Air Pressure Curriculum

Section 1—Lesson 2: When Non-obvious Causes Become Obvious

Understanding Goals

Non-obvious causes become obvious when certain kinds of changes take place. In the case of air pressure, as the balance of amounts of air pressure changes between two places, corresponding effects make the presence of air pressure more obvious.

Subject Matter

• Air pressure exists all around us all the time. We sometimes forget to consider air pressure because its effects are such a common aspect of our lives; air pressure becomes non-obvious.
• Air pressure is the collective result of individual molecules that make up the air bouncing around and applying forces against any object in contact with them.
• A change in air pressure can make its usually non-obvious effects obvious.

Causality

• When causes or effects are non-obvious, we often have to infer that they exist.
• Changes in non-obvious variables that correspond to changes in obvious effects provide evidence that those variables exist and may be responsible for the outcome.