An astronomer who maps extremely slight temperature changes in the cosmic microwave background, or the thermal afterglow of the big bang, will describe the newborn universe in a talk at the University of Arizona on Friday, April 2.
Princeton University astronomer Lyman E. Page Jr. will give the 2004 Marc Aaronson Memorial Lecture, "Light from the Edge of the Universe: Our Oldest Fossil." The lecture will be at 7 p.m. in Room N210 of the Steward Observatory, 933 N. Cherry.
UA's Steward Observatory and the National Optical Astronomy Observatory have presented Page with the Marc Aaronson Award for his work in measuring temperature changes in the cosmic microwave background (CMB), a radiation that pervades the universe. Over the past decade, Page has developed precision tools and techniques for measuring CMB temperatures, which vary only by a few hundred thousandths of one degree Celsius from spot to spot in the sky.
"The cosmic microwave background is the afterglow of the big bang," Page said. "The expansion of the universe has cooled this primeval fireball radiation to just a little under three degrees above absolute zero."
In the 1930s, Edwin Hubble showed that the universe is expanding. Hubble's observation implied that in the past, the universe was a smaller, denser, hotter place. The photons from this hot, dense time are the earliest possible record of the structure of the universe.
Because the universe has been expanding and cooling since the big bang, those photons of energy now appear in the microwave/radio part of the electromagnetic spectrum. Bell Labs researchers Arno Penzias and Robert Wilson discovered this relic radiation in 1964. The late physicist David Wilkinson, Jim Peebles and other Princeton University scientists explained the implications for the structure of the universe.
Page is a key scientist for the Wilkinson Microwave Anisotropy Probe (WMAP), a satellite that NASA and collaborating universities are using to observe the cosmic background radiation from a million miles away.
"WMAP is giving us an all-sky picture of the universe in exquisite detail," Page said. "The picture corresponds to a snapshot taken just 379,000 thousand years after the big bang. By examining this radiative fossil we can determine the age and composition of the universe, and we can begin to understand how the structure in the universe, such as galaxies and clusters of galaxies, came to be."
The Aaronson Award is given to "an individual or group who by his or her passion for research and dedication to excellence, has produced a body of work in observational astronomy which has resulted in a significant deepening of our understanding of the universe," according to the Aaronson prize selection committee.
The award consists of a plaque and $2,000 cash prize. UA astronomer Ed Olszewski chairs the committee, which includes Marianne Kun, widow of astronomer Marc Aaronson.
Page received his doctorate in physics from Massachusetts Institute of Technology in 1989. He joined the Princeton University faculty in 1991. The Tucson-based Research Corp. selected Page as a Cottrell Scholar. He has won the Packard Foundation's David and Lucile Packard Fellowship.
Marc Aaronson (1950 1987) was a gifted astronomer on the UA faculty who died in an accident while observing at Kitt Peak, Ariz. Aaronson's research focused on some of the most important problems of observational cosmology the cosmic distance scale, the age of the universe, the large-scale motion of matter, the distribution of invisible mass in the universe, and the evolution of stars and galaxies.