We all known that soldiers must pass a bridge walking out-of-sync. You don’t want to trigger and amplify a vibration that could destroy the bridge.
So when the Millenium Bridge was opened and people complained about a wobble scientists expected to see a rythm in the way people walked across the bridge. To their surprise they found that the wobble could be generated by people walking out-of-sync. It appears that the human mind has a certain “algorithm” that directs how your legs and feet will behave when walking on a more or less flexible surface. It appears to be possible that the reaction of the bridge to a person walking on it can create a feedbackloop through that “algorithm”, amplifying the wobble.
