What happens inside an avalanche. Duke Today, March 5, 2015. When you walk on the beach, the sand supports your weight like a solid. What happens to the forces between the sand grains when you step on them to keep you from sinking? Researchers have developed a new way to measure the forces inside materials such as sand, soil or snow under pressure. The technique uses lasers coupled with force sensors, cameras and advanced computer algorithms to measure the forces between neighboring particles in 3-D. Picked up by the News & Observer and the National Science Foundation.