- cross-posted to:
- askscience
- til
- cross-posted to:
- askscience
- til
cross-posted from: https://lemmy.world/post/6080744
The sun is not yellow or orange as we see in books and movies. It emits all the colours in the visible spectrum (also in other spectrums as well) making it white!
It is white when seen from space. Here on Earth, the atmosphere disperses the blue part of the spectrum so that the blue sunlight comes to our eyes from all directions, making the sky blue. Without the blue light, the sun appears more yellow. So the color depends on your point of view :)
Wow, that’s really interesting! I had no idea that the atmosphere worked as a diffuser for only a small part of the spectrum like that
https://xkcd.com/1145/
Yep the atmosphere is transparent to all colors of light except blue. It doesn’t absorb blue light but it does get scattered. That’s why no matter where you look in the sky, you see blue. Because the gasses there are scattering blue light in all directions, including toward you.
Isn’t that because blue is higher frequency and therefore refracts more than the other colors?
Good question. No idea. If higher frequency correlates with more scattering, then UV should also be scattered, right? Or is it something about blue visible light being just right for our mix of gases? Interesting question since that mix has changed over time. Perhaps the sky was another color during life’s early years. Is that why they’re called the Cyanobacteria? Because they turned the sky blue?
My understanding is that higher frequency == more refraction, visible or not. So in theory, x and gamma radiation should also experience more refraction. Though I wonder at what point (it any) something too high energy can somehow “pierce” through a medium rather than refracting.
Rayleigh scattering
It’s weird that diagrams and models of our solar system still depict the sun as yellow.
Unless you’re a kid in Japan, in which case it’s depicted as red.