The summer got off to an outstanding start as we separated into four different groups, each with a different project. However, before we could get too far into the work we had to stop and have a pool party at Professor Moore's house, complete with burgers and games. Summer work is tough, but somebody has to do it!
Having gotten the important part over (i.e., the party) we began the serious work of original research.
Brad (class of 2004) and Cherie (class of 2006) dedicated their summer to understanding the physics of orchestral crotales. Crotales are center weighted cymbals that are really flat bells. They produce a beautiful sound and can be found in the percussion section of most orchestras. These bells are found in octave sets arranged like a piano keyboard, and to our knowledge no one has ever investigated why they sound as they do. Brad and Cherie designed and performed acoustical and optical experiments to understand how crotales vibrate, and why they sound so beautiful. Then they spent several weeks trying to understand the crotale theoretically.
Brad modeled the crotale as a flat plate, then an annular plate, but to no avail. The results did not agree well with the experiments. Fortunately, while pursuing this line of theory he discovered a better way to make crotales and actually designed a set of crotales that should sound better and be less expensive to manufacture than those currently available. While Brad was trying to understand the crotale theoretically Cherie resorted to finite element analysis to understand how these bells work. The result of their work was that we now have an excellent understanding of what the important parameters are in manufacturing crotales, and the two students have published an article in the Journal of the Acoustical Society of America explaining the physics of crotales. Below are pictures of some of the fun (and frustrating) times that Brad and Cherie had as they pursued the elusive crotale.
Sarah, Alexandra, and Michelle (all class of 2006) began a new project this year investigating the physics of the piano. They spent the summer learning what is known about the piano, and developing an understanding of how the piano works. Sarah and Alexandra decided to concentrate on the physics of the soundboard while Michelle began looking and the strings. The experimental part of the project began with the development of an artificial finger to play the piano exactly the same way each time and ended with Sarah studying the vibrations of the soundboard with the electronic speckle pattern interferometer. Alexandra began working on a finite element model for the vibrations of the soundboard and Michelle ended up studying time-resolved measurements of the spectrum of piano strings. This project will continue into next year with an emphasis on understanding the vibrations of the soundboard.
These pictures are of Sarah, Alexandra, and Michelle as they learned about pianos, instrumentation, and how to move around a laboratory with a cast on.
Dr. Hunt in the Department of Psychology has become very interested in the ability of alcohol to ameliorate the effects of hypothermia in patients who are under the influence of MDMA (i.e., the drug ecstasy). In order to do the necessary research Dr. Hunt needed a temperature-controlled cage for her rats. Andrew (class of 2005) took up the challenge and designed and built a rat cage that keeps the temperature to within one-half of a degree for hours at a time. He designed the cage and wrote the software to keep the cage at the right temperature, but his software will also constantly record the temperature of the cage in several different locations as well as the temperature of the rat. This was a very complicated project, but unfortunately we don't have too many pictures of Andrew at work. All he did was sit in front of the computer all day!
Our work on the physics of the trumpet continued this summer. Erin (class of 2005) and Isaac (class of 2007) tested a new theory of how bell vibrations affect the sound of the trumpet. Their working hypothesis was that the effects found last year were due to a change in the viscous boundary layer when the bell vibrates. After an entire summer of work they conclusively proved that this is not the case. We have since developed a new theory and next summer Isaac and Erin will test this theory.
For Erin and Isaac this was a summer of frustrating results and learning new experimental techniques. This is a tough experiment but as the pictures show, these two are always smiling.
It wasn't all work and no play. There was time to enjoy each others company, Friday colloquia, and the never ending computer games. There was the constant question, "Where is Cherie?", and of course there was Sarah's birthday party with Alexandra's special cake.
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