Feature
Family members discover the world of optics through the University-sponsored PACES program.
When physics is a social science
Physics teachers make scientific curiosity a family affair
By Deane Morrison
April 18, 2008
Curtains barely hold back the early evening light in the Marcy
Open School lunchroom. At the tables, children squirm with
anticipation as they and their parents listen to laser-wielding
physics teacher Nancy Bresnahan. "Can you see light as it passes
through space?" she asks. Bresnahan aims the laser at the back
wall, instantly lighting it up with a bright red spot. But the
light streaming from the laser to the wall is invisible. "No,"
comes the answer. Then another physics teacher sprays fog into the
room, and suddenly a straight red beam can be seen piercing the
cloud. "How about now?" asks Bresnahan. The room erupts with oohs,
ahs--and yesses. The families take a moment to reflect on the
behavior of light they've just witnessed, then it's on to an
exploration of how light produces images. So begins a typical
encounter between families and physics in PACES (Parents and
Children Experiencing Science), a program of the President's
Initiative on Children, Youth and Families at the University. Run
by high school physics teachers, it brings parents and children
together to ask scientific questions, predict how simple
experiments will turn out, and then see the results for themselves.
The most important thing is that the parents exhibit scientific
curiosity for their children. This was the driving factor for
University physics professor Cynthia Cattell and Bresnahan, a
teacher at Hopkins High School, in obtaining seed money for PACES.
"We wanted parents to model the behavior we wanted to see. Parents
manipulate the equipment, and kids do, too. They interact as
families," says Bresnahan. This night at Marcy Open in Minneapolis,
Bresnahan is joined by three other PACES teachers: Jon Anderson
(Centennial), Claire Hypolite (Edison), and Louise Weldon (Tartan).
All are performers in the Physics Force, a group of physics
teachers--including Cattell--who regularly perform entertaining
physics-based stunts for young students.
"My goal is to ultimately go into a school,
church, or mosque about four times a year, until everybody is not
only comfortable with doing science, but looking forward to
it."
But while the Physics Force shows kids the joy of physics, PACES
has them experience it for themselves. The PACES team stages
programs of 45 to 60 minutes in metro-area schools whose students
have the most need for scientific stimulation.
Picture this
Each family at Marcy Open has an incandescent lamp in front of
them. When turned on, light from its filament will pass through a
lens, then a tiny pinhole in a sheet of aluminum foil (poked out by
the children). Light that makes it through the pinhole will hit a
cardstock screen. Now, the teachers ask, when you switch on your
lamp, how will its light pass through the pinhole and project an
image of the filament on the screen? Will the image be rightside
up, upside down, or what? Talk about it with each other. It's a
risky moment; no one wants to guess wrong. But the four teachers
stress that being wrong is a great way to learn. When everybody has
had time to make a prediction, they switch on their lights and
watch as images of the U-shaped filaments appear on their
screens--upside down. "What happens when you move your screen?"
asks Hypolite. The families move their screens nearer or farther
from the pinhole and watch the image shrink and expand. When they
move a stick from top to bottom across the pinhole, its shadow on
the screen moves too--but from bottom to top. The wonder of it
isn't lost on young Isabel Olson. "I was surprised how the image
moved and how it changed when you put the pinhole in front of it
and when I moved the stick," she says. The families add more
pinholes, producing multiple images. But when they move their
screens just right, the images merge; they have just created, and
focused, a rudimentary camera. What happens when they cover half
the lens? They still get a nice, sharp image. "It raises more
questions than it answers," observes Theresa Wolf as she works on
the experiment with her husband and two kids.
Still plenty of growing space
This was one of more than a dozen programs the teachers have
presented to about 200 families in 2007-08, the first year of
PACES. At every one, they not only teach but pass out information
to encourage students to keep up with school. One brochure
describes the Power of You program, which sponsors two free years
at area community and technical colleges for qualifying public high
school graduates in Minneapolis and St. Paul. But for Bresnahan,
there is still much to be done to reach all the students who could
benefit from extra help in science. For one thing, PACES presents
its programs in the evening, when families--or at least
parents--are usually tired. Better to aim for daytime and weekends
and catch families when they're already being sociable. "I think to
really reach the people we want to reach, we should go into
churches or mosques," she says. "My goal is to ultimately go into a
school, church, or mosque about four times a year, until everybody
is not only comfortable with doing science, but looking forward to
it." In setting up PACES, "it seemed to me families were a key, and
we have to get the kids early." PACES already draws a diverse mix
of people, including Hispanic and Somali families. It helps that
Hypolite speaks Spanish and that Gladys Torres-Skendi, an Edison
math teacher who also belongs to PACES, is a native speaker of the
language. One of Bresnahan's favorite moments came when an elderly
Spanish-speaking woman arrived at a presentation by herself. "She
wandered in and asked for equipment [to perform the experiments],"
Bresnahan recalls. "What a wonderful sight, an elderly woman doing
science."