There’s an old post on Charles Stross’s blog about how many people you need to maintain given tech levels. Comments there are closed–the post is from midsummer 2010–so I’m going to talk here about something I saw there.
Most of the discussion goes way over my head. Metallurgy, chemistry, electronics: none of these are stuff I’m good at. But one commenter hit right in the middle of one of my specialties, that being fiber technology.
He says something along the lines of, “We don’t need silk and rayon and nylon and all that; cotton and wool and we’re good to go, maybe data on a few synthetics in case there’s something there that eats cotton or wool.”
First: if you’re going to take only one plant fiber (and he’s ignoring the fact that he already mentioned hemp), linen is a vastly better choice than cotton. It doesn’t deplete the soil nearly as much, is vastly easier to harvest, process and spin, is stronger, and has desirable qualities such as “doesn’t kill you if your linen garment gets wet on a chilly day”. About the only downside of linen is that it’s hard to dye, and our ancestors spent literally millenia using linen for the plain next-to-body layers and wool for the bright public layers (in areas where they were using sheep’s wool rather than silk, alpaca, camel…).
Second: Yes, you really do need silk. For all the things you’re not using rayon for, or did you think you were going to make your lightweight backpack out of wool or (linen) canvas? Silk is a polymer, essentially plastic manufactured in bug guts rather than in a big tub. Its big drawback is the amount of work it takes to make it useful, and that’s not tough (for the values of “tough” that a society contemplating interstellar colonization must consider) to automate. The food silkworms require, mulberry leaves, even comes from a plant that produces useful human food too. And silk is great for all sorts of things, including clothes that are warm without being bulky and fabric that takes dye easily.
Third: You need synthetic fibers for things other than clothing. Rope, fr’instance. And also that lightweight backpack, though you might sensibly choose to make that out of the organically-manufactured silk rather than the industrially-manufactured synthetics.
I think what we have here is a case of someone assuming that the fiber is a simple field, because it’s something that low-tech people and women do, and making further, reductive assumptions therefore. It’s irritating. I mean, I don’t know much about metallurgy but I don’t claim we can get by with just copper and iron, either.