The Edgeless & Ever-shifting Gradient

If there is a more descriptive title for a site I'd love to know of it but, for now, I think The Edgeless & Ever-Shifting Gradient: An Encyclopaedic and Evolving Spectrum of Gradient Knowledge wins the prize. It is, as it says, an index of gradients; both naturally and unnaturally occurring. It covers a wide range of topics - Diffused Skies, Circumhorizontal arcs and even Gender Fluidity. A fascinating gathering of topics that kept me reading for far longer than I suspected I would.

via Daywreckers.