Last Tuesday, I had the pleasure of speaking to a group of entrepreneurs at the Draper University of Heroes. During Q&A, one asked if I had any suggestions for pitching highly technical products. He explained that the sophisticated nature of his product made it difficult to describe to people outside of his niche industry.

“I know exactly how you feel,” I said and described a similar situation that I once found myself in.

A gyroscope is a device that measures rotation in things like planes, boats, or spacecraft. My boss had asked me to summarize the concept behind a new device called the Hemispherical Resonator Gyroscope (HRG).

Surprisingly, the fundamental principle behind the HRG wasn’t discovered in some modern, high-tech research laboratory. A professor found it in the late 1800s after noticing that his wine glass behaved oddly as he spun around in his barstool. (Yeah, you can’t make this stuff up.) Evidently, after he flicked the rim with his fingernail, rather than propagating a pure tone while he rotated, professor G.H Bryan heard “beats.” So, he took his wine glass back to his lab to find out what was going on.

The animation at the bottom of this post illustrates how the rim of a wine glass bends and flexes while it rings. The professor noted that four parts of the rim barely moved (nodes) while four others (antinodes) move the most. He postulated that the “beats” that he heard resulted from the nodes traveling at a different angular rate than the bar stool. Therefore, if his theory proved true, the phenomenon could be used to build a gyroscope that calculates the angular rotation of the barstool—err—spacecraft, by simply monitoring the locations of the nodes.

The concept was simple enough, but I struggled with how to actually demonstrate it in front of a large audience. You see, it was 1986. Animated GIFs didn’t exist yet. Heck, PowerPoint wouldn’t be released for another year and even if it did, how could I animate through a carousel slide projector or an overhead projector?

I needed a prop—something that was both flexible enough to demonstrate nodes and antinodes and big enough for the whole room to see. I needed a Hula Hoop.

And so there I was, a 23-year-old electrical engineer, standing in front of an audience, bending and flexing a Hula Hoop over my head to simulate the rim of a ringing wine glass.

When I finished my story, I looked at the student who’d just asked for my advice. “You just need to find your Hula Hoop,” I said.

He smiled brightly. “Thank you. That’s very helpful.”

And off he went…to find his Hula Hoop.




On the Beats in the Vibrations of a revolving Cylinder or Bell by G.H. Bryan, MA, St. Peter’s College. Cambridge. 1890.