FACULTY PROFILE: Gregory Moses
guy who’s fascinated by technology, Professor Greg Moses develops elaborate computer models that predict and then analyze the results of large-scale inertial-confinement fusion experiments.
Such experiments explore a method of producing fusion energy using high-powered laser beams that fire “photon bullets” at marble-sized fuel pellets at a billionth of a second a shot. Those bullets blow the pellets’ surface off and super-compress the center. If everything goes according to plan, the center, which measures in the micron range, will become so dense and hot that the fuel will fuse, burn and release energy — just like the fusion that occurs on the sun.
It all sounds simple, but there are a number of earthly factors that prevent this astronomical event from occurring as planned. “The physical phenomena that come into play here are shock waves; so-called laser-plasma interactions, which are electromagnetic theory and electromagnetic waves in reactions; and X-ray and atomic physics, because the plasmas get extremely hot and generate lots of X-rays, and the X-rays are the way that heat gets transferred from one part of the plasma to another,” says Moses. “So understanding the details of that is really important.” In addition, everything is constantly moving. “If you can make all of this work, then theoretically, you could go on to make electricity,” he says.
At UW-Madison, researchers are studying ways to design a reactor to do just that. Moses’ radiation hydrodynamic simulations are designed to predict what will happen when you bombard the fuel pellets with laser shots. “The experiments themselves are very expensive and they’re pulsed, which means that the experiment is over in a matter of nanoseconds,” he says. “And so the diagnostics used to measure what’s happening are largely indirect measurements.”
In other words, in real life, its impossible to measure every aspect — and one experiment might run around $1 million. So first Moses predicts what should happen, then researchers run the actual experiment at one of a half-dozen or so large national facilities. Finally, Moses conducts additional simulations that analyze the experimental data and determine if it occurred the way the researchers thought it would.
Advances in computing technology have made his job easier and the data more precise. “As computers get faster and faster, you can use more and more accurate physical models of various processes and be able to afford to do the computation,” he says.
On the biggest computer, a calculation today might run for four days. Depending on his needs, Moses uses a parallel computer at the University of Rochester (New York), computers at Los Alamos National Laboratory, a supercomputer at the University of California-San Diego, or on campus, the department’s PC cluster.
Moses has maintained an affiliation with the San Diego Supercomputer Center since the early 1980s, and in the mid 1990s, spent his sabbatical at the university. During that time, he helped to write a proposal for the center’s renewal and became involved in its $1.5 million education and outreach component. As a result, a vision he shared with Computer Sciences Professor Larry Landweber to exploit the Internet as a medium for instructional technologies came to fruition.
Several years ago, Moses, Computer Sciences and Mathematics Professor John Strikwerda and researcher Mike Litzkow developed eTeach, a multimedia presentation authoring tool that enables faculty members on campus and elsewhere to integrate and synchronize video lectures, animated PowerPoint slides, web links and closed-captioning for online instruction. The elements appear in quadrants in a single window on the computer screen and students who view each multimedia lecture can pause, rewind or fast forward the video. “It tries to appeal to different learning styles, because there’s an ability to do a self-assessment as part of the presentation,” says Moses. “With each question, there are buttons you can click that will take you back to the part of the lecture where the material was presented, so if you don’t understand the questions, you can always go back and review it. Whereas, if you were in a live lecture, once its done, its done.”
Today, he and other faculty members use eTeach to maximize the in-class time they spend with their students — or in some cases, to teach them at a distance. In Moses’ class, students view the lectures at their leisure as homework assignments, then come to a small-group laboratory session ready to work, interact with the instructors, and practice what they’ve learned. “The idea of the online presentations is to remove the characteristic that they’re an ‘event,’ but rather that they’re just another resource like a textbook,” he says.
The software is one of a few such tools that include closed captioning and work with a screen reader. “It’s gotten a lot of attention in the community of blind and deaf people,” says Moses, who worked closely with staff at the college’s Trace Center and the university’s
Division of Information Technology to build those features into eTeach.
It’s not surprising that the man who uses computers to learn everything he can about a fusion experiment also uses them to maximize the way students learn. “While I started in a technology-push mode, I ended up in a different place — which is a much greater concern for student learning and using that to select appropriate technologies for doing that,” he says.
Moses participates in the university’s Center for Integration of Research,Teaching and Learning, through which he teaches, “Effective Teaching with Technology,” a professional-development course to spark PhD students’ enthusiasm and concern for student learning.
In recognition of the way Moses uses eTeach to fundamentally change how he teaches his courses, the college presented him with the first Harvey Spangler Award for Technology-Enhanced Instruction this May.