If two polarizing filters are placed perpendicular to each other, both horizontal and vertical vibrations will be blocked, allowing little light to be transmitted. In this activity, two polarizing filters are overlaid on an overhead projector. As the top filter is rotated, the amount of transmitted light varies from nearly as much as that allowed by one filter to almost none. This activity is a visual participatory analogy for how students come to “see” science concepts differently as their conceptual networks are modified as a result of new learning experiences. As a science demonstration, this activity would fall in a unit on light, optics, and lenses.