January 26, 2024• Physics 17, 15Which direction would an S-shaped lawn sprinkler rotate if it were submerged and the flow were reversed? Experiments now provide a definitive answer. K. Wang et al. [1] A fluorescent dye traces out the flow pattern as the submerged part of the device, resembling a sprinkler, expels water. (Video is sped up by 2×. See another video and a schematic image of the device below.)Physicist Richard Feynman wondered what would happen if an S-shaped lawn sprinkler, which r...