The power of scientific observation

BY MICHAEL BRADLEY '98

Asking the right questions is important to Associate Professor of Physics Barbara Walden. Since coming to Trinity 10 years ago, Walden has challenged her students to question their assumptions about the natural world, while she herself searches for answers to questions posed by an aspect of physics invisible to most of us.

            An experimental condensed matter physicist, Walden specializes in Raman spectroscopy--a process that employs visible laser light--and infrared spectroscopy to uncover information about the structure of materials at lengths as small as a nanometer, or one-billionth of a meter.

            “Microstructure has long been a special interest of mine because of its direct influence on the properties of materials,” Walden explains. “If different processing conditions can lead to the production of materials with vastly different properties, then the reason for this can often be found in an understanding of the material’s microstructure.”

            Walden has brought her expertise to an ongoing research project with colleagues at Brown University, centering on the origin and evolution of stress in diamond films and other hard materials. “The ability to grow diamond as a thin film is a relatively new development, and it has been the focus of considerable technological interest for more than a decade. Diamond itself has many desirable optical, electrical, and structural properties, and the ability to produce thin films of this material has opened up a wealth of potential applications.” Walden, who has co-authored several published articles on this topic in recent years, cites the chemical inertness, smoothness, and extreme hardness of diamond as features that make it an ideal low-friction surface coating, and she notes that diamond film technology holds great potential for future integration into a variety of practical technological applications.

 Asking the right questions

            “Science all too often is viewed as remote from the concerns or the reach of the everyday person--something done only in laboratories using complicated pieces of machinery and incomprehensible mathematical formulas to address esoteric questions,” Walden asserts. “In the courses that I teach, and especially those for nonmajors and first-year science majors, I attempt to address these misconceptions by stressing the power of personal observation and the need for skepticism, judgment, and sound reasoning.” Walden encourages students to ask questions of themselves and the curriculum so they may develop a deeper understanding of principles they may have taken for granted as true or false prior to studying physics at Trinity. “I place an emphasis not only on what it is that is believed to be true but also on why those beliefs are held.”

            Walden challenges her students by questioning their most essential assumptions about the natural world, such as the earth’s revolution around the sun. By forcing students to explore the foundations of their scientific beliefs through careful observation of the natural world, Walden establishes an inquisitive spirit in her classroom.

            This approach clearly resonates with Walden’s students, who cite her probing classroom discussions as valuable supplements to topical lectures. “She likes to question us,” says physics major Christopher Koning ‘02, describing Walden’s teaching method.”

            She makes us look at things in several different ways. It’s a really effective teaching style.” He notes that Walden encourages students to build on concepts they have already learned, which helps them find answers to new questions while gaining a perspective on how various topics in the discipline relate to each other.

Broadening student experiences

            Whenever possible, Walden encourages students to broaden their classroom knowledge with physics-related work or study off campus. This summer, for example, one of her students worked at nearby Loctite Corp. Others have benefited from her close connections with research scientists at Brown University. This summer, Jeff Peo ‘03 worked in the engineering department at Brown under the supervision of Walden’s colleague Brian Sheldon. Two summers ago, Kelly Feller ‘01 also was able to work there under the National Science Foundation grant shared by Walden and Sheldon. “I was at Brown between my sophomore and junior years,” says Feller. “It was very helpful to be able to use the advanced equipment in their materials science department so early in my college experience.”

 Changing times, changing classroom     

            With constant improvements in laboratory research methods, particularly in the area of computer-based research applications, Walden appreciates the importance of exploring new developments and integrating new ideas into her curriculum. “One of the most powerful analysis tools available to a scientist is the computer, and I place a strong emphasis on computer-oriented graphical data analyses in the laboratory,” Walden says.

            One computer program used in Walden’s “Optics and Modern Physics” course allows students to build optical systems by adding lenses and mirrors, allowing them to see immediately what effect this has on the image generated. “These programs provide a very visual and conceptual introduction to physical concepts,” Walden says.

            Walden brings a genuine passion to her work, both in the classroom and in her own research. “It gives me a great sense of satisfaction to teach physics and astronomy at a liberal arts institution,” Walden notes. “I strongly believe that every educated person needs to have at least a moderate understanding of what science is and how it is practiced.”