VictorBorun wrote: ↑Sat Jan 07, 2023 11:17 pm
Ann wrote: ↑Sat Jan 07, 2023 7:18 am
Our clear sky is bluer than the Sun. Indeed, while our skies are blue, the Sun is not blue at all.
but close to Sun sky shine must be pale yellowish and, closer still, even amber.
Because the light is not exactly filtered by the scattering; it is rather just separated. Shorter wavelengths are scattered by wider angles and can be seen further away from the star, are not they?
No, that's not how it works.
The true color of the Sun is white. And there is a very simple reason for it: It is white
to us.
Sunlight has always been the brightest light that humans can see. Our eyes have evolved so that we see sunlight as white, which is the brightest "color".
But what happens on a clear day is that some of the blue light from the Sun is scattered away by the atmosphere. This effect causes the sky to be blue, but it also makes direct sunlight look a little yellower.
Let's look at two pictures:
Note that the parts of the ground that are in shadow look quite deeply blue, because they are illuminated by the blue sky only, not by direct sunlight. Note that the color of the shadows are a deeper blue than the color of the sky, particularly when compared to the color of the sky near the horizon. Also note that the shadows are much darker than the sunlit snow, because (as we all know) direct sunlight is so much brighter than the blue light of the shadows.
Now let's compare daylight on a sunny day with daylight on a cloudy day:
On a sunny day, the face and hair of the girl take on a warmer, slightly golden-yellow hue, even the parts that are actually in shadow. On a cloudy day, her face and hair become "paler" and more "silvery". Her face also becomes somewhat flat.
Note, too, that on the "cloudy photo", the green background becomes more colorful and vivid. The leafy background is in shadow in the "sunny picture", and it looks muted and dark. Also note that the girl's dress looks more intensely blue in the "cloudy picture", where the blue hue also looks somewhat "flat". On a cloudy day, the blue dress contrasts rather sharply with the girl's pale skin.
As you can see from the two pictures of the girl, sunlight itself is yellowish. But note that the illumination in the "cloudy picture" is daylight. When clouds make daylight look all uniform, the color of this daylight is, well, neutral. It is not yellowish. And daylight is, of course, sunlight.
It is a mistake to believe that the sky is yellow or amber near the disk of the Sun, when the Sun is high in the sky. That part of the sky is brilliantly bright, of course, and it is dangerous to look at it.
Ann