Why The Sky Is Blue And Sunsets Are Red
https://image.gsfc.nasa.gov/poetry/ask/a11354.html
http://spiff.rit.edu/classes/phys440/lectures/optd/optd.html
https://www.skyandtelescope.com/astronomy-resources/transparency-and-atmospheric-extinction/
From the sun’s core and up, spans 696,000 km of primarily electron-stripped hydrogen molecules. Photon, neutrally-charged particles of light are able to pass through such particles, being absorbed and spit back out again and again and again. From the physics-based mathematical explanation in the first url, a photon will wait about 3.1 x 10^7 seconds or 4000 years to reach the sun’s surface. Since light travels at 300,000km/sec and the earth is about 150million km away, overall this little photon will travel about 400 years — and 8.5 minutes, given that it makes it through obstacles like radioactive dust, gaseous forms, atmospheres, and any other type of debris. Earth has many, many layers of its atmosphere, and anything from atoms, molecules of water, air, carbon dioxide and more contribute to a phenomena coined stellar light extinction—in which light observed from earth is somewhat dimmed or obscured. This amount is dependent on ever-changing variables such has the amount of air to transverse through, or weather (think fog, or clouds) and the angle at which particles are traveling towards earth (this angle is called the zenith angle). The spectrum of visible light ranges from ultra-violet to red with ultra-violet being the higher energy end of the spectrum. Particles traveling through charged electrical fields are somewhat influenced by this passage, which is why the higher the energy a photon absorbs, the bluer it seems to the high. Conversely, the lower the energy, the more closer to red on the spectrum it seems. Higher-charged particles are more likely to attract and run into things and are therefore, extinguished (absorbed) by things Earth’s atmosphere than those comprised of lower-energy levels.
During day time, photons travel the shortest path towards our location on earth and it more make it through the atmosphere because of the directness of the angle and the shortening of distance. This means, of course, that more high-energy photons make it through, bouncing off of things rather than being absorbed, which is why when you look up you see a blue sky, rather than the blackness of space. Conversely, as the sun is setting, the zenith angle has changed as the earth has tilted throughout the day and light particles now have to not only travel a partner distance to make it to you, but less in general (of all but especially high energy photons) are going to make it through. In summary, the closer your target source is to your horizon, the more air particles have to go through to reach you. This is why a sunset or sunrise appears red, pink and/or orange as these are colors on the lower energy end of the spectrum (remember, lower-energy particles have a higher chance of not being absorbed).
A great way to visually show how changes in the air can affect light is through a Nash equilibrium. We will examine two different places on earth. Both, for clarity, under the assumption that we are initially observing light at an optimum time (i.e. when the air is as clear as it can get and the source of light is directly over our location). One place is Mt. Mauna Kea, at 4,200 meters, which experiences a zenithal extinction around 0.010 magnitude when the air is clear. The other, general sea level where the extinction is roughly 0.16 magnitude in these conditions. The actual chart will show the different two possibilities for each location, optimal meaning the source is directly above, and not, meaning the source is at any other (zenith) angle.