galloping gertie

galloping gertie...

*my trivia entries mysteriously vanished last week*

so as my 4th and final entry for today, here's some monday science-buff tiger trivia:

since i majored in english/american lit as an undergrad, a lot of people have no idea how much i also love the sciences. in fact, in h.s. and college, i always got flying color A's in those courses.

one of my favorite projects of all time was an AP(advanced placement)/honors physics paper i did on "galloping gertie".

galloping gertie was the first tacoma narrows bridge, completed on july 1, 1940. its collapse on november 7, 1940 illustrates one of the best-known, and most spectactular examples of suspension bridge failure.

the bridge collapsed due to a simple physics phenomenon known as resonance. resonance is a property that most objects have, of vibrating more strongly when exposed to an external force which itself vibrates at the object's natural frequency. the tacoma narrows bridge vibrated strongly even when there were very light winds. but november 7, 1940 was very windy, and the bridge took a 30 hertz transverse vibration with an amplitude of 1 and 1/2 feet. this is akin to moving the end of a rope up & down to send waves down that rope. this compromised galloping gertie's structural integrity and caused torsion, making the bridge twist and split apart in two. this is why wind tunnels are used to test modern bridge designs.

the bridge has since been rebuilt, although the remains of galloping gertie still lie underwater today.

to see pictures and the well-known video of those bridge motions, go check out this page .