Science of the Rainbow

The spectrum depends upon light of different colours being slowed by different amounts: the refractive index of a given substance, say glass or water, is greater for blue light than for red. You could think of blue light as being a slower swimmer than red, getting tangled up in the undergrowth of atoms in glass or water because of its short wavelength. Light of all colours gets less tangled up among the sparser atoms of air, but blue still travels more slowly than red. In a vacuum, where ther...

 Newton's Experiment Proving White Contains All Colors

Newton wasn't the first person to make a rainbow with a prism. Other people had already got the same result. But many of them thought the prism somehow 'coloured' the white light, like adding a dye. Newton's idea was quite different. He thought that white light was a mixture of all the colours, and the prism was just separating them from each other. He was right, and he proved it with a pair of neat experiments. First, he took his prism, as before, and stuck a narrow slit in the way of the co...

 How a Rainbow Works

If you want to see a rainbow you ' have to have the sun behind you when you look at a rainstorm. Each raindrop is more like a little ball than a prism, and light behaves differently when it Sits a ball from how it behaves when it hits a prism. The difference is that the far side of I raindrop acts as a tiny mirror. And that is /hy you need the sun behind you if you want 0 see a rainbow. The light from the sun turns somersault inside every raindrop and is reflected backwards and downwards, wh...

 Colors of Sea Life Match the Layer of Ocean in Which they...

In a curious way, the colors of marine animals tend to be related to the zone in which they live. Fishes of the surface waters, like the mackerel and herring often are blue or green; so are the floats of the Portuguese men-of-war and the azure-tinted wings of teh swimming snales. Down below the diatom meadows and drifting sargassum weed, where teh water becomes ever more deeply, brilliantly blue, many creatures are crystal clear. Their glassy, ghostly forms blend with their surroundings and m...