Journalists are invited to attend the Cosmo-02 workshop Sept. 18 to
21 at the Adler Planetarium and Museum in Chicago. Journalists may
register for the workshop by sending an e-mail to
cosmo02@pancake.uchicago.edu.

An international group of more than 200 scientists at the
workshop will attempt to shed light on the dark side of the universe
and what happened in the first few fractions of a second of its
existence.

The workshop is co-organized by the Center for Cosmological
Physics at the University of Chicago, by the Adler Planetarium and by
the Fermi National Accelerator Laboratory. The Center for
Cosmological Physics is a Physics Frontier Center of the National
Science Foundation.

Most of the presentations will focus on theoretical science,
said workshop co-chair Sean Carroll, Assistant Professor in Physics
at the University of Chicago. Over the last five years, observational
astronomers working at their telescopes have answered one set of
questions while opening up a whole new set, Carroll said. “Now it’s
really turned over to the theorists to figure out how to make sense
of this. We know much and we understand nothing.”

They know, for example, that the observable stars and
galaxies account for only 5 percent of the mass and energy in the
universe. They call the mysterious 95 percent of the remaining
universe “dark matter and dark energy.” Dark matter is thought to
consist of hypothetical particles that have not yet been observed in
particle accelerators, but whose existence is inferred by measuring
their gravitational pull. Dark energy is an exotic form of energy
that causes distant galaxies to accelerate away from Earth.

“We’ve learned to describe these things about the universe,
the dark matter and the dark energy, but we still don’t know what
they are,” Carroll said. “So I think that getting theorists together
to talk about some of the crazier ideas is something for which the
timing is right.”

One important development that bolsters the workshop’s
importance is the recent set of discoveries about subatomic particles
called neutrinos and their interactions, said workshop co-chair John
Beacom, the David N. Schramm Research Fellow at Fermilab. Neutrinos
once were touted as a candidate for the dark matter.

“We’ve recently learned that neutrinos really can’t be a
substantial component of the dark matter,” Beacom said. “That puts us
in an interesting position. No particle that we’ve ever seen in an
accelerator or other laboratory could be the dark matter. That’s
exciting.”

The annual Cosmo workshop, which first met in 1997, brings
together physicists and cosmologists who are attempting to merge two
fields of study: particle physics and cosmology.

“It’s bringing together a unique group of people,” said
conference co-chair Evalyn Gates, vice president for research and
education at Adler Planetarium. “It’s very international. It’s
definitely going to be a series of talks about what’s going on at the
very edge of this vibrant, active field.”

The workshop participants this year will place a special
emphasis on the extremely early universe, string theory and extra
dimensions.

In this case, the extremely early universe means “the first zero
seconds,” Carroll said. Much research in recent years has focused on
cosmic inflation, when the universe underwent a gigantic growth spurt
in a fraction of a second just moments after the big bang.

“We’re at a state right now where people are beginning to
think seriously about what happened before inflation,” Carroll said.

String theory attempts to unite the four fundamental forces
of nature that govern the motion of everything from the smallest
subatomic particles to the largest galaxy clusters. In theory, a
string is the fundamental building block of the universe that gives
rise to all particles and exists in 10 dimensions rather than the
three spatial dimensions of the known universe. Scientists are
interested in string theory because it may help explain the
conditions that appear to have prevailed in the earliest moments of
the big bang.

“People believe that general relativity just breaks down at
that point,” Carroll said. “On the other hand, they don’t know how it
breaks down or what replaces it. String theory is supposed to replace
it and people are trying to think very hard right now about how that
could actually work.”

The conference will feature 27 plenary talks, as well as 72
talks in parallel sessions. Among the workshop speakers will be Wendy
Freedman of the Carnegie Observatories and a leader in the effort to
use the Hubble Space Telescope to measure the expansion rate of the
universe. Freedman will present the opening remarks.

Other plenary speakers will be Alan Guth of the Massachusetts
Institute of Technology and Lisa Randall of Harvard. Guth, who
originated the widely accepted cosmological theory of inflation, will
discuss “eternal inflation,” the idea that inflation could still be
occurring in certain regions of the universe. He also will give a
public lecture at 7 p.m. on Thursday, Sept. 19, at the Adler
Planetarium titled “Inflationary Cosmology and the Accelerating
Universe.” Randall, a particle theorist, has proposed an influential
scenario in which the known universe is embedded in an invisible extra
dimension of spacetime.

The public is invited to view an electronic poster session
put together by the scientists that may contain video clips, plots,
and a variety of other images and graphics. As many as 12 different
posters will be on view each day throughout the conference on 37-inch
computer screens.

Poster sessions have long been a mainstay of academic
conferences, but an electronic poster session is a new concept, Gates
said. “This is an experiment. It’s never been done anywhere.”

Although the posters will contain highly technical material,
“the public can see science as it’s being done at the very edge,”
Gates said.

For more information, see the workshop Web site at
http://pancake.uchicago.edu/~cosmo02/.