145
July 26–30, 2014
Wednesday afternoon
GH03:
1:20-1:30 p.m. A Dissociated, Progressive Introductory
Physics Laboratory
Contributed – Bruce Thompson, Ithaca College, Department of Physics and
Astronomy, Ithaca, NY 14850;
I am the current caretaker and reviser of an introductory mechanics
laboratory in the first-year curriculum at Ithaca College. Substantial revi-
sions since its inception in the 1980s have created a coherent laboratory
experience that alumni remark upon as having continued relevance in their
careers. The course is dissociated because students take it in the semester
following their introductory mechanics course. It is progressive because
multiple themes and skills are developed and refined over the course of the
semester. Some of these themes are: logical thinking (digital circuit analy-
sis, trouble shooting, raw data evaluation), dexterity skills (circuit wiring,
Erector Set skills), physics (linear kinematics, pendular motion and energy,
rotational dynamics), modeling (increasing sophistication in linearized
modeling and model verification), analysis (linear graphical analysis by
hand, min/max error propagation, spreadsheet calculation and graphing),
communication (binary reporting, summary reports, extensive report). I
will present an overview of the course.
GH04:
1:30-1:40 p.m. Learning: Two Steps Forward, One Step
Back
Contributed – Nathaniel Lasry, John Abbott College, Hampstead, QC H3X
3A2 Canada;
Eric Mazur, Harvard University
Jonathan Guillemette, John Abbott College
Previous work on how students change conceptions in introductory phys-
ics courses has focused on conceptual gains without taking losses into
account. We analyze Force Concept Inventory data collected before and
after an introductory course for 13,422 students learning physics in high
schools, two-year colleges, public universities and elite universities. When
looking at individual answers, we argue that current gain metrics are only
valid under the assumption that there are no losses. Across all students,
we find mean losses of 30%, with little fluctuation from this value in all
institutions except in elite universities (15%). This suggests that conceptual
losses are important and that conceptual trajectories may be described as
two-steps forward, one-step-backward. The instability of initially correct
responses also provide more support for the resources model (positing
conceptions as flexible and context-dependent) than for the misconception
model (positing conceptions as deeply rooted and resistant to change). For
conceptual assessments, we propose replacing current one-dimensional
gain measures - that average over gains and losses- by a three-dimensional
metric that reports students initial knowledge state and accounts both for
gains and losses.
GH05:
1:40-1:50 p.m. Flux and Divergence with an Overhead
Projector
Contributed – Robyn L. Wangberg, St. Mary’s University of Minnesota, Wi-
nona, MN 55987;
Aaron D. Wangberg, Winona State University
The idea of flux and the connection between divergence and flux is often
confusing for students. We designed an activity that lets students discover
properties of flux and divergence using light from an overhead projector
and a piece of thin, flexible Plexiglass. The activity provides opportunities
to challenge students’ conceptions and ultimately leads them to the diver-
gence theorem with a visual aid.
GH06:
1:50-2 p.m. Inexpensive Equatorial Mount Design for
Medium-sized Telescopes
Contributed – Mark W. Jacobs, Northern Michigan University, Physics Depart-
ment, Marquette, MI 49855;
An equatorial mounting simplifies some astronomical imaging, but com-
mercial options for telescopes used at small universities and some high
schools (say 12 to 16 inch apertures) can be expensive. I describe a simple
design that is relatively inexpensive, easy to build, adaptable, and that has
given good results. Students can be meaningfully involved in both design
The IceCube Collaboration is launching a new educational program that
will give high school students the opportunity to learn about neutrinos and
what they tell us about the universe while discovering a unique experi-
ment: IceCube, a cubic-kilometer neutrino detector buried in Antarctica’s
ice. It is based on the highly successful particle physics MasterClass pro-
gram. High school students, and accompanying teachers, will join IceCube
scientists and staff and perform an analysis using IceCube data. They will
also meet active physics researchers and will link up with student peers
from other countries. The students will be introduced to IceCube through
a lecture and then will work on a guided activity to reproduce a recent
research result published by the collaboration in science. The students will
participate in a web conference with the South Pole and, finally, they will
discuss their results in a virtual meeting with other students from across
the U.S. and from other countries in Europe. Examples from the Master-
Class will be provided.
GG10:
2:30-2:40 p.m. The Physics of a Uniform Gravitational
Field
Contributed – Elisha Huggins, Dartmouth College, 29 Moose Mountain Lodge
Rd., Etna, NH 03750;
We compare two uniform gravitational fields. One is the repulsive gravita-
tional field created by dark (vacuum) energy that causes the Hubble expan-
sion, the other is in an elevator shaft at Harvard University. Both cause
photon redshifts, one in the light from distant galaxies climbing against
repulsive gravity, the other in photons sent up the elevator shaft from Glen
Rebka at the bottom to Robert Pound at the top. And both redshifts can
be explained as resulting from an expansion of space caused by a uniform
gravitational field. But these fields are limited in strength. The space be-
tween galaxies expands, yet galaxies do not because the uniform repulsive
gravity is overwhelmed by stronger forces inside the galaxy. In our analysis
of the Pound-Rebka experiment, the space inside the elevator shaft ex-
pands, but the building does not because it was designed to support itself
against gravity. We also calculate the Hubble times for both uniform fields.
Session GH: Post-deadline Session II
Location: Tate Lab 166
Sponsor: AAPT
Date: Wednesday, July 30
Time: 1– 2:20 p.m.
Presider: Karie Meyer
GH01:
1-1:10 p.m. We Share Solar, a STEM Program to Build
a Solar Suitcase
Contributed – Tiberiu Dragoiu Luca, The Hun School of Princeton, 176 Edger-
stoune Rd., Princeton, NJ 08540-6799;
We Share Solar is a STEM education program, which uses the building of
a We Share Solar Suitcase (a 12V DC Stand-Alone Solar Power System) as
a learning platform for solar technology. It is a program that is offered by
the parent organization We Care Solar (CNN Hero). The We Share Solar
kit (also referring to as Solar Suitcase) was developed to allow teachers to
easily have all the necessary parts to build a solar electric system, and to
provide a supportive educational program with enriching curriculum in
solar energy literacy. In this short talk I will present the implementation of
this program at my school.
GH02:
1:10-1:20 p.m. Exploring Five Different Physics
Concepts Using Soap Films
Contributed – Swapnil Tripathi, UW-Washington County, West Bend, WI
53095;
In this talk I will demonstrate how the topic of soap films can be used to
teach various important physics concepts in a very engaging and novel
way. I will discuss many experiments and demonstrations that will capture
students’ interest and can be performed with a moderate effort. Some
advanced applications of soap films in science and engineering solutions
will also be discussed.
