Nicole Held, Sven Hendricks, Heiko Moors
Our project started with the goal of building a Michelson interferometer and using it for measuring distances and velocities. However, initial experiments failed as our apparatus was extremely sensitive to vibrations. We addressed this problem by building an optical table from sand and tire inner tubes. This provided a vibration-free support for our laser apparatus. We decided to exploit the high sensitivity of our apparatus to measure plant growth. For this, we had to design a mechanism that would allow plants to be connected to our interferometer in a way that would allow measurements of their growth. We succeeded by using a pulley, a transparent plastic lid and a variable weight. Our mechanism significantly reduces the force needed to move the relatively heavy mirror of our interferometer. We conducted short growth measurements using cress. The measured values were recorded using an electrical chart recorder and a light dependent resistor. Other experiments on different plants, such as sunflowers and runner beans, are in preparation. We hope to be able to report several interesting results in February.
