Robert Swendsen is in his lab. There’s no atomic microscope or supercomputer—just a desk, two computers, and some melting snow trampled in from the wintry outside. The setting is actually an office, but the Carnegie Mellon professor of physics could tell you differently.

His desk? It’s made up of a tremendous number of atoms. The melting snow—add heat, and it turns from water to gas. Add heat and pressure, and the atoms start to behave very strangely. Are they gas or liquid? Called “critical phenomena,” these types of mysterious states have long since intrigued physicists, including Swendsen.

V11n2 Newsflash 1What are the atoms actually doing? How do they interact? These are questions he asked while doing post-doc work in Germany in the 1980s. He knew that predicting how atoms behave under fluctuating heat and pressure would be key to developing better technologies that impact our everyday lives.

However, the math involved in these predictions is complex. So, Swendsen turned to a field that was just emerging: computational physics. Here, you can turn physics problems into computer simulations and predict far beyond the possibilities of pen and paper. In other words, feed it the right algorithms, and the computer will plot out an accurate image of how water molecules or protein molecules, for example, change over time.

Eventually, Swendsen discovered a way to continuously predict how temperature, pressure, and magnetic fields affect systems. His method has been used by scientists in many fields, particularly in biophysics, where simulating protein synthesis can help us learn how to fight disease.

Cited more than 10,000 times, Swendsen has helped to pioneer computational physics, which has redefined what was once thought possible, from engineering medical technologies to simulating the entire universe itself.

His “multiple, groundbreaking algorithmic developments in computational statistical physics” have earned him the 2014 Aneesur Rahman Prize for Computational Physics from the American Physical Society, which represents more than 50,000 physicists in academia, research, and industry.
—Danielle Commisso (DC’06)