Some time ago I ran across an amazing Linear Reciprocation to Rotation Conversion item on At first, I thought this was a video, but now I’m (almost) 100% sure it’s a very tasty animation.

Not surprisingly, I quickly shared this with my engineering friends… well, acquaintances… well, people whose email addresses I have in my possession whose owners haven’t yet worked out how to block me.

Anyhoo, one of my chums — we’ll call him Matt (because that’s his name) — replied saying, “I’ll see your Reciprocation to Rotation and raise you with a Wilberforce Pendulum.” This cryptic comment was accompanied by a link to this video on YouTube.

Wow! In this video, the guy from The Action Lab explains how a Wilberforce pendulum performs its magic, also how coupled oscillators work, and also how all this relates to quantum superposition.

But wait, there’s more, because another of my chums — we’ll call him Rick (because that’s his name) — sent me an email asking. “Have you ever heard of a mechanical digital-to-analog converter?” Well, I hadn’t, so it was fortunate that Rick included a link to this video on YouTube.

According to the video by Engineer Guy, many early computers used purely mechanical digital-to-analog converters (DACs) because they didn’t have a reliable electronic way to perform such conversions.

I tell you — every day I learn something new that makes me exclaim “Say what?” (quietly, in my head). How about you, were you already familiar with Wilberforce pendulums and Wiffletree converters, or are these as much a surprise to you as they are to me?