Bending time: The tubular water clock

A water clock is a device that is either filled or drained and shows time through a changing water level. The ancient design challenge is to fashion a container where the water level rises or falls at a constant rate, and thus sweeps out equal height intervals in equal time intervals. Here, we present a new solution to this challenge that involves draining bent plastic tubes. This experiment may be used as an introductory physics lab activity that encourages creative problem solving, and can be adapted to the needs of calculus-based and algebra-based physics courses.