Alan Champneys: Why pedestrian bridges wobble - synchronisation and the wisdom of the crowd

There is a beautiful mathematical theory of how independent agents tend to synchronise their behaviour when weakly coupled. Examples include how audiences spontaneously rhythmically applause and how nearby pendulum clocks tend to move in sync. Another famous example is that of the London Millennium Bridge. On the day it opened, the bridge underwent unwanted lateral vibrations that are widely believed to be due to pedestrians synchronising their footsteps.

In this talk Alan will explain how this theory is in fact naive and there is a simpler mathematical theory that is more consistent with the facts and which explains how other bridges have behaved including Bristol's Clifton Suspension Bridge. He will also reflect on the nature of mathematical modelling and the interplay between mathematics, engineering and the real world.

Alan Champneys is a Professor of Applied Non-linear Mathematics at the University of Bristol.

Please email [email protected] to register.

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The Oxford Mathematics Public Lectures are generously supported by XTX Markets.