David of Prutchi.com wrote in to tell us about this awesome sand pendulum he and his daughter, Abigail, made.
On a recent trip to Israel, Abigail (10) saw a very pretty, large, and expensive sand pendulum. In it, the pendulum was able to swing, while at the same time, the sand pan was able to rotate freely. We applied our motto “Why buy it if we can MAKE it!”.
Not only did they make one themselves, they also documented the process and share it on their blog. I love this project, and imagine it’s hugely mesmerizing to watch the pendulum draw on the sand. Related: Water Droplets Dancing Around a Knitting Needle in Space