Science on the River

If you visit the Museum on a particularly blustery day, don't be surprised if you hear an unexpected sound while making your way to our front door. On certain days, when the wind is just right, a low whistle can be heard originating on the levee behind to the Museum. This eerie, wind-powered music is created from the above ground portion of a device used to control the flow of water underground. Here's what happens. 

All sound is create caused by oscillations created by the rapid back and forth movements of air. Whenever you hear a sound, something is vibrating. A vibrating object produces sound waves, which can travel through the air. 

This pipe-like device, which is part of a valve below ground, causes air to vibrate as a wind passes by. All hollow tubes have a natural frequency which passing air can cause a tube to vibrate. As air rushes past the vertical pipe, the vibrations create a distinctive sound. Short pipes will produce a high-pitched sound, while longer pipes will create low pitch sounds. Because the pipe on the Ohio River is a rather long tube, it produces a low pitch tone.  

Wind instruments, such as trumpets flutes and pipe organs are constructed to make various sounds. Look again  at the photograph of the pipe. You are looking at a breeze powered musical instrument! 

Mitch Luman, Director of Science Experiences