good and sensors don’t work well (so a vibe a bit like B5 hyperspace), I could say the Big Bang nucleosynthesis era lasted longer in hyperspace and there produced a substantial amount of heavy elements, some of which then condensed into dust (probably more like smoke if it’s similar to interstellar dust in our space - nanometer to micrometer particles). This dust would probably be pretty insubstantial on human scale distances (again, if it’s like the interstellar medium matter in hyperspace would be about 99% mostly hydrogen and helium gas and plasma and 1% dust, and even a relatively “dense” hyperspace with billions of atoms per cm^3 would have less than a billionth the gas density of sea level air), but over AUs it would scatter light and that effect might add up. This would make hyperspace similar to a dark nebula.

If I want to take the “hyperspace is a scary place” further, I could add sources of energy that might further confuse sensors and add dangerous radiation and other dangers to the mix. Maybe hyperspace has a few large black holes or something, with energetic accretion disks and polar jets fed by all that relatively dense gas and adding turbulence to it. Or maybe spacetime in hyperspace is “lumpier” than spacetime in our space and hyperspace has weird “rivers” formed by something related to whatever force drives cosmic expansion and some of the gas/plasma gets caught in that and accelerated to large fractions of the speed of light and then slams into the low-velocity material in the “still” parts in places, creating lots of turbulence and various other interesting and scary things (powerful magnetic fields, radiation, locally intense heat, maybe some of these collision zones are even giant naturally occurring inertial confinement fusion reactors; maybe that’s where the heavy elements in the dust come from). Maybe hyperspace has a lot of cosmic strings; it makes a certain intuitive sense that, hyperspace being more compact than our space, its cosmic eggshell might be densely veined with cracks.

This gets into another interesting aspect; hyperspace might have something equivalent to terrain; hyperspace travel may be easier in some directions than others. And there’s lots of worldbuilding and plot hooks you could hang from that idea.

For example, let’s look at that idea of hyperspace having “rivers” formed of exotic spacetime structures and filled with gas/plasma streams moving at high fractions of the speed of light. If the edge of these “rivers” has a gradual enough velocity gradient and the plasma in the “rivers” is ionized, with enough skill a spacecraft pilot might be able to catch that “current” with a magsail and ride it, then when they’d gotten about as far as they needed to go they could leave the “river” and do magsail braking against low-velocity plasma in the “still” areas. Just gotta be careful to stay well away from the dangerous collision zones! This might be a huge part of the short-cut offered by hyperspace travel! It could be that distances across hyperspace are only modestly shorter than distances across our space (say, Alpha Centauri is 1 light year away in hyperspace), but the really big savings is you can catch one of these hyperspace “currents” and use it to get up to large fractions of c without expending any fuel. A set-up like that does raise some awkward questions about conservation of energy, but I could say something like “the hyperspace ‘rivers’ are areas where dark energy is being converted into kinetic energy, slightly slowing down the expansion of the universe in the process.” It’s not like we know much about how dark energy works, or even what it is, so for all we know that’s a thing that might happen under certain conditions.

Those collision zones would generate substantial radiation, including light, so unlike a calm hyperspace a turbulent hyperspace with energetic “currents” would probably have light. Don’t know how bright it would be; all that dust (made of heavy elements built up over the eons by inertial confinement fusion in collision zones, I like that idea!) would absorb a lot of light over cosmic distances, and stars are pretty bright but most of our space is pretty dark.

That set-up would make hyperspace travel kind of like sailing; there would be “currents” or “winds” you want to catch, and travel might be a lot faster along directions where the currents are favorable. Travel times in hyperspace might only loosely correlate with distance; Alpha Centauri might take longer to reach than Zeta Reticuli. There would also be hazards you’d need to avoid, e.g. the collision zones.

Maybe part of the explanation for the Fermi Paradox might be that Earth is in the middle of a big “still” part of hyperspace; few ships went here because we’re in the middle of a cosmic doldrums that takes years to crawl across.

With a set-up like this, hyperspace may have “weather” that influences interstellar commerce, and “climate change” on historical timescales that influences the trajectories of interstellar societies. Ages when hyperspace is particularly turbulent might cause Dark Ages as hyperspace travel becomes very dangerous. Ages when hyperspace becomes unusually calm might also cause Dark Ages as there are no fast hyperspace “currents” to ride and hyperspace travel becomes relatively slow. In one age hyperspace “currents” may be arranged such that a world is isolated; a few thousand years later the hyperspace “currents” might have shifted and that previously isolated world might be much more accessible and back in the mainstream of interstellar civilization.

One wrinkle: a turbulent, energetic, opaque hyperspace such as this probably wouldn’t be good for sending radio signals across. Maybe the universe actually has multiple “basement” levels, hyperspace is just the one that’s “closest” to our “living room” level and the only one that’s “close” enough that ships can travel to and from it, but there’s a clearer layer that’s “farther away” but still “close” enough that you can send radio signals through it, and that “deeper” clear layer is the one used for interstellar communication. Bonus idea I like: the deep clear layer is even more compact than hyperspace (by orders of magnitude) so it’s overall a much better short-cut in every way except being “too far away” to send ships through it, so finding a way to send ships through it is a huge potential breakthrough that tantalizes generations of scientists and engineers who so far have not managed to figure out a way to do it.

Really, on that note, I like the idea that the universe is analogous to an onion with many “layers,” and hyperspace and the deep clear layer are just the layers that are most easily accessible from our space. There are a lot of “basements” below the deep clear layer, and generally as you get farther “down” the “basements” get smaller, denser, and hotter; going “down” is a little like time travelling to eras closer and closer to the Big Bang (though this isn’t a completely reliable rule - the deep clear layer is smaller than hyperspace and perhaps warmer, but seems to be a lot emptier; maybe most of its matter has been sucked into black holes?). Maybe the whole thing is a bit timey wimey wibbly wobbly and if you go “down” far enough you eventually hit what 2020s science knows as the moment of the Big Bang. As well as “basements” there are also “attics,” but they’re less accessible because going “up” is harder than going “down.” If going “down” into the basements is a little like time travelling to the early universe, going “up” into the attics is a little like time travelling to the deep future, to places that look kind of like what our space may look like in the deep future black hole era (assuming the Big Rip doesn’t destroy our universe before that deep future proton decay story has time to play out). The “attics” are vast, empty, and deeply cold; cosmic microwave background temperatures a tiny fraction of a degree above absolute zero and precious little else to generate energy, maybe one atom in every cubic kilometer of space. They probably expanded too quickly for stars to ever form there. The total number of layers might be large; maybe hundreds or thousands, maybe billions, maybe a number so big it would need to be expressed in scientific notation. I like this idea because it makes hyperspace feel less implausibly convenient for humans; we’re just taking advantage of a particularly convenient part of a big macrostructure that’s mostly inaccessible to us.

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Hyperspace is a natural phenomenon, so it probably isn’t going to be neatly quarantined to just being a thing humans can use for communication and travel. Hyperspace-related phenomena are going to show up in nature, and this offers a neat explanation for any exotic soft SF-ish natural phenomena you may be interested in incorporating into your setting.

Hyperspace (and other “basements” of our universe) also gives you a built-in parsimonious explanation for any other bits of soft SF technology your setting might feature. Want your setting to have e.g. Star Trek style forcefields? You can say they work through interaction with one of the “basement” layers of the universe.

On that note, I have an idea for a more hard SF version of the Babylon 5 “going beyond the Rim” thing or Stargate ascension, based on the “onion universe” concept I described above, which might serve as a partial explanation for the Fermi Paradox. Maybe some “layers” of the “onion” are “superhabitable” to advanced machine intelligences (though not to primitive flesh and blood beings like us). You know the aestivation hypothesis? If advanced machine intelligences could move to an “attic” they wouldn’t have to wait billions of years for our space to cool down; the cosmic microwave background temperatures in many of the “attics” would already be some tiny fraction of a degree above absolute zero. Maybe they could move to a nice big cold “attic” and live there and “mine” a nice compact “basement” that is rich in matter and energy, getting the best of both worlds. Most of these “attics” and “basements” would be completely inaccessible to humans, but beings with better technology and more resources might be able to access many more of them (or maybe even get beyond the “onion” and search the entire multiverse for universes with conditions more to their liking). So the universe’s most powerful and most enduring civilizations might usually leave our space and move to another “layer” or universe that has conditions more ideal for them, and thus be mostly undetectable to us.

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See: the concept of hyperspace is loaded with potential plot and worldbuilding hooks if you use a little imagination, and I like that!