09 June 2014

Mystery, Music and the Magic of Maths

Rosslyn Chapel

My wife Genie was looking up Celtic symbols in our reference books when she came across a short article about Rosslyn Chapel. She pointed this out to me as we were planning to visit the chapel in the near future. What excited us both was a reference to the series of carved stone cubes which are etched with symmetric patterns. It had taken Thomas Mitchell 20 years of research to realise that these patterns were in fact Chladni figures. His son Stuart based his Rosslyn Motet – a lovely piece of music that you'll find online – on the notes encoded in these stones.

Ernst Chladni and Chladni Plates

In the 18th century Ernst Chladni repeated experiments carried out in the 17th century by Robert Hooke, running a violin bow along the edge of a metal plate covered with flour and seeing nodal patterns emerge. Folk are still doing this. It's fun, educational, and strangely satisfying. The standing waves of sound create these so-called Chladni figures as the resonating plate shows areas that are vibrating and areas that do not vibrate. Where no vibration occurs (nodal lines) a boundary of flour remains. These days folk tend to use salt or sand on their Chladni plates. The plates themselves can be glass or plastic, and to see the effect all you really need to do is put a sound source near enough to the plate to cause it to resonate.

These Chladni figures remind me of mandalas. I'm sure the ancients were aware of this relationship between sound and vision. A friend returning from Kathmandu once gave me a beautiful thangka painted on silk. Everything is connected. Now I love creating video mandalas using mirror and kaleidoscope effects.

I've made a playlist of a few videos on YouTube showing folk having fun with Chladni plates. My favourite is Chladni Song where Art meets Science.

If you've built your own Chladni plate I'd be interested to know what materials you used. Cheers!