Visualizing the Big Picture
While telescopes,
spacecraft, and other means of collecting data are critical, not
all researchers turn to the heavens for inspiration. Some turn to
their computers to take a closer look at the big picture.
The Grand Challenge Cosmology Consortium (GC3) is a collaboration
of cosmologists, astrophysicists, and computer scientists who are
modeling the birth and early infancy of the universe. Consortium
members use high performance computers at the NSF-supported National
Supercomputing Centers-the precursor of the current Partnerships
for Advanced Computational Infrastructure program-to create a three-dimensional
model of the formation of galaxies and large-scale structures in
the early universe. The consortium uses some of the most powerful
supercomputers available to perform the billions of calculations
required to figure out how the universe came to be.
In an effort
to understand the role of dark matter in galaxy cluster formation,
Michael Norman and Gregory Bryan carried out a simulation at the
National Center for Supercomputing Applications at the University
of Illinois at Urbana-Champaign in 1994. The simulation produced
a model that accurately predicted the number and arrangement of
galaxy clusters. The prediction was confirmed by recent observations
by an orbiting X-ray satellite. While the simulation did not capture
exactly the measurable ratio of luminous gas to dark matter, efforts
are underway to improve the model's resolution. "Everyone is motivated
to find out what dark matter is," says Norman, "but there is nothing
definitive yet."
Perhaps the
most intriguing aspect of the GC3 is
its ability to simulate situations
never seen by humans. In a public display of computer simulation,
members of GC3 teamed up with
IMAX to create the 1996 film Cosmic Voyage, a short
feature that was nominated for an Academy Award.
From the safety of their theater seats, audiences can view the life
of the universe, from its explosive, Big Bang birth, to the current
hubbub of galaxy life. The film also includes a startling animation
of what would happen if two spiral galaxieslike the Milky Way and
neighboring Andromeda Galaxywere to collide.
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