", "What makes a rainbow?

BBC: rainbow

The spectrum of light that emerges from such a container will show a series of dark lines interrupting what would be a continuous rainbow.

ECONOMIST: Fundamental physics

Many African countries are looking to the crop-driven "green revolution" of Asia for ideas, but Ms Sibanda points out that what Africa needs is a "rainbow" revolution.

BBC: Women are central to feeding Africa

Andrews talks fondly of the Five Sisters, a range of peaks in Kintail, the landscape of Highland Perthshire and also what he calls the "rainbow bridge", the arching road crossing to the Isle of Skye.

BBC: Andrews and Sarafian on Disney-Pixar's Brave

One wonders, though, what tales Rainbow Warrior 3 will have to tell at the end of its working life - and how much of a dent it'll manage to make on the less tractable issues that head today's agenda.

BBC: Greenpeace Rainbow sails again