What is the basis of Red Sky at Night, Shepherds delight?

There's a rhyme that goes 'Red sky at night, shepherd's delight. Red sky at morning, shepherd's warning'. I don't understand it.

02 October 2005

Part of the show The Science of Lasers, Light, Kung fu and Archimedes

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Question

There's a rhyme that goes 'Red sky at night, shepherd's delight. Red sky at morning, shepherd's warning'. I don't understand it.

Answer

I think it's just a myth. Red sky at night, Hackney's burning!

It's a well established old proverb, but I'm not sure whether it has any validity scientifically. When you have a very very rich sunset, it's because there's a high quantity of particulate matter (or dust) in the atmosphere.

A lot of dust in the air is usually down to volcanoes, traffic, industry and the harvest. But I don't think that it has any linkage to making the weather better.

I suppose you could argue that dust might lead to global warming, and that that will warm the planet up, but I don't think the rhyme is all that true to be honest.