On the Landing of Rigid Cylinders*

When a cylinder is dropped, what are the factors that determine whether it lands upright or on its side? Sir Hermann Bondi (see European Journal of Physics 14, pp. 136-140) asked this question in 1993 with the intention of determining the theoretical probability of a coin landing on its edge. The Society of Physics Students (SPS) has embarked on an experiment to test some of his ideas using data taken from many places around the country via the SPS Outreach Catalyst Kits (SOCKS). Sets of matched cylinders were sent to SPS chapters to use in dropping experiments with school children as a way of teaching about science while performing science. One goal of the experiments is to determine the relative importance of center of mass location and aspect ratio. One surprising result is the extent to which observers over-predict the occurrence of upright landings for cylinders with a square profile. \newline \newline In collaboration with Gary White, Society of Physics Students