MORE SCIENCE AT THE MUSUEM: At San Francisco's Exploratorium, a scaled-down model of the city made with Jell-O helps visitors visualize how the city would shake during a major earthquake. In another display, a bowl filled with wet sand and a mallet shows how shockwaves can cause soil to liquefy, swallowing buildings like quicksand -- a grave threat for many San Francisco neighborhoods that were built on sandy landfill.
