Physics professor works to improve accuracy

Almost everything in the world is made of atoms, which currently are believed to be held together by electricity and magnetism. David Shiner, associate professor of physics, is conducting research to determine if these are the only ways that atoms are held together.

His studies of the physical laws of matter and, in particular, atomic particles relate to consumer demands for smaller and smaller technological devices. An understanding of atomic particles helps in designing computers, fiber optics in telecommunications and other cutting-edge communication products.

"Historically, scientists have discovered very practical things through the pursuit of pure science," Shiner says. "As our world grows smaller, we use technological devices that involve microelectronics. Computers, fiber optics in telecommunications and other cutting-edge communication devices are dependent upon understanding the atom and its constituent particles."

Shiner's approach to understanding physical laws starts with measurement rather than theory. His work on precision laser studies of basic atoms is novel in that he uses an integrated electro-optic device called a phase modulator to conduct his experiments. Using this tool, he can identify what is unknown in a test sample.

In his experiments, Shiner is seeking to determine a more precise value for the fine structure constant. This constant measures the strength of the electric charge on the electrons or protons in the atom. It explains the strength of their electromagnetic interaction - their attraction and repulsion to one another. The more accurately scientists can test theories about the charged particles, the stronger the evidence for proving or disproving current knowledge about the structure of the universe.

"By performing experiments of great precision on basic physical systems whose properties can be calculated and described with the most exacting detail, our understanding of nature in terms of physical laws is put to an extraordinary test," Shiner says.

Experimental tools have been developed to study atomic structure and ultimately to help scientists discover new physical laws. Shiner is aided in his research by spectroscopy, a sophisticated tool that uses lasers and optics to identify what is unknown in a test sample.

Shiner's objectives involve more than addressing fundamental problems in atomic physics. In the process, he is helping high school, college and graduate students in the field of electro-optics and lasers. He has developed apprenticeship programs allowing students to use his experiments as a springboard toward careers in technical fields.

Drake Livingston, one of Shiner's former students who now works for a worldwide telecommunications company, says the experience he gained in working in Shiner's lab prepared him for his profession.

A scientific competition to determine a more precise value for the fine structure constant is occurring among several groups with goals similar to Shiner's. The participants in these studies include Gerald Gabrielse at Harvard University, Eric Hessels at York University in Canada and Massimo Inguscio at the European Laboratory for Non-linear Spectroscopy.

BY CATHERINE CASHIO ccashio@unt.edu

Other featured articles in this issue

• Retired football coach Gene Stallings joins UNT as athletics consultant
• Updates from the president
• Campus construction continues
• Weather closing information
• New state rep speaks at Fall 2000 commencement
• Two TAMS students have promising year ahead
• UNT beats SECC $100,000-goal by $28,172
• Network set to accommodate students

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