2011/06/17

De Romanicorum Physicalium IV

Thoughts sur le SF. Bit of equipment, bit of exobiology, bit of stuff that falls out of trees. Please to enjoy.
  • My nitpick about the carrying capacity of the SR-71 led me to an interesting idea. So I looked at its specifications. Assuming its "loaded" weight to be just with fuel (I imagine that'd be the major factor), its mass ratio would be 152/67.5, or 2.25. Now, a magnetic confinement fusion rocket (according to Project Rho) has a minimum mass of 600 kg, while the Blackbird's engines each weigh 2700 kg.

    This means that, with the same size engine, and the same fuel mass (given the much lower density of fusion rocket propellant, I'd expect a much higher tank volume), you could move a vessel with the same mass as a Blackbird to 1% lightspeed, at which speed you can do 1 AU in 13h50m. Unfortunately you get up to that speed at 1/3 g—5400 kg worth of MC fusion rocket gives 450 kN thrust, and a fully-fueled Blackbird masses 152 Mg.

  • I was reading this book about xeno/exo/astro/etceterobiology, and I realized, a lot of these guys come at it from the wrong angle. So you think my aliens shouldn't breathe oxygen? Yeah fine, but then why would they be fighting humans? So you think they shouldn't use visible light? Again, if they come from a climate range close enough to earth for them and us to fight, odds are good visible is the most efficient part of the spectrum, that's why all the animals on earth that use something else use it as a backup, though I'll concede lots of aliens might also see UV, which birds, reptiles, and some bugs see, just like you can see red (which is freakish of you, by the way, I don't know if you know that). If they see in visible light, their eyes will be as much like yours as an octopus's are—except even more so, because odds are good they'd be a land animal and octopus's vision (which is sketchy even in water) goes right to hell in air.

    Which brings us to body shape: they're not, I apologize for breaking it to you, likely to have an octopus-like shape or texture. You can get away with lacking a skeleton underwater, but have you noticed nothing up here bigger than a banana slug doesn't have one? Ditto exoskeletons: they're inefficient above the size of very big bugs. So, hard endoskeletons. It's not a coincidence that land vertebrates are tetrapod, either; there may've been six-finned lobe-fin fishes but most fish are two finned. Evolution abhors extra complexity that doesn't have a payoff, and extra limbs don't have enough extra payoff. Unless some planet's six-finners have some other huge advantage, they're going to lose out to the four-finners who don't have to worry about literally having two left feet. Eyes for light, ears for vibrations, something for particulates and chemicals: all those organs will be as close to the brain as possible, to shave reaction times. Mouth quite likely as close to the sensory organs and brain as it can be, in order to snap things up the second they're spotted.

    Thus, an alien who's any use for an SF story is likely to have a hard endoskeleton; four limbs and a head; eyes, nose, mouth, and ears. Considering these are aliens humans encounter (i.e. they need their own spaceships), and the role toolmaking played in our own development, they're likely to need limbs free to manipulate things, so they're probably going to be bipeds. Now, within each of those categories there's huge possibility of variation—they may not necessarily use their front limbs to manipulate, though again proximity to the brain might be a factor—but you are not allowed to complain about aliens in an SF story, if they interact with humans in any way, being somewhat humanlike. Especially not if they're fighting with them: "It is the moment when men realize they are brothers," as Chesterton said, "that they immediately begin to fight."

  • Speaking of that Chesterton quote, I want to do a Twilight Zone-type story where someone invents a machine (maybe a gene therapy that modifies pheromones or something) to make people regard everyone else as brothers. And then, when they're shocked that people fight just as much as before (though perhaps less viciously), a friend of theirs says, "You were an only child, weren't you?"

    Well, that, and mankind would go extinct, because all sex would feel like incest, and we've proved—suck on that, Freud—that you're actually programmed not to be attracted to people you regard as kin. It's called the Westermarck effect.

  • I guess (based on a recent viewing of Terminator 2) that Skynet actually wiped out mankind because it was scared when they tried to shut it off. But seriously, wiping out an entire species is severe overkill, especially for an AI—if it doesn't have feelings it wouldn't have an impetus to overreact like that. Let's ignore the questions of how it just became sapient, and of who the Hell, Michigan was dumb enough to put it in charge of defense. Oh, well, unless it was people who were interested in cutting the defense budget: quick, Mr. Cameron, which party favors that again? You can't even write a good preachy anti-war movie, dipshit. Apparently we should've realized that long before Avatar.

    Speaking of, dude, what Scientologist wrote the scenes at that mental hospital? And what's with all the stupid "it's in your nature to destroy yourselves" nonsense? It's in our nature to destroy anything that looks at us sideways, I'll give you, but we're actually pretty good at saving our own miserable hides. You know how the Cold War didn't heat up? Yeah, that's 'cause at least a healthy plurality of us know how to avoid destroying themselves. Ditto Sarah's speech about how men don't know what it's like to create life, "feel it growing inside them", etc.: I'm guessing you brought Joss Whedon in to write that "womb-envy causes wars" bullshit? While womb-envy is definitely more plausible than penis-envy, "the guy who was best at making hunting gear was the best provider and thus had the most children, possibly with the most wives" is even more plausible, as an explanation for why male humans make shit, weapon or otherwise.

  • Which reminds me, remember in Sarah Connor Chronicles how John Henry was saying it's inefficient that humans don't have more ball and socket joints? Actually, that is not merely untrue, it is the opposite of the truth. Our system—one muscle on each side of each joint, to pull in only one direction—is more efficient, both in the simplicity of the muscle layout and in the arrangement of the nerves to control them.

    What's very funny is, know what really brought that to our attention? Robotics research. They started out saying "Screw the muscles in your arm, monkey, we're gonna have one actuator do both jobs." But that's much harder, more complicated, and often both less exact and more fragile. Switch to "one muscle for each direction", and...ah, poetry, like a haiku in its elegance and simplicity.

2 comments:

penny farthing said...

As someone who has studied anatomy, I can tell you, ball and socket joints are crazy complicated! You know how many muscles are involved in your shoulder? I learned it so I could draw better, and shoulders are even hard to draw. Knees, elbows, etc - easy peasy.

Sophia's Favorite said...

It's also weaker. Think how many curls you can do, and how big the weight can be: that's lifting with your bicep. Now, quick, how many reps can you do with your arm straight the whole time, swinging outward from the shoulder? Hinge joints are just stronger.