Wobble of Millennium Bridge Solved

When crowds of people first crossed London 's Millennium Bridge, the structure swayed so violently it had to be closed.

Mathematician Steven Strogatz of Cornell University has now developed a mathematical description of the bridge's tendency to wobble as people walk across it.

It is based on the same 'chaos' mathematics used to understand synchronous behaviour in fireflies and brain cells. The equations should allow civil engineers to prevent the same thing happening to other bridges.

from here, but more here as well