U.S. and British researchers claim to have found a better explanation for the wobble of London's River Thames Millennium pedestrian suspension bridge than the one prevailing for over 20 years. Alarming swaying of the bridge was caused not by synchronization of walkers' footsteps, as previously believed, but the negative damping effect of their efforts not to fall over.
The conclusion "should enable bridge designers and other structural engineers to develop more accurate design criteria to avoid human-induced instability of a wide range of structures," reports the team, led by engineers and mathematicians from Georgia State University and the U.K.'s University of Bristol.