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-   -   colour of sky (http://physicshelpforum.com/light-optics/6264-colour-sky.html)

ohm Jun 5th 2012 07:09 AM

colour of sky
 
why is sky blue? why not violet? Coz I know that shorter wavelength scattered more than longer wavelength. Violet is the shortest wavelength so why not violet?

werehk Jun 5th 2012 08:27 AM

I guess the reason is about the angle needed for us to see to light. If the scattering is too large, the violet light might not reach the ground

ohm Jun 5th 2012 09:19 AM

this link has confused me
http://milesmathis.com/sky.html

ChipB Jun 5th 2012 12:50 PM

Quote:

Originally Posted by ohm (Post 18538)
this link has confused me
http://milesmathis.com/sky.html

It should confuse you - it's full of nonsense.

ChipB Jun 5th 2012 01:00 PM

Quote:

Originally Posted by ohm (Post 18536)
why is sky blue? why not violet?

Two effects that both contribute to the reason for seeing "blue not violet":

1. The sun puts out light that has more blue light in it than violet. The solar spectrum peaks in yellow - you can see that with this illustration: http://en.wikipedia.org/wiki/File:Solar_Spectrum.png
This is why the sun looks yellow to us. Violet is further from yellow than is blue, and hence there is less violet light than blue light in the sun's spectrum.

2. Human eyes have evolved to see in a wavelenth band centered on yellow (as that's where the most light is), and so our eyes are less adept at seeing violet light than blue. Hence we perceive light that has both blue and violet in it as being basically blue.

These effects combine so that blue swamps out violet in the way we perceive the color of the sky.

ohm Jun 6th 2012 07:02 AM

thanx. there is no option to thanx here. how can I thank?
something has changed here.
thnks chipB

jaydonc Nov 25th 2012 09:31 PM

Because of our environment
 
The sky color from our earth is green and on mars its red, because of the environment of planets, on earth there are so much gases where oxygen and hydrogen are in majority that is why sky looks green from here.

ChipB Nov 26th 2012 07:48 AM

Quote:

Originally Posted by jaydonc (Post 19210)
The sky color from our earth is green

Green?

Quote:

Originally Posted by jaydonc (Post 19210)
...on earth there are so much gases where oxygen and hydrogen are in majority that is why sky looks green from here.

Actually nitrogen is the majority of gas in the earth's atmosphere, followed by oxygen. Hydrogen is present only in very small concentration - only about 0.000055%. But even if you were right about the composition of the atmosphere, it would not explain why the sky is blue. You really must consider the scattering of sunlight to explain it.

johnydeep196 Feb 10th 2013 11:47 PM

i have a question,in ancient time what thing used for lighting at night inthe Place,and underground cave palaces.....????????????????

johnydeep196 Feb 10th 2013 11:49 PM

i have a question,in ancient time what thing used for lighting at night inthe Place,and underground cave palaces.....????????????????


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