"Microscopically speaking, compressing a gas must involve a surface, let's say a piston, charging into the gas. During this process, the piston is like a giant tennis racket smashing back all the trillions of tennis balls, i.e. the gas molecules, that happen to collide into it."
Feel free to be the first
Please review the linked page for context.
If you can think of something better than this,
please add it to the database