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Curious bicycle reflector incident
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Curious bicycle reflector incident
On Jun 15, 4:38*am, wrote:
http://www.niquette.com/puzzles/cornrefp.htm And check out the solution to the puzzle at http://www.niquette.com/puzzles/cornrefs.htm The commentary by Myles Buckley on the solution, starting about halfway down the page, explains very well why I so much like flashing lights on my bike, front and rear, day and night. Andre Jute A little, a very little thought will suffice -- John Maynard Keynes A good education helps too -- Andre Jute |
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Curious bicycle reflector incident
On Jun 15, 9:35*am, wrote:
The same goes for Scotchlite that one should not overlook as a good safety reflector. *What is more annoying are the many HID lights with nearly collimated illumination that illuminate road signs poorly, signs that are not in the middle of the traffic lane. *To make up for that, these lights on cars and bicycles are blinding to oncoming traffic until they are close enough that the collimated beam misses the approaching observer. That is mostly due to NHTSA and their unwillingness to adopt ECE regulations for beam pattern for headlamps. The ECE lights have a sharp horizontal cutoff with a kickup to the curb side to illuminate roadside signs. I've been running them in my personal car for years with no noticeable effects other than that I can see the road better; I haven't noticed any inability to see overhead signs (most of which are lit anyway) which is the usual argument put forward by NHTSA as to why they are unacceptable. Also, ECE codes mandate automatic levelers for HID lights (to compensate for empty/loaded conditions) while NHTSA regs do not, only making the problem worse. You'll notice that they are most irritatingly blinding when still far away and less so at close range... unless it is one of those bicyclist who aim their light at oncoming observers to demonstrate their powerful equipment, mostly in daylight... and how safely equipped. To be fair, there's plenty of automobile owners that do that too. The thing that I really hate is the cyclists (and motorcyclists too) with strobing headlights, it's just annoying to look at. Not really dangerous though unless poorly aimed. Of course some motorcyclists leave their high beams on during the day, which can be painfully blinding... nate |
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Curious bicycle reflector incident
wrote:
Peter Cole wrote: If you Google the terms "corner cube" and "cube corner" you'll find that both are used to reference retro reflectors, but "corner cube" is the more popular term. When I did laser interferometer application design the term used was "corner cube". Google is smart and knows that these backassward terms are used by enough folks that they need search targets. It is the corner that reflects and it is a cube corner into which light enters. When working in retro reflectors, I was curious about the logic of the reversed name given to the cube corner that is a trihedral corner. Google isn't tagging these sites with synonyms, just indexing the text they find as they crawl. Apparently, "cube-corner" was the original term, but has been largely replaced (even in technical books, and journals) by "corner cube". The following abstract from 1987 is an example of the mixed use, presumably the author used the more correct term in the body of the paper while using the more popular term in the title so people could find the paper: http://adsabs.harvard.edu/abs/1987SPIE..818..162F "Retroreflector concepts - Corner-cube compared to catseye" -- Fuller, Joseph B. C., Jr. "A standard solid and open cube-corner retroreflector (CCR) is compared with a catseye retroreflector (CER) in terms of field of view (FOV) and expected wavefront errors." It's not uncommon to see a paper using one term to reference one using the other. |
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Curious bicycle reflector incident
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Curious bicycle reflector incident
aka Jobst Brandt 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. 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. And found in your local hardware store at reasonable prices. 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. This is not new. AAA formerly made STOP signs of porcelain coated steel signs using glass retro reflectors. These were the earliest reflective road signs on our highways and are collector's items today. http://sfbay.craigslist.org/nby/clt/1212893604.html The same goes for Scotchlite that one should not overlook as a good safety reflector. What is more annoying are the many HID lights with nearly collimated illumination that illuminate road signs poorly, signs that are not in the middle of the traffic lane. To make up for that, these lights on cars and bicycles are blinding to oncoming traffic until they are close enough that the collimated beam misses the approaching observer. You'll notice that they are most irritatingly blinding when still far away and less so at close range... unless it is one of those bicyclist who aim their light at oncoming observers to demonstrate their powerful equipment, mostly in daylight... and how safely equipped. Automotive HID lights are also very irritating when being tail-gated at night. -- Tom Sherman - 42.435731,-83.985007 I am a vehicular cyclist. |
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Curious bicycle reflector incident
On 16 June, 04:25, Tom Sherman °_°
wrote: aka Jobst Brandt 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. 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. And found in your local hardware store at reasonable prices. 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. This is not new. *AAA formerly made STOP signs of porcelain coated steel signs using glass retro reflectors. *These were the earliest reflective road signs on our highways and are collector's items today. *http://sfbay.craigslist.org/nby/clt/1212893604.html The same goes for Scotchlite that one should not overlook as a good safety reflector. *What is more annoying are the many HID lights with nearly collimated illumination that illuminate road signs poorly, signs that are not in the middle of the traffic lane. *To make up for that, these lights on cars and bicycles are blinding to oncoming traffic until they are close enough that the collimated beam misses the approaching observer. You'll notice that they are most irritatingly blinding when still far away and less so at close range... unless it is one of those bicyclist who aim their light at oncoming observers to demonstrate their powerful equipment, mostly in daylight... and how safely equipped. Automotive HID lights are also very irritating when being tail-gated at night. Stick a couple of white cube corner array panels to a raincoat and hang it on the back of your drivers seat. |
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Curious bicycle reflector incident
On Jun 15, 8:19*am, wrote:
Peter Cole 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 retro reflectors, but "corner cube" is the more popular term. When I did laser interferometer application design the term used was "corner cube". Google is smart and knows that these backassward terms are used by enough folks that they need search targets. *It is the corner that reflects and it is a cube corner into which light enters. *When working in retro reflectors, I was curious about the logic of the reversed name given to the cube corner that is a trihedral corner. I suppose people also ride bike roads and bike mountains in that sense. 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 retro reflector must be explained either by his "unsophistication" at problem solving or his ignorance of retro reflectors. *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. I don't see it as a puzzle as the writer apparently wanted to make it seem. *I guess he once looked into a laser surveyor's target and saw only his own eye regardless of how he moved his head. Jobst Brandt- Hide quoted text - - Show quoted text - Thank you for recommending that I should change the expression "corner cube" at... http://niquette.com/puzzles/cornrefp.htm ....to the argot of the optical engineer, "cube corner." A Wikipedia search on "corner cube" turns up... http://en.wikipedia.org/wiki/Corner_cube ....and a search on "cube corner" turns up no article by that name. Perhaps you will offer an expert change via the discussion page, which is currently blank. Excuse me for wincing, but it is hardly collegial to imply "...that something else [is] going on than rational discussion." Try humor. And a satirical illustration of “Perfection est l’enemie du bien.” Perhaps the calendar plays a part in the mystery. The self- deprecative narrative describes events that occurred in 1972, which possibly pre-dates the terminology as applied to both "Botts dots" and "Scotchlite." You are invited to do the research on that. Meanwhile "corner cube" is the only expression I have ever heard as a synonym for "retro-reflector," beginning with my staff responsibilities at Electro-Optical Systems in Pasadena during the Apollo Program. Best regards, Paul Niquette P.S. The "Corner Cube" puzzle has been quite popular, with most people expressing appreciation for the graphic-intensive explanation. |
#10
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Curious bicycle reflector incident
hibike wrote:
On Jun 15, 8:19 am, wrote: Peter Cole 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 retro reflectors, but "corner cube" is the more popular term. When I did laser interferometer application design the term used was "corner cube". Google is smart and knows that these backassward terms are used by enough folks that they need search targets. It is the corner that reflects and it is a cube corner into which light enters. When working in retro reflectors, I was curious about the logic of the reversed name given to the cube corner that is a trihedral corner. I suppose people also ride bike roads and bike mountains in that sense. 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 retro reflector must be explained either by his "unsophistication" at problem solving or his ignorance of retro reflectors. 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. I don't see it as a puzzle as the writer apparently wanted to make it seem. I guess he once looked into a laser surveyor's target and saw only his own eye regardless of how he moved his head. Jobst Brandt- Hide quoted text - - Show quoted text - Thank you for recommending that I should change the expression "corner cube" at... http://niquette.com/puzzles/cornrefp.htm ...to the argot of the optical engineer, "cube corner." A Wikipedia search on "corner cube" turns up... http://en.wikipedia.org/wiki/Corner_cube ...and a search on "cube corner" turns up no article by that name. Perhaps you will offer an expert change via the discussion page, which is currently blank. Excuse me for wincing, but it is hardly collegial to imply "...that something else [is] going on than rational discussion." Try humor. And a satirical illustration of “Perfection est l’enemie du bien.” Perhaps the calendar plays a part in the mystery. The self- deprecative narrative describes events that occurred in 1972, which possibly pre-dates the terminology as applied to both "Botts dots" and "Scotchlite." You are invited to do the research on that. Easy, both products were widely available long before 1972 (although I don't know what that has to do with anything). Meanwhile "corner cube" is the only expression I have ever heard as a synonym for "retro-reflector," beginning with my staff responsibilities at Electro-Optical Systems in Pasadena during the Apollo Program. A brief browse should acquaint you with the uses of both terms, shouldn't take more than 10 minutes, even for a slow reader. Best regards, Paul Niquette P.S. The "Corner Cube" puzzle has been quite popular, with most people expressing appreciation for the graphic-intensive explanation. Even with optical engineers? |
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