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Curious bicycle reflector incident
hibike wrote:
On Jun 15, 7:33 am, Peter Cole wrote: wrote: Carl Fogel wrote: http://www.niquette.com/puzzles/cornrefp.htm Cheers, That item is interesting in a few ways. Unlike optical engineers, the writer chooses to call a "cube corner" (trihedral) reflector, a "corner cube" in a jargon that should include "shell eggs" instead of "egg shells", or "tread tires" instead of "tire treads" as is common in English for compound words. This is often a flag that something else going on than rational discussion. If you Google the terms "corner cube" and "cube corner" you'll find that both are used to reference retroreflectors, but "corner cube" is the more popular term. When I did laser interferometer application design the term used was "corner cube". Beyond that, the writer is apparently unaware that road signs, Botts dot lane dividers, and spot reflectors, those 3-inch round, red, yellow, and blue plastic reflectors in a two screw hole metal frame use cube corners and serve well as safety devices. Overlooked is that these cube corners do not have perfect 90° corners so they reflect a diverging beam that does not go only back to the light source. If that were not so, road markings wold not be visible in headlight beams. Indeed, that was the "solution" to the "puzzle". That the problem was a "puzzle" reflects the author's unfamiliarity with optics more than anything else. These "gotcha" problems to me often reflect badly on the posers. In his explanation he says: "The query in the puzzle calls for an explanation, which will be elementary for a sophisticated solver who understands how a Corner Cube works". So, the fact that he was surprised by the failure of his retroreflector must be explained either by his "unsophistication" at problem solving or his ignorance of retroreflectors. Presumably it's the latter since he seems to regard himself a very clever fellow. If so clever, why does he attempt to use things without a basic understanding first? It's just plain vanilla ignorance on his part, which he also presumes of his audience. Excuse me for parsing your antipathy for "gotcha" problems, in which you say that a "puzzle" reflects the author's unfamiliarity with [the subject] more than anything else. Maybe you are making an ironic joke. If so, I shall be pleased to laugh alongside you. Your assumption seems to be that the poser does his or her posing out of ignorance and without knowing what the gotcha is going to be. Here is a counter example entitled "Surgical Precision"... http://niquette.com/puzzles/surgeonp.htm . . .which, of course, affords pleasure to good natured solvers and draws resentment from others, the latter illustrated by "Riddle? -- or Hoax?"... http://niquette.com/puzzles/angryp.htm Every word of the 1972 narrative in the "Corner Cube" puzzle is true, but the narrative in the solution was tinctured with a bit of self- deprecative fiction. Gotcha. Best regards, Paul Niquette I wish you would stop dredging up old posts of mine. I don't have much interest in an ongoing discussion with you, partly because I don't like your tone, but mostly because I find your writing incoherent. I hope that's clear. |
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