News Math

Here’s why the geometric patterns in salt flats worldwide look so similar

The shared geometry across playas may come from fluid flows underground

A photo of the salt flats in Badwater Basin in Death Valley, California in the foreground with mountains and sky in the background.

Salt flats around the world — such as these in Badwater Basin in Death Valley, Calif. — form polygons of similar size.

Rudy Sulgan/The Image Bank/Getty Images Plus

By Matthew R. Francis

From Death Valley to Chile to Iran, similarly sized polygons of salt form in playas all over the world — and subterranean fluid flows might be the key to solving the long-standing puzzle of why.