5 Comments

  1. Just re-reading WUG and came across your comments when researching spring energy density. Just wanted to throw out a couple thoughts/rebuttals: first, there are plenty of reasons why fission reactors would prove unworkable in a scenario where not only are advanced machining techniques radically curtailed, but also water levels are in extreme flux. No rational entity would risk a coastal reactor in such situations, and one must assume that inland populations have largely declined to subsistence levels due to the posited famine cycles, leaving fission power only available in limited capacity to the elites (as we can assume Emiko’s original owner to have been, hence the availability of climate control.)

    Secondly, carbon nanotube springs are already achieving an energy density of between 1 and 6 million kilojoules per cubic meter (see Wikipedia for verified references). No reason to think that this would not have increased a few more times, we’re already in the right order of magnitude. And, incidentally and perhaps coincidentally, the mechanical stability issues being observed by such springs now are similar to those posited in WUG, as are the manufacturing processes, assuming the book’s technological limitations and advances.

    Finally, it is strongly implied in the book that the petrochemical crisis is not the result of a “peak oil” model, but rather a consequence of microbial bioengineering. Thus the need for novel polymers, etc.; furthermore, the book takes place in a world where the CO2 cycle is well enough understood that the relationship between climate change and combustion is no longer beset with politicized skepticism, and therefore, biofuels, or any combustion based power, has been drastically curtailed and regulated in the interests of survival. (As fission power is today, so, ya know, not so bizarre an idea.) Finally, again, the bioengineered plagues posited have simply wiped out the great majority of plants and animals that could have been used to produce biofuels, replacing them with single-use sterile strains or with exceptionally vigorous, invasive strains.

    Much as I had expected to find fault with the science and the world-building in WUG, for me — and I am kind of a science guy, and easily irritated by nonsense — it holds up.

    1. Very interesting –consider me schooled, and thanks for the researched argument.

    2. Carbon nanotubes storing 6 million kilojoules per cubic metre are by no means in the right order of magnitude for a fist-sized kink-spring to store a gigajoule of energy. My fist is about 500cc, maybe 1/2,000th of a cubic metre. So we need more than 100 times as much energy in something less than 1,000th the volume, and we’re off by more than five orders of magnitude.

  2. Right about your calculations in size, but not about the calculations in energy. 6 million kilojoules are 6 gigajoules, so it means that a device of 500cc would store 3 megajoules. Sure this is 300 times less than in the book, but not 5 orders of magnitude less.

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