"Solution Found for Feynman's Reversed Sprinkler Puzzle in Physics"
Researchers have definitively resolved physicist Richard Feynman's puzzle about the rotational direction of an S-shaped lawn sprinkler when submerged and its flow direction reversed. Experiments show that the sprinkler reverses its rotational direction, driven by jet propulsion, with unsteady and slower motion. The study's carefully designed geometry and low friction help to understand the mechanisms involved, with potential applications in fluid mechanics for controlling flows and modifying forces in technologies that harvest energy from air or water.