The universe is shrouded in a dark mystery that Carnegie Mellon University astrophysicists hope to solve, with help from a major contribution.

Here's the cosmic plot: The physics of the universe cannot be explained without adding a humongous portion of black matter -- matter that cannot be seen and resembles no other matter known to humankind. But dark matter is necessary to describe the large gravitational forces at work in the universe.

Adding to the mystery is dark energy -- an unknown source of energy that's necessary to describe why the universe is expanding at such an accelerated pace.

It's akin to explaining how an automobile works without the ability to see or understand the steel used to build it or the gasoline used to power it.

But the Carnegie Mellon cosmology program now has a fresh opportunity to tackle these major astronomical conundrums with a multimillion-dollar gift that will be used to create the Bruce and Astrid McWilliams Center for Cosmology at the university.

The university expects to announce the gift tomorrow.

Bruce McWilliams, a Carnegie Mellon alumnus and chairman and chief executive officer of Tessera Technologies, made a major contribution whose exact amount was not released. Tessera Technologies' Web site says it's the world's leading provider of miniaturization technologies for the electronics industry.

Dr. McWilliams' goal is to advance the understanding of dark matter and dark energy, the university said.

Carnegie Mellon currently has four astrophysicists with theoretical and experimental expertise in microwave and X-ray radiation, optical surveillance and computer simulations of the universe. It also has experts available in computer science and statistics.

Fred Gilman, dean of the Mellon College of Science, said the gift will allow the university to put new professors in endowed chairs, and with post-doctoral researchers, to tackle the problem.

"These three strengths give us a unique set of tools to understand dark matter and dark energy," Dr. Gilman said. "The gift gives us a jump start in putting this together."

To test theories, researchers do computer simulations of the evolution of the universe based on certain assumptions about dark matter and energy. Then they run their simulations for the computer equivalent of 13.7 billion years, the estimated age of the universe. Results that resemble the known universe provide evidence that assumptions about dark matter and dark energy were correct.

"Dark matter sets the skeleton for the universe," Dr. Gilman said, noting that the department's goal will be determining "how dark matter and dark energy play an essential part in the universe we see."

Already Carnegie Mellon has a strong lineup of astrophysicists. Richard Griffiths worked 14 years with the Hubble Telescope before arriving at the university 11 years ago. He has extensive experience in optical telescopes and cosmic X-rays generated by black holes and neutron stars.

Astrophysicist Jeff Peterson focuses on microwave radiation from space and currently is constructing a microwave antennae on the grounds of Robot City in South Oakland.

Rupert Croft, astrophysics theoretician, uses computer simulations to test theories of dark matter and dark energy. Tiziana Di Matteo, also a theoretician, studies black holes, high energy astrophysics and cosmology.

Dr. Gilman said Dr. McWilliams donated the money with interest in answering the big cosmic questions.

"Bruce is personally involved and wants to answer this for himself," Dr. Gilman said. "He feels he's part of the team."