(Insert Quote Tying Together Material Culture and Exobiology Here)

What? I can't always come up with clever titles. I had some more thoughts on SF equipment and alien biology.

• Remember the "tweel" thing? Turns out, there's a much better idea, the non-pneumatic tire. Basically it uses a rubber honeycomb instead of a pneumatic tube to absorb shocks. They're already designing them for Humvees.
  
  And they look goldern awesome:Here's what they look like when they squish down:What's neat is they're a lot more resilient than pneumatic tires, but you could obviously still walk over and slash the honeycomb section out of some poor bastard's tires. That's important in my line of work, for drama and whatnot.
• I realized, my felinoids' feet (with the two ankle-bones that cross each other so they can flip their feet) are basically very short human forearms at the end of their legs, and they walk on thumbless hands. That is disturbing as all hell, but it also activates the gee-whiz center of the SFionist brain. On a related note, I think it's the norm on their planet not to have a fibula. Birds and frogs do just fine without them (theirs are fused with their tibia—their calf bones often still have two separate cores, though).
  
  I'm trying to figure out how their ribcage, and presumably ribcages in general on their planet, should be different. One idea I had is that it could be a little like a second skull, with a "heartcase" that parallels the braincase; I imagine a felinoid would have one a bit like a snake's skull—with lots of flexible parts—while the giant Cape hunting dogs (with leg anatomy and running gait more like a horse) that they domesticate as mounts would probably have a more standard rigid "skull" in their chests. Gotta think about it a bit more, though.
• Their cars that don't have wheels anymore, but have the undulating snake-belly nanomaterial? So I decided they basically have them on runners, like on a sled, and the engine consists of the system that makes the runners' surfaces, uh, slither(?).
  
  What's cool is, their tanks would be a hell of a lot less vulnerable—treads are relatively a weakpoint on tanks—and without having to have them levitate like Wraiths do. It always just bugs me, floating vehicles: any advantages would be far outweighed by the power requirements (as in, even something the size of a big motorcylce has to carry a powerplant that makes an amp feedback noise and 'splodes).
• On the other hand, you know my perpetual impatience with the puerile cries of "where's my jetpack?" Forget about that one I mentioned before, there's an even better answer: "It's in the movie 'Agent Cody Banks', with the kid from Malcolm in the Middle."
  
  In that, apparently (dude, you think I've seen it?), there's a scene with the SoloTrek XFV, which is a personal VTOL aircraft. According to Wikipedia, you can't call it a jetpack if the pilot's strapped to an exoskeleton that bears the thing's weight, but I don't believe I ever agreed to define the terminology that way. Also, the damn thing actually uses jet engines; the things you Zinjanthropi are always harping about are actually rocket packs. Yes I'm splitting hairs, you would too if you were this sharp (I just came up with that line, you can use it too if you like it).
  
  The XFV was apparently a bit dangerous (it disintegrated in an accident, though the pilot was all right). But its successor the Springtail Exoskeleton Flying Vehicle, is probably a bit safer than a parachute. And remember, this was a DARPA project: XFVs (always use an X in an acronym instead of an E if the word starts with "ex" or "extra", gentlemen) might well replace chutes in several military applications at some future date.
• Another idea I had on the alien ribcage front, probably for another species, is to use what's called longerons between the ribs, to hold the thing together. Longerons (stiffeners, stringers) go perpendicular to the 'ribs' in a plane, and hold it rigid...something, it occurred to me, like those struts that come off the sides of a bird's ribs (birds have really rigid ribcages).
  
  And yet another idea, possibly for the felinoids, was a geodesic frame like they'd sometimes use in airplanes, or maybe some sort of tension or tensegrity frame like in freaky-looking skyscrapers—maybe have a light geodesic frame for structural support and muscle anchoring, and have outer (subcutaneous?) hardened sections take over the ribs' protective function. I just can't decide!
  
  By the bye, a shark's body is basically a tensegrity frame, did you know? They don't have much in the way of a ribcage; instead, their abdominal muscles are connected right to their skin, and those tooth-scales they have hold the whole thing tense. You'd need bony elements in a land animal (sharks on land get crushed under their own weight), but you could definitely have some sort of tendon-ligament tensegrity system.
• Huh, how have I failed to mention T[erahertz] rays up till now? A terahertz ray is EM radiation whose frequency is between microwaves and infrared. They pass through a bunch of things, but they're much lower-energy than x-rays: they're especially good for dentistry, weapon detectors, and seeing into buildings.
  
  Speaking of, did you know thermal imaging won't actually penetrate buildings? Yeah. But T rays will; they can pass through wood, masonry, plastic, and ceramic (metal and water stop them, though).
• If you are not an electrical engineer...actually, quite possibly even if you are...let me amend that. If you are not well-versed in the theoretical underpinnings of electricity (lots of engineers are of the "I don't care how it works, just that it does" school), you may well have asked, as I once did, "What's the difference between a capacitor and a battery?"
  
  Well. Apparently, a capacitor stores charge electrostatically, and a battery stores it electrochemically. A battery causes chemical changes (the example I saw is sulfuric acid and lead in car batteries changing to lead sulphate, and back again), while a capacitor just shuffles electrons around between two poles with an insulator between them. Also, capacitors charge faster and don't wear out until they physically fall apart, while batteries charge slow and eventually succumb to the cold hand of Second Law. On the other hand capacitors' voltage drops as their charge drops (apparently with the square, since apparently 1/2 charge=1/4 voltage), and normal capacitors can't store anywhere near as much charge.