What's The Frequency, Kenneth?

I am slowly recovering from a slight hamstring hindrance, we’ll call it, and these days I go for walks instead of runs. I meander, I dawdle and when I remember I want to fit into my preferred jeans, I start yomping. This leads to a sort of speed walking, not unlike a coupon clipper trying to maintain a bit of decorum on a post-holiday mission just after mall doors open at 6 a.m. The consequent rhythm (when I really get going) reminds me of soldiers marching in lockstep. And this reminds me of a myth I once heard about sympathetic vibrations and their capacity for destruction.

Supposedly, back in the first half of the 19th century, a corps of English rifleman began to fall off the Broughton Suspension Bridge which they expected would carry them over the River Irwell to the town of Pendleton on the opposite shore (not to worry, the water was ankle deep, so no one died). Though reports show other possible reasons for the collapse, bad vibes were very likely at play, too.

Buildings, bridges and similar structures have their own frequencies and when such an object’s naturally occurring resonance is joined by other nearby objects’ frequencies, the combined efforts amplify each. This typically has no obvious effect...except when it does. The movement caused by this phenomenon becomes too much to bear and eventually has its way with the structural integrity of the more vulnerable object - it’s the same principle as the soprano’s shattering a wine glass, or, a bridge’s collapsing under a group of soldiers.

To be fair, engineering has come a long way since 1831, though some folks noticed a wiggle and a wobble in the Millennium Bridge in London soon after it opened. And, of course, I must mention the infamous Tacoma Narrows Bridge of 1940 in Tacoma, WA (R.I.P. Tubby), which gave in to vibrations produced from really strong winds that morning and crashed into the Puget Sound below.

Today, signs throughout England warn of this ominous quirk of science: