With a giant glass pipe, a slice of ceramic cut from a diesel exhaust system, and a strip of toaster wire, I built an acoustical cannon: The Horn of Jericho. It is the brainchild of Dr. John Wight, a research scientist at Corning Incorporated, and it is probably unique. It is a vast enlargement of a test tube-sized design, distributed as a $14 kit by Penn State.
The setup has no moving parts. There is no speaker; in fact, nothing is mechanically driving the air, which is what makes this effect interesting. Air passing back and forth through the channels of the ceramic resonates, driven by the temperature difference across the ceramic. One side of the ceramic is heated by toaster wire and the other is cooled by zip lock bags filled with iced water. (The glass pipe itself keeps the electrical wiring and the water safely separate.) As long as the temperature difference is maintained, the pipe shakes with a deep, pure tone that can be felt several rooms away! (For more science, read about thermoacoustics.)
The video is a quick visual tour. The sound does not do justice to the sheer volume of the rumble.
Video Sweep of the Horn of Jericho…
More pictures…
Wow, Dan this is really cool! Your website is very interesting, keep up the good work. Email me once in awhile.
Janet
You’re lucky you got to put this online. The most I was able to take from a Corning Internship was a paper copy of the paper I had written! In any case, I like the new layout. Glad you’re using extensible packages. One can’t do thier entire page in notepad in their free time these days.
Dan,
What is the white ring around the glass tube between the open end and the ceramic/heating element assembly? What is its function?
The only giant glass tubing available to us happened to be open at both ends. To close one end, we attached a cylindrical glass bowl using white cement. I think the ring you are seeing is the cement.