What does everyone want to be... - Page 14

Deepwaters · #**131** 08-03-2007, 11:09 PM

OK, well, I wasn't living in Washington yet -- or anywhere else for that matter -- in 1940.

Should know my history better, though. Thanks for the lesson.

fsquared · #**132** 08-03-2007, 11:28 PM

It's a famous example in physics classes when you get to the "resonance" unit, although apparently it's not all that simple.

http://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge

If I recall, one emotional statesman spoke shortly afterwards, something to the effect that "we'll build it right back exactly as it was!!", to which the response was that it would shake itself apart again exactly as it did.

Rev · #**133** 08-04-2007, 12:10 AM

Quote:

Originally Posted by fsquared

It's a famous example in physics classes when you get to the "resonance" unit, although apparently it's not all that simple.

True. This bridge's behavior was a surprise to everyone at the time.

Since then we have learned a lot.

For example, bridges and buildings in earthquake zones are checked for multiple vibrational modes, to check to see if they will resonate with the likely frequency of ground movement during an earthquake.

If it seems likely, they are detuned in some way.

For example, for a building, they might put a large mass on one of the high floors, along with shock absorbers that only let it move at a frequency well out of tune with the earthquake.

Rev · #**134** 08-04-2007, 12:23 AM

Quote:

Originally Posted by fsquared

If I recall, one emotional statesman spoke shortly afterwards, something to the effect that "we'll build it right back exactly as it was!!", to which the response was that it would shake itself apart again exactly as it did.

Aren't some people amazing.

By the way what do you do/indend to do?