Unlocking the Mystery of Gravitational Waves

Thanks to a $14.5 million National Science Foundation grant, Professor David Nice and his team of student researchers may be one step closer to understanding one of the mysteries of the universe.

Nice is part of the North American Nanohertz Observatory for Gravitational Waves, an international group of physicists exploring the existence of gravitational waves through the observation of pulsar stars.

According to Nice, gravitational waves are ripples in space-time produced by moving objects such as super-massive black holes orbiting each other or remnants of cosmic inflation, the period just after the Big Bang. They are a prediction of Einstein’s theory of relativity, but have not yet been directly detected.

The team uses radio telescopes to observe millisecond pulsars—distant, rapidly rotating stars that emit pulses of radio waves. As pulsar signals travel through space to the Earth, gravitational waves affect their motion, and the signals can arrive at telescopes a little earlier or later than they otherwise would.
“We want to measure this effect by making high-precision observations of many pulsars over many years,” says Nice, associate professor of physics. “The pulses travel for thousands of years to reach us, and the gravitational waves affect the pulses only at the level of tens of nanoseconds.”

Data is gathered from Arecibo Observatory in Puerto Rico and Green Bank Telescope in West Virginia, operated remotely with computers at Lafayette. Models are created to compare when the pulses should arrive at the telescope in the absence of gravitational waves with the actual arrival.

Sarah Henderson ’16, a physics and math double major, and physics majors Hao Lu ’16 and Enia Xhakaj ’17 are working with Nice as EXCEL Scholars.