The article currently reads "usually just within the bounds of technical feasibility". Shouldn't this read "just beyond the bounds of technical feasibility"? At least as of the date Daedalus wrote the article. Phytism (talk) 16:20, 17 December 2009 (UTC)
Well, that is definitely a matter of opinion (oops! ohmygod, the wikistapo may be listening! forget I said that obscene word!). Methinks that many of Daedalus's inventions were *technically* feasible, strictly speaking, although they would probably not be *commercially* feasible due to a poor cost/benefit ratio or severe collateral problems, such as reliability, safety, ease of use, etc.. Take the train powered by grass clippings, for example: it was based on the math (growth rate of grass in kg/hr/m2) × (1 meter width) × (50,000 meters length) × (fuel's worth of fresh grass shavings) ≥ (fuel consumption of a fully laden train at 50 km/hr). If this math was indeed correct (the article did not give the numbers), Daedalus's pioneering "ecotrain" would probably have been technically feasible, as the mechanics do not seems out of the ordinary; and might have worked in test settings. But it probably would not be economically interesting. Or perhaps it would, who knows?
Another of Daedalus's "inventions" was a sock with a layer of small stiff hairs on the inside, all pointing down; so that the wearer's movements would tend to make the sock climb up the leg, instead of slipping down. The author even got a serious query from a sock manufacturer about that "patent".
Another of his inventions was an "invisibilty machine" based on a video projector projecting an arbitrary background image, with feedback from a camera so that a person standing in front of it would be "painted" by the projector with precisely the same colors as the background. This invention was technically feasible at the time, although the cost of the equipment would then be prohibitive and its applications would be nil (since the trick only works if the viewer is sitting right next to the projector). I think this one was easily implemented once the costs came down, but it still seems to be lacking an application.
Some inventions may have been really beyond feasibility, though. Consider the "skin-less steam ballon", consisting of a powerful heater mounted above a parabolic reflector, so as to heat up the column of air above it. According to the article, the thing barely managed to get off the ground --- until it happened to set off a fire sprinkler on the hangar's roof, when it shoot up like a rocket. The reason being, of course, that steam (H2O) is less dense than air (O2 + N2). Would that be technically feasible? Well, I doubt that the air or steam column could be heated fast enough to provide sufficient lift for the heater and mirror, much less for the required power source. But again, who knows?
Perhaps the article should say "right at the boundary of technical feasibility", just to be safe. 8-) All the best, --Jorge Stolfi (talk) 15:19, 19 December 2009 (UTC)
OK, I've ruminated on this a bit. The most precise, both technically and spiritually, would be "usually just within the bounds of technical plausibility." That captures the idea that the inventions challenge us to suspend disbelief.Phytism (talk) 21:06, 18 February 2011 (UTC)