Hell’s Bells!Â
Physics major invents new musical instrument.
Physics major Evan Peairs ’16 built a new kind of bell for his senior thesis using an innovative design that is capable, in theory, of generating musical tones never previously achieved by a percussive instrument.
Evan’s instrument—which is related to a musical family known as the bell plate—consists of a slab of aluminum carved in an otherworldly shape that resembles a mutant unicorn. When you strike it with your finger, however, it rings with the sweet, reverent chime of a church bell.
Using the acoustical wizardry he developed for his thesis, he is now designing bell plates that sound like a gong, a xylophone, and a woodblock. “And I’m working on one that sounds like a trumpet,” he adds, showing a visitor around a laboratory bristling with lasers, mirrors, wires, and pipes.
Evan has a longstanding interest in obscure musical instruments, and originally thought of writing his thesis on the acoustics of church bells. But it turns out that church bells are expensive and difficult to make. So he began to investigate other instruments, including bell plates—rectangular sheets of metal which sound vaguely like gongs.
One day he asked himself what would happen if he changed the shape of the plate. “I thought it was kind of strange that bell plates were always rectangular,” he says. “Nobody ever thought to change the contour.”
It turns out that changing the contour has a striking effect on the tone. Using an engineering technique known as structural optimization, Evan set about designing a bell plate that sounded just like a church bell.
“This project was completely Evan’s own idea and I feel like I’ve been on a super fun, wild ride with him all year,” says his thesis advisor, Prof. John Essick [physics 1993–]. “A few months ago, Evan brought back the flat plate from the machine shop that he had cut into a shape that looked like a fanciful misshaped unicorn and said that his computer simulation had predicted that it would vibrate just like a church bell. When he flicked it with his finger and it sounded exactly like a church bell, I was stunned. I thought, ‘Wow, this crazy, whimsical idea actually works.’”
By altering the contour—one looks like a coiled python, another bears vague resemblance to the state of California—he can make instruments with all kinds of voices, from the hollow thunk of a xylophone to the sunburst cadence of a pipe organ. He can even design instruments with bizarre sounds, hitherto unknown.
Evan wasn’t satisfied, however. “The church bell was a good target to start with,” he says. “But once I figured it out, I asked myself, ‘Why stop there?’”
The musical aspect of his thesis suits Evan, who plays mandolin, guitar, and bodhrán, and who took several classes in the music department during his time at ºìÌÒÊÓƵ. He also operated ºìÌÒÊÓƵ’s and led the madcap student construction group Defenders of the Universe, which builds outlandish contraptions such as a , a , and a seesaw bicycle.
His thesis is titled “Designing, Building, and Testing Novel Musical Instruments.” He also gave a shout-out to Prof. Jerry Shurman [math] and Prof. Morgan Luker [music].
“I want to build things to help the world,” he says.
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