Harvard Natural Sciences Lecture Demonstrations | Reverse Sprinkler @NatSciDemos | Uploaded January 2016 | Updated October 2024, 1 hour ago.
Which direction does a lawn sprinkler spin if fluid enters the nozzle rather than being expelled from it? Inspired by Richard Feynman's story in his 1985 book "Surely You're Joking, Mr. Feynman."

For more information on our setup and references for further study, see http://sciencedemonstrations.fas.harvard.edu/presentations/reverse-sprinkler