The human retina has three types of receptor cones, each sensitive to a different range of wavelengths of visible light, as shown in this figure (the colors are merely to differentiate the three curves from one another; they do not indicate the actual colors represented by each curve):

(c) Explain why the sky appears blue even though all wavelengths of solar light are scattered by the atmosphere.

Video transcript

Hey everyone, we're told that the human retina has three types of receptor cones, each of which is sensitive to a particular range of visible light wavelengths. As illustrated in the following figure, know the color of the graph does not represent the actual color illustrated by each curve, which of the following explains why the sky looks blue despite the fact that the atmosphere, scattered solar radiation at all wavelengths. Now looking at our answer choices, it looks like we're comparing the length of our wavelength and determining whether blue light is scattered well or not. Now thinking about our visible spectrum, we know that our blue light Is going to be in between 450 - 495 nm. And looking at a graph, it looks like it's going to be this blue bell curve right here comparing our wavelengths. We can see that we have a shorter wavelength for our blue light, which ultimately means that this is going to be scattered and because it is scattered well, we will have more blue light to see. Also looking at this absorption curve, we can see that we have a higher amplitude for our blue light, which means our eyes are more sensitive to this light. Now looking at our answer choices, it looks like C is going to be our answer choice. Blue light has a shorter wavelength so it is scattered well and our eyes are more sensitive to blue light. Now I hope that made sense. And let us know if you have any questions