China and Madagascar are home to vast “stone forests” made up of towering, spiky rock formations. Scientists aren’t sure exactly how these geological wonders were created. But a team from New York University had an idea: They thought the rocks may have once been underwater, which eroded the rock into points. To test their hypothesis, they created a model by soaking a block of hard candy in water. As the candy dissolved, it created a sugary solution that was denser than the surrounding water. “This liquid streamed downward under the force of gravity,” says Leif Ristroph, a physicist who led the study. “That carved the candy into spikes.”