Be Cool, Be Cool

A laser calculator I find online (I think some of its assumptions are simplified) says that the waste heat of a 10 MJ laser is 882.353 watts, assuming 85% efficiency (50% is considered the max for the near future—currently we top out at around 12%—but the 24th century isn't quite "near" future, and the zledo are 300 years more advanced than we are). I find an efficiency for micro-channel heat-exchangers of 1.5 kW/cm2 (presumably per second); at .882 kilowatts, that means almost exactly 1.7 shots per square centimeter.

A zled laser's power mainsprings can supply it with power for 48 shots. One face of the hexagonal prism casing on a zled laser is 4.053 centimeters wide; suppose we put a band of micro-channel heat-exchangers around the laser (toward the end), but not covering the bottom face or the bottom half of the two faces touching the bottom. If we do that, we basically have 3 whole faces and 2 half-faces to work with, giving us (3+(2×(1/2)=)4, for a total width of the heat-exchanger of (4×4.053=)16.212 centimeters. That, right out of the gate, means that merely by being one centimeter wide, we can exchange the waste-heat of (4.053×4×1.7=)27.56 shots. Make it an eighth of a bãgh—"aliens don't use nice round numbers of Earth units"—or 1.60875 centimeters, and it's got the ability to dump the heat of 44.34 shots, meaning that, if that cooling-efficiency is per-second, it can dump the heat of firing its entire charge, in one and one-elevenths seconds.

The hand laser has a waste-heat of a bit over 282 watts; assuming the same kind of heat-exchanger, that comes to 5 and 5/16ths shots per square centimeter. The faces of the hand laser's hexagonal casing are a little over half the width of those of the long laser (not exactly half because though the lens has half the diameter, its casing is the same thickness), 2.533 centimeters. The hand laser's springs power it for sixteen shots; a band a centimeter wide can dump 17.23 shots. Make it a twelfth of a bãgh, or 8.58 millimeters, and it can dump 14.78 shots' worth of heat in one second, and the whole spring in just over 1.08 seconds.

Incidentally, my old calculations for laser power-supplies forgot the fact that lasers are inefficient; I just went by the power of the beams themselves. What 85% efficient actually means is that for every twenty joules you pour into the laser, you get seventeen joules out as laser (and what our current best, 12%, means, is that for every twenty-five joules you put in, you get three joules of laser—we're not looking at laser weapons except on nuclear ships for a long, long time). So I guess that, assuming the .1 megajoule/kilogram minimum for polymer molecular springs, powering the 3.2 kilojoule hand laser for 16 shots would require a 602 gram power supply, while powering the 10 kilojoule long laser for 48 shots would take one weighing 5.6 kilos. Fortunately, polymer molecular springs have a theoretical maximum of ten megajoules (their range is apparently two orders of magnitude wide); merely going up to the "1 megajoule/kilo" kind gives us a lighter spring than the one the hand laser uses. Except it probably weighs a bit more, the extra weight being reinforcement (you really, really don't want a spring under that kind of tension breaking on you).

Note: I messed up the calculations, earlier, for the width of the hexagon. It's better now. I think I was also doing something wrong on the calculations for the hand laser's heat exchangers.


De Colores

So, I'm making a change: now zled lasers are "frequency agile". What this means is, for close-in work you set them to near-infrared, for medium range you set them to visible light, and for long range (or anti-materiel—or shooting through two people at once—at close range) you set them to near-UV. I discovered that switching from near-infrared to visible light (specifically c. 500 nanometers, which is at the green end of blue-green) doubles the range at which a 10 kilojoule "long" laser will do the damage I need it to do, in a scene in my book (sniping troop-transport choppers, specifically by lasing holes in their tilt-rotors). Switching from that to 250-nanometer near-UV doubles the range again, to the point where it can vaporize 10.5 centimeters of aluminum (I figure a good proxy for any other aerospace material) at a whole kilometer. Go down to 210 nanometers (you want to stay above 200 nanometers or you're not talking "near UV" any more, and a planetary atmosphere becomes opaque) and you can vaporize 10.5 centimeters of aluminum at 1,190 meters.

I don't think I need to have them be very scary, "gets its laser from ionizing radiation" free-electron lasers—which it's also kinda hard, if not actually impossible, to make man-portable. I've found several papers online about other ways to do frequency-agility in lasers; I'm not sure they demonstrate the ability to tune the laser all the way from 250 to 1000 nanometers, but zledo invented the space-fold drive the year we landed on the moon, Earth's 2015 tech is not exactly indicative of what they can do in the 24th century. I imagine there's a fire-selector on the laser, somewhat like the one that switches an assault rifle between full-auto, burst, semi-auto, and safe (actually many assault rifles only have burst or full auto, e.g. the M16A2 only has burst, while the AK often if not usually only has full-auto). I imagine the typical troops get a series of pre-sets to switch between—near-IR, one or maybe two near-UVs, at least one visible wavelength—while the sniper-types might have a more fine-tunable device.

The main reason one changes one's laser's wavelength is for range, so there might be a "ideal range for" indicator next to the wavelength-selector. Then again perhaps not, since a lot depends on e.g. whether one is fighting armored or unarmored opponents, and how armored, or whether one is doing anti-vehicle stuff.

Interestingly apparently near-infrared is more likely to blind you than visible, since the whole eye is transparent to those wavelengths; it's not that big a concern, though, since even 24th-century humanity has medicine that can regrow those cells, and the zledo are 300 years more advanced. Still I imagine most military personnel wear protective contact lenses, and they might be a part of civilians' "survival kits" for if shit hits fans before they can evacuate. Not sure if zledo do things like put in contacts with their fingertips or with the backs of their extended claws—maybe they stick the lens to their fingertip and open their eye with the back of their claw, that's somewhat like how humans put in contacts. I imagine having a whole third-eyelid nictitating membrane (also called a "haw" on horses at least) makes the whole thing a bit more difficult.


All Is Grist

Thoughts. 'S really almost a SF-thoughts post, but a lot of it, indirectly.
  • Found out I was wrong, that sound TV's Frank makes does have an IPA letter. I was just looking in the wrong place. It's not a click, it's an implosive: the voiced velar implosive, written [ɠ].

    The way one writes that sound Frank makes, then, is [jʌɠwiː]. "Cuckoo kids out for cuckoo kicks. [jʌɠwiː]!"

    (This IPA is so much more fun than the other kind, though admittedly it's not hard to be more enjoyable than a beer so over-hopped you'd be forgiven for thinking you got hold of a toxic chemical equipped with a safety-bitterant by mistake.)
  • Decided one of the zled languages uses a click in some places where the other two members of its group have a stop—the dental click, the sound Americans spell "tsk" and Brits spell "tut" (and God only knows about Australians, Canadians, or South Africans; my guess is Aussies and Afrikaners write "tut" but Canada is a 50-50 chance of either).

    That zled language uses it to replace the alveolar stop (t) in certain words; I haven't worked out the entire rule but since it's so far only shown up as the first letter of two proper names, one of a supporting character and one of a mythological figure, I figure I'm okay. Not sure if I should change some of their other sounds too, like maybe make some of their Ds into a voiced velar implosive (I can't hear the difference between voiced and unvoiced clicks, not having been raised speaking isiZulu).

    I discover that human languages don't like to end syllables or words on clicks; the Khoisan languages only put them at the beginning of root-words, while Hadza, Sandawe, and the Bantu languages with clicks can also put them at the start of syllables within words. Some of my alien languages, however, end syllables on clicks; fundamentally it's not much weirder than you people ending words with aspirated voiceless stops (my dialect of American English doesn't "release" those stops at the ends of words—"bock", "bot", and "bop" are hard for speakers of other dialects to tell apart, when we say them).
  • Re-doing my pistol round. The bullet is still 9 millimeters diameter, 16 millimeters long, but I realized that .357 SIG is weak—its resemblance to .357 magnum is greatly exaggerated. Decided to go with actual .357 magnum. 1 gram, even, of nitrocellulose will move a 12-gram bullet at 430 m/s (giving a muzzle energy of about 1.1 kilojoules). It'd take 420 milligrams of octanitrocubane to achieve the same thing, which has a volume of 203.883 cubic millimeters.

    Going with the 10.77 casing diameter of .357 SIG means the "casing" is 13.4 millimeters long, and goes 12.1 millimeters up up the side (so only a quarter of the bullet sticks out past the top—a lot of these caseless rounds are practically telescoped). Thus, the round becomes 9×13 millimeter—two whole centimeters shorter than the CIP designation for .357 magnum. (Overall length is less than half that of .357 magnum, 17.35 millimeters as opposed to 40.)
  • Thought I'd go a bit into depth on my PK armor. Decided, the standard Peacekeeper armor is a sheer-thickening fluid undersuit, which might also contain the power-assist exosuit (not in the same systems, they'd interfere with each other), under a breastplate that's harder. Might also wear shoulder, elbow, and knee plates, but like now, those are optional. The helmets come with or without faceplates.

    Remember the Australian lady in the short story there on my DeviantArt? And how she says most special forces don't do heavy armor? The special forces guys—Peacekeeper Special Purpose Forces, to give them their full name—wear only the flexible undersuits, without the breastplate or any of the other rigid parts. Their helmets always have the faceplates. Due to their clothes being less bulky, I imagine they get referred to by other Peacekeepers as things like "longjohns" or "union suits".
  • In another entry under the heading "even Cracked knows that's stupid", we have the guy in Jurassic World who wants to weaponize raptors. See also the xenomorphs in Alien, and the idiotic plot of straw corporation Weyland-Yutani to weaponize those.

    Aside from what that article points out, about living things making lousy weapons—xenomorphs made a little sense, at least, for the Engineers, since they had no future plans for Earth—is the ugly hypocrisy and Freudian projection involved in this leftist trope. Go look up who made the closest thing to a doomsday weapon ever. It wasn't a corporation. It was two leftist darlings working in tandem: the government and academia, i.e. the War Department and a bunch of physicists.

    Incidentally, what's with this idea you sometimes see, that the Manhattan Project guys were dupes? Who, pray, in the US military, is supposed to have bamboozled Einstein and Oppenheimer into building a fission-bomb without their realizing it? How's that supposed to work? "Gasp! You monster! Those equations we keep having to explain in layman's terms for you—their implications! You knew all along—about this concept some of us personally created about half the theoretical underpinnings of!"
  • Partly for xenobiology purposes, partly for my own interest, I've been looking into the transition from lobe-finned fish to tetrapods. Some cool stuff. Apparently our spines being shaped the way they are, rather than like those of fish, is one of the features in question. Another one? That so many land animals taste like chicken, and not like fish, the "fishy" taste being something to do with substances produced by the death of aquatic animals' tissues.

    Of course the limbs are the big change. The fins of lobe-finned fish are kind of like horse forearms, just a stack of joints, up to a point, where they start dividing. You can identify one of the divisions as the precursor of the radius and ulna. The transition from the bunch of bones that makes up the fin, to tetrapod digits, is kinda vague; we can point to some bones toward the end that became the carpals and metacarpals, but how exactly the phalanges show up is sketchy.

    Oddly, lobe-finned fish have bones in their limbs that aren't connected to the rest of the skeleton. The two halves of the pelvic girdle were once just the ends of the "leg"; they fused to each other and to the spine I think some time during the fish-to-tetrapod transition. The shoulder, of course, is still only held on by the clavicle and muscles. I think some of the ancient lobe-finned fish (not coelacanths or lungfish) had ribs; those are fairly obviously modified vertebral processes.
  • The interesting thing about coilguns and railguns is that they don't seem to work differently from regular guns—not in some of the ways you might expect. Like, you might be surprised by railguns with muzzle flash and smoke almost indistinguishable from a firearm, but that's the plasma. I don't know if they make quite the same "cork popping" sound as guns, but they have the precise same sonic boom, if they fire at supersonic velocity.

    Which reminds me, it's probably not accurate to say that lasers make a gunshot noise from the wound. They almost certainly do make a "pow" sound, but, not being contained and pressurized like a gun barrel, it's probably not as loud. Probably more like popping a potato in the microwave or a soda can in the freezer—which probably solves the "no suppressing a laser" problem , since that's about the sound-level a suppressed firearm does.


Shoot All Week

Another gun post. Title's a reference to the Henry repeater, "the damn Yankee rifle they load on Sunday and shoot all week." It's a pun: "repeat" and "firearms", i.e., another gun post.
  • Had occasion to get down to brass tacks about my coil vulcans. The man-portable, three-barrel ones fire relatively standard HEIAP ammunition with ferrous-metal "driving belts" (which some modern .50 caliber machinegun rounds seem to have), to give them 20-millimeter performance in a 13-millimeter package. The six-barrel ones mounted on aircraft are 30 millimeter, basically a magnetic version of the GAU-8 or GSh-6-30.

    Instead of "spinning up" electrically, like most American vulcans, or via gas, like the Soviet ones, I think 24th-century coil vulcans actually do it with their recoil—and given a 390-gram 30-millimeter round at 845 m/s has a muzzle energy of 139.235 kilojoules, the recoil is considerable. You might as well get some use out of it. (Yes, you can use recoil to spin part of a gun; the Mateba and Webley autorevolvers did it, along with cocking the hammer.)
  • The coil-vulcans mounted on battle-spacecraft ("starfighters") are only 5.56 millimeter, because they go at 1% c and mass only 4 grams, the same as M855 "ball" M16 bullets. The kinetic energy calculator says the muzzle energy for that is 4.3 megagrams of TNT.

    You can counter part of that with a soft recoil system, but that usually only halves the recoil energy, so you're still talking about slamming the vessel with just over two tonnes of TNT every time the thing fires. Maybe those ones spin up electrically, and the topological inertia protections keep the guns from tearing the ship apart.

    Ooh, I like that. The topological protection would cause huge "muzzle flare" for the people who use topological sensors. (Since they use metric-patching guns, their own weapons are equally detectable, if not more so.)
  • Brought back bayonets on zled lasers. Since my favorite weapons are halberds, thought I'd have their bayonet be heavy, for chopping as much as stabbing. The shape would be a bit like a skeggöx "beard" (some of which came to a point), upside-down and at a somewhat different angle.

    The bottom half of the hexagonal prism that forms the outside of zled lasers has an accessory rail set in it, something like the Smith & Wesson TRR8 . The bayonet attaches to the rail, rather than with a special lug or socket. They don't need a laser-pointer, because laser weapons can be used for their own, by using the same optics as the weapon does: the dot you're sighting with suddenly explodes. (You can also use the laser's optics for a scope; zled lasers have a little panel that pops up under the rear sight to show a reflex-image of the laser-optics picture.)

    Their long lasers are 117.7 centimeters long, of which 91.4 cm is the optical cavity. That's the equivalent of a human having a gun 97.7 centimeters long—and remember, they wear their lasers like swords. 97.7 centimeters is about seven centimeters shorter than the M1860 light cavalry saber.
  • Decided my zled anti-materiel laser does about 30 kilojoules; it's about five thirds as strong as the .50 BMG we use in our anti-materiel rifles, and about three-fifths as strong as the 20×110 millimeter round used in the strongest anti-materiel rifles currently in existence.

    The normal zled laser is 10 kilojoules, which is high for an infantry weapon but not unreasonably, for a society where all soldiers wear armor (also where they don't have to worry about recoil). I have the anti-materiel laser use the same power-cartridge as the normal ones; it just goes through them three times as fast.

    The anti-materiel ones are basically the same shape as the standard ones, but their lenses are wider, so they can focus at a longer range.
  • The laser equivalent of machinegun fire is continuous-beam; burst-fire is presumably a brief zap for a set period of time. Since for optical wavelengths you have to pulse the zaps, you can talk about the "burst" in terms of the number of pulses.

    Whether "burst" or full auto-fire, the main way you use it is to keep the enemy behind cover while your allies advance, just like machinegun fire. As anyone who's played Reach (at least on Legendary) will tell you, continuous beams are just as likely to make you keep your head down as a machinegun is.
  • I think I've pointed out that the oft-quoted "shots per enemy kills" numbers don't actually show anything about "reluctance to kill", they show use of suppressive fire. Besides, we don't actually have a way of tracking how many rounds have been fired; at least some of those "shots" stats actually use "rounds shipped over" (e.g. to Vietnam) as a proxy measure for "rounds fired"—never mind they're two quite different things.

    But apparently, one of the major studies often cited in support of the "reluctance to kill" interpretation, the famous one by Brig. Gen. S. L. A. Marshall, was, at best, deeply flawed...if not fake. Apparently Marshall didn't even actually ask the people he interviewed the questions he claimed to be answering—as in "how often did you fire?" or "how often did you actually shoot to hit the enemy rather than just at him?"

    Of course, none of that changes the fact artillery, not small-arms fire, is the main killer on battlefields. There was a reason Stalin called it the God of War. (Well, in premodern war, dysentery was the main killer, but the only people who'd name that "God of War" are Nurgle's Plague Marines.)
  • This paper (Google the title to find the article as a pdf) says it takes 6 megajoules to accelerate an 18-kilogram projectile to 420 m/s. Now, .50 BMG Raufoss, like the coil-vulcans basically shoot, has a muzzle velocity of over twice that—915 m/s—which comes out (if it scales linearly) to 13 and 1/14th megajoules. Of course, the projectile masses only 43 grams, not 18,000, which (agaim, assuming linear scaling) means a power-requirement of 31,226.1905 joules. That means to power the coil-vulcan for 1000 shots requires a silicon-air battery massing only 1.65 kilograms.

    Late addendum: The GSh-6-30 shoots 390-gram bullets at 845 m/s. That would mean that firing each shot takes 43,591.2698 joules, which, assuming 1,350 rounds (the maximum capacity of the A-10 Thunderbolt) requires a silicon-air battery of 1,148.75 grams. That's about the size of a motorcycle's battery.

    The aircraft autocannon's battery is smaller than the "1,000 shots at 31 kilojoules" battery because I did the first one backwards, and divided the battery's energy density by the power requirement instead of the power-requirement by the energy density. The correct battery size for the 13-millimeter coil vulcan would be 609.55 grams, the same as a lithium-ion battery used for power-tools nowadays.
  • Zled uniforms are armored; they can block the "sidearm" hand lasers up to pretty close (within about thirty meters, typical "battle zero" for the Beretta M9; up to ten meters, they keep the wound smaller, reducing the bleeding), and at least are better than "exposed skin" against the long laser (so it's only lethal out to, say, half a kilometer instead of a whole one). The interesting thing is, the main way the uniform is armored is it's got a layer of energy-dissipating stuff sandwiched inside it, peeking out at the ruffles on the cuffs; the cuffs glow when the uniform has to dump a lot of energy.

    Zled powered armor isn't just powered in terms of lifting assistance (which, given it's designed for people who can lift several times their own weight, is really just "cancel out its own weight and that of any other equipment"). It's also made of "smart" material, adjusting its molecular structure to cope with any attack. The only way to get through is to hit it with too much to cope with at once; zled long lasers can do it by hitting from about 150 meters away, their hand lasers from about a sixth that. Humans do it with anti-materiel rifles or actual anti-tank grenades.
  • If the Serdyukov SPS is the future-y Makarov, what's the future-y version of the M1911 (America's service pistol for most of the Makarov's run)?

    My vote is the Detonics Defense MTX, an entry for the Modular Handgun System competition for picking the M9's replacement—which somehow manages to be a 10(+1)-round M1911 while still being .45 ACP.

    If one wanted a futuristic M9 (America's service pistol when it won), I would go with either the Px4 (P×4?) Storm, or possibly the 90two. Probably the first one, just to punish the 90two for its stupid name.


All I Survey IV

Random thoughts.
  • I made my AIs be in Prolog because Prolog is cool, and also because Prolog is a big deal in AI. I may have to specify, though, that they're actually in Prolog and JavaScript; Prolog is declarative-only, JavaScript is imperative.

    Why JavaScript, and not, say, Python? Python's not an ISO standard. JavaScript is. Why, then, not C#, which is very similar to JavaScript and is an ISO standard? There are a whole bunch of bridges between Prolog and JavaScript, many more than there are between Prolog and C#.

    I guess I'll be adding references to ISO 16262, then.
  • That thing I harp on about people putting things in their work that are dictated by "drama" rather than "what makes sense", has made it very difficult for me to watch movies and TV. For instance, one complaint I had about Dark Matter (really about the only one) was the part when the android (that's her name, "the android", they're going for a weird minimalist approach with the whole series and somehow it doesn't piss me off) goes out on the hull of the ship to fix something, and gets knocked out by the static on the hull. Um..."tether"? The barely-Iron Age ancient Hebrews knew about that one, they tied a string around the priest's leg before he went into the Holy of Holies on Yom Kippur, so if he was struck dead by the presence of God they could get his corpse out without violating the sanctum.

    Or, everything in Jurassic Park (the first one) that has to do with the Velociraptors. Aside from their naked skin and sideways hands and having voice-boxes, I mean. For instance, that redshirt guy who dies at the very beginning? Well, how the hell did that happen—except that they designed their pen incredibly badly? Leaving to one side that one raptor would not be strong enough to move the car-thing, we, um, kinda have a handle on moving big, dangerous animals so your staff don't get eviscerated. A Velociraptor—even if we're pretending that's a senior synonym of Deinonychus, and was noticeably smarter than a sparrow (which it wasn't)—is not more dangerous than a Bengal tiger. It's probably a lot less dangerous. We are talking about a cassowary here, basically, those aren't even as dangerous as peccaries, let alone Bengal tigers.
  • I found on the the intertubes that Kenshiro, the human-mimetic robot, uses (=is capable of outputting) five times the power its predecessor Kojiro could. And I find that the motors on Kojiro have 40 watts of output power, and there are about a hundred of them. Now, I don't know if that means 40 watts each or 40 watts total; I'll assume the former.

    That means Kojiro has a power requirement of 4 kilowatts—comparable to DARPA's Atlas—and therefore that Kenshiro has a requirement of 20. If true, that means over 200 times the energy requirements of an average human being (2000 kcal/24 hours=96.85 watts). That's also 78.57% more power than is used by TOPIO, but remember, Kenshiro also has (64/39=)64.1% more degrees of freedom than TOPIO (and 16/7 as many degrees as, =128.6% more degrees than, Atlas).

    Remember also that Kojiro and Kenshiro are barely even an "alpha"-build on human-mimetic robotics. Remember thirdly that with the average 72 kWh laptop battery, you can power a 20 kW system for 3 hours 36 minutes—and with 24% of its mass (the percent of the average human's mass that's fat) made up of polyvinyl-gel lithium-air battery (11.14 kWh/kg), you can power a 180 centimeter, 74-kilo version of Kenshiro for 9 hours 53 minutes 32.35 seconds.
  • Changing the way my human ships are named. I had gone with a Chinese-style system—"Type [Number]"—which is how they name e.g. missiles, and indeed also naval ship-classes, in China, but not how they name spaceships or aircraft. So at first I went with the same system as my guns: a two-letter abbreviation of the company name (e.g. GA for General Atomics), followed by a one-letter abbreviation for the type of ship (M for mothership, E for escort ship, P for patrol ship, etc.), then a number.

    But then I decided to change it to the actual Russian system for naming aircraft (my gun-naming is a modification of the Russian one), with a two-letter representation of the names of companies that are single words ("Ka-27", a helicopter from Kamov), before the number, and a three-letter one for companies with two-word names ("MiG-29", the fighter plane from Mikoyan-Gurevich). "KoE-382 mothership" has a nice ring.

    The number after the prefix is "years since 1945 that it was introduced", because they're Peacekeeper ships and the UN was founded in 1945. The aforementioned KoE-382 was introduced in 2327. (That's also where I get the numbers for the guns.)
  • Revising that classificatory scheme gave me an idea for the zledo: so now, instead of collating things by letter and number, they collate them by the periodic table. So, e.g, instead of "Variant C" or "Model 14", they say "Lithium Variant" or "Silicon Model". (Still think they add sub-versions numerically, but ordinally—"Oxygen Model, third variant" would be our "Model 8, version 3".)
  • I think that the idea of rugged individualism on the American frontier, which as I have pointed out has no reference to reality, may have been born of literary romanticism. No, I don't mean dime-novel Westerns, as much as those did distort the popular conception of the pioneer phenomenon.

    I mean the Transcendentalists, who, after all, were the big thing in American literary and intellectual life just before the pioneering enterprise really kicked into high gear. Sure, the fact is that nobody was really self-reliant out here, except some half-demented hermits; sure, the "pioneers" were people who jailed you for cussing and hanged you for stealing livestock. But the idea of getting away from society and its supposed corrupting influence, living a "self-reliant" life in a state of nature more unrealistically idealized than any two "Noble Savage" theorists, was a powerful influence on the popular conception of the frontier.

    Transcendentalism covers the period from about 1836 up into the 1870s or even 1880s, though it lost influence starting around 1850. That pretty much is the "frontier era". And they were huge; the American branch of Romanticism is almost inseparable from Transcendentalism.
  • Apparently it's hard to make lithium-air batteries rechargeable...and lithium reacts violently with water, kinda a big deal for robots that have to live in environments humans do. Not to worry, though, silicon-air batteries are, according to Wikipedia, more efficient, theoretically (they're just as hard to recharge but my thing's set in the 24th century, they've had time to work on it). The new number given for silicon-air (a new study, maybe?) is 14.23 kWh/kg; that lets a 74-kilo, 180-centimeter Kenshiro-clone that's 24% battery operate for 12 hours 38 minutes 10.46 seconds.

    I'm keeping the gel itself as a subcutaneous layer of polymer. It's subcutaneous not to supply all the body with power (most of the power is supplied by wiring), but to evenly distribute the "like a three-year-old" weight of the battery. It's also brightly colored (dyed), because it looks cool, but also because you want to be able to know when your robot has been punctured. I'd said it was polyvinyl, but that turns out to only mean PVC (polyvinyl chloride), and apparently the main polymers used in batteries are things like PAN (polyacrylonitrile). It has a number of properties to recommend it.

    They don't really need to cause the liquid PAN to solidify when exposed to air under conditions other than the oxidation of the silicon suspended in it—i.e. clotting, to keep them from bleeding to death—because my androids normally have a small amount of limited-lifespan nano-bot goo, for self-repair. In an emergency where the nano-bots weren't working fast enough, they could probably spray something on the wound to harden the "blood" around it.
  • My setting has something called "toothpaste", but it's actually mouthwash. Mouthwash with non-replicating nano-bots suspended in it, that activate when inside a mouth, and seek out and destroy plaque and germs. "Paste", you see, as distinct from "goo", is the term for non-replicating nano-bots.

    They also have programmable nano-bot hair-gel, because of course they do (it can also act as dye—dye that can be removed at a moment's notice). People wear shirts powered by their bioelectric fields that have slogans in light-emitting polymers; I think some people might wear programmable images and patterns on their clothes.

    Nobody has moving images on their shirts, though, because that would be freaking annoying. "I'm a walking animated Flash-ad"—that's not a sentence that would ever be spoken by a mouth with all its teeth.