Imagine that you and a companion are out for an evening stroll after a big dinner, say in a park somewhere. You hear a curious whining sound and look up to see an alien spaceship on a landing approach to the park. The craft lands and the crew scuttles off to perform some tedious abduction or organ harvest in the neighborhood.
Your companion exclaims “Golly! There is something you don’t see every day!”. But you’re unmoved by your companions incisive commentary. Because you see this as a long sought opportunity to examine an alien craft up close.
What would you look at? The propulsion system? Or perhaps the weapons array or guidance system? Pffft.
I would look at something much more mundane. I think it would be very enlightening to see what kind of fasteners they use. That’s right. Fasteners. Nuts, bolts, latches, bungees, straps, nails, hinges, hooks & loops, and rivets. How do these confounded exo-buggers hold things together? What’s the deal?
Fasteners are mechanical contrivances used to restrain objects into a desired configuration, often by the application and fixing of tension or compression through some structural element. Think of all of the fasteners we encounter before we set foot out the door every morning.
Elastic articles of clothing perform a fastening function through the application of tension about numerous body parts through the miracle of Spandex/Lycra. Shoe laces are fastening devices that apply and hold tension on opposing shoe upper elements wrapped over the arch of the foot.
Moving upwards, the zipper is a fastener that works in concert with a trouser/skirt button or snap fastener. The belt and buckle are a fastener ensemble that together apply and hold tension about the circumference of the waist to keep ones trousers from succumbing to the pull of gravity.
Other fasteners include shirt buttons, brassiere connectors (damn those things!), earring wires, eyeglass frames (they connect to your face), cell phone belt attachments, the deadbolt on the front door, all manner of electrical connectors, and the list goes on and on. Electrical connectors are especially interesting because they combine the functions of electrical continuity and fastener. All are a compromise between the competing interests of biomechanics, convenience, safety, regulatory standards, and custom.
So, back to the space ship. How would space faring beings approach the problem of fastening materials and components. Would they use individual components fastened together or would they use integrated component assemblies that support multiple functions? Perhaps the mechanical fastener question is moot because components would be cast, glued, or welded.
Integrated components have a certain appeal, but, by their integrated nature could serve as a node from which to initiate failure propagation to multiple systems. For instance, if a battery was built to serve as a structural element for the craft, could a battery failure of some sort serve to initiate a structural failure mode? At what point is it foolish to integrate systems rather than leave them distributed? As always, it depends.
I think an alien spacecraft would have at least a few kinds of obvious fasteners. Surely alien technologies are subject to component failures and would require occasional repair. Of interest would be the concessions to alien biomechanics.
Humans occasionally use wingnuts to fasten objects that need not be permanently affixed. The wingnut is simply a style of threaded nut that has two modest protuberances that allow for torsion and compression to be applied by the fingers and wrist. The wingnut is not functional for beings who lack the sort of articulated digits that we have. Perhaps an alien being would have a latch or other contrivance to accommodate its appendages.
Of course, all of this alien talk is just a device with which to cast the matter of fasteners into a more interesting light. Fasteners are part of our collective technological heritage and are rather under-appreciated. But, if you are unfortunate enough to be abducted by aliens, I suspect that the matter of alien fasteners might be of immediate interest.