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September 27, 2005 - Image 5

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Publication:
The Michigan Daily, 2005-09-27

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Tuesday
September 27, 2005
news@nichigandaily.com

SCIENCE

5

v

BUBBLES & BALLOONS

IN THE BIG

HOUSE

More than a hundred University students and faculty conduct wind experiments in Michigan Stadium

STADIUM
Continued from page 1
Forecasting the Stadium
To map out the wind currents of the stadium, the
classes equipped themselves with the latest in weather
technology along with balloons and bubble soap that
could mark the movement of the wind for the students
to see.
Dave Pawlowski, a Rackham student and event
organizer, said faculty members decided to separate
students into four experiments. Each group would mea-
sure specific features of the wind currents - like wind
direction and temperature - with the students' par-
ticipation.
AOSS research scientist Frank Marsik, a faculty
member who participated in the experiments, said
because of the bowl-like shape of the arena some pro-
fessors initially speculated wind passing over would
spiral inside the stadium.
Engineering senior Elizabeth Siegel, a student in
Samson's AOSS 463 class also known as Air Pollution
Meteorology, said students also predicated that incom-
ing wind would cascade down the stands to the floor of
the arena where the temperature is warmer and there-
fore at a lower pressure.
The wind would then naturally rise with the warming
of the air on the
1football floor.
But several
"It'v rdays before the
experiment,
turbulent in here. Samson along
with some of his

The wind isn't
all that strong,
but the mixing
is greater than
we thought."
-Perry Samson
Atmospheric Oceanic
Space Sciences Professor
Engineering senior Alex Braden

students and fac-
ulty scoped out
the arena. There
they found piec-
es of trash float-
ing across the
stadium floor.
Coincidently,
the pieces of
trash acted as
visual markers
that showed the
direction of the
wind.
"The trash
was just crash-
ing together,"
said, adding that the

GRAPHIC BY LINDSEY UNGAR

wind was acting in an erratic pattern no one could real-
ly discern.
"You could watch it blow together. There was
a lot of turbulence," Samson said.
It was only a taste of the wind currents' unpre-
dictability that Samson and the students would see on
Saturday. The night before the experiment, Samson
couldn't sleep.
Experimental difficulties
By noon on Saturday, students from six classes filed
through the vacant stadium, clad in yellow t-shirts with
the words Extreme Weather written on them.
At the center of the football field, AOSS faculty
members set up a meteorological tower and weather
balloon to record the vertical and horizontal wind con-
ditions.
Scattered across the stadium seats floated blue bal-
loons tied to the ground, each acting as a marker to
indicate wind direction. Meanwhile Samson directed
the students to his attention on the south end of the
football field in what would mark the start of the exper-
iment - bubble blowing.
Holding bubble bottles, dozens of students blew bub-
bles through the air to indicate the overall wind direc-
tion. But the hundreds of bubbles hovered up in the air
in a chaotic motion.
About 15 minutes later, students lined in a "human
dispersion" experiment where they released a neutrally
buoyant balloon - a balloon filled with enough helium
to prevent it from rising or dipping in the air - on the
stadium floor.
One by one, students followed their balloon for about
ten seconds before retrieving it and leaving a marker on
where the balloon was recovered. In the end, the markers
would indicate the dispersion of incoming wind plumes.
Yet by the end of the experiment, the spatter of markers
didn't leave a distinct trail.

DAVID TUMAN/Daily
LSA Freshman Hilary Bronson chases her ballon in the
Big House on Saturday.

GRAPHIC BY GERVIS MENZIES

In the last moments, students holding balloons
on twenty-foot-long strings stood across the foot-
ball field in assigned positions to mark the different
wind paths. But again, no evident pattern formed.
While the students thoroughly conducted the
experiments, Samson said none led to any substan-
tial results.
"The streamers (on the goal post) performed
better than the balloons did," Samson said. "The
human dispersion experiment. Nothing expected
happened with it."
Although the faculty and students will need time
to decipher the results, which were recorded on vid-
eotape, Samson said, "It's very turbulent in here.
The wind isn't all that strong, but the mixing is
greater than we thought."

Back to the drawing board
Samson said the stadium is very symmetrical but there
are clearly nuances within the stadium, which are causing
the erratic flow of wind.
Research scientist Marsik said one of the factors that
may have caused the erratic wind patterns could be due
to the different colors throughout the sections of the sta-
dium.
Because the dark colors absorb sunlight, Marsik said
the different coloring of the sections might create various
temperature levels throughout the stadium. The resulting
temperature levels would create disparate pressure levels,
which could exacerbate turbulence in the stadium.
Marsik added that another possible factor that could
also increase the turbulence in the stadium would be the

heat on the surface of the football field. If the temperature
of the football field is warmer than the air above it, Marsik
said the warm air will gradually rise. This will cause cold
air from incoming wind currents to flow into the areas the
warm air is leaving, ultimately causing greater wind flow.
Despite the difficulties of the experiment, Samson said
he and his students hope to obtain concrete results from
the information of their weather balloon and meteorologi-
cal tower.
"Hopefully we can make some generalizations," Sam-
son said.
But even though Samson might not come with
results this time, he plans on coming back next year
with better experiments and more equipment.
Samson said it's not really the results that really
matter. "It's the act of trying to experiment that
went well."

'Robots and their makers vie for
$2 million grand prize at race

Unmanned vehicles will travel
across 150-mile course in
government sponsored race
LOS ANGELES (AP) -- Wanted by the Pentagon:
A muscular, outdoorsy specimen. Must be intelligent
and, above all, self-driven.

- fitted with the latest sensors, cameras and computers
- have aged a generation since last year.
Teams have beefed up their vehicles' artificial intelli-
gence through improved computer algorithms that will
help them avoid pitfalls such as ditches and boulders
strewn across the roughly 150-mile-long course. To get
there, the robots must compete in a semifinal show-
down that starts tomorrow.
Entrants include several converted SUVs, souped-

ver mountain switchbacks, squeeze through choke
points and avoid man-made and natural obstacles.
The sponsor of the Grand Challenge is the research
arm of the Pentagon known as the Defense Advanced
Research Projects Agency, or DARPA, whose best-
known success story is the Internet. The Pentagon
wants one-third of the military's ground vehicles to be
unmanned by 2015.
DARPA Director Anthony Tether hopes that a robot

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