Exhibition · Series IX · Many Scales
Impacts Become Pressure
How do thousands of separate wall collisions become one macroscopic quantity?
What to notice
No particle contains “pressure.” The macroscopic quantity appears when many local momentum transfers are accumulated over time and compared with the ideal-gas prediction.
Everyday analogy. A single ping-pong ball tapping a wall feels like a tap. Fill the box with countless fast-moving balls and all those separate impacts become something that looks like a steady push: pressure.
Pre-rendered from a dimensionless two-dimensional ideal-gas reference model with noninteracting point particles.