The sea is blue because of the way water absorbs light, ... Is water blue or is it just reflecting off the sky? – The students of Ms Brown’s class, Neerim South Public School, Victoria.

Put these three things together, and a blue sky is inevitable. Here's how it all comes together. Light of many different wavelengths, not all of which are visible, are emitted by the Sun.

THE view has been expressed that “the much-admired dark blue of the deep sea has nothing to do with the colour of water, but is simply the blue of the sky seen by reflection” (Rayleigh's ...