Illinois engineering student helped improve instruments that led to gravitational wave breakthrough
The recent observation of gravitational waves, or ripples in the spacetime fabric, has been heralded as one of the greatest accomplishments of astrophysics in our time – the first step in advancing our understanding of the Big Bang theory, colliding neutron stars, and supermassive black holes.LIGO Collaboration in 2013 (listed as an author in the LIGO Document Control Center here).
“There is no way this accomplishment could have happened without engineers, who built an instrument capable of measuring these waves,” said Sujan Kumar Gonugondla, who was an undergraduate student at the Indian Institute of Technology Madras at the time. “State-of art engineering techniques were used to improve the accuracy of the observatory. At the end of the day, we created an interferometer of a type and scale that had never existed before.”
A concept first proposed by Albert Einstein a century ago, gravitational waves were indirectly observed in 1974 when scientists at the University of Massachusetts Amherst observed radio flashes emitted from two neutron stars rotating around each other. The timing of the flashes coincided with Einstein’s predictions of how gravitational waves would transport energy.
In the 2000s, the LIGO Collaboration formed in an attempt to observe the phenomena directly. But it wasn’t until 2015, when a $200 million upgrade to interferometers at twin observatories in Washington state and Louisiana was completed, that scientists succeeded in “hearing” the waves.
During the upgrade process, Gonugondla spent a summer at the LIGO observatory in Louisiana working to overcome “noise” that interfered with the waves. He worked on measuring the effect of seismic tremors on the detector and helped create a new mode of operation for the sensors that monitored seismic noise. In addition, he helped improve the impact of transient noise, which could be the result of a car driving or a carnival 10 miles away, and wrote a new program to help identify those sources as noise.
“I applied more of my engineering skills to that project than I had until then,” Gonugondla said. “It was an amazing experience.”
These days, Gonugondla is seeking a PhD in electrical engineering under adviser Naresh Shanbhag, the Jack S. Kilby Professor of Electrical and Computer Engineering at Illinois and director of the Illinois-led SONIC Center. Gonugondla is working with other SONIC researchers to build energy-efficient and reliable computing systems on nanoscale fabrics by exploring techniques that seek to cancel or compensate for circuit noise.
While the approach is different, the goal is the same: To build more reliable and effective engineering systems.
“We were able to help make an interferometer that was now limited by something of a quantum nature,” he said of his time with LIGO. “At the end of the day, it was an engineering marvel.”