Here’s why icicles made from pure water don’t form ripples

The skewers grow drop by drop instead of via a coat of water like their salty counterparts

A closeup photo of a large icicle with others hanging out of focus in the background.

Most icicles in nature are made from water and a little salt. Over time, small bumps in the ice grow into large ripples because liquid water coating the ice is thinner above the bumps and can freeze more readily.

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Icicles made from pure water give scientists brain freeze.