Presentations

Active Learning

John Baier, johnbaier@isp.com  or
                     john_baier@glenbard.org
Active Learning, Friday afternoon
Equipment needs: None
Comments:  Please schedule me after 3:00 pm on Friday.

Inexpensive equipment for circuits and resonance. John Baier, Glenbard South High School, Glen Ellyn, IL 61037.

Covers for one and two inch diameter four foot long fluorescent tubes can be used to do resonance and the speed of sound. I will also show an inexpensive way of using a 4x6 inch board with nails to do series, parallel, and other simple circuits.

Make Your Own Helmholz Resonator. Lenore Horner, SIUE, Edwardsville, IL 62026.

Most people have blown across the top of a bottle to produce a pitch and in general taller bottles produce lower pitches. Introductory physics classes inadvertently perpetuate this over simplification by teaching about pitch in cylindrical wind instruments where longer instruments produce lower pitches. I present a relatively cheap and simple in-class activity where students can discover for themselves that the pitch of a bottle is more complicated than that of a cylindrical instrument.

At Southern Illinois University Edwardsville, we have restructured our introductory astronomy course to include hands-on inquiry-based in-class group activities. These activities utilize a modified learning cycle approach to cover specific astronomical concepts that traditionally resist conceptual change, such as phases of the moon and seasons, or that students have difficulty mastering, such as Hubble's law and the Hertzsprung-Russell diagram. Each group activity is designed to be completed during one 50-minute class period and utilize hands-on equipment whenever possible. In this workshop we will discuss the design and implementation of these group activities into our introductory astronomy course, as well as results of evaluation of the successfulness of these activities at promoting conceptual understanding and reasoning skills.

Teaching Methods

Group Work in the Introductory Astronomy Class. Noella D'Cruz, Joliet Junior College, Joliet, IL 60431.

Research has shown that one of the ways students learn is through social interactions. This semester I have incorporated a substantial amount of group work in my introductory astronomy class to enable my non-science major students to learn the material more deeply through interactions with each other. I will discuss group projects, group tests, and other activities that my students are involved in.

Demonstrations

Using the Wiimote to teach Mechanics. Lenore Horner, SIUE, Edwardsville, IL 62026.

The remote for Nintendo's Wii gaming system has a built-in 3-axis accelerometer and some position capability. I will illustrate the possibilities and pitfalls of using the remote to teach elementary kinematics.

Research

Like many terminal masters programs, SIUE faces a shortage of qualified graduate students and thus risks elimination during funding crises. To better understand this problem, we undertook a research study investigating why students pursue terminal masters degrees in physics. As part of this research we collected survey data from nearly half of the identified terminal master's programs in the US. In addition, we conducted site visits at three institutions to determine why they produced nearly twice the national average of master's degrees in year. Results of this research will be presented.

Student Research Symposium

Jacob Brown, JE-Brown2@wiu.edu
Student Research Symposium, Either day
Equipment needs: Powerpoint file

The Mass-Radius Relationship of Neutron Stars. Jacob Brown, Western Illinois University, Macomb, IL 61455.

I will start off by explaining the different principles that are important to finding the mass-radius relationship. This will include the Pauli principle for compact stars vs. gravity, the Tolman-Oppenheimer-Volkov equation, and the many different equations of state. Next I will go into the project that I have been working on to create a flexible program that will allow us to take different equations of state and compare them to find the ultimate equation of state. The final part of my presentation is to go into the goals for the future that I want to attempt to do in getting this program up and running.

Application of Molecular Dynamics to the Simulation and Visualization of the Motions of Gas Atoms. Daniel Rolando, Jie Zou, Eastern Illinois University, Charleston, IL 61920.

This project applies a computational method, Molecular Dynamics, to the study and simulation of the microscopic interactions and the resulting motions of gas atoms. The current study is carried out for a simulation cell of fifty Argon atoms based on the approach in Ref. [1]. Future study will be performed for other materials, such as silicon. The force between atoms is modeled by the Lennard-Jones pair potential. The atomic positions and velocities are computed as functions of time by numerically integrating Newton's Equations of Motion based on the finite-difference method. A computer program is written in MATLAB to implement the numerical algorithm. The obtained atomic trajectories are presented in both still images and animations. The animations will help students visualize the motions in a many-particle system. Equilibration and equilibrium properties, such as the velocity distribution, are also studied. [1] N. Giordano and H. Nakanishi, Computational Physics (Addison-Wesley, 2006), 2nd ed.

CDMS Veto Stability Study and Calibration. Gabriel Caceres, Augustana College, Rock Island, IL 61201.

Most experiments searching for dark matter particles have been led deep underground to minimize the background produced by cosmic rays. The Cryogenic Dark Matter Search (CDMS) lies 1/2 mile underground in the Soudan Mine in Minnesota. Even though the muon rate is lowered by a factor of 10^5, the rate is still high enough to produce background signals. To solve this problem, scintillator panels have been placed around the detector to veto cosmic induced events. This work studies the behavior over time of the scintillator veto panels. By analyzing and tracking the response to a LED pulser system, the stability was determined to be within 3%. The absolute energy scale of the spectrum was then calibrated using radioactive sources, as well as the muon distribution. Knowing the absolute energy scale and where the veto trigger threshold lies provides useful information for calculating the amount of background that can be rejected.

The angular dependence on the efficiency of crossed polarizers was measured. Polarized light with axis perpendicular to the transmission axis of a polarizer was incident on that polarizer. Transmitted light was measured with lock in amplification. The efficiency of the polarizer was measured as a function of incidence angle for the light. Data will be presented indicating that the polarizer transmits less than 1 part in 10,000 of the incident light it but this efficiency can change by a factor of 4 over an angular incidence range of about 10°.

Investigation into Factors Affecting the Operating Deflection Shapes of a Mandolin.  Thomas Traynor, Illinois Wesleyan, Bloomington Il, IL 61701. Like any vibrating object the front and back plate of a mandolin will have mode shapes and operating deflection shapes when vibrated. The goal of this project was to test whether or not shaking the front plate, a common practice by luthiers during construction, changes the operating deflection shapes that occur during the vibration of the front plate. Some luthiers claim that shaking the front plate during construction will actually break down some of the cellular structure in the wood causing the instrument to have a better sound, like a well played mandolin. Using speckle pattern interferometry, the front plate of a mandolin was characterized during construction before and after it had been shaken. This data will also be compared to the analysis of the front and back plate of a student mandolin.

Limitations of Decomposition Based Imaging. Sebastian Grobe, University High School and ILP, Illinois State University, Normal, IL 61790.

We examine theoretically and experimentally an imaging scheme that uses the scattered light intensity profile to reconstruct the locations of absorbers embedded in a turbid medium. This method is based on an a priori knowledge of the scattered light patterns associated with a single absorber that is located at various positions inside the medium. We discuss the range of validity of this method, its sensitivity with regard to noise and propose an algorithm to improve its accuracy.

Calibration of Webcams for Imaging. Sawyer Campbell, Intense Laser Physics Theory Unit, Illinois State University, Normal, IL 61790.

We generalize a previously proposed imaging scheme to situations for which the set of hidden objects embedded in the highly scattering medium can take arbitrary shapes. We compare the accuracy of images obtained from optical detection fibers with those from a CCD camera. The latter approach is more efficient and can be applied to non-contact geometries, but it requires an a priori linearization of the obtained digitized images. We discuss some details of this calibration for the camera and establish its potential as a new tool for decomposition based imaging.

Classical Phase Space Approach to Pair-Creation. Nic Chott, Intense Laser Physics Theory Unit, Illinois State University, Normal, IL 61790.

We explore the mutual coherence properties of electrons that are created by a sub-critical time-dependent force field. We compare the spatial evolution of the quantum field theoretical density with that of a relativistic classical mechanical ensemble. We find that portions of the electron cloud that were created sufficiently far from each other are not able to show interference patterns as they pass each other. The corresponding classical phase space density reveals interesting spiral shaped gaps, which have their manifestation in the corresponding quantum field theoretical data.

Role of External Forces in Pair-Creation. David Wischhusen, Q. Su, R. Grobe, Intense Laser Physics Theory Unit, Illinois State University, Normal, IL 61790.

Relativistic quantum electrodynamics describes the complicated quantum field theoretical nature of electrons and positions during the interesting process of their creations. Theoretical studies to date about these interactions are limited by our ability to obtain and analyze the solutions for the complicated systems. The newly developed computational quantum field theory has opened the field to answering many fundamental questions. Many famous mysteries such as the Klein paradox and the Zitterbewegung have been revisited and could be resolved. The validity of some models, on the other hand, has been questioned concerning important issues regarding locality and causality during these processes. I am proposing a set of computer simulations to investigate the effects due to a scalar potential versus a vector potential to model an external force. This work will help us to understand the fundamental nature of locality and causality.

Monte Carlo Simulations to Optimize Portfolios. Matthew Norton, Q. Su, R. Grobe, E.A. Norton, Intense Laser Physics Theory Unit, Illinois State University, Normal, IL 61790.

The counter intuitive reduction of the variance for a combination anti- and uncorrelated random signals is not only of interest in statistical physics but of essential importance in understanding the multi-stock portfolios in the financial world. The balancing (minimization of the variance) of portfolios has been intensely studied by Markowitz, Michaud and Ibbitson. I will use random number based Monte-Carlo numerical simulations to study the stability of the weights that characterize a particular portfolio. I will study the sensitivity of the optimization with regard to a small variation in the parameters that define the random signals. I will also examine the question whether the optimization operation and the time averaging commute. This question is non-trivial as the optimization can be a nonlinear process for which is it difficult to get a good intuition.

Laser Beam Widening Mechanisms in Turbid Media. Tim Garvin, Intense Laser Physics Theory Unit, Illinois State University, Normal, IL 61790.

We examine theoretically and experimentally the transverse intensity profile of a laser beam as it traverses through a turbid medium. By increasing the concentrations of milk in an aqueous solution we examine the transition from the weakly scattering to the diffusive regime. The experimental data of the transverse beam profiles are inferred in a non-contact geometry from photos of the exit surface of the medium for various scattering strengths. The intensity distributions are compared with theoretical data are obtained from Monte Carlo simulations.

Using Shadows in Imaging in Highly Scattering Systems. Isaac Goodin, Intense Laser Physics Theory Unit, Illinois State University, Normal, IL 61790. We suggest that the concept of the point-spread function traditionally used to predict the blurred image pattern of various light sources embedded inside turbid media can be generalized under certain conditions to predict also the presence and location of spatially localized absorbing inhomogeneities based on shadow point spread functions associated with each localized absorber in the medium. The combined image obtained from several absorbers can then be decomposed approximately into the arithmetic sums of these individual shadow point spread functions with suitable weights that can be obtained from multiple regression analysis. This technique permits the reconstruction of the location of absorbers.

Other

Jeff Chamberlain, jchamber@ic.edu
Other, Either day

Economy Robot using the SX Chip: The Programmable Acceleration Car. Jeff Chamberlain, Illinois College, Jacksonville, IL 62650. This project modified a radio-controlled car by replacing the motor control circuitry with a simple circuit using the SX microcontroller. Programs in BASIC control the motor allowing a wide variety of motion. LED indicators and pushbutton switches were added to the car's body to create a self-contained variable acceleration car. Potential experiments in basic mechanics and in robotics will be discussed.