While working with shadows outside on a sunny day, many students will be surprised how fast they move. You may want to combine the shadow length measurements with investigations into shadow lengths and direction over time, focusing on the earth / sun system and the relative motions of the two bodies.

When working inside using light bulbs, please note that they do get hot and can cause burns. The bulbs provided have power ratings of 40 watts or less in the kits specifically to limit the heat they produce.
When setting these up please note that clear bulbs with the simple v-shaped filament make sharp shadows and frosted bulbs make fuzzy shadows. You will want to use clear bulbs in the activity on measuring shadow sizes; note that shadows are sharpest in the direction that sees the filament edge-on.

We recommend that you use the light stations provided in the kits - the plastic bases with porcelain sockets and pull chain. Screens can be boxes with white paper taped to the side or posterboard propped against a stack of books.
Box:

More activities on shadows!

Next section: diffraction gratings.