Pushing a shovel through snow, planting an umbrella on the beach, wading through a ball pit, and driving over gravel all have one thing in common: They all are exercises in intrusion, with an intruding object exerting some force to move through a soft and granular material. Predicting what it takes to push through sand, gravel, or other soft media can help engineers drive a rover over Martian soil, anchor a ship in rough seas, and walk a robot through sand and mud. But modeling the forces involved in such processes is a huge computational challenge that often takes days to weeks to solve. Now, engineers at the Massachusette Institute of Technology and Georgia Tech have found a faster and simpler way to model intrusion through any soft, flowable material. Daniel Goldman, Dunn Family Professor in the School of Physics, joined MIT researchers for this project.