Atmospheric
Optics
About - Submit Optics Picture of the Day Galleries Previous Next Today  
                   
(Nearly) Endless Rainbows

Rainbows have no pots of gold at their end because - if raindrops spread complete enough - they are without end. They need no earthly golden pots, they are already beyond value.

Pictured by Alexander Hau�mann at Gro�er Zschirnstein in the Elbe Sandstone Mountains.

All images ©Alexander Hau�mann, shown with permission







Drops anywhere near the cone surface - near or far - can glint light to form a rainbow. The bow itself moves and behaves as though it is an infinite distance away. It is fixed by the position of the sun alone - and that is a long way away indeed.

Sunlit raindrops anywhere send light back sunwards. It is mostly directed into an intense circle around 42° away from the antisolar point.

There is an infinity of unseen rainbows. Does a rainbow exist if there are no eyes to see it or brains to comprehend?

The primary rainbow that we do see comes from the glints of those raindrops that lie near the surface of a cone. It extends downwards from our eye (one eye because each eye sees a different bow) with its axis towards the antisolar point.

Drops outside the cone glint elsewhere and we only see dark sky - Alexanders dark band.

Drops inside the cone do glint towards us. But faintly. The eye mixes their colours to white. We see sky brighter there than elsewhere