Over the summer, an American photographer captured a truly astonishing scene. In Colorado, he snapped pictures of a sunrise ...

When the sun is straight up at noon, you see blue sky because all the other colors in the spectrum up until blue and purple are scattered away. This is known as the Rayleigh effect. We usually don't ...

Researchers at the University of Bristol have confirmed that spherical gold nanoparticles are responsible for the purple smoke that appears when fulminating gold is detonated. With this discovery, the ...