Focus on Research
Penn State Intercom......January 24, 2002

Center for Gravitational
Wave Physics established

By Barbara Kennedy
Eberly College of Science RESEARCH_Finn

A multi-million-dollar, multi-year grant from the National Science Foundation (NSF), along with significant support from the University, has created the Center for Gravitational Wave Physics at Penn State -- funded at $1 million a year for each of the next five years and led by Lee Samuel Finn, associate professor of physics and astronomy and astrophysics.

The center supports an interdisciplinary team of scientists at the University and eight other participating institutions in the United States, Scotland, Canada and Germany. The researchers are poised to explore the mysteries hidden in the first signals ever detected from gravitational waves generated by the most massive and violent objects in the universe -- which they anticipate will be collected by new gravitational-wave detectors in the United States, Europe and Japan, plus by a space-based detector to be launched later this decade.

"We will be the first to explore this brand-new field where no observations of this kind have been possible before," Finn said. "As we move forward, we expect our anticipated research approach might change as we learn what problems we must address. That type of flexibility for doing aggressive and timely studies, which the NSF encourages, is the key to frontier research."

Pablo Laguna, professor of astronomy and astrophysics, and Peter Mészáros, distinguished professor and head of the Department of Astronomy and Astrophysics, are co-principal investigators. Ashtekar is chair of the executive committee. Steinn Sigurdsson, assistant professor of astronomy and astrophysics; and Alexander Wolszczan, Evan Pugh professor of astronomy and astrophysics, are among the University researchers associated with the center.

The center is among the first to receive support from the NSF Physics Frontier Center program. According to the NSF, the program funds research at the frontiers of physics and at the boundaries of physics with other disciplines that are of a scope and co mplexity requiring combinations of talents and disciplines, specialized infrastructure, large collaborations, and centers that catalyze rapid advances on promising research topics.

"Einstein predicted the existence of gravitational waves in 1917 as ripples in the fabric of space and time, but for several decades the idea seemed exotic and remained in the realm of theory," explained Abhay Ashtekar, holder of the Eberly family chair in physics, director of the Center for Gravitational Physics and Geometry, and chair of the executive committee of the center. "It was only in the 1980s that the existence of these waves was firmly established through a decade of careful astronomical observations -- an achievement so important it was rewarded with a Nobel prize. We are now reaching a truly exciting era when these waves will be directly detected on Earth, opening a brand new window to the universe."

The new center has three main research thrusts: astrophysical modeling and interpretation of the forthcoming observations of such massive objects as colliding black holes, developing the numerical and analytical tools for testing Einstein's theory of general relativity and for understanding both the sources of gravitational waves and the nature of space and time, and contributing to the design of more advanced gravitational-wave detectors.

Ashtekar said the theoretical and experimental research communities in general relativity have not previously been strongly linked, but now the gravitational-wave observatories are rapidly changing this status-quo and a new field of "gravitational wave phenomenology" is emerging at the interface.

The center's establishment as a geographic and intellectual focal point with a strong program for visiting scientists is expected to promote important, and comparatively quick, contributions to the field.

Barbara Kennedy can be reached at bkk1@psu.edu.

Hatchery fish can spread fungus
to toad embryos, research says

New research shows that hatchery-reared fish can spread a fungus implicated in the mass deaths of the embryos of toads and other amphibians in the Pacific Northwest. This is the first evidence that fish stocking can spread amphibian diseases.

Although the research was performed at wilderness ponds where amphibians breed in Oregon, the researchers believe the findings might apply to any lake or stream environment where fish stocking occurs.

'With hatchery-reared fish, the potential for disease is greater simply because the environment in which they are raised is not natural," said Joseph Kiesecker, assistant professor of biology and the principal researcher, who also has study sites near Penn State. "Once those fish are introduced into a lake or stream where amphibians breed, the potential then exists for the transfer of disease. It could happen anywhere stocking occurs."

To determine whether fish stocking could spread the fungus to amphibians, Kiesecker, and his colleagues collected rainbow trout from a fish hatchery and fresh western toad eggs from Lost Lake, Ore.

Experiments confirmed that trout can spread the fungus to toad embryos: Exposing the embryos to infected trout increased their death rate by about 15 percent. Researchers also found that trout can spread the fungus to soil, which can then infect toad embryos.

Middle-aged women
take charge, but
supportive of moms

By Barbara Hale
Public Information

Results of a University study show that middle-aged daughters tend to dominate in interactions with their aging mothers but they do it while being just as nice as they can be.

Eva S. Lefkowitz, assistant professor of human development and family studies, led the study. She said, "Our results show that middle-aged women take charge in conversations with their mothers, just as they do with their teen-age children. However, the women structure, rather than control, the conversations with their mothers and offer supportive, encouraging, engaged, enthusiastic and humorous exchanges."

Karen Fingerman, associate professor of human development and family studies, co-authored the research. She said, "Mothers and daughters in late life have strong relationships, in part, because they are so good at expressing positive feelings and not expressing their negative ones. We know that the daughters in our study all had some problems with their mothers based on their responses in individual interviews but, in their mothers' presence, they acted with good humor, grace and acceptance."

In the study, 46 mothers, ages 69 to 93, were audio-taped while completing a problem-solving task with their daughters. Each of the women had been shown a picture of a mother and daughter and asked to write a story about it. When complete, the mothers and daughters were brought together and asked to prepare a joint story.

In some pairs, the daughters resolved the problem of preparing a new story by suggesting that they simply submit the story that the mother had written independently. Other pairs negotiated solutions by developing a new story together. Conversations that took place during the negotiations were recorded and coded for overall talking time and rated.

While both the mothers and daughters were very careful of the other's feelings, the daughters displayed more positive involvement with their mothers.

Fingerman said, "As people enter late life, in general, we see decreases in negative emotions. The older mothers are not negative, in part, simply because they are old. Middle-age is generally a generative period when people have a lot of responsibilities and care for a lot of people. In this case, the middle-aged daughters were being generative towards their mothers."

Barbara Hale can be reached at bah@psu.edu.

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