April 26, 2018
Ellis Johnson, Matt Persick, Ralph Hernandez, Zifan Lu and Erin Wynne will present their senior research.
Ellis Johnson & Matt Persick - “Light Pollution: The Mathematical Model and Theoretical Analysis”
The production of light has served as a milestone in human technological advancement however, it also has demonstrated how light can impact the world we live in. Light pollution, or the brightening of the night sky due to wasted energy and inefficient lighting from artificial sources is one of these impacts. Using the town of Carlisle Pennsylvania and Shippensburg Pennsylvania as a case study, this talk will address how light produced from various man-made sources can impact sky brightness and how alterations in outdoor lighting sources can minimize the effects of light pollution. By extrapolating the output of a single outdoor light source we developed broad-based assumptions about the light emitted into the sky by the entire town of Carlisle and compared the results to Shippensburg to verify our model. By comparing the output of the model to primary and secondary observational data sets from a Sky Quality Meter, we can display the light pollution with accuracy. Further research leads us to apply our model to surrounding towns in Pennsylvania.
Ralph Lawrence Hernandez & Zifan Lu - “Photometric Analysis of RR Lyrae Variable GM Orionis”
RR Lyrae stars are pulsating variables that have been used in determining the cosmic distance scale. There are currently seven known sets of observations of the RR lyrae Star GM Orionis since 1935. Taken at face value, the observations within the last 80 years indicate that GM Orionis, on average, has decreased in magnitude (an increase in brightness)—a rare phenomenon for the RR Lyrae Variable class. In our research, we will discuss the steps we took to analyze the most recent set of data of GM Orionis taken at the NURO Observatory during the Fall of 2017 and Spring of 2018. Our objective is to acquire a real magnitude, compare it with the historical observations, and test to see if the phenomenon is continuing today.
Erin Wynne - “Using an Arduino in a Coupled Logistic Map Circuit to Record Bifurcations and Chaos”
The logistic map is a simple non-linear dynamical system used to model the time-discrete growth of a population. In a previous project, a circuit was built that successfully reproduces the behavior of a system of two coupled logistic maps. However, the major limitation of this project was its non-automated data collection technique. In this project, the Arduino Uno microcontroller was used to improve data collection by running the timing of the circuit, incrementing the coupling voltage, and triggering data collection. The experimental bifurcation diagrams produced were compared to numerical simulations and found to have substantial agreement. One difference pertains to the selection of initial conditions. In the experiment, where we have no control of initial conditions, we found hysteresis behavior within the chaotic regime that was not present in simulations. Basic chaotic principles such as period doubling and the onset of chaos, in addition to more exotic behaviors such as “almost synchronized” and “anti-synchronized” chaos were observed in the experimental data. We are also able to explore the interaction between a chaotic and a cyclic oscillator.