Group Projects in Particle Physics: 
Going beyond ‘sliding blocks down ramps’

 

Daniel Friedman

St. John's School

Houston, Texas

April 2005

 

 

 

Student projects in particle physics were conducted during the 2004-2005 academic year, as a requirement of a Physics 1 AP course at St. John's School (SJS) in Houston, Texas.  This report describes the motivation for the project, development of project activities through the QuarkNet program and the implementation of the project.  Results are presented in the form of samples of student work and quotes from their feedback.  Plans for refining the project during the next academic year are discussed.

 

 

 

 

 

Introduction

 

I began work designing a student project in particle physics while participating in the QuarkNet program at the University of Houston (http://outreach.phys.uh.edu/quarknet.htm) during the summer of 2004.  QuarkNet, funded by the National Science Foundation and the Department of Energy, is a nationwide educational outreach in particle physics.  The program provides high school physics teachers with research experience and mentoring in collaboration with universities and national research labs (FermiLab, the Stanford Linear Accelerator, Argonne, Lawrence Berkeley Labs and Brookhaven Labs are among the participants).  A full-time staff at FermiLab manages the QuarkNet program (http://quarknet.fnal.gov). 

 

QuarkNet challenges participating teachers to bring their research experience back to their classrooms.  Using particle interactions as examples of physical processes is one means of meeting this goal:  Teach conservation of energy and momentum through particle collisions, rather than relying solely on bouncing balls and crashing cars.  QuarkNet’s goals may also be met through the use of longer-term projects, creating opportunities for students to research and explore aspects of particle physics in greater depth.  Discovering that they already know many of the basic principles involved, a well-designed project brings students to the point where they can see how those principles are applied.

 

Acknowledgements for this work are due to Dr. John Wilson, UH QuarkNet coordinator, Dr. Marg Corcoran at Rice University and Tom Jordan, QuarkNet project coordinator at FermiLab.  I also acknowledge the numerous sources for project materials; the quality of physics education improves each time a physicist posts a well-designed simulation on the internet.

 

 

 

Project motivation and development

 

Physics 1 APC is a relatively new course at SJS, offering a rigorous full year study of classical mechanics.  Students in this physics class must take an AP Calculus course during the same school year.  Co-enrollment in calculus and calculus-based physics provides students with immediate and tangible application of the equations they see and hear in math class. 

 

Labs and projects are the primary means of reinforcing the links between the disciplines.  Weekly labs give students regular experience in scientific process and a greater appreciation of content.  In Physics 1 APC, quarterly independent projects are designed to create more in-depth connections between the curriculum and the world beyond the classroom.   

 

The Mechanics portion of the Physics C AP exam is an expectation of Physics 1 APC.  Over the last two academic years, students taking both Physics 1 APC and Calculus BC achieved a very high percentage of 4’s and 5’s on both AP exams.  However, the course is far more than mere exam preparation.  The structure of Physics 1 APC allows a great deal of flexibility in content:  Topics outside the AP curriculum, including special relativity, wave motion and acoustics are discussed in some detail.  One of the goals of the course is to give students reason to strive for a greater degree of scientific literacy:  Assignments frequently require students to find needed information.  Students are routinely expected to analyze information and concepts, synthesizing the answers to questions and/or making independent judgments.

 

The companion to Physics 1 APC is Physics 2C (a full year of electromagnetism, with additional topics).  Designed for students who are at advanced levels in math, these two courses replace the traditional two-year sequence of an algebra-based Physics 1 followed by the calculus-based Physics 2 (containing both mechanics and electromagnetism).  Additional information regarding these courses of study may be found in the SJS Upper School curriculum guide, http://www.sjs.org/academics/curriculum/upper.asp.

 

Fifteen students (13 juniors, 1 sophomore, 1 senior) are enrolled in Physics 1 APC during the 2004-2005 school year.  Three students (the senior and 2 juniors) completed Calculus BC during the prior school year and are currently studying Multivariable Calculus and Differential Equations.  Eleven students (the sophomore and 10 juniors) are enrolled in “Calculus BC with Mathematica” (a laboratory-style math course).  The remaining junior is in the more traditionally taught “AB Calculus with Trigonometry.”  All of these math courses are challenging and fast-paced, covering more than a typical academic year’s worth of material. 

 

Physics meets seven class periods a week, allowing ample time for investigative labs.  Time is also built into both the student and faculty schedules to allow for tutorials outside of class.  By the winter break of the 2004-5 academic year, Physics 1 APC completed the introductory topics in classical mechanics:  Kinematics and dynamics of one and two dimensional motion, Newton’s Laws, work, conservation of mechanical energy and conservation of momentum.   The first two projects in the 2004-2005 academic year were (1) an analysis of a moving object using VideoPoint software and (2) an analysis of the physics (good or bad) of a scene in a popular movie (see http://www2.sjs.org/friedman/PhysAPC/projects.htm for additional details).  Each of these individual projects allowed students to select their own topic.  Students found that both of these projects were successful in drawing connections between the curriculum and their world.  For some students, the projects provided opportunities for self-teaching.  For example, in the first quarter project, a student analyzing velocity vectors of colliding billiard balls ‘discovered’ conservation of momentum (weeks before it was taught in class).  For both projects, each student prepared a brief presentation to the class to highlight their results.  Each completed project counted as 15% of the quarter grade. 

 

The beginning of the 3rd quarter was reserved for an extensive unit on gravitation and an introduction to special relativity.  I felt that in-class coverage of this material was a necessary preparation for the 3rd quarter particle physics project, which was to be the first long-term group project. 

 

During the QuarkNet summer at UH, I developed a particle physics webpage (http://www2.sjs.org/friedman/PhysAPC/particle.htm) with an extensive collection of links to reference materials and applet-based activities and simulations.  I developed a series of questions to accompany the background physics section, requiring students to visit the referenced links to find answers.  The remainder of the webpage consists of annotated links to activities or simulations developed by universities and research institutions.  These activities formed the basis of the 3rd quarter project.  As a result, rather than re-inventing the wheel by generating original activities, all I needed to do was assemble and coordinate the parts.  I did pre-test each application, to verify utility of content and consistency of pedagogical process.  As an administrative note, any web-based project requires periodic screening to ensure that all links are still working.

 

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Sample activities used in the particle physics project

 

Each project was based upon a simulation with an active component.  Simulations give students access to sophisticated experiments and provide rapid feedback.  A good simulation allows variation of parameters to test a hypothesis, allowing the student to play ‘what-if’  scenarios.  The best simulations have easily understood instructions and clear visual output.   

 

I use similar assignments, on a much smaller scale, for independent work throughout the year.  I find that giving students a brief introduction to a topic, together with a series of questions to be answered, to be a particularly effective teaching tool.  Web-based teaching tools, particularly Physlet-type simulations (http://webphysics.davidson.edu), are far more stimulating for students than ‘chalk and talk’ or ‘read the chapter and answer the questions.’  Classroom time and laptop computers are sometimes used for these assignments.  As students work through their simulations, I can walk around to answer questions.  However, this quarter project was the first time I implemented this technique on such a large scale. 

 

a.  Shown below is a double slit diffraction simulation developed by Kansas State for University for VQM.  Available parameters are for experimentation are particle type (each white tubes is a separate type of particle source), energy (or photon wavelength), source rate and slit separation. 

 

Each simulation run produces a panel such as those on the upper right.  By studying various patterns of photon diffraction, students can discover wave properties.  Using a particle source to produce a similar pattern leads to the conclusion that particles do indeed have a wave-like nature.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

b.  Shown below is a screen from the BaBar project, developed by SLAC.  This activity takes students through the exercise of identifying and reconstructing collision products from energy and momentum measurements using particle tracks.  This screen illustrates the project’s highly interactive, visual nature:  The three dimensional view of the detector rotates; the applied magnetic field strength is variable.  The curved tracks make clear the relationship between curvature and the simulation reports particle momentum and energy for subsequent analysis.

 

Instructions for this simulation guide students through the process one step at a time.  The visualization tool provided is an extremely powerful means of observing particle tracks.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

c.  Shown below is a sample screen from the X-ray spectroscopy project, developed at Lawrence Berkeley Labs.  The upper frame contains the spectrum of an unknown and the lower frame is the spectrum of a sample of pure copper.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Clearly, copper’s 8.1 keV peak is a major part of this unknown!

 

 

 

 

 

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Statement of expectations for this project

 

The project was assigned in early January 2005 with a due date of March 3.  Students were given this document, outlining the expectations for the project:

 

 

 

Initial results

 

Students quickly formed their own teams of two or three; selection of topics proceeded a bit more slowly.  I accepted project selections by email only so that I had a written record with time and date.  Duplicate projects were not approved (although setting multiple teams to the same project could create an interesting opportunity for competition between groups).  A few class periods were allocated for project work over the course of the quarter; the bulk of the work was done by students outside of class.

 

The following list shows the projects chosen, number of students on the team and source of project:

 

·        BaBar (3 students) – SLAC’s ‘B factory’ electron-positron collider experiment, http://freespace.virgin.net/j.allnutt/mphys2/babarteach/teach/top.htm

·        Muon lifetime (2 students) – QuarkNet  (Jeff Rylander), http://www.jlab.org/~cecire/muonexp.html

·        X-ray spectroscopy of chemical elements (2 students) – Lawrence Berkeley Labs, http://ie.lbl.gov/xray/

·        Wave-particle duality (3 students) – Matter Waves at Visual Quantum Mechanics (VQM)

·        http://web.phys.ksu.edu/vqm/tutorials/matterwaves/index.html

·        The Laser Adventures (3 students) – VQM http://web.phys.ksu.edu/vqm/laserweb/index.htm

·        Applying spectra and energy diagrams to stars (2 students) – VQM, http://web.phys.ksu.edu/vqm/tutorials/applyingspectra/

 

 

At an early stage, students reported that the background work was surprisingly time-consuming.  Some of the reference websites proved to be multi-page.  However, this objection seemed to disappear quickly, as professionally designed websites such as Particle Fireworks (http://pdg.lbl.gov/fireworks/intro_eng.swf) are beautifully constructed.

 

The project was administered over the course of the quarter with minimal input from me.  Students were given choices of how, where and when they would complete the project.  A few class periods were allocated to computer time specifically on the project.  Over the course of the quarter, there were few questions from students regarding their reading.  None of the student groups indicated any dissatisfaction with the quantity of work required.

 

It was clear that only a few of the groups got an early enough start.  Most of the groups worked in typical high school student fashion, leaving as much as possible to the last minute.

 

 

 

The physics questions

 

I conceived of the physics questions as a means to direct student research and stimulate deeper reading of the content of the component websites.  Answering the questions was by no means the main thrust of the work and the written answers did not figure as a large component of the overall project grading. 

 

Linked is a sample of these questions, required as independent work by each student.

 

 

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Notes from student presentations

 

Students presented their projects to the class on March 1 and 2, 2005.  The presentations were short (under 15 minutes each).  Several groups prepared PowerPoint presentations, although this was not a requirement of the project.  At the time of each presentation, the written work was also submitted.

 

Wave-particle duality was presented in a highly entertaining fashion:  a debate between “Professor Particle” and “Dr. Wave”.  The third student in this group served as the moderator and eventually proposed the compromise solution by reviewing deBroglie’s matter wave equation.  Examples and illustrations were chosen from the activity to illustrate key points.

 

The students presenting X-ray spectroscopy showed actual examples of their work, including a demonstration of identification of an unknown compound by matching its spectrum with known spectra of the chemical elements.

 

The group presenting lasers covered the photoelectric effect, electron energy states, with a voyage into quantum mechanics as well as optics.  One of the students in this group used Mathematica to determine laser wavelengths.  They concluded with a discussion of real-world applications (CD/DVD players, laser printers, nuclear fusion and holograms).

 

The students presenting stellar spectroscopy discussed the origin and interpretation of dark lines, citing the early studies of the solar spectrum as the means of discovery of the element Helium.

 

 

Student journals

 

Some of the journals included additional resources (webpages) located by students.  By requiring citation of the source for all such materials, new references will be added to the project for next year.  Journals also provide chronological evidence of progress as well as evolving conceptual understanding.  The following is an intriguing journal entry attempting to interpret the law of Reflection as a special case of Snell’s Law (figures omitted):

 

 

(sketch of reflected and refracted rays at a planar boundary)

 

 

 

 

“it seems as though reflection can be described with a negative index of refraction to air.  However the index of refraction for air is 1?  Curious!  It can be described with a negative index of refraction but I think it is a trick!  Let’s try that again:

 

 

 

 

 

 

(sketch of person looking at own image in mirror with left and right indicated)

 

“Reflections can be seen because the angle that comes out is the angle that goes in.  Unfolding [the reflected ray], it appears straight in the line of sight just as though you were looking at it.  So anything looked at is unfolded straight across from where it is.  This is where the left/right problem in reflections comes from. …  looking at someone else facing you, it is as if they were rotated around to face you producing the contradiction … scienceworld.wolfram.com was used as a reference.”

 

 

These handwritten notes show a lot of thought, as this student sought to create his own fundamental understanding of subtleties of geometric optics.  The ‘contradiction’ noted (an person’s right hand is the left hand of the person’s reflected image) is an example of a parity violation.  Although unaware of the process, this student experienced educational constructivism and now has a deeper connection to the law of reflection and Snell’s law than is usually achieved in the classroom.

 

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Quotes from student reflections (snipped, but not edited)

 

I value the student reflections as the main barometer of the success of this project.  Far more significant than the content of the project, these students have had successful exposure to a new world of physics and physics education.

 

“It is good to know that physics is not all about rolling balls down ramps.  In fact, I was fascinated by the particle physics research I did …”

 

“Although the particle physics questions were tedious, I think the activities and exploration of the websites were good ways to delve into particle physics without becoming overwhelmed with notes and lectures.  … doing more extensive group research on a topic of my choice was another good way to approach particle physics.  This project was actually fun!  And that is rare for quarter projects …”

 

“I found the questions for this project long and difficult but I think they taught me a lot in a short amount of time.    I believe this project gave me a good start for learning about particle physics.”

 

“This project was very meaningful to me because I was able to thoroughly learn and understand a very esoteric and daunting aspect of Quantum Physics … I enjoyed having the opportunity to be able to teach the class an interesting yet difficult concept … I was able to learn Physics on my own successfully …”

 

“Overall this project was pretty fun. … I definitely felt like I learned about my topic by looking at the applets on the internet, reading different sites and reading the textbook. The only complaint I have would be that some of the questions we had to fill out on the worksheet were difficult to find straight answers to on the internet.  Sometimes I feel that my interpretation of the information I found on the web didn’t exactly answer the questions accurately.  I posted most of the links from which I got my information, though.”

 

“To me, this project has been a great introductory example as to what physicists do.”

 

“This project took a lot of work, especially the questions … once I started reading information on my groups specific topic and doing related activities, I was more interested in the material and as a result I understood it better.  I’m glad we did this project … but honestly it was hell. … answering those questions made my eyes cross.”

 

“This project meant a lot to me.  Quite honestly, if it weren’t for this assignment, I would never have even considered the possibility of my understanding particle physics … with each new slide and webpage, I not only understood what was being described, but also became more and more interested in the subject.  … I am grateful that I had the opportunity to take an in depth look into this new topic.  … a great learning experience.”

 

“This is an interesting project.  I found a new way of looking at the connection between chemistry and physics.”

 

 “I think I would’ve liked some more class based guidance, because my grasp of some concepts in some case were tenuous at best … Over all, this was an intellectually stimulating project and I found it quite rewarding.  Good fun.”

 

“This project appealed to my attitude for learning outside of a structured course … .  By putting the learning in my own hands, I was able to learn at my own pace and in my own fashion.  … I discovered I could rely more fully on friends to help me through tougher concepts …”

 

“I feel that it was a foolproof alternative to an entire unit on particle physics because it also gave everyone in the class the chance to truly master a facet of the topic.  I willingly put more time and effort into researching and studying … I highly recommend that this unit is done similarly next year.”

 

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Peer assessments

 

A confidential peer assessment was included in the project to promote a measure of responsibility between teammates.  None of the students indicated any overt ‘slacking’ on the part of their teammates.  One team split into two during the quarter due to schedule conflicts and a new topic was chosen so that work could resume without too much delay.

 

“Everyone in my group worked very hard … we split up the work equally … we had a good time.”

 

“Working with my group was fun and efficient.  … everyone handled a separate part of our topic and willingly explained their findings to the others.”

 

“We each made the portion of the slideshow which we were presenting and did research concerning our topic.  We each had input on how the presentation would go and what we would include.  I felt like we worked well and evenly as a group during this project.”

 

“Honestly, we waited to a bit late to start the project. … the significance of our efforts was that we were able to come together and pull something coherent out of this madness. … Though we started late, because of the caliber of my partners, I really think this is going to turn out alright.”

 

 

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My reflection

 

I was overwhelmed with the high quality of the student presentations and the care many students took in researching the answers to the assigned questions.  The student reflections quoted above surpassed my expectations for the impact of this project on the class.  I believe that providing some freedom of choice over both project content and method of work contributed to the overall educational effectiveness that the students suggest.  A recurrent theme in the reflections is the pleasure that students took in a self-guided learning process. 

 

The project required a great deal of self-motivation on the part of the students; in part, the groupwork (and the peer evaluations) served as a motivator.  Clearly, this class is comprised of exceptional students; my challenge was to capitalize on their maturity and responsibility and grant them a share in the control of their educational process.  I believe that this project helped these students move a bit further along the road towards scientific literacy.

 

With apologies to the one student who found the project to be ‘hell,’ I believe that the physics questions were necessary guideposts for the background reading.  I wonder how much detail would have been glossed over without the questions.  The project may benefit from a degree of additional structure on the research end and less in terms of questions.  I am considering some refinements for next year. 

 

 

 

Refinements under consideration

 

·        Publicize the project expectations and scope during the 2nd quarter, so students can do background work over winter break if desired.  Spend at least one class period discussing this year’s work – if for no other reason, then to provide a model of a successful project.

·        Reduce the number of questions to be answered in the individual portion; require early submission of the answers to prevent students from waiting until late in the quarter.

·        Establish a system of milestones to be met throughout the quarter.  Meet with groups to discuss their journals and progress. 

·        Use an email or bulletin-board forum for student reporting or discussion of questions.  Devote additional class time to questions and answers during the course of the project.

·        Create or identify a project on accelerator and/or detector design.

·        Create a project using publicly available particle detector data (such as cosmic ray or neutron monitoring data).  Investigate sharing the results of such projects through the grid computing resource at FermiLab.

·        Include some historical reading material, perhaps from Lederman’s ‘The God Particle,’ Gel-Mann’s ‘The Quark and the Jaguar,’ a Feynmann story or two, Herman Wouk’s ‘A Hole in Texas’ or similar non-technical source.

 

 

 

Summary:  Steps in implementing this group project:

 

·        Assignment and discussion of expectations

·        Formation of groups (2-3) student each

·        Selection and approval of topics

·        Background research – Class time for initial work

·        Student responses to background questions

·        Student presentations to class

·        Written work (journals) submitted

·        Reflections and peer evaluations

 

 

 

Acknowledgements - Project source material

 

 

BaBar – Josey Allnutt, University of Manchester

Lasers  - Rami Arieli, Weizmann Institute

Muon lifetime – Ken Cicere, Jeff Rylander, QuarkNet

Xray spectra – Eric Norman, Lawrence Berkeley Labs

Wave particle duality and stellar spectra – Physics Education Group at Kansas State University

Foxtrot (inspiration, below) – Bill Amend


 

Sample slides from student presentations

 

 

 

 

 

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April 8, 2005