While frequently attributed solely to , the full explanation involves several interacting physical concepts:
When you blow air across the top of a curved sheet of paper, the paper rises . This phenomenon is a classic physics demonstration often used to illustrate fluid dynamics and the generation of lift. The Physics of Airflow and Paper air flow
: Some researchers argue that the lift is better explained by the change in momentum as the airflow is deflected downward by the paper's shape, resulting in an equal and opposite upward force. While frequently attributed solely to , the full
: More advanced explanations, such as those from the Japan Society of Mechanical Engineers, note that the air plume follows the curve of the paper. This curved path creates a pressure gradient where the pressure is lower on the inside of the curve (near the paper), contributing to the lift. : More advanced explanations, such as those from
: According to the NASA Bernoulli's Principle guide , when air moves more quickly over a curved surface (like the top of the paper), the air pressure decreases. The relatively higher atmospheric pressure underneath then pushes the paper upward.