Last updated:聽8 june, 2010 - 15:53 GMT
Wave watching
The British author Gavin Pretor-Pinney tends to get a bit obsessive about the natural world around him.
Until recently he has been completely enthralled by clouds - writing a best selling book about them and setting up the Cloud Appreciation Society.
But now he has turned his attention to waves - not just waves in the sea, but waves in the air, in our bodies, and even in traffic.
When Gavin came to the Outlook studio, Matthew Bannister asked him where his new pre-occupation came from.
The Wavewatcher's Companion by Gavin Pretor-Pinney is published by Bloomsbury.