Frosty Fractals

Frosty Fractals

From Curious Cases by BBC Radio 4

January 2, 2026 · 29 min

About this episode

Hannah and Dara explore the complex patterns formed by ice and the chemistry behind them.

One winter morning, listener Jane opened her curtains to find her car roof covered in breathtaking, fern-like frost so intricate it looked like a William Morris print. But how does something as ordinary as ice create patterns so beautifully complex? Hannah and Dara explore this crunchy, slippery, delicately patterned branch of chemistry to uncover the rules and mysteries that govern the extra-ordinary world of ice. Why does ice come in so many shapes and sizes? And does all ice form at 0 degrees Celsius? Is every snowflake truly unique? We have questions a plenty for our eager chemists, who, as all good chemists do, have a few demonstrations up their sleeves to help explain. And we explore nature’s hidden geometry to find why these frost ferns follow the same rules as lightning bolts, river deltas and even human lungs. You can send your everyday mysteries for the team to investigate to: curiouscases@bbc.co.uk Contributors Sarah Hart – Professor Emerita of Mathematics, Birkbeck University of London Christoph Salzmann – Professor of Physical and Materials Chemistry, UCL Dr Thomas Whale – Lecturer, Institute for Climate and Atmospheric Science, University of Leeds Producer: Emily…

People in this episode

Hosts: Hannah, Dara

Guests: Sarah Hart, Christoph Salzmann, Dr Thomas Whale

Topics covered

  • ice patterns
  • chemistry
  • snowflakes
  • nature's geometry
  • frost
  • mathematics

Keywords

  • frost
  • ice
  • snowflake uniqueness
  • chemistry
  • mathematics
  • patterns
  • geometry

Mentioned in this episode

Organizations: Birkbeck University of London, UCL, Institute for Climate and Atmospheric Science, University of Leeds, BBC, BBC Studios

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