Sierra Foxtrot 14

SF thoughts.

• Had considered using the parallax microradian as the zled equivalent of a light-year, and then maybe the picoradian for in-system measures and then "ten yoctoradians" for a day-to-day one. But, I hadn't considered that the "parallax" in question is from Earth's orbit, so I'd need to calculate what a parallax radian is from Lhãsai's orbit, instead (from Earth's you just convert arcseconds to radians). Apparently I never wrote down the orbital distance I had decided for Lhãsai around mÕskoi, and while trying to re-calculate it online, I discovered that science had determined 18 Scorpii, which I'd been using as mÕskoi, to be too young, by at least half a billion if not a full billion years.
  
  Fortunately I found that λ Serpentis is a similar star not that far from 18 Scorpii, so they don't have to move that much. And it has a nice Bayer designation with a Greek letter—lama in the Greek radio alphabet, which, for extra cool, means "blade". Its Chinese designation, similarly, is (Tiānshìyòuyuán)Shǔzēngyī, the First Shǔ Addition (to the Celestial Market Enclosure). That'd be Shǔzēngyāo on the radio, and thus in space-colonies. It's definitely old enough, at 3.8 to 8.7 billion years; I can also still fit Lhãsai's old orbital period inside its habitable zone, which saves a huge headache in rewriting.
• Self-driving cars won't be. They will be driven by an algorithm, by the existing traffic and road conditions, and to a large extent, by tech conglomerates like Google. It will be like if you could get into a carriage and tell your horse your destination, but had no reins—and your horse is controlled directly by the goddess Epona or Demeter in her guise as Great Mare. (You might be able to take the wheel, but I wouldn't count on that being the normal procedure.)
• Still wanted to give the zledo some sort of 'natural' unit. Turns out the zled "parsec" is just the semimajor axis of Lhãsai's orbit in AU, times our parsec, which means their "parallax radian" is also that much bigger. The old "parallax microradian" was 0.67275 light-years, or 6,364,666,884,499.273 kilometers; the zled parallax microradian is 7,078,947,990,186.918 kilometers. The parallax picoradian would be 70,789,479.902 kilometers, and the parallax yoctoradian would be 7.079 millimeters, ten of which would make 7.079 centimeters.
  
  But having realized that the parsec (or any other unit based on a parallax angle) isn't exactly a natural unit, it occurred to me that 100 million Bohr radii is 5.291(772) millimeters. Obviously that's not a very useful unit on its own (half a centimeter), but multiply that by 12 (1.2 billion Bohr radii) and you get 6.350 centimeters, which is about half the old zled unit, the bãgh, which was 12.87. 100 of them is 6.350 meters, a good length for e.g. surveying. And then 10,000 ("one myriad") bãghã, 12 trillion Bohr radii, is 635.01 meters, roughly comparable to a kilometer. A million-bãghã, 1.2 quadrillion Bohr radii is 63,501.265 meters, comparable to the Byzantine "day's journey" of 47 kilometers. A hundred-million-bãgh/120 quadrillion Bohr radii is 6,350.127 kilometers, and then a "myriad million"-bãgh/12 quintillion Bohr radius one, 635,012.563 kilometers—the latter two useful for things like low planetary orbit and lunar orbit.
  
  For larger ones I'd go with a trillion-bãgh one, which is 1.2 sextillion Bohr radii and 63,501,265.296 kilometers, or 0.424 AU—not quite three-fifths of a zled AU. 100 trillion bãghã is 120 sextillion Bohr radii, 6,350,126,529.6 kilometers or a little over 42.448 AU—38.165 zled AU. "1 myriad trillion" bãghã, 12 septillion Bohr radii, is 635,012,652,960 kilometers, 4,244.797 AU (3,816.488 zled AU) or 0.067 light-years; finally a quintillion bãghã, 1.2 octillion Bohr radii, is 6,350,126,529,600 kilometers, 424,479.740 AU, or 6.712 light years, just a little over two parsecs.
• Come to think of it, the zled mass unit, the dhaelã, is 2.22 kilos. But the Planck mass is 21.7645 micrograms; 100 million times that, is 2.17645 kilograms. So I guess I can "metricize" their mass unit, too. Maybe 120 million, so it divides by 12 more easily? That's still relatively close at 2.6117 kilos—also almost exactly 7 Troy pounds. Then 100 of those, 12 billion Planck mass, is 261.174 kilos.
  
  Deriving the equivalent of newtons, joules, and watts from all this was a bit of a headache, but the result was interesting. Even though the mass unit was bigger than the kilogram, the length and time units being much smaller than meters and seconds made the derived units a lot smaller. Their newton is not quite two-thirds, closer to seven-elevenths, of ours, and then their joule is like a twenty-fifth of ours. Their watt's something like three-fortieths ours.
  
  I'm just naming their derived units "thrust", heigõsu and "work", yadhõplai, and then I'm just calling their power unit "dothã of work".
• I'll leave their time units, the dothã, the aech (120 dothã'o), and the zbeihõlt (120 aecho, alone; in their colonies they derive those from the rotation-period of the planet they're on. The "standard" dothã is 1/172,800th of a Lhãsai day, because they make it twelve zbeihõlto each of 120 aecho each of 120 dothã'o (and, again, their "stellar" aech is the same length as a "stellar" minute).
  
  Though 10⁴³—10 tredecillion, or, if you're continental Western European, 10 septillion—Planck times is a similar length, at 0.539121 seconds. But just like how we define the second as exactly 1/86,400th of a Julian day (1/60th of the minute that's 1/60th of the hour that's 1/24th of the day), because it's useful to astronomers, zledo define the dothã relative to their "standard" day, and don't worry about anything else. (The zled day is about 166,000 of the "10 tredecillion Planck times" unit.)
• Turns out there are contact-lenses you can wear for up to 30 days without taking them out, now, so you probably wouldn't need to do nano-bot eyedrops all that often while wearing the filter ones. That certainly saves on rewriting, though I am gonna add zled military and police occasionally being glad of their filter-contacts. (Presumably they're a form of photochromic lenses, since they don't stop you from seeing color—maybe they're like ballistic ear-plugs and kick in instantly when they're hit with sufficient intensity of light.) Also occurs to me that zled signalers, their computer techs, might wear similar ones, but for filtering out certain light-wavelengths from screens.
  
  Another bit of safety equipment that's widespread in my setting, is suppressors: decided all my firearms are integrally suppressed. The sonic boom from supersonic ammo still makes a gunshot noticeable (though I don't think it's loud enough to be a hearing-loss risk), but it no longer gives away your position as much. (A big deal, fighting zledo.) Even their revolvers are suppressed, by just sealing the cylinder gap in such a way as to allow the cylinder to still rotate freely—presumably they have to be lubricated regularly. I was worried they might not be able to suppress shotguns, but as it turns out, we actually have suppressed shotguns now. (You'd still want shooting earplugs for blast noise, though.)
• Apparently the projected energy density of carbon nanotube springs is 3.4 gigajoules per cubic meter. But apparently boron nitride nanotubes are an order of magnitude stiffer than carbon ones. 34 gigajoules per cubic meter is slightly higher energy density than gasoline, which is 32.4 gigajoules. Um…do zledo actually need to power anything smaller than a spaceship or a city with anything other than springs? I think I might have 'em even power their powered armor with springs now. Certainly their semi-feudal, subsidiarity-preserving social order would likely prefer to power things like cars with BNNT springs rather than with beamed power, since BNNT springs preserve privacy so much better. (Though they don't have quite our concept of privacy—with their hearing it's not really a custom you'd acquire.)
  
  Anyway. At a laser efficiency of 85%, the hand laser's sixteen shots, which are now 3,143.825 Joules (80,000 yadhõplai'o) each, requires ((3,143.825×16)÷.85=)59,177.882 Joules. That, with BNNT spring energy density, has a volume of 1.74052 cubic centimeters, and, with a cross-section as big as the hand laser's lens, is 0.220 centimeters high. Meanwhile the long laser's 48 shots of 10,060.240 Joules (256,000 yadhõplai'o) each, comes to ((10,060.240×48)÷.85=)568,107.689 Joules, which comes to a spring volume of 16.70904 cubic centimeters; with a cross-section as big as the long laser's lens, that's 0.528 centimeters high. The hand laser's spring cartridge (the proper term is "barrel", but in the context of weapons that would be confusing) is much more casing than it is spring.
• Had to change references to superconductors in my descriptions of zled armor, since "superconductor" normally means electricity, not heat. Heat superconductivity is a thing, though, it's called "second sound"—so named because the heat propagates through the material analogously to how sound propagates in air. It occurs in superfluids, like liquid helium, and certain kinds of crystals. Basically zled armor changes its structure instantly, or at least in microseconds, from one like composite metal foam (vs. kinetic attacks) to one like those crystals, presumably somehow without changing its volume. They use lasers because lasers can, from close enough, put enough energy into a small area fast enough that the structure can't cope with it—though a laser shot still takes several hundred microseconds, i.e. an appreciable fraction of a millisecond, so the laser has to be within a certain range, to concentrate the energy into a small enough dot. Lasers can go through CMF like it's not even there; a 1.5 kilojoule laser, in a 1 millimeter diameter dot, having to penetrate a 1-inch-thick CMF plate, is 75,229 megajoules per cubic meter…whereas CMF can stand up to 68.
  
  Actually leaning toward changing all the references to "adaptive" armor to just "metamaterial" armor. Say, a dielectric foam "quasicrystal" with Umklapp scattering low enough to enable second-sound heat transfer, that can also deal with kinetic attacks as well as composite metal foam? If it's a metamaterial its composition is less important than its structure—because if I knew what kind of dielectric foam had that kind of thermal conductivity and the armor properties of CMF foam, I'd be patenting it. (Also apparently no second sound heat conduction has ever been observed at anything hotter than 120 Kelvin, i.e. -153.15° Celsius or -243.67° Fahrenheit.) And then I think sandwich the foam between layers of boron nitride nanotube weave, the outer side having a coating of n-tert-butoxycarbonyl-protected diphenylalanine, to stop blades (BN also stops neutron radiation). Then after a fight you use a nano-assembler to check for damaged BN nanotubes and fix scratches in the BOC-protected Phe? I think a foam that manages to have both properties, with an outer layer that imparts two others, is somewhat more plausible than an armor that can shift between all three.