104
Portland
Wednesday morning
PST2B04: 9:15-10 a.m. Is Earth’s Warming Equally Distributed
Geographically?
Poster – Gordon J. Aubrecht, Ohio State University at Marion, 1465 Mt.
Vernon Ave., Marion, OH 43302;
One consequence of human use of energy is emission of greenhouse gases.
Many nonscientists (as well as a few real scientists) do not think that
climate change could be caused by human actions. Reasons range from
doubt that tiny humans could affect an entire planet to belief that human
life on Earth will soon end. Science is about experimental data, reasoning
from those data, and theoretical perspectives supported by the data. Svante
Arrhenius provided (in 1896) the first theoretical (and compelling) reasons
that carbon dioxide could influence Earth’s energy budget. Multiple sources
of modern data underlie the belief of virtually all climate scientists that
humans are changing our climate. Earth’s temperature is rising. Is the rise
distributed uniformly around the world? We compare the world record to
the U.S. and Australian records, and those to records in a small part of the
U.S. to see what the temperature data show.
PST2B05: 8:30-9:15 a.m. Twin Paradox? There Is No Twin
Paradox! (Really!)
Poster – Stephen M. Rodrigue, Yakima Valley Community College, South
16th Ave., and Nob Hill Blvd., Yakima, WA 98907-2520;
The Twin Paradox is explored mathematically using the Lorentz coordi-
nate transformations and spacetime diagrams for four different reference
frames. Calculated results demonstrate that all observers will agree on
the spacetime intervals for the traveling twin and the Earthbound twin,
and thus all observers will agree that the traveling twin ages less than the
Earthbound twin. The symmetry of time dilation is demonstrated to still be
valid, as it must, but in a manner such that no paradox actually arises.
PST2B06: 9:15-10 a.m. The Science Education Initiative: Free
Instructor, Course, and Workshop Materials*
Poster – Stephanie V. Chasteen, University of Colorado, Boulder, 390 UBC,
Boulder, CO 80309;
Katherine K. Perkins, University of Colorado
The Science Education Initiative at the University of Colorado has engaged
in research and course development in a variety of courses and disciplines
for over six years. In this poster we highlight (a) the free, downloadable
archives of course materials in physics and other sciences, (b) workshop
materials available for facilitating workshops in peer instruction and learn-
ing goals, and (c) our “first day framing” project which compiles materials
that instructors use to introduce their students to active learning strategies.
*Materials can be found at
/
C – Physics Education Research II
PST2C01: 8:30-9:15 a.m. Examining Identity Development with
Cultural Historical Activity Theory
Poster – Sissi L. Li, California State University, Fullerton, 800 N. State Col-
lege Blvd., Fullerton, CA 92831;
Michael E. Loverude, California State University, Fullerton
Becoming a physics major involves learning to be part of physics commu-
nities. In this process, students socially interact with these communities,
grapple with changing expectations over time as students become more
physicist-like, and make use of tools in ways that are unique to the field. A
theoretical framework is needed to incorporate elements beyond the social
ones. Cultural Historical Activity Theory (CHAT) examines human actions
through activity systems characterized by a motivation for action; compo-
nents within the system include social, structural, and temporal artifacts
that are often in conflict and drive an individual or group to action. For ex-
ample, students joining a research group experience conflict between what
counted as good lab work in classes and new expectations in the research
lab. Using CHAT, we examine the physics major identity development
through the interactions within an activity system and between activity
systems that shape the trajectory of becoming a physicist.
PST2C02: 9:15-10 a.m. A Case Study in Leveraging Biology
Experiences in Physics
Poster – Vashti Sawtelle, University of Maryland, College Park, 082 Regents
Drive, College Park, MD 20742;
Chandra Turpen, University of Maryland, College Park
Julia Gouvea, University of California, Davis
When we discuss courses designed to be interdisciplinary, such as our
course in Introductory Physics for Life Science (IPLS) majors, we often fo-
cus on what students can gain from taking a course (physics) outside their
chosen discipline (biology). Rarely do we consider what advantages might
be gained from students’ experience with biology in learning physics. At
the University of Maryland we have designed an introductory physics
course that attempts to leverage students’ biology experiences in an authen-
tic interdisciplinary manner. In this presentation, we will examine case
study data of a student who initially describes herself as hating physics.
We will look at longitudinal data across her experiences with our yearlong
IPLS course and explore how, in an interdisciplinary classroom, her prior
experiences as a biology student came to influence her evolving relation-
ship with physics.
PST2C03: 8:30-9:15 a.m. A Scenario for Exploring the
Relationship Between Energy and Free Energy*
Poster – Abigail R. Daane, Seattle Pacific University, 3307 3rd Ave. W, Se-
attle, WA 98119;
Benjamin D. Geller, Vashti Sawtelle, Edward F. Redish, University of Mary-
land, College Park
Rachel E. Scherr, Seattle Pacific University
The energy available to do useful work is different from the total energy
in a system. This distinction is particularly relevant to biology and pre-
health science students who encounter a disconnect between “energy”
as described in their introductory physics courses and “free energy” as
described in their biology and chemistry classes. It is also relevant to K-12
teachers who are asked to explain how it is that energy can be “used up”
even though the total energy is conserved. The relationship between energy
and free energy is made visible when learners are asked to compare two
systems having the same total energy but different capacities to do work
on their surroundings. Unpacking this scenario requires ideas related to
entropy, energy degradation, and the second law of thermodynamics. This
poster examines how taking up these ideas can help to reconcile seemingly
disconnected concepts about energy.
*This material is based upon work supported by the HHMI NEXUS grant and by the
NSF under Grant No. 0822342 and NSF-TUES DUE 11-22818.
PST2C04: 9:15-10 a.m. Like Dissolves Like: Unpacking Student
Reasoning About Thermodynamic Heruristics*
Poster – Benjamin D. Geller, University of Maryland, College Park, Depart-
ment of Physics, College Park, MD 20742;
Benjamin W. Dreyfus, Vashti Sawtelle, Chandra Turpen, Edward F. Redish,
University of Maryland, College Park
In our Physics for Biologists course at the University of Maryland, we are
attempting to build interdisciplinary bridges that help students under-
stand thermodynamics better. One aspect of this endeavor involves having
students grapple with the physical processes underlying heuristics that they
bring to our course from their biology and chemistry classes. In particular,
we have implemented a series of activities and problems intended to un-
pack the hydrophobicity of oil, a key step in understanding the formation
of cell membranes. Student reasoning about this process illustrates the
challenges we encounter in trying to bridge physics and biochemistry cur-
ricula. Understanding the spontaneous separation of oil and water requires
careful consideration of the sometimes competing effects of energy and
entropy. Reconciling disciplinary distinctions in how these ideas are de-
scribed is an important step in helping our students develop more coherent
thermodynamics concepts.
*Supported by the NSF-TUES DUE 11-22818, and the HHMI NEXUS grant.
