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A wavelengh quiz!!

oikos

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okay! no open-book and no Googling or other cheating allowed!


Q: what is the wavelength in nm of the 3 colors of traffic lights (red, yellow, green)


the person who get the correct number for ALL 3 colors get +rep :yh:

NO CHEATING ALLOWED NO CHEATING ALLOWED NO CHEATING ALLOWED
 

FireMyLaser

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It varies allot from traffic light to traffic light, but my answer is 624nm red, 585nm yellow, 525nm green (sometimes as low as 505nm). Really there is no correct answer IMO. :)
 

RA_pierce

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This would be a cool quiz, but I have seen traffic lights that are very different colors. They are not always the same.

Some yellows are more yellow, while the majority around here are more amber. I have also seen several green lights in one area that were blue-ish.

Also, they will not be perfectly monochromatic. So an exact answer will not be possible.
 

daguin

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The eye picks up some combinations better than monochrome. For example people see the red better if a little blue is added. There were some experiments (I don't know how well adopted the are) where some traffic lights have a blue reflective ring or blue filter lens around the red filter.

Also, any older lights with the white light behind a lens will be different than the newer LED based lights

It's never simple anymore, now is it?

Peace,
dave
 

oikos

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umm... the traffic lights near my house are LED ones.... yea dave... it's not that simple as i thought :( ookay +/- 5 nm difference allowed now
 

oikos

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It varies allot from traffic light to traffic light, but my answer is 624nm red, 585nm yellow, 525nm green (sometimes as low as 505nm). Really there is no correct answer IMO. :)
umm... you're sooooooooooooo close!
 

FireMyLaser

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Hehe did I get any of them right? The red may be a little higher, 635nm-ish. The yellow maybe 590nm. I'm happy with the green at 525nm OR 505nm.
 

aryntha

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For LED traffic lights im gonna go out on a limb here:

Red - 626nm AlInGaP
Yellow/Amber - 590nm AlInGaP
Green (BlueGreen) - 505nm InGaN
 

FireMyLaser

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ummm..... 525nm OR 505nm what's your FINAL ANSWER??
7!

No, but I find ~525nm looking to be more common here, though I'm only guessing it to be 525nm. But I know 505nm when I see it so I'm gonna say 505..?
 

oikos

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For LED traffic lights im gonna go out on a limb here:

Red - 626nm AlInGaP
Yellow/Amber - 590nm AlInGaP
Green (BlueGreen) - 505nm InGaN
GOT IT! my answer:

625±5
590±5
505±2

p.s: soo sorry FireMyLaser... your answer was a little broad! but you ere close thou :eek:
 




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