杏吧原创

Feedback is our weekly column of bizarre stories, implausible advertising claims, confusing instructions and more

Environment

The sky is blue because the atmosphere scatters the shorter wavelength (blue) end of the visible light spectrum more than the red end. As a result, more of this reaches the ground when the sun is high in the sky. Why then aren't we aware of being bathed in a bluish light? Or do we in fact see a bluer world, but, because we always see it this way, our senses accept it as neutral? And is that why a tinge of blue is often added, for instance to washing detergent, to make things look whiter?

Physics

Technology