Sand flowing uphill

Defying Gravity? Lehigh Researchers Discover Sand That Flows Up

The discovery could lead to a vast range of applications in a variety of field including healthcare, material transport and agriculture.

By applying torque and an attractive force to each grain of sand, Lehigh researchers found that the sand can flow uphill, up walls, and up and down stairs.

According to the researchers, the discovery could lead to a vast range of applications in a variety of field including healthcare, material transport and agriculture.

“After using equations that describe the flow of granular materials,” says James Gilchrist, the Ruth H. and Sam Madrid Professor of Chemical and Biomolecular Engineering in Lehigh’s P.C. Rossin College of Engineering and Applied Science, “we were able to conclusively show that these particles were indeed moving like a granular material, except they were flowing uphill.”

A brief video shows what happens when torque and an attractive force is applied to each grain of sand—the grains flow uphill, up walls, and up and down stairs.

A paper, published in the journal Nature Communications last week, details the team's findings.

Visit the P.C. Rossin College of Engineering and Applied Science's website for more details on this research.