Air Pressure Curriculum

Section 2: Overview—Explanation of Photographs

This section addresses students' tendency to think of pressure as a force that actively pushes and is unidirectional. Students are encouraged to think about pressure as a passive cause that is omnidirectional.

Explanation of Photos

What makes an arch bridge stay up? It can be described as a form of passive causality. The distribution of weight and the balance of forces results in the bridge staying up. We don't notice anything actively happening to keep the bridge up, but if the balance was disturbed, we would quickly realize how it caused the bridge to stand.