Sierra Foxtrot 16

SF thoughts.

• It turns out (I was worried) that it is, indeed, possible, for Lhãsai to have two appreciable-size moons that are in a Trojan orbit. The way it works, apparently, is that the bigger satellite has to be at least 100 times as big as the smaller one, and probably ought to be 1% the size of its primary. 0.01% of Lhãsai's mass (which is 1.189 times Earth's mass) is still bigger than a fairly big moon, like Tethys.
  
  Lhãsai's larger moon is 0.96% as massive as Lhãsai is, has a diameter of 3,211 kilometers, and orbits at an average distance of 414,500 kilometers. This gives it an angular size of 26.6 arcminutes, about 86% the size of Luna in Earth's sky; the smaller moon has the same orbital distance (Trojan orbit, remember) and has a diameter of 845 kilometers, giving it an angular size of 7 arcminutes, or about 23% the size of Luna.
  
  Interestingly, since Lhãsai's orbital distance and the diameter of λ Serpentis mean mÕskoi has an angular diameter of 30.5 arcminutes in Lhãsai's sky, it's impossible for the larger of Lhãsai's moons to completely eclipse the sun, though they can get close—their equivalent of a total eclipse is a ring of the sun showing around the silhouette of the moon.
• It occurs to me that zled electronics have sound as a non-optional component, since zledo are less visually-oriented, more audially-oriented, than humans. The sounds would be very low, only audible to the user from the usual distance you hold a phone, which from a human's one-sixth as good of hearing would be totally inaudible. Since zled hearing can pinpoint a sound to at least 5° (human hearing can do 1° right in front but only within 15° if it's to either side), and given people hold smartphones an average of 40 centimeters away, it's only 3.493 centimeters for them to have full 3D audio effects even sidelong—far less than the width of a handheld even if theirs weren't slightly bigger than ours.
  
  This idea was occasioned by a fascinating article about how interfaces take too much inspiration from movies, which are based on what looks good, and not on how our hands actually interact with things. I think he's actually wrong, given that handheld computing is still fundamentally about conveying visually-symbolized information; tactile is always going to take a back seat to visual. About the only thing affected by the tactile difference between vellum or parchment, and paper, is paper's smoothness allowed a more flowing handwriting to develop. But in worldbuilding for alien cultures, who aren't as "put all their points in vision" as us, this kind of thing is important.
• Speaking of zledo and tactile sensation, decided that their fingertips are much tougher than ours, but no less sensitive. See, I'd long ago decided their fingertips, and the other pads on their hands, were covered in scales, which scales are, like those of birds, actually modified versions of their hair (feathers in the case of birds). And you can stick each of those "scale"-hairs into a vacuole willed with liquid, like the one a cat's whisker sits in. In zled finger scales they're oil-glands not blood, but it still lets them have that sensation-magnifying effect. (This also means, I realized—I should have before—that when a zled gets a burn on his hand, it smells like burning hair, even if his fur isn't touched.)
• Adding one colony to the Solar System, in my setting: Venus. No I haven't taken leave of my senses, you can put cloud cities there, above the sulfuric-acid rainclouds—at an altitude of 50 kilometers the conditions almost approximate those on Earth, as in 1 atmosphere of pressure and 273 to 323 Kelvin temperatures. (Though the atmosphere is CO₂ instead of O₂.) Even up that high it's as good as Earth's atmosphere at blocking radiation.
  
  About the one real downside is the winds up that high go at 95 meters per second, which is just shy of Hurricane Patricia's windspeed, fast enough that a cloud city would circle the planet every 4 Julian days. So you'd definitely need to have your colonies equipped with something to protect from the winds; you'd probably have something akin to airlocks for vehicles (not just the wind, also it's not breathable air out there), and tether people working on the outside.
  
  I think I'll name the cities Ourania, Pandemos, Peitho, and Philommeides. Or some of those.
• The Venus colonies are the only non-station colonies in the Solar System before the invention of true, topological artificial gravity, because Venus's 91% Earth's gravity is almost certainly close enough to be safe for humans to gestate and grow up in. Mars's 38% Earth gravity is a lot more questionable, so they didn't build any permanent habitations on Mars till they had topo grav. (They did build research-stations akin to the Antarctic ones; an adult can probably survive Martian gravity indefinitely, at least if they're strict about their exercise regimen.) Other than that they built one O'Neill Island (not sure if it's a Two or Three…actually it might be a Stanford torus?) in the lunar Lagrange point.
• Everything the media calls "liquid body armor", isn't. What it is, is polymer-fiber armor (along the lines of Kevlar), soaked in a shear-thickening or magnetorheological fluid. That reacts to impacts by hardening, purely mechanically in the first place or via something akin to piezloelectricity in the second.
  
  Fibers treated with a liquid are not "liquid armor", any more than water-proofed tent fabrics are "liquid shelter". Yes, the treatment itself becomes the armor, sort of, while the shelter is just made leak-proof—but it's not a liquid when it's on the armor fibers, it's like a wax. Just like the tent's waterproofing.
• I think I'll have there be a rule, in my setting's space-travel, that when communicating between species, aliens speak a UN official language and the humans speak whatever language the aliens do (zledo have one official language, the khângây have three, nobody knows how many the thoikh have but they seem to all have at least one in common). Apparently on the Apollo-Soyuz missions, the Russians would speak English and the Americans would speak Russian, on the assumption it's easier to listen and act in your own language and speak in a foreign one, rather than vice-versa.
• Zledo of course have sign-languages, but deafness, probably pretty rare with their modern tech, is more significant in their lives than it is in ours—closer to blindness, and then some (more like being a blind eagle). Think they keep knowledge of their sign-languages alive, though, not only for historical and linguistic interest but for communication while (for instance) artillery fire is happening (they use chorded keyboards and just text each other, of course, but you can't rely on that in a fight), or while wearing spacesuits whose communications are damaged. I think their military gesturing is probably at least as advanced as a typical village sign language.
  
  One thought is that maybe their main form of sign-language started as a taboo-avoidance sign language like those used by some Australian Aborigines (and once used by Armenian women, apparently), in one of their cultures, and was then spread back to the rest of the society that now uses it by returning missionaries. Thought I'd have the other big one used in a different group of civilizations, by traders? Like maybe one of their sign-languages is like Australian Aboriginal sign languages, and the other is like Plains Indian signs. Maybe their military signing is a standardized pidgin (creole?) of the two forms?
  
  One thing that occurred to me is that hearing zledo can hear someone signing behind them, without turning—I doubt they can actually tell what's being signed, but the sound of the gestures is probably really obvious and fairly distinctive.
• Come to think of it, how come nobody's realized the obvious? The best gestural interface, for many purposes, is actually a spoken interface…but using sign language.