Inverse sprinklers: Two simple experiments and the resolution of the Feynman–Forrester conflict

The phenomenon of the inverse sprinkler can be demonstrated simply by using two or three flexible straws. This experiment throws some doubt on Feynman’s observation of a twisting hose in a carboy by confirming Forrester’s conclusion that an inverse sprinkler will exhibit no motion. The Feynman–Forrester conflict of whether or not forcing water into a sprinkler is the same as if the sprinkler were sucking in water is resolved experimentally in Feynman’s favor.