2022 Physics Capstone Symposium

Senior Physics capstone presentations will take place Wednesday, May 18th starting at 2pm in Morken 103. If you’d like to join the capstone Zoom session, please email Professor Rich Louie at louie@plu.edu.

2:00pm Kelly Pham – “Airstream Magic: ‘Levitating’ Tower of Spheres”
This capstone project focuses on the physics behind balancing spheres within a vertical column of air. A physical model relating the ball radius, mass, terminal velocity, equilibrium height, and the drag coefficient is analyzed for experimental viability.

2:15pm Duncan Haddock – “Optimization of Organic Electrochemical Transistors”
Weight fraction blends of a charge-conductive and an-ion conductive ROMP-based polymers were used in an analysis, characterization, and optimization of ion transport through organic electrochemical transistors.

2:30pm Kyle Cross – “Analysis of a double pendulum”
A two-armed double pendulum was constructed, and video of its movement was analyzed using Tracker software and compared to the numerical solution of the associated differential equation. The velocities of the bobs at the bottom of the arc were compared to those predicted by the mathematical model.

2:45pm Hannah Tate – “Cosmological Possibilities: Extra Dimensions and Apparent Horizons”
Einstein’s theories of relativity have allowed scientists to probe the nature of the Universe, revealing its intricacies. We explore fundamental properties of spacetime, the possibility of extra spatial dimensions, and the constraints on such phenomena.

3:00pm Erick Arcos – “Propeller Lift Coefficient”
A toy hovercraft propeller was rotated at various speeds using an Arduino microcontroller and a brushless DC motor. The experiment compared the lift produced by the propeller to predictions of a mathematical model, and determined the propeller’s lift coefficient.

3:15pm Andrea Irwin – “Numerically Modeling the Navier-Stokes Equations”
This project runs a simulation of fluid flow. It uses the Unity game development engine and a graphical processing unit. The goal is to compare it to known solutions of the Navier-Stokes (fluid flow) equations, and gauge its accuracy while running in real-time.

15-minute break

3:45pm Joseph Sweitzer – “Measuring the Bandgap of Intrinsic Silicon”
Electrical measurements were performed on an undoped (“intrinsic”) silicon thermistor, a semiconducting device where the carrier concentration and mobility are temperature-dependent. This project determined the bandgap energy of silicon by measuring the thermistor’s resistance as it was heated, finding Eg = 1.072 eV (~4% from the accepted value).

4:00pm Ben Poplin – “Investigations with a Fluorescent Microscope”
Fluorescence microscopy is an important technique used in the life sciences and physical sciences. A Nikon Eclipse 80i fluorescence microscope system was used to obtain images at 3 excitation wavelength ranges, seeking optimal exposure and software settings. Commercial and open source software tools were then used for post-processing and image analysis.

4:15pm Suzanne Shumaker – “The Moments of Inertia of a Racquetball Racquet”
The moments of inertia (moi) of a racquet about 2 particular axes are interesting: the moi about an axis along the handle determines how resistant the racquet is to twisting in one’s hand when the ball is hit off center, and the moi about an axis passing through the hand, perpendicular to the handle and parallel to the racquet head reveals the weight of the swing. Results are determined for 5 racquetball racquets and compared to a similar experiment regarding moments of inertia for tennis racquets.

4:30pm Evan Ringler – “Simulations and Analysis of Tiered Scoring Systems”
An example of a 3-tiered scoring system is in tennis, where m points are required to win a “game”, n “games” are required to win a “set”, and p “sets” are required to win the entire match. Monte Carlo simulations of 2-tier, 3-tier, and 4-tier scoring systems are performed and compared to theoretical results from the negative binomial probability distribution to investigate trends in the match win probability.

4:45pm Abby Trenary – “Among Giants: Searching for Stable Orbits of Rocky Planets Between Jupiter and Saturn”
The project was to numerically solve the problem of 2+ astronomical objects interacting under the influence of their mutual gravitational attraction (“N-body problem”). The goal was to determine which initial parameters, if any, could allow for a small, rocky planet to orbit between the gas giants Jupiter and Saturn.