Talk:1145: Sky Color

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I always wonder: Since the sky goes from red to blue to red and the optical spectrum goes from red to green to blue. How come the sky is never green?
 
I always wonder: Since the sky goes from red to blue to red and the optical spectrum goes from red to green to blue. How come the sky is never green?
 
: Because of human color perception. You only perceive green in polychromatic light when said light is stronger in the middle wavelengths than the low or high wavelengths; in other words, you would need a process in the sky that removed ''both'' the high and low wavelengths from white light. As the sun sets, only the lower wavelengths are removed, so you perceive yellows and reds -- this perception of color is "one-sided", i.e. it is not interfered with by even longer wavelengths. By the way, sometimes you do see green briefly in the sky, it's called a [http://en.wikipedia.org/wiki/Green_flash Green Flash]. --[[User:Prooffreader|Prooffreader]] ([[User talk:Prooffreader|talk]]) 16:41, 10 December 2012 (UTC)
 
: Because of human color perception. You only perceive green in polychromatic light when said light is stronger in the middle wavelengths than the low or high wavelengths; in other words, you would need a process in the sky that removed ''both'' the high and low wavelengths from white light. As the sun sets, only the lower wavelengths are removed, so you perceive yellows and reds -- this perception of color is "one-sided", i.e. it is not interfered with by even longer wavelengths. By the way, sometimes you do see green briefly in the sky, it's called a [http://en.wikipedia.org/wiki/Green_flash Green Flash]. --[[User:Prooffreader|Prooffreader]] ([[User talk:Prooffreader|talk]]) 16:41, 10 December 2012 (UTC)
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::I used to go outside after a rain storm during the day, and sometimes the sky would seem very green.  The effect could last for hours. [[Special:Contributions/76.122.5.96|76.122.5.96]] 12:15, 12 December 2012 (UTC)
  
 
This sentence doesn't make sense: "(from "his" right to left instead of from "his" left to right)" [[User:Trek7553|Trek7553]] ([[User talk:Trek7553|talk]]) 15:15, 10 December 2012 (UTC)
 
This sentence doesn't make sense: "(from "his" right to left instead of from "his" left to right)" [[User:Trek7553|Trek7553]] ([[User talk:Trek7553|talk]]) 15:15, 10 December 2012 (UTC)

Revision as of 12:15, 12 December 2012

Of course with vertical mirror vertical axis is selected: perceived switching of left and right (really close with far to mirror surface). When standing on horizontal mirror we will perceive switching bottom from top. --JakubNarebski (talk) 09:09, 10 December 2012 (UTC)

You're certainly correct, but I think that the original question is not really asking about text (or other things) which are perpendicular to the mirror, but rather text which is parallel to it (and thus the close vs. far doesn't come into it). For example, when reading signs in your rear view mirror or holding a book in front of your chest while looking in a mirror. I've added a little bit to the explanation to attempt to help clarify what's happening in that situation. I'm not sure if it really helps or not. KeithyIrwin (talk) 10:00, 10 December 2012 (UTC)

Easier way to describe it: Imagine you hold a piece of glas. Write on the glass and hold it in front of the mirror, so that you can see both the original text and the mirrored text. Both versions of the text will look identical. So the mirror doesn't change anything. 62.220.2.194 11:10, 10 December 2012 (UTC)

Another way: draw a line between the real object and its reflection. Things are reflected around that line. If that line is going up & down (relative to your eyes), then things are reflected left/right (relative to your eyes). If that line is horizontal (again relative to your eyes), then things are reflected top/bottom. So it's not so much whether the mirror is horizontal or vertical, but rather what direction you are looking into the mirror (although that can be influenced a lot by the mirror's orientation).CityZen (talk) 04:17, 11 December 2012 (UTC)

I always wonder: Since the sky goes from red to blue to red and the optical spectrum goes from red to green to blue. How come the sky is never green?

Because of human color perception. You only perceive green in polychromatic light when said light is stronger in the middle wavelengths than the low or high wavelengths; in other words, you would need a process in the sky that removed both the high and low wavelengths from white light. As the sun sets, only the lower wavelengths are removed, so you perceive yellows and reds -- this perception of color is "one-sided", i.e. it is not interfered with by even longer wavelengths. By the way, sometimes you do see green briefly in the sky, it's called a Green Flash. --Prooffreader (talk) 16:41, 10 December 2012 (UTC)
I used to go outside after a rain storm during the day, and sometimes the sky would seem very green. The effect could last for hours. 76.122.5.96 12:15, 12 December 2012 (UTC)

This sentence doesn't make sense: "(from "his" right to left instead of from "his" left to right)" Trek7553 (talk) 15:15, 10 December 2012 (UTC)

Repeat Character Watch: The girl has appeared previously in 842: Mark, 892: Null Hypothesis, 1058: Old-Timers, and 1104: Feathers (A similar looking character also appears in 635: Locke and Demosthenes but this is actually the character Valentine from the book Ender's Game). The mother is seen in comics 806: Tech Support and 813: One-Liners. lcarsos_a (talk) 18:12, 10 December 2012 (UTC)

About this edition: 1/(x^4) does not look like a root to me. IMHO the forth root of x would be more like x^(1/4) but it's not the formula from the comic. (I'm too lazy to try to type lambda). Lmpk (talk) 19:00, 10 December 2012 (UTC)

You are correct. It's been fixed. The editor that made that edit was probably confusing 1/x4 with x1/4, the latter of which would indeed be the fourth root. lcarsos_a (talk) 19:53, 10 December 2012 (UTC)

This page, linked from the explanation says that "the most strongly scattered indigo and violet wavelengths stimulate the red cones slightly as well as the blue, which is why these colours appear blue with an added red tinge." -- this seems rather strange. Assuming the cones are simulated based on frequency/wavelength, ultra-blue colors shouldn't stimulate the red cones because the electromagnetic spectrum is linear, not circular, despite the appearance of similarity between violet and red. Or am I missing something? --Waldir (talk) 16:14, 11 December 2012 (UTC)

If you look at the response curve (middle of cited page) you'll see that red receptors have two peaks, one in the red wavelengths, and another (very tiny one) in the violet. That's why purple (which is red + blue) looks so similar to violet, and why the "color wheel" works. 207.225.239.130 21:59, 11 December 2012 (UTC)
PS: "first years" is an idiom. Wouldn't that be "first year students" to be proper English? 207.225.239.130 22:05, 11 December 2012 (UTC)
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