Spring 2020 Meeting of the Illinois Section of the AAPT

"Online meeting of ISAAPT due to COVID-19 situation"

April 24, 2020

Online resources courtesy of Department of Physics, University of Illinois


We are pleased to invite you to attend the Spring 2020 online meeting of the ISAAPT. Join us by Zoom to learn more about physics, discover new tools and techniques for teaching physics, and share your experiences via contributed presentations.

All those who are on the ISAAPT membership listserv will receive the Zoom invitation to this event.

Contributed Presentations

9:15 am

A1. The Spread of COVID-19: Analysis of Current Data and Research

*Mark Mathison and Narendra Jaggi - Illinois Wesleyan University - 5 - Student Research

Traditionally, data about pandemics (deaths, new cases, recoveries, etc.), including the COVID-19 pandemic, is presented as a time series. I will present a slightly novel way of viewing the data related to the COVID-19 pandemic that makes it much easier to recognize different regimes in the data where growth is exponential and where it has deviated from an exponential model.

In addition, I will provide a short exploration and summary of literature published on the basic reproductive number of COVID-19. There is a wide variety in these estimates, and I will present my attempt to understand and reconcile the differences in these findings.

9:30 am

A2. Using Mathematical Models to Determine the Basic Reproduction Number in Infectious Diseases

*Steven Raybould and Narendra K Jaggi - Illinois Wesleyan University - 5 - Student Research

I have explored the existing literature to determine how the SIR (Susceptible-Infected-Removed) model of infectious diseases can be used to determine the key factors of the so-called Basic Reproduction Number for any infectious disease. I have also used some online simulation tools to develop an intuition for what determines the value of Basic Reproduction Number, and how these values are, in turn, used in guiding control strategies, including finding the minimum threshold of vaccination needed for herd immunity. I will share some of my experiences and conclusions.

9:45 am

A3. Effects of Diamagnetism on Current Sheet Equilibrium

Jonathan Sullivan-Wood - Illinois State University - 5 - Student Research

Earth’s magnetosphere is very complicated nonlinear system with many regions interacting with each other. Here, we work to model magnetic reversal in the plasma sheet of Earth’s magnetotail. Using the Modified Harris Model we self-consistently calculate B-Field reversals accounting for both bound current density from diamagnetism and for a free current in the midplane. We also show transient, chaotic, and integral ion orbits and a simulation of separatrix crossing.

10:00 am

A4. Effects of edge roughness on artificial spin ice magnetoresistance signatures

*Minzhao Liu, Narendra Jaggi - Illinois Wesleyan University - 5 - Student Research

We investigate the effect of edge roughness on the magnetization and magnetoresistance (MR) response of a brickwork artificial spin ice (ASI) system to an applied in-plane magnetic field that is cycled quasi-statically to enable us to focus on the hysteretic features of the MR response. Specifically, we study the changes in these responses due to controlled amounts of edge roughness by combining electromagnetic and micromagnetics simulations. We identify three main effects of edge roughness. It systematically reduces the magnitude of the overall longitudinal MR response, and it deepens a particular well-established prominent characteristic signature of longitudinal MR curves in the brickwork ASI system. In addition, we find that a specific feature in the transverse MR migrates to smaller coercive fields as edge roughness increases. By a close inspection of the evolution of spin density maps at various stages of the hysteresis cycle for different amounts of roughness, we are able to identify visual models/descriptions of the physical processes that are linked to the emergence and evolution of these features. Specifically, the first two aspects are connected to the amount of distortion of the local spin density away from the long axes of the nanowires. An increased transverse (cross-wire) edge roughness energy density is identified as a coarse grained explanation for this particular distortion. The third feature is connected to the difference between the magnetization reversal mechanisms that appear to dominate horizontal and vertical sections (nanowires) in the rough system.

10:15 am

A5. Machine learning and artificial intelligence applied to acoustics

Jack Yost*, Xing Fang, Q. Charles Su, Rainer Grobe - Illinois State University - 4 - Research

Neural Networks have a wide variety of applications in modern computing and one of these applications is the ability to effectively distinguish between different voices. Using data obtained from the Wolfram Data Repository, we are able to develop and train a simple network capable of not only distinguishing but identifying human voices by recognizing acoustic characteristics beyond even the capabilities of the human ear. We will discuss how the computer is able to read information from data files with the help of different mathematical operations and how the computer uses that information to correctly identify different vocal patterns. We will also be discussing the structure of our network and just how simple it is to reproduce.

10:30 am

Coffee break (get your own coffee!). Zoom will remain open if you wish to converse.

10:45 am

B1. GPU in Zernike Polynomical Adaptive Optics Atmospheric Aberration Correction and Epidemiology

*Minzhao Liu, Narendra K. Jaggi - Illinois Wesleyan University - 5 - Student Research

Graphic processing unit (GPU) acceleration is now widely available to researchers and students, enabling unprecedented speed of progress in science and technologies. Two fields in which GPU acceleration is implemented in Illinois Wesleyan is Optics and Epidemiology. Real time atmospheric aberration correction for free space laser communication is challenging due to the high rate of aberration change. Deep neural networks were proposed to speed up aberration correction using Zernike polynomials, commonly used to represent optical aberration. We attempt a physical implementation of this scheme using a spatial light modulator, with GPU accelerating the generation of aberration correction profile from the polynomial coefficients. On the other end, epidemic simulations using networks mimicking real-life social networks are studied to understand the effects of network degree distribution and clustering on the spread of diseases. We propose a GPU accelerated program to enable parallel execution of hundreds of simulations with different epidemiological parameters to help researchers quickly characterize response surfaces of these parameters.

11:00 am

B2. Symbiotic vs. non-symbiotic optimization for spatial and temporal degrees of freedom in pair creation

Jordan Bryan*, Q. Charles Su, Rainer Grobe - Illinois State University - 4 - Research

The field-induced decay of the quantum vacuum state associated with the creation of electron-positron pairs can be caused independently by either multi-photon transitions or by tunneling processes. The first mechanism is usually induced by appropriate temporal variations of the external field while the second (Schwinger-like) process occurs if a static but spatially dependent electric field is of supercritical strength. The ultimate goal is to construct an optimal space-time profile of an electromagnetic field that can maximize the creation of particle pairs. The simultaneous optimization of parameters that characterize the spatial and temporal features of both fields suggests that the optimal two-field configuration can be remarkably similar to that predicted from two independent optimizations for the spatial and temporal fields separately [1]. This work has been supported by the NSF and Research Corporation.

[1] J. Unger, S. Dong, J. Bryan, Q. Su and R. Grobe, Phys. Rev. E 101, 013310 (2020).

11:15 am

B3. Detecting Products of Ion-Neutral Reactions in the Interstellar Medium

*Sarah Pombar and Manori Perera - Illinois Wesleyan University - 5 - Student Research

In order to make progress in our understanding of chemistry in the interstellar medium, we need to look into the ion-neutral reactions in the gas phase that occur. We have built a custom designed instrument in order to recreate these reactions in the lab. I will go over the designing and building of the octopole ion guide that will be used to steer ions in the vacuum. Some of the potential work using this instrument will be presented as well.

11:30 am

B4. Dirac vacuum can resolve rapidly chirped external fields

Chi Gong*, Q. Charles Su, Rainer Grobe - Illinois State University - 4 - Research

We study the dynamical response of the Dirac vacuum state to a very strong time-dependent electric field pulse, whose frequency is chirped in time [1,2]. The resulting field-induced electron-positron pair creation process can be used to examine various proposals for time-dependent frequency spectra of the external field. It turns out that the Dirac vacuum can be used as sensitive probe that can respond to the instantaneous values of the frequency at each moment of time by producing electrons with the appropriate energy. This almost instantaneous response feature of the vacuum state permits us to introduce a new generalized rate-equation. It is based on the concept of a time-dependent decay rate and can provide semi-analytical solutions to predict the number of created electron-positron pairs during the interaction with arbitrary chirped electric field pulses. This work has been supported by the NSF, Research Corporation, and the China Scholarship Council program.

11:45 am

B5. Changes in student attitudes and curricular benefits as a new course activity becomes standard

*Katie Crook, Amber Sammons, Grant Kaufman, Rebecca Rosenblatt, and Raymond Zich - Illinois State University - 2 - Teaching Methods

An instructional intervention consisting of students interacting with eight short videos on scientific topics was introduced to a general education physics class. The effects of these videos on student attitudes about science and their scientific reasoning skills were assessed by comparison of pre- and post-test data from the CLASS and Lawson’s Test of Scientific Reasoning for two control and three treatment semesters. Initial findings showed improved student attitudes toward science and improved scientific reasoning skills. With continued use of the videos in additional semesters, similar pre-post gains in scientific reasoning skills were observed, however, less improvement in student attitudes toward science was measured. This decrease in improvement of student attitudes as the new course activity became standard has implications for the number of semesters a new curriculum aimed at improving student attitudes should be studied. Most new curricula only report a semester or two of results before wide implementation occurs.

12:00 pm

Lunch (On your own). Zoom will remain open if you wish to converse.

1:00 pm

C1. Investigation the effectiveness of two simulation-based curricula for teaching fluid concepts

*Jeffrey Rosauer, Justin Szela, Amber Sammons, Grant Kaufman, Rebecca Rosenblatt, and Raymond Zich - Illinois State University - 4 - Research

Student difficulties with fluid statics and dynamics concepts often persist with conventional instruction. Two curricula were developed using a simulation to improve student understanding of fluid statics and dynamics taught in an introductory algebra-based physics course. A guided inquiry session that uses the PhET simulation “Fluid Pressure and Flow” was compared to a twice-watched 10-minute video that integrates voice-over explanations and real-life examples with recorded demonstrations using the same simulation. Screen capture videos were made of students completing the guided inquiry tutorial using the PhET simulation, and these videos were studied using qualitative thematic analysis to identify common actions and patterns of actions as students worked through the curriculum. Pre- and post-activity assessments of student knowledge of fluid speed and pressure in pipes were made. These data were examined to establish what connections exist between actions made while working with the simulation and changes in students conceptual understanding of fluids.

1:15 pm

C2. Changes to equipotential diagrams to improve student ranking of electric potential

*Andrew Princer, Amber Sammons, Jeffrey Rosauer, Rebecca Rosenblatt, and Raymond Zich - Illinois State University - 4 - Research

This study extended prior research on students’ difficulties with equipotential diagrams and the effect of visual modifications to these diagrams on students’ ability to correctly interpret these diagrams. Equipotential diagrams were modified by adding color, additional markings, and increased symbol sizes to emphasize the signs of the electric charges and the value of the electric potential. A prior study showed equipotential diagram modifications significantly increased student gaze times at the diagrams without increasing students’ overall correctness rates. In this study we present the results of further modifications on students’ proficiencies in reading equipotential diagrams and ranking electric potential. Students were randomly assigned to two treatments where presentation order of traditional and modified diagrams was varied and were asked to compare electric potentials for indicated points on the diagrams. Comparisons between the treatments and the results of student interviews are presented to clarify the specific issues students have reading equipotential diagrams.

1:30 pm

C3. Participation and Expansion in the Step Up program

*Emily Steininger - Illinois Wesleyan University - 5 - Student Research

Working in collaboration with AAPT and the Step Up program, a group of undergraduate student leaders have created a community outreach chatroom on Discord to further expand connections of the STEM community. In addition, I would discuss the lessons plans and structure provided for this program targeted toward high school teachers.

1:45 pm

C4. How did Huygens Measure the Refractive Indices of the Calcite Crystal?

- Western Illinois University - 4 - Research

Christiaan Huygens is a genius in the study of wave propagation in media. Huygens’ principle states that when a wavefront meets a medium, it emits secondary wavelets. The new wavefront is the envelope of the wavelets, and a ray travels from the source of a wavelet to where it touches the envelope. This principle first appeared in his famous book “Treatise on Light”, where he studied ray refraction in a calcite crystal. In the book he mentioned the size of the ellipsoidal light wavelet, which gives the ordinary and extraordinary refractive indices of the crystal, without giving explicit proof on how the values were obtained. In this presentation, I will follow his book and discover how Huygens actually measure the refractive indices of the calcite crystal.

2:00 pm

C5. Student Center Remote PBL Structure

*Michael Zwartz *Abel Farias - Joliet Township High School District - 2 - Teaching Methods

In this talk, we will discuss a project based learning structure that is being used by the teachers at Joliet Central and Joliet West High Schools. The project based learning task is designed to span 10 days. The PBL structure was made in compliance with the NSTA project based learning rubric. This structure is meant to support students scientific curiosity and research skills. We will present an outline that can be adapted for any essential question a teacher would like their students to investigate. Also, we will present and share materials used in the electromagnetism unit for 10th grade physics students.

2:15 pm

Break (Bring your own cookies)

2:30 pm

D1. Lemons to lemonades: Transforming the last three weeks of a Signature Experience Seminar

Narendra Jaggi - Illinois Wesleyan University - 2 - Teaching Methods

One of the three courses I was teaching during Spring 2020, Signature Experience Seminar, had to be, by necessity, completely reimagined after the extra week of spring break followed by a locked down campus. I will share my experience of conceiving this course differently, in a rather abrupt fashion, having students buy into the proposal, and then teaching/learning about mathematical and computational approaches to understanding and predicting the behavior of the COVID-19 pandemic.

2:45 pm

D2. Online Labs

Zak Knott - Joliet Central HS - 2 - Teaching Methods

With the sudden onset of remote learning I wanted to keep the lab experience for my students as similar to what they had done in class as possible. I will share the resources and templates I utilized as well as student work.

3:00 pm

D3. Goals for on-line labs

Tom Foster - Southern Illinois University Edwardsville - 1 - Active Learning

The COVID-19 pandemic and the temporary end to face-to-face laboratory has provided a unique opportunity to see what faculty value in the laboratory course.

3:15 pm

D4. Teaching Online Learning Assistants

Morten Lundsgaard - University of Illinois at Urbana-Champaign - 2 - Teaching Methods

In this presentation, I will discuss the status of the Learning Assistant (LA) program at U of I in general but and, how in particular we have dealt with teaching LAs online.

When forced to teach online, we had to come up with online tasks that would substitute the LAs’ assignments to help in the now cancelled lab sections. In the presentation, I will present some of these tasks and the LAs reactions to them.

Host - Morten Lundsgard, mlundsga@illinois.edu