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a human brain contains 100 trillion synapses each transmitting a signal of about 100 bits per second, and weighs 1.3 kg, for something like 10¹⁶ bit operations per second, 8 × 10¹² bit operations per second per gram. the cpu i'm typing this on weighs about a gram and has four cores, each of which typically manages about 1.5 64-bit operations 2.6 billion times a second, about 10¹² bit operations per second and also about 10¹² bit operations per second per gram. evidently the brain tissue is about an order of magnitude more computationally powerful per unit weight, and as it happens it also uses an additional three or four orders of magnitude less energy per unit weight. manufacturing it is also much cheaper. if we knew how to program it, we'd probably program globs of neurons rather than the very fine photolithographic microelectronics we are using today neurons, however, fossilize very poorly indeed; after death they typically liquefy within days, losing all of the structure that could betray how they functioned the particular shape of our industrial civilization is based on mass production in centralized facilities of durable goods that are identical to high precision (deep submicron precision in the case of this cpu). clearly this is not the only possible way to produce massive abundance; the rain forest or even the corn field does not work this way, but produces much more detail than tsmc does much of the durability and fossilizability of our conventional technology stems from its stupidity. to remain standing, a two-story house would once be made with meter-thick walls, while modern hollow brick with plaster and reinforced concrete reduces this to perhaps ten solid centimeters between indoors and outdoors. more frugal balloon-frame designs consist entirely of metastable materials like wood and steel, materials which will lose their structure if left exposed to air and water, either suddenly in a fire or gradually over decades. but even a balloon-frame house is wasteful and inefficient compared to a five-meter-tall stand of bamboo remaking the planet for your convenience is much cheaper if you can avoid spending resources on durability and fossilizability which don't benefit you during your lifetime could you get there without a transitional phase of making lots of thick, solid objects out of materials that are stable on geological timescales? probably, but maybe not if your uplift path starts with fire instead of math... |