The sweet sound of the saw

MY PROJECT:Máirín Ryan (14), Our Lady's Bower, Athlone, Co Westmeath on the physics of the musical saw

I DECIDED to enter the exhibition after visiting last year. It looked like so much fun and a great experience and it seemed that those who won went on to do so well and have great careers.

My project on the musical saw looks like an unusual choice but I got the idea when watching the 2008 X Factor. A contestant Austin Blackburn played the saw and I thought wow that is cool, I want to find out more about it.

While there was plenty of information on the web about playing the saw there was very little about the science behind it and so I decided to do my project on that.

The project was meant to answer three questions: how does the saw change pitch; how does the saw make such a loud sound; and what characteristics make a saw suitable for playing.

I found a research paper on the musical saw but it was far too difficult to understand.

Dr Brendan Kelly of Athlone Institute of Technology helped me, reading through the paper and explaining it to me.

My research showed that the key to making sounds was to bend the saw into an S shape. I designed and built a test frame to study this with help from my dad, and fitted an ordinary saw to it. I learned that the sound comes when just a part of the saw blade vibrates, with different S bends giving different notes.

I took pictures of the bent saw first at middle C and then at notes above and below this to get information about the notes that could be produced. I also used sugar spread on the saw to get an image of the vibration. The sugar pattern that formed on the saw changed with each note and I could take a picture of this. I play the violin so it wasn’t too difficult to learn to play a proper musical saw and I have done so when visitors come to my stand.

I have learned so much during my project. I began working on it in October and finished in December but really most of the work was done in December before Christmas.

I really enjoyed doing it and was surprised because it gave me a completely new view of physics. I wasn’t keen on the subject before, I thought it was boring. But this made it come alive and made it much more interesting. I already had some interest in science but I found the project work was brilliant. I don’t know yet if I will study science or physics, it is too soon to decide, but I really liked doing the work. It is so satisfying when you try something and get a good result.