Most of us know for a fact that the daytime sky is usually blue on a sunny day but few of us stop to ask why. We know the sun isn’t blue so why does the sky turn that color when the sun rises? Why isn’t the daytime sky orange, or yellow? Well, if we were to venture a collective guess, we could reason that the “blueness” of the daytime sky is probably due to the risen sun. This guess makes sense because when the sun completely sets, the sky turns black except for maybe the moon and little specks of light, which are actually other stars from distant solar systems.
According to our current level of scientific understanding, we humans perceive the daytime sky as blue in color for two primary reasons. The first reason is because of the way our atmosphere interacts with light from the sun. The second reason is because of the way the human eye detects color. Let’s look at these two points from a deeper perspective to see if we can really grok why the daytime sky is so often colored blue. Continue reading Why is the daytime sky blue?