At sunset why is part of the sky still blue, sunlight now traverse further why isn't the whole sky reddish?

Question

In many photos sunset are only orange around the sun which sits in the middle of the photos, the part of the sky nearer to us is blue or purple.

Since the sunlight now travels further to reach us why is the part of the sky which is further from the sun but nearer to us blue.. shouldn't it be orange?

e.g. is this photo

http://www.agt.net/public/dhauschi/images/Jamaica_sunset.jpg

Answer 1

it's light passing through air and space at different times. This is an element of Spectroscopy...... Light is measured in red, orange, yellow, green, blue and then purple.

Answer 2

Actually, unlike what everyone else here says it has nothing to do with light bending or refraction. It has to do with an effect called Rayleigh scattering.

Like how sound resonates, certain molecules vibrate when struck with a certain frequency of light. Larger molecules resonate with lower frequency waves (like radio, microwave, infrared, and red-yellow on the rainbow) while smaller molecules resonate with higher frequency (violet, UV, x-ray and up). When they resonate with these requencies, instead of absorbing the light that hits them, they retransmit it in random directions, called scattering.

Water vapor, CO2, and nitrogen in the atmosphere resonate with blue light, and so they scatter blue light in random directions, thus the sky is blue overhead. During sunset, instead of light shining straight through the atmosphere it shines tangentially with the curve of the earth, passing through a much thicker patch of air than if it just cut through from the top. After passing though all of this atmosphere most of the blue light scattered naturally by the atmosphere has become so scattered it is no longer visible, and thus only the non-scattered beams consisting of red-yellow make it. The edges of the sky are still blue because when rays of light released by the sun strike the fringes of the atmosphere, where it's still thin, it still scatterers it in random directions, including down at you, but it's much more reduced because that sunlight is no longer direct.

Answer 3

The atmosphere blocks the red colour spectrum from the sun where the sun is not.  The blue/purple colour spectrum passes through easily everywhere else.

Answer 4

what you are seeing in the orange sky is the sun's light bending around the atmosphere... in the front, by the sun it is more intense therefore bright orange, as you go back the wavelengths change changing the color... at the far back (DARK blue) you are seeing the earth's shadow because that location is no longer getting light

Answer 5

Blue light bends more than red light.

When you look higher in the sky, you're seeing the blue light from the Sun that has bent more sharply, and comes to your eyes. The red light from that part of the sky is passing straight on through the atmosphere and out into space. (You get to see this red light during total lunar eclipses - this is the red light that causes the moon to turn red during the eclipse).

The red light that you see near the Sun is being bent less , and has entered the atmosphere at an angle where it is bent down and hits your eyes. The blue from that part of the sunlight has already hit the ground somewhere to the west of you.