This graphic shows how a laser beam that has been modified to form a line shines onto a board with optical sensors that function as on/off switches. In the newly proposed system, a laser would be mounted on a ceiling and a sensor on a floor. If the laser moves, then the sensors turn on and off, which informs researchers how much the laser — and by inference, the point at which the laser has been mounted — has moved relative to the location of the sensors. Seeing that movement in real time can inform investigators what parts of buildings are damaged and to what extent. Credit: Diana Swantek/Berkeley Lab