Position of the free end of a double pendulum with linear springs, subjected to a follower force. This is related to a classical problem in elastic stability, which was first investigated by Hans Ziegler and Vladimir Bolotin in the 1950s and 1960s. This computational image shows the history of the trajectory, with the time coordinate projected out (removed). The shade indicates the portion of time, out of the whole simulation, that the free end spends at each point in the image. Overlaid solutions of 36 problem instances, each with the initial condition near the trivial equilibrium. Data-adaptive dynamic range compression has been applied to show maximal detail.