Star Struck: Physics Grows Astronomically

Growing up in a big city like Baltimore, Elizabeth Raun never got a really good look at the stars and heavens -- all those street lights obscuring the skies. It wasn't until she got to another big city, Philadelphia, and Penn, that she got a really good look at what's up there. And now is hooked.

Raun, a math and economics major, is required to take a course in the physical sciences to fulfill her graduation requirements. With some trepidation, she took Astronomy 1, a course designed for non-science majors.

It turned out to be a lot more fun than she thought.

"I'm thinking about buying a telescope," she says. Raun enjoy

ed the observations so much that she did many additional ones beyond what was required. It's an exciting time for astronomy -- with the Hubble Space Telescope and other scientific tools utilizing advanced technology, researchers are getting closer to the one of the oldest questions: How did the universe come to be the way we see it today?

"We are on the threshold of understanding the origin of all the structure we see in the universe," says Paul Steinhardt, a professor of physics and a noted scholar on the evolution of the universe.

"Why isn't all the matter and radiation just spread out smoothly, as the Big Bang Model would suggest? Why does matter come in lumps: planets, stars, galaxies? We have some provocative explanations for why this occurred, and these ideas will be put to the test in the coming decade," says Steinhardt.

The department of physics and astronomy has begun expanding, in the hope that attracting new faculty engaged in cutting-edge astronomy and developing new theoretical explanations will lay the foundation for Penn to have one of the world's finest astrophysics programs -- and that Penn students will be able to appreciate and understand those findings.

"It's my hope that students who take our courses will become intelligent witnesses to what's going to happen; they will know what it all means," says Steinhardt, one of the driving forces behind a redesign of Astronomy 1.

Several years ago, realizing that several faculty members would soon be retiring, the department of physics set out to define new directions that had the promise of being exciting frontiers in the coming century, says Steinhardt. Astrophysics, he says, was unanimously identified as one of those areas. Spurred by the extraordinary discoveries of the repaired Hubble Space Telescope and the findings of primordial structure in the background radiation detected by the COBE satellite -- a fingerprint, if you will, of the Big Bang, the original event that created the universe -- public interest and federal and private funding in cosmology has increased and is likely to grow in the foreseeable future.

To build a cohesive and competitive effort, the departments of physics and astronomy merged and recruited new, dynamic faculty.

"But we're not the only ones to recognize this," Steinhardt says. With more research opportunities and graduate students pursuing careers in cosmology, departments of physics and astronomy across the nation have been scurrying to expand or upgrade their astrophysics programs.

"Our challenge has been to recruit outstanding faculty amidst this competition and to create an interactive and productive research and teaching environment" he says. In the past year the department has hired four young astrophysicists as new assistant professors in the Department: Steve Myers, Mark Devlin, Jordi Miralda-Escude and Chung-Pei Ma. The plan, says Steinhardt, calls for the addition of at least three additional astrophysicists to form a world-class, competitive effort.

Miralda-Escude, who came to Penn last year from a prestigious five-year position at the Institute for Advanced Study in Princeton, studies galaxy formation -- how gases are distributed throughout the universe, collapse and then form structures that become galaxies.

Myers is a "radio astronomer" working on a wide range of experiments, including the study of how the gravitational forces of galaxies "bend" light that travels through space. By examining the bending of the light, he says, astronomers can determine the mass of the universe. Myers, says Steinhardt, is one of those rare scientists who does both observations and theory -- he has also been developing a theory to explain why some regions are devoid of galaxies and other regions have high concentrations of galaxies. Devlin studies photons that were created only 100,000 years after the Big Bang, what he calls "a real echo of the very beginning of the universe." To collect data on them, he launches a satellite onto a high-altitude balloon. It reaches heights of up to 220,000 feet, about five times as high as a jet airplane, he says. The balloons -- which land close to where they are launched -- are launched by NASA in remote areas in Texas and New Mexico. "You don't want people around when the balloon comes down," he says. This summer, he'll launch a balloon from Chile.

Ma's research interests are studying the later development of the universe, how galaxies and clusters of galaxies were formed from the primordial distribution of matter and energy created in the first instants after the Big Bang. She has developed some of the world's best computer simulations of the formation of structure to test how much and what kind of dark matter or invisible structures exist in the universe, says Steinhardt.

But expanding the department's expertise in astrophysics was only half of the vision the department had for astrophysics, says Steinhardt. "Realizing that we are headed towards some extraordinary scientific achievements in this field, we wanted to prepare Penn students -- science and non-science majors alike -- to appreciate the historic discoveries to come and, in some cases, to participate in them. Getting non-science majors to understand and appreciate these scientific discoveries necessitated a new way of introducing the material."

The result has been a new, totally revitalized version of Astronomy 1, run for the first time this Fall. Each of the seven sections of the class requires its students to use the department's new telescope (on the roof of David Rittenhouse Laboratory) to make two observations -- one in the day to study the properties of the sun, and one at night to study a variety of phenomena, depending on the season. This spring, the comet Hale-Bopp promises to provide a rare and spectacular sight when it comes close to Earth. The astrophysics faculty is preparing a series of observational opportunities for the students and the general public.

Another new of way of introducing material so Astronomy 1 students can come to appreciate the historic discoveries to come is the new Internet site, where students can find graphic illustrations of concepts taught in courses, as well as facilities for communicating with faculty or scheduling their observations. The site also includes breaking news in astronomy and the latest images from the world's best telescopes.

Of course, many non-science majors start out with little or no knowledge of computers. But, within the first week, students must "register" on the course's homepage. Students who aren't familiar with computers get a quick lesson on working the Net.

Also developed for the course are a host of in-class demonstrations and a novel "electronic slide library," used to display images in the classroom.

Myers is teaching an introductory astronomy course designed for science and engineering majors. His course Web site includes a novel project in which the students each design their own satellite mission to a planet in an imaginary solar system. The assignment is set up just like a real NASA program. There is a call for proposals and the students have to submit a grant proposal to investigate the planet of their choosing. They are given a budget, and possible equipment to put on board consistent with a weight limit and power limitations.

"It is almost too realistic," says Steinhardt. "They even get their budget cut at one point during the process! The student's really enjoyed this project, and we are planning to adapt this for Astronomy 1."

Steinhardt says the Astronomy 1 staff -- Professors Ma, Bludman, and Steinhardt and instructors Frederic, Frei and Goldader -- met three hours each Thursday evening fall semester to hammer out and evaluate the course, determining what is working well and what needs to be refined in content and presentations. Lessons learned from the first semester are being used to develop improved plans for the Spring.

Ma, the only one of the four new faculty to teach the course this semester, says she averaged about 30 hours a week preparing and refining her Astronomy 1 course. But she enjoyed teaching, especially when she was able to surprise some of her students with little known but true facts of the universe:

"I think they were most surprised to learn that they're made up of star dust," says Ma. After a star explodes, or goes nova, she says, chemicals are released and travel the universe. Before the Earth was formed, those chemicals hooked up with other substances in our galaxy and then helped form the Earth and life.

Other items discussed in the course were Einstein's theory of relativity and black holes, which some students didn't know are only "thought" to exist; no one has ever seen one.

Raun says she was surprised to learn about "dark matter," or what scientists also call "missing matter." The leading model of how the universe evolved predicts a certain amount of matter will have been created and distributed throughout the galaxies. But what scientists actually "see" (or detect light from) adds up to much less matter than is predicted. The notion is that most of the matter is in the form of particles which do not emit or scatter light. Although we cannot see them, we can detect the gravitational effect that they produce, as in the bending of light studied by Myers, or the formation of galaxies studied by Ma and Miralda-Escude, or the photons studied by Devlin. In Astronomy 1, students are learning about dark matter first-hand from its explorers, says Steinhardt.

Nicole Melchiorre, a freshman from Philadelphia, was surprised to learn that by using math and physics, she could calculate the orbits of plants and motion of stars.

"You get the idea that there's a plan to the universe; it isn't just everything thrown out there," says Melchiorre, who doesn't rule out majoring in science at Penn. She says she was also impressed by the sight of Saturn's moons dancing around the main planet's infamous rings during her nighttime observation.

So, with a little math, some physics, a computer and a little imagination, Steinhardt and his colleagues were able to make the complex world of astronomy understandable.

"They gave us the tools to understand the skies," says Raun.

Originally published on January 21, 1997