Danya was reading about earthquakes in science today in her Usborne Children's Encyclopedia. For a fun "experiment" we built block towers on the "fault line" between two books. We pushed the books up against each other then built right on top of the line.
Next we tried different methods of creating our "quakes". We shook the two books, pulled them apart, shoved them together, slid them opposite directions. We observed how they affected our towers and tried to build towers that would withstand the "quakes".
Then we got off on a tangent (some of the best learning opportunities come from being willing to be side tracked) about architecture and wind. We tried building towers that couldn't be toppled when Danya, Gloria, and I would all blow on them. They eventually determined that low rectangular buildings were the toughest. It was so much fun I don't think they even considered it school work!