January 05, 2009
Student Daniel Zietlow (Class of 2009) answers questions about his research on “High-Speed Electronic Speckle Pattern Interferometry of a Struck Circular Flat Plate” working with Professor of Physics Thomas Moore.
1. How did you and Professor Moore form your initial research ideas? How did you collaboratively come up with a research topic?
This summer I worked on a project called “High-Speed Electronic Speckle Pattern Interferometry of a Struck Circular Flat Plate.” The project actually found its roots in another project on which two of my colleagues were working. Laurie Stephey (Class of 2009) had been investigating the American five-string banjo for nearly three years by this point and David Parker (Class of 2008) was working on developing a theoretical model that would predict the resonant modes of the banjo head. Unfortunately, we found the banjo to be a very difficult instrument to model, so David decided to begin work on a model of a much simpler system - a circular flat plate. My faculty adviser (Thomas Moore) and I realized that experimental work needed to be done to verify the accuracy of Dave's model, so I began work on investigating how a circular flat plate reacts to being struck.
2. What was the research process like?
Our day started between 8 a.m. and 8:30 a.m. For the first couple of weeks of summer research, I was gathering data on how a circular flat plate reacted to being struck. This was done by use of a laser, a high-speed camera and electronic speckle pattern interferometry. Essentially, we illuminated the circular flat plate with laser light, which than reflected off the surface of the flat plate and interfered with light that originated from the same laser beam. Our high-speed camera imaged this interference and after some image processing, we could visually see how the flat plate was reacting to being struck. The amazing thing really was that we were able to combine a high-speed camera with interferometry in a way in which we could see how the plate began to vibrate. This allowed us to study how the plate began to move within the first one-one hundredth of a second after being struck. After we had produced some high-quality videos which clearly demonstrated how the flat plate began to vibrate, I spend the next couple of weeks beginning to understand the thin-plate theory and past research which presented information on the transient response of a struck circular flat plate. We also used the summer to begin to write the article which we submitted for publication as well as prepare for the poster talk I was giving at a conference in June.
3. How did the research project enhance your learning experience at Rollins?
Working in a laboratory provides you with a different set of skills that can't be taught in the classroom. While the classroom provides the basis for the knowledge that you ultimately utilize in a lab situation, there is something more immediate about using both your knowledge and your hands to solve a problem. You can't truly say you understand how an interferometer works until you've spent days setting one up and making sure it works properly and that your results are just mere accidents. Furthermore, lab research definitely forces you to think not only critically, but also creatively. Every day, you are presented with numerous problems, whether it be with poor laser alignment, terrible beam balance, or blowing up amplifiers, and you must think of a solution quickly. This research program also gave me the opportunity to present my work at an international conference of acoustics in Paris, France which is definitely something you don't get to do sitting in a classroom. It was an incredible experience to be able to converse with acousticians from all over the world and have them comment on your own work. I must say it's a bizarre feeling to have one of the leading researchers in your field walk up to you and begin to ask you questions about your work and converse with you like an equal.
4. What kind of unexpected problems did you encounter during the research?
Problems are an inherent part of laboratory research, but the biggest problem we encountered was actually after both the experimental research had been completed. We needed to determine why there were discrepancies between the theoretical predictions and the experimental evidence of how a flat plate began to vibrate immediately after being struck. It took weeks of digging through books on flat plate theory, published articles, and discussions with not only my professor, but scientists from all over the world to finally make some preliminary conclusions on our results.
5. To what professional publications did you submit your results?
We submitted our paper, "Transient motion of a circular plate after an impact" to the Journal of the Acoustical Society of America (JASA).