Teach Engineering: Soapy Stress

To experience the three types of material stress related to rocks - tensional, compressional and shear - students break bars of soap using only their hands. They apply force created by the muscles in their own hands to put pressure on the soap, a model for the larger scale, real-world phenomena that forms, shapes and moves the rocks of our planet. They also learn the real-life implications of understanding stress in rocks, both for predicting natural hazards and building safe structures.