Comentario 4

Pensées aléatoires.

• Eliminating thoikh funerary cannibalism. Funerary cannibalism is actually an idea I find intriguing, and apparently the fact many human populations are resistant to kuru, which by rights would be called "mad human disease" suggests it was once a widespread practice. But the thoikh (all of whom are psychometers) cannot abide to be in the same room with Foucaultian transgressivists, so having them practice any kind of cannibalism weakens the theme. Also cannibalism is over-played (e.g. the Bosmer in Elder Scrolls, although how they can still join Namira's cannibal-cult when for them it's the worship of an Aedra is never explained), which is kinda a freaky little fact about our pop-culture.
  
  Had considered maybe having the thoikh have evolved as an apex predator (which, again, are the only things that can become sapient—which is not the same thing as saying all apex predators will become sapient), but then become herbivorous. There's a bear and a...mustelid, -ish, that did that. Because they're still Carnivora (capital-C is a particular order, not just "any meat-eating animal", T. rex is a carnivore but not a Carnivore), though, they can't digest cellulose well and pretty much spend all their time eating and sleeping, which is why the bears are too dumb to breed and the mustelid-ishes are so dopily adorable.
  
  Instead I'll have the thoikh have an African wild dog/Asian dhole type of social structure, where instead of having a dominance hierarchy they have a submission one—dominance isn't marked but submission is. That's not actually terribly unusual. On the flip-side some animals do it in reverse, cats for instance have absolutely no submission postures, a cat "submits" by ceasing to offer threat-postures. But I don't know of any gregarious animals with that behavior. (Incidentally, blind cats, who can otherwise survive okay due to their other senses being so good, tend to get the crap kicked out of them by other cats, because visual cues are very important in feline social interaction and a blind cat is the definition of "kûki yomenai" and "nunchi eopseumnida", literally in that second case, "nun" is Korean for "eye".)
• Been watching Almost Human with my dad. It's, what, six episodes in? And it hasn't once pissed me off. Me being me, I begin to wonder, "what are they planning to spring on us?"
  
  I kinda like how they have very Vangelis electronic pseudo-sax, and people walking around with neon-lit umbrellas. I mean hell, they were ripping off Blade Runner either way, they might as well do it with some freaking style.
  
  I'm a call this thing right now, though, the captain is the real villain of the piece. She told Kennex he's special. Nobody but a villain tells your protagonist he's special unless he's obviously an alien or some such thing.
• I haven't talked about it here (now it's ending), but I liked this anime season. "Kyôkai no Kanata"/"Beyond the Boundary" takes a little getting into, but your time is well rewarded. I like the siscon dude's sister, like when she replaced everything on her brother's iPod with yaoi drama-CDs after he signed her up for not-AKB48-at-all auditions without her permission. "Yûsha ni Narenakatta Ore wa Shibushibu Shûshoku wo Ketsui Shimashita"/"Unable to Become a Hero I Reluctantly Got a Job"/Yûshibu for short is also good, although its fanservice is inelegant and its girls' figure-drawing needs work. I just love the whole "trained to become a hero, now works in retail because he has a degree he can't use" aspect. Also the magic runes that look like circuit diagrams.
  
  Probably the best series out this season was "Ore no Nônai Sentakushi ga, Gakuen Love Comedy wo Zenryoku de Jama Shiteiru"/"My Mental Would-You-Rather is Really Interfering with My School Love Comedy"/Nôcome for short. I enjoy a good severely messed up raunchy comedy, and this one probably had a higher rate of laughs than Baka Test (although Baka Test was stronger in other areas). The girl with the short silver hair is a new type, which I shall presume to name the "hendere".
• Occasioned by something else similar, but there are people who complain when, e.g. during a D&D game, you describe something by reference to something modern/this-worldly. "My character wouldn't know what a freight-train is," they say, after you've compared some monster to one.
  
  The only response is, "Yeah dude, but your character also doesn't need the thing described to him, he's there seeing it. Now are you gonna kibbitz my attempt to convey the wholly imaginary to your mind, or can I get back to that attempt?" Objectively, things are like the things that they are like; a person who had never encountered either before would, once acquainted with them, know their likeness.
• Got a fairly recent translation of The Tengu's Discourse on the Martial Arts, the one sold as "Demon's Sermon on etc." (a tengu is only a demon in the original Greek sense, "crow-fairy" would be a better description). It's interesting, basically a collection of fables illustrating a certain number of related points, but one sorta wonders if there has been some mistake, when even the translator refers to the themes the stories illustrate as being "Zen". To my knowledge, Zen, while it may be an odd combination of Pelagian and quietist, is still a type of Buddhism. Yet each of these stories is about not sweating reincarnation and the cycle of rebirth, because the life of everything is just as its karma dictates it should be. "Everything is properly born to the station its karma dictates, and must fulfill the law proper to its station" is not any kind of Buddhism I know of, since it happens to be Hinduism; "did away with the caste system" is something even Americans know about Buddha!
  
  I'm guessing that the actual worldview informing the essays was not Buddhist, Zen or otherwise, but Neo-Confucian. Japanese Neo-Confucianism never persecuted Buddhism, and was almost as likely to quote Buddhist writings as Confucian ones. Part of that, though, was that Japanese Buddhism had already been partly tamed by Kûkai's identification of Amaterasu-Omikami with Mahavairocana Tathagata. To a degree, of course, the main form of Japanese Buddhism avoided being quite that deracinated (most of the Japanese populace has always been Pure Land, which is fortunately as devoted to "What is necessary to be saved?" as any altar-call Evangelicalism), but Kûkai's interpretatio japonensis filtered to other Buddhist sects from his own Shingon. While Pure Land Buddhists are still primarily concerned with soteriology rather than theology, Japanese Pure Land practitioners still thought of Shinto and Buddhism as the same religion (until the actual laws against it, at the Meiji Restoration). Nobody else in Asia ever did that; while everyone in China and Korea who worships the native pantheon will say "Buddhist" when asked what religion he is (because that defines his conception of the cosmos and his place in it), they don't identify Guan Yǔ or the Dokkaebi-daegam as Buddhist figures.
• The Japanese word "shumi" ordinarily means "hobby", but it's also the polite term for "fetish" (I actually get the logic there—fetish-subcultures are made up, if you think about it, of somewhat alarming hobbyists). It sometimes makes people in anime seem crazy, though. For instance, in Fullmetal Alchemist, at some point someone (Sergeant Brosch and Lieutenant Ross?) ask why Al's always wearing armor. Since he can't very well say "We tried to bring our mother back to life in violation of the strongest taboo of alchemy—also the laws of our militaristic police-state—and the armor is actually his body now", Ed says, "It's kinda his hobby." And the others react as if that was deeply disturbing, which doubtless struck most of the American audience as quite an overreaction. But remember: they might interpret it as "It's kinda his fetish." Their reaction is actually quite mild if you interpret it as "Sweet kindly Alphonse with the little-boy voice that belies his huge frame, is also a twisted gimp who goes everywhere in full-body fetish gear."
• I think a lot more aspects of the human condition are explicable by reference to ethology than most analysis seems to think, and without recourse to silly outré Just-So stories. Ownership is territoriality, (romantic) love is the creation of pair-bond, reverence is dominance behavior. Of course, all those things are colored by the fact humans are the only animal that knows it or anything else exists, and that can actually abstract concepts—being an animal, though, humans apply territoriality and dominance behavior to their concepts, exactly as if they were physical places and creatures. Also only humans, in the whole of Earth's biosphere, have a thing called "society", where unrelated conspecifics negotiate their territorial disputes rather than fighting over them.
  
  That is, on the other hand, one of the dirty little secrets of animal behavior—everything we and animals share is transformed by our peculiar ability to abstract and conceptualize, and most of the things put forth as evidence we differ from animals only by degree is, on examination, only very qualifiedly evidence at all (when it's not just outright fake). The linguistic abilities of apes, for example, are generally grossly exaggerated, and often are more a combination of wishful thinking (and innocent pareidolia) with their trainers' insight (insight which anyone gains from interacting with any animal, whether it's been taught sign language or not). Even the most promising of bonobo language experiments have yet to demonstrate sentences more complex than "subject object location"—being very generous with our interpretation of particular juxtapositions of uninflectable symbols—and not even the faintest glimmering of abstract conceptualization has ever been even hinted at.

Sierra Foxtrot 5

エスエフの思考、五話。 I don't know what you count blog-posts with, but "話" is used for TV episodes and volumes in a book series.

• I happened to see a National Geographic article about the speed of human expansion. From Ethiopia (origin of H. sapiens) to Tierra del Fuego (last place settled by prehistoric man), is 21,000 miles. It took 60,000 years for us to get there. Do you happen to know how many stars we can realistically reach, with one of the several interstellar rockets proposed in the 60s and 70s, in 60,000 years? Here's a hint: Assuming hydrogen-bomb powered Orion rockets, which we could build tomorrow if we had to, you can do 4-5% of the speed of light (if you're into stopping at the end). In 60,000 years, that's 2700 light-years of travel.
  
  Interestingly, a lot of things about interstellar colonization seem like they'd put civilization back on a Neolithic footing—an interstellar civilization, if possible at all, would not be like even a Bronze Age civilization, let alone an Iron Age or later one. Remember how I compared them to water-monopoly empires? That's something you get in the Neolithic and Chalcolithic (which includes the earliest stages of Egypt and Sumer); people like to claim China is one but that's not really defensible if one analyzes the details of Chinese history.
  
  That sounds terrible, until you remember how many other science-fiction themes are basically trying to put things back on Paleolithic terms, and not Upper Paleolithic, either. Gender feminism and transhumanism are, both of them, attempts to undo Behavioral Modernity, the former by dispensing with sex-role specialization and the latter by modifying the body instead of just making tools.
• Saw Pacific Rim. It's not bad, but man is it dumb. Just one way, that I think other people have pointed out: no way no how is the Gypsy Danger "analog", it's precisely as conventionally computerized—ipso facto "digital—as any of the others. And it being nuclear and it being "analog" are in no way related. What they could and should have said is that, being nuclear, it has lots and lots of shielding on all its electronics that the non-nuclear ones don't.
  
  Of course, the other issue is, why on earth would you hook people's brains up to your giant robots? You can just have them wear mo-cap suits if you're married to the idea of having the mecha ape their motions—like the pilots in G Gundam and Pricilla in GunXSword—and have them train to synchronize, if you're also married (bigamously?) to the idea of having one to control each half. We know exactly how to train mecha pilots to synch, see episode 9 of Evangelion. You probably have to come up with another justification for two pilots, although I can think of a whole bunch of perfectly plausible reasons to need two pilots in any vehicle. (Also, one word: "Gattai.")
  
  And really, the only reason you'd hook the things to people's brains is if you wanted to significantly increase the likelihood of losing two pilots, instead of just one, when things go wrong (see also "you'd only design a ship like the one in Alien if you knew a monster would be crawling around it at some point").
• Do people realize that saying risibly false things about global warming's risks only undercuts the credibility of the policies they favor? You get it a lot in science fiction stories, with the whole world or significant portions of it flooded (Water World being the extreme case). The simple response to that is, "Only if the Earth gets hit by a whole lot of solid-ice meteorites." The other scenarios are equally millenarian (which in practice means "apocalyptic for the sake of being apocalyptic, without reference to facts").
  
  Leaving all questions about anthropogenic global warming to one side, it cannot actually threaten the lives of a large portion of humanity. Newsflash, even if the ice-caps melted completely (which they won't, there are no models of climate change that predict complete ice-cap melt), the planet remains thoroughly livable; its coastlines barely even change. We, uh, do actually know how much water is contained in the ice-caps, and how much that amount of water would change sea-levels.
  
  One thing that I do not think people understand is that we haven't always had ice-caps. Antarctica was in roughly the same place it is now, in the Cretaceous and Paleocene, but it had no ice-cap (there wasn't one at the north pole, either). Animals with the same physiological needs as modern ones lived in both regions. And hey, if you're so scared of global overpopulation (which is far less likely than any form of climate change—including the one depicted here), "10.6% more of the planet's land surface is now habitable" seems like something you should want!
• Similarly, nuclear winter can't happen. It requires that dozens of things about the particular dust at the point of impact and the particular way the particular bomb's particular blast hits it, all simultaneously be in their absolute pessimal condition. It is an absolutely textbook spherical cow, and people cite it like it's "Storey's Guide to Raising Beef Cattle".
  
  Carl Sagan made up nuclear winter because he didn't like Mutually Assured Destruction, and wanted to hide behind clericalism and authority because he was incapable of ethical reasoning ("it's wrong to take each other's civilian populace hostage even if it prevents a shooting-war"—how freaking hard was that?).
  
  And, seriously, "clericalism". Sagan's conception and portrayal of science is pretty much dedicated to denying any human failings on the part of an elite class that wears white robes. The narrative he peddles isn't even run-of-the-mill Catholic or Jewish clericalism, though, it's full-blown Calvinist or Cathar clericalism, with scientists as the Perfect members of the Spiritual Elect.
• RE: "animals with the same physiological needs as modern ones", another thing that irked me about Pacific Rim is that the dinosaurs are said to have been a test-run of the Kaiju. Uh...please explain how the creatures with the blue acid-blood are served at KFC and nobody noticed?
  
  Of course then again, they repeat the "dinosaurs with two brains" thing nobody has believed for at least twenty-seven years, so maybe we should just assume they're going by children's books about dinosaurs published while we were still doing moon landings. (Also, the flying kaiju would've been much scarier if it'd been built like an azhdarchid rather than a vampire bat, but that, too would require some actual knowledge on the part of filmmakers.)
• I saw "Impostor", or rather about the first fifteen minutes of it, and then I had to turn it off. It lost me with its "Oppenheimer saw nuclear weapons were evil and was branded a Communist sympathizer". Two things. One, Oppenheimer has been proved to be a Stalinist agent (he was also a sexual predator and attempted to poison at least one person that annoyed him). When one of the guys at General Atomics was trying to start an international coalition of scientists who refused to work on nuclear weapons, he expected Oppenheimer's help, because of Oppenheimer's much-publicized remarks about nuclear disarmament. Oppenheimer begged him not to start the group...probably because an international group might include Soviet scientists.
  
  But two, and much more important, why would a guy in a dystopian police-state bring that up while looking out at the bomb he's building? Aside from the fact you're beating your audience over the head with your symbolism, the war is different—the Soviets were not regularly air-raiding US cities, the Centauri were doing that to Earth. Also, if the state in your setting is so all-fired evil, they don't have to elaborately frame the dude. They can just liquidate him without a trial, or with proceedings that aren't so much a trial as an expression of contempt for the concept. And they will, the second he starts comparing the weapon he's working on (for the regime) to other weapons in history whose designers "realized" the "madness" of their weapons. The fact you think a state needs to frame people is what separates us from the Soviets, it's kinda ironic that you undercut your moral-equivalency allegory with your moral-equivalency allegory.
• One thing I've recently been getting into (all that fooling around with batteries led me to some interesting places) is non-nuclear explosives. Like, say, if you need a bomb-plot in a science fiction book? A hypothetical one that's 5.47 times as strong as TNT is "octaazacubane", although really we should just call it "metastable nitrogen", because that's what it is (metastable anything is weirdsville, and often a pretty dangerous part of town, too).
  
  Then, not so hypothetically, there's RDX, also known as cyclonite and hexogen (I like "hexogen"). It's 1.6 times as explosive as TNT, and we've been using it in military applications since World War II. There's also HMX, AKA octogen (the main reason I like "hexogen" for RDX), which is 1.7 times as explosive as TNT, and yet can be disguised by mixing it with flour—and you can even cook it and eat it, it's not toxic. It was also used in World War II, we supplied Chinese guerrillas with it disguised as flour, under the codename "Aunt Jemima".
  
  If "only 2/3 more powerful than TNT" doesn't cut it for you, how about hexanitrobenzene? It's 1.8 times as powerful as TNT. DDF ("4,4'-Dinitro-3,3'-diazenofuroxan"—your guess is as good as mine how to pronounce those numbers) is 1.95 times as powerful as TNT; something called MEDINA (methylene dinitroamine) is apparently 1.93, but it apparently doesn't keep very well. And then there's always octanitrocubane. A cube of carbon with an NO₂ at each corner, it's 2.38 times as explosive as TNT. It's also currently so difficult to make that it's more expensive than gold, but in a science-fiction setting it would presumably be easier and therefore cheaper (same goes for metastable nitrogen).
• Did some calculating, to have realistic numbers for the zledo. Apparently the portion of a cat's mass that's muscle is 59-63% (i.e. the average is 61%). It doesn't vary by sex; cat dimorphism is mostly just a matter of brute size, not proportions. The portion of a human that's muscle is, on average, 42% for males and 36% for females. I decided to go with (36/42*61=)52% for zled females, since they do have different builds between their sexes.
  
  What this means is that an average human male (mass 70 kilos) has 29.4 kilos of muscle. A zled male the same size as him (who would look a lot smaller, because their proportions are different—when I say "humanoid", I mean "four-limbed biped with a head") would mass 104 kilos. In both cases, 40.6 kilos is the amount of the body that's not muscle, it's just that it's 58% of a human's mass and 39% of the zled's.
  
  What that means in terms of mass is, assuming similar proportions for the individual muscles, a zled's muscles are ((61/42)^1/3—also as it turns out (52/36)^1/3) c. 13% thicker than a human's. That results in 27% greater cross-sectional area, which is the main determinant of strength (assuming identical performance in their muscle tissue). They come from a planet with 8% higher gravity than Earth, though, so their muscle tissue is actually slightly better, performance-wise—but that's a good baseline.

Auxiliary Power

More power-source thoughts.

• That last post, and a Facebook discussion on a thorium-powered steam-driven car (which actually heats its steam by pumping a laser with the radiation from a heat-boosted thorium sample), gave me occasion to look around radioisotope thermoelectric generators (RTGs).
  
  I'm not sure where, if at all, my humans will use RTGs; their rockets are designs whose main problem is what to do with all that extra energy, and you'd have to be nuts to put most RTGs on a ground- or air-vehicle. Then again I don't really go into teeny-weeny space station outposts (all the space-stations I mention are colonies along the lines of "O'Neill Island" designs), maybe some of the smaller ones use RTGs. I imagine the big colonies use some mix of solar and fusion, maybe some fission (presumably thorium-fueled).
• Another thing I realized is that zledo would probably have made much more use of strontium-90 in their RTGs (back when they still used 'em), since the main danger of strontium-90 exposure (if you don't physically crack open the containment capsule in an RTG with your hands, or aren't nearby when the capsule is opened by an accident) is that it gets into the soil, where it is incorporated into plants and water, where you can eat or drink it—and then your metabolism incorporates it into your bones. Their bones are made of a type of biogenic silica, so they don't have to worry about that.
  
  Of course, they probably have to worry more about tin-126 (since it's in the same line as silicon on the table), albeit chiefly as a nuclear-fallout component, since it doesn't really form in ordinary fission power-plants, and they never used nukes on planetary surfaces. They did use them in space, both for weaponry and to ignite Orion rockets—actually, I'm considering making them have used Orion rockets from planetary surfaces, since you can do that relatively safely by putting an even bigger armor plate under the rocket, and coating both armor plates in a thick layer of graphite. (The one flaw with that link, by the way, is it says we're "more than prepared" to use nuclear bunker-busters, when in actual fact absolutely nobody seriously considers doing that.)
• One other thing? I think I'm going to have zled equipment powered by regular mainsprings, rather than "dilaton alternators" or Planck-scale mainsprings. Cool as the dilaton alternator is—it gets around the relative inefficiency of gravity as a power-source (consider how much water has to move through typical hydroelectric plants) by going down to the scale where gravity's force is much greater, before it leaks into other parts of space-time geometry—I'm doubtful as to whether it would be very portable ("giant lab apparatus", etc.).
  
  The mainspring of a windup-radio provides 4 watts for 25 minutes, which translates to 1 and 2/3 W/h...which is six kilojoules, meaning (the power of a spring is proportional to the change of its length i.e. to the tightness of its winding) a just slightly longer or more tightly-wound spring is enough for four shots of 1.6 kJ laser. A little research into windup phonographs reveals they often had multiple springs in their motors, so maybe zled lasers just use regular, non-nano-material springs, with, say, four extra springs in the hand-laser and a big ol' stack of, say, twelve in the long one (reducing the number of shots per magazine—or "barrel" as the housing of a mainspring is actually known—from 18 to 16 and from 50 to 48). Don't know if they're gonna call 'em "barrels" when they're being used to power what is basically a gun, that's just likely to cause confusion.

Not Included

Material culture thoughts, chiefly as it turns out concerning power-supplies.

• Someone might (you see it happen often) take exception to me saying that things like anti-gravity might be used in buses and airships, after I explicitly compared that kind of ultra-tech to nuclear fission. We'll leave nuclear-powered spacecraft, which have already been fielded, to one side, not least because the Soviets were less than meticulous in their disposal of the scary pieces. But the thing is, fission is a special case; we need weird radioactive substances to pull it off and it's easy for the reactions to get away from you. That's not the case for, e.g., fusion, which simply stops happening when you stop making it happen (which is why we can't use it for power yet), although other issues with fusion probably require a certain minimum facility size. It probably wouldn't be the case for most things involving the Casimir effect. (Antimatter, on the other hand...)
  
  I was thinking that all those hand-held ultratech devices in our fiction would probably strike a future society much like the Ford Nucleon strikes us, but then it occurred to me that a lot of science fiction still seems not to understand that fusion is incredibly dangerous—just because it doesn't go critical or require uranium doesn't mean it's not a nuclear reaction that involves loads of lethal radiation and megakelvin temperatures. It's extremely doubtful fusion can ever be produced, as a power-source, in anything much smaller than a fairly good-size fission facility. Fusion power-plants almost certainly require lots of room and lots of sheer brute mass, between the fact fusion produces temperatures beyond any process that ordinarily happens on a planet, and the radiation, both EM and particle. (Even if aneutronic fusion were remotely feasible right now, and it's orders of magnitude less so than many things we still don't actually know how to do—even helium-3 isn't wholly aneutronic unless you fuse it to itself instead of deuterium—you'd still need huge facilities to magnetically contain the protons).
• The space-requirements of fusion, of course, means that the planes and buses (and mecha) in my books use some kind of battery. I've reexamined AMTECs (alkali-metal thermo-electric converters), and decided that their energy-density (2-3 kW·h/kg) isn't really that great. Think I'll go with silicon-air batteries, since they're almost as energy-dense as lithium-air (8.47 kW·h/kg for Si-air vs. 12 kW·h/kg for lithium-air) and yet made of the eighth most common element in the universe (second-most in the Earth's crust), rather than an element rarer than platinum, palladium, neodymium, and cerium. Those are theoretical energy densities, mind, not the ones we're gonna actually get for the foreseeable future, but it's set in the 24th freaking century, so I figure I can get away with that.
  
  An electric motor is three to four times more efficient at driving a propeller than an internal combustion one. If we assume an average improvement (3.5 times as efficient), then to propel, say, an Ilyushin Il-18 transport plane, which has four Ivchenko AI-20M internal-combustion turboprops with a power of 3,170 kW each, would require only (12,680/3.5=)3,623 kW. If we assume the same mass of batteries as the Il-18 carries fuel (30,000 liters, which has a mass of 23,850 kg given the density of jet fuel), then the battery provides (8.47*23,850/3,623=)56 hours of operation, which is plenty respectable. Dividing its listed max range by its cruising speed gives 10.4 hours, for which you'd only need 4,448.5 kg battery.
  
  An electric motor is 2.5 times as efficient as an internal combustion engine in powering a car—again, electric motors spin, and what does a drive-train do? To propel a Prévost X3-45 bus (the kind used by both the current and previous US Presidents, as well as by bus-lines like Greyhound), which has a 324 kW Volvo D13 engine, you need (324/2.5=)129.6 kW. If we assume the same mass of battery as it currently carries fuel (787 liters, which masses 582.4 kg given the density of gasoline), the bus gets 38 hours of operation. Dividing its tank by its fuel economy (1.58153 km/l) gives a range of 497.6, which takes 6.63 hours at highway speeds. To power the bus for that time with batteries takes only 101.4 kg of battery.
• While we're at it, an M1 Abrams tank has a power-plant of 1100 kW, which an electric motor could replace with 440 kW; at 1406 kg of battery, the mass of its 1900 liters of gas, it gets 27 straight hours of operation. Dividing its range by its top speed gives 6.36 hours operation; the silicon-air batteries to power that are only 330.4 kg.
  
  A, say, Honda Accord, has a 138 kW engine (=55.2 kW electric), and carries 65.1 liters of gas, which masses 48.2 kg. Carrying a comparable mass of Si-air battery means it gets (8.47*48.2/55.2=)7.4 hours of operation, which translates to over 550 miles range at highway speeds. Dividing its tank by its fuel economy of 14.88 km/l gives 4.375 hours activity, which can be powered by 28.5 kg of battery.
• Of course, a mecha is not a car. Let's take the example of, say, TOPIO, the Vietnamese ping-pong playing robot, since ASIMO is a poor model for military hardware. TOPIO uses a 48-volt, 20 ampere-hour battery, which is probably derived from an electric scooter battery. All the scooters I can find with that battery have 15 horsepower engines, so we can assume that it's got an effective 11.2 kW power plant. If we scale the 188 cm, 120 kg TOPIO 3.0 up to 10 meters tall, we get a weight of 18.1 megagrams, which presumably needs 1,686 kW to power it. If it carries as much battery as the similarly sized (17.7 megagram) M18 Wildcat anti-tank armored gun carried gas (624.6 liters, massing 462.2 kg), we get...2.3 hours of continuous operation.
  
  Whoa, I guess they weren't kidding when they said a bipedal design is power-intensive! Hang on, though, y'all, I got this. I never put a ring on silicon-air batteries' finger, we maybe can go with something else. Lithium-air gives us (12*462.2/1,686=)3.3 hours. Maybe do the whole "the mecha never go far from some other form of transport" thing? ...Come to think of it, Asimo's battery is a whopping 1/8 its mass; just stick 2,262.5 kg of lithium-air battery on the thing, that gives us 16.1 hours. We can go half that to get 8 hours operation, which is all anyone expects of a tank, as the Abrams demonstrates, above. Plus, 1,131(.25) is only 3.07 times the weight of the Tesla Roadster's battery, and the Roadster only masses 1,235 kg.
• Androids, I think, might have to use something a little weirder, since if they use a battery the size of ASIMO's (7.7 kg), then, even if it's lithium-air, they'll only get eight and a quarter hours off the charge. Then again 22.4 kg, the amount of lithium-air battery you need to get a day's activity, isn't unworkably heavy. It's basically slightly more than the mass of an average human's torso, but androids don't have organs or need to make sure that tubes running through their body (one of which opens at both ends) aren't interrupted.
  
  Maybe they'll store the power supply in structures more like those sticker-batteries, but presumably thicker, all over their bodies, under the skin—since we're just now beginning to work with lithium-air batteries, it's possible we'll have figured out how to make them work like that in the mid-2300s. The reason I suggest they'd have a "battery" layer is that, well, humans store our energy like that—it's called fat. If we assume an android with an overall mass of 120 kg, like TOPIO 3.0, 22.4 kg is only 18 and 2/3 percent its body mass, which is right between the male and female recommended body-fat percentages of humans. Maybe some lighter-duty models only mass 60 kg and have enough battery for 12 hours (or only need half as much power since they're moving half the mass).
  
  ...Holy shit. So a little further reading reveals some lithium-air batteries aren't solid, but use gel-polymers based on, basically, polyvinyl, both to separate their cathode from their anode and as an ion-transport medium. And the way metal-air batteries work is they need to be oxidized. My androids need to breathe! Even better, when they get injured? I have something for them to bleed that's not only more directly important than coolant (or hydraulic fluid, which I hadn't used but had considered), it pretty much actually is blood!
• Finally, I think I mentioned that mecha weapons carry their own power-sources. The rail-rifle I conceived of, that operates like a tank gun, would propel a projectile much like a modern KE-penetrator. Assuming tungsten carbide (in a ferromagnetic discarding sabot), and comparable dimensions to modern penetrators (an average of 2.5 cm diameter, an average of 55 cm long—volume of c. 270 cm³), it would have a mass of 4.22 kg. With a muzzle velocity of 2,000 m/s (very modest), each shot takes 8.44 MJ. That's the equivalent of 2.34 kW·h; a single-kilogram lithium-air battery gives sufficient energy for five shots (tanks usually carry around 40 rounds, which is the equivalent of 8 kg of Li-air battery). A total mass of c. 300 kg, counting the magazine and its battery, seems reasonable—and puts the rail-rifle more in the size-range of an anti-tank cannon like the 25 mm Hotchkiss Mle. 1934 than a tank gun. Except its bullets are twice as long as a typical anti-tank cannon's.
• All those people who think robot, or, God forbid, cyborg arms could have whatever number of times greater strength nanowires offer over muscle? Uh...what's powering that?
  
  If they're moving hundreds of times as much mass as a human can, or a humanlike mass hundreds of times faster, they're going to be using hundreds of times that much energy, and as I've just demonstrated, it takes the whole weight of an average human's torso to power a robot of normal strength for just one day, with the theoretical optimum of a currently-experimental battery.
  
  Also, of course, good luck finding materials to make those robots out of. A robot that has to be made of materials as costly as wholly-hypothetical orbital insertion structures like space elevators just to resist the strength of its own muscles...doesn't sound like a good idea to me, how 'bout you?
• If you think about it, the scale of outer space essentially (lacking FTL) puts space-expansion on the same time-frame that humanity's original expansion over this planet was. It took myriads of years for humanity to leave Africa; it took several more for them to leave Eurasia. The great civilizations of the New World, in the Renaissance, seem to have been roughly comparable to where Europe was 13-20 millennia ago—because it took them that long just to get over there. The Maya, whose last major center fell into decline in the 1200s AD, were not measurably superior to the Epi-Olmec (neither had anything over the Olmec but writing), and the Olmec began in the 1500s BC—much as many Neolithic Old World sites were inhabited by recognizably continuous material cultures for thousands of years, compared to the rapid upheavals of the Bronze and Iron Ages.
  
  We think of space-travel as slow only because it is only possible to people whose material culture has given them the ability to circumnavigate the globe in a bit under a day and a half. But what if you could give Neolithic people interstellar rockets? Would they think of reaching Alpha Centauri in forty years with Project Longshot (which I think would have an average speed of 12% lightspeed) as very long? How long did it take to settle Polynesia, or the Valley of Mexico? Two generations to reach a new place is pretty typical, actually, in prehistory. Admittedly that's mostly because foragers and pastoralists (not to speak of subsistence farmers) have to travel much slower than the actual top speed of humans on foot, but the point is that "we arrive in a new place and set up our new center generations after we left our old one" is not, taking the broad view, actually some new phenomenon for the human race.