The Bouncing Bridge

Great cycle today from Barnton to the Forth Road Bridge, along the coast. Took in a castle, big hoose, beach, golf course (oops), a lifeboat rescue ( not us), and the 2 bridges.
We cycled to the mid point of the Forth Road Bridge and had a chat with some engineers who were checking out the 'bounce' of the bridge. There was a fair breeze so the movement was very evident, in fact it was a challenge to keep the camera steady. The guys told us it could move a couple of metres. What?