Science Friday What’s Happening On The Slippery Surface Of Ice?
Jan 19, 2026
Dr. Robert Carpick, a mechanical engineer and tribology expert at the University of Pennsylvania, dives into the science of why ice is slippery. He discusses tribology, revealing its origins and how it relates to ice's unique properties. Carpick explores the debate surrounding the liquid layer on ice's surface and shares insights from new simulations about surface disordering. He also explains how wax can lower ski friction and introduces innovative nanogenerators that can detect and melt ice, making winter sports even more fascinating!
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How The Word 'Tribology' Was Born
- Peter Jost coined the term 'tribology' in the 1960s to name the field of friction, wear, and lubrication.
- He asked the Oxford English Dictionary for approval, and the word was adopted into use.
Surface Disorder Explains Ice Slipperiness
- Computer simulations suggest ice forms a thin, disordered amorphous layer at its surface when another surface approaches.
- This soft, electrostatically driven layer can make ice slippery even without pressure or frictional melting.
Dipoles Drive Surface Rearrangement
- Water molecules sense nearby surfaces via their strong electric dipoles and rearrange electrostatically.
- This rearrangement drives the crystalline-to-amorphous transition that reduces friction at the ice surface.