Here in Philadelphia, we are fortunate to have the Franklin Institute at our fingertips! My class spent a day at this science museum exploring concepts related to our classroom study, and getting an introduction to some new ideas.

We spent about an hour in a room called "Changing Earth". Half of the class rotated through three stations, while the other half joined me at the giant stream table in the center of the room.

The three stations included a large wall of layered rock with evidence of volcanic and tectonic activity, a seismometer attached to a large rock which could be hit and kicked, and a chamber of slow-moving liquid demonstrating convection currents.

At the stream table, I introduced my class to water erosion. We had gone over some basic vocabulary in class, but this was our first hands-on encounter. Adding water sources to a dry stream table, we explored the ways water erosion could carve landforms into a flat surface. We discussed the terms silt, sediment, and saturation.

We also spent time exploring how humans change the way water erosion creates landforms. Students listed modifications that people make to rivers, and tried creating some dams and building model houses near riverbanks.

Overall, the Changing Earth room was an excellent way to solidify some concepts we had already investigated, and to build interest in the concept of erosion.

After our time in the Changing Earth room, we viewed an IMAX film about the dying out of coral reefs. What a fantastic follow-up! The narrator describes the silt produced by island logging as a major reason that the reefs are not as healthy as in the past.