Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: rosalind dna on 16/01/2008 21:04:55

Title: What makes the Sky go Blue, scientifically though?
Post by: rosalind dna on 16/01/2008 21:04:55
This question has been puzzling me for ages and which is this:

What makes the Sky go Blue, scientifically? Yet on some days as we all know it can be
grey and overcast or wet, snowy, cloudy.

I found this link earlier today. http://www.sciencemadesimple.com/sky_blue.html
Title: What makes the Sky go Blue, scientifically though?
Post by: paul.fr on 17/01/2008 02:52:21
Or you could read the many topics related to this, right here in the forum...such as

http://www.thenakedscientists.com/forum/index.php?topic=7909.0
http://www.thenakedscientists.com/forum/index.php?topic=7909.0

sort of related,
http://www.thenakedscientists.com/forum/index.php?topic=6347.0
Title: What makes the Sky go Blue, scientifically though?
Post by: rosalind dna on 17/01/2008 10:09:20
Quote from: paul.fr on 17/01/2008 02:52:21
Or you could read the many topics related to this, right here in the forum...such as

http://www.thenakedscientists.com/forum/index.php?topic=7909.0
http://www.thenakedscientists.com/forum/index.php?topic=7909.0

sort of related,
http://www.thenakedscientists.com/forum/index.php?topic=6347.0

Thanks Paul but I got this idea from talking to a friend, who'd sent me
that link and I only joined last December. Those other threads are just as interesting although I was aware of them.
Title: What makes the Sky go Blue, scientifically though?
Post by: Pumblechook on 17/01/2008 13:48:20
Guessing here..  Without opening any links or reading up..That it is to do with lower light attenuation at longer wavelengths...   Hang on.... Got that wrong.  That would make the sky red. 
Title: What makes the Sky go Blue, scientifically though?
Post by: lightarrow on 18/01/2008 19:55:17
Quote from: Pumblechook on 17/01/2008 13:48:20
Guessing here..  Without opening any links or reading up..That it is to do with lower light attenuation at longer wavelengths...   Hang on.... Got that wrong.  That would make the sky red. 
Shorter wavelenghts (blue) "bumps back" from molecules more than longer ones (red).
Violet wavelenght is even shorter than blue, but in the solar spectrum violet is less intense than blue.
Title: What makes the Sky go Blue, scientifically though?
Post by: lyner on 19/01/2008 17:06:32
Quote from: Pumblechook on 17/01/2008 13:48:20
Guessing here..  Without opening any links or reading up..That it is to do with lower light attenuation at longer wavelengths...   Hang on.... Got that wrong.  That would make the sky red. 
The sky DOES look red(ish) when you look in the exact direction of the setting Sun. The shorter wavelengths  have been scattered away more than the red. The effect is stronger and stronger, the lower the Sun is in the sky. The atmosphere is very thin, compared with the radius of the Earth so light grazing the horizon passes through many times the thickness of atmosphere compared with when it arrives from overhead.
It is important to realise that the colours we see in the sky are very unsaturated- they contain a lot of all wavelengths - just a predominance of part of the spectrum. The sky is just  blue(ish) or red(ish) etc..