The Water Sprinkler Experiment

In his book “Surely You’re Joking, Mr Feynman!“, Richard Feynman tells the story of an experiment he attempted in the cyclotron laboratory while a student at Princeton.  The experiment was intended to answer a question about the behaviour of an S-shaped water sprinkler if, instead of being used to expel water from the S-shaped pipe on a pivot, it was used to draw water in.  Would the sprinkler turn the same way as it did when it squirted the water out, or would it spin in the opposite direction?

According to Feynman, the people he discussed this with couldn’t agree on what would happen.  He fashioned an experiment to answer the question using a large carboy that he placed under pressure, with very messy results.

Here, is happy to present a video of a safer version of that same experiment, using air as the fluid instead of water.  The experimental apparatus was designed and constructed by Henry Ariail, who sent us the video tape to share with the world.

The short snippet of music accompanying the titles features Richard Feynman playing the drums with Ralph Leighton.