# Scientists Solve Feynman's Puzzling 'Reverse Sprinkler' Problem Researchers determine the rotation direction of water-sucking sprinklers. - **Source:** [NYT > Science](https://brifing.si/source/794f9fbd-c10f-44d6-932d-9039af67922c) - **Published:** 2026-07-14 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/ab211114-e01d-48cb-b1d1-155d3786e7f3 ## Historic Physics Puzzle The reverse sprinkler problem that stumped Richard Feynman has puzzled physicists for decades. The question of which way a water-sucking sprinkler would rotate served as an ideal test case for fundamental physics principles. ## Experimental Setup Researchers built a specialized apparatus using precision laser measurements and high-speed cameras. They meticulously measured flow dynamics and torque effects during water suction with millimeter precision. ## Unexpected Findings Experiments revealed the reverse sprinkler behaved differently than predicted. Vortex patterns and pressure distribution during water intake showed deviations from classical physics expectations. ## Significance for Fluid Mechanics The findings validate fluid dynamics theories while raising new questions. The research suggests complex flow systems may require novel modeling approaches. ## Practical Applications This discovery could impact various engineering applications from water pumps to hydraulic systems. It offers new perspectives for designing systems requiring flow direction and pressure control. ## Power of Scientific Curiosity The scientific curiosity initiated by Feynman found its answer years later through technological advancements. This study stands as a testament to how fundamental research can yield practical outcomes. ## Sources covering this story - https://www.nytimes.com/2026/07/14/science/reverse-sprinkler-physics-problem.html — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._