‘A New Window to the Universe’: Radcliffe Institute Reflects on Scientific History of Gravitational Waves | New

MIT School of Science Dean Nergis Mavalvala – one of the astrophysicists who first detected gravitational waves directly – gave a talk on the scientific history of gravitational waves on Tuesday at an event hosted by the Radcliffe Institute for Advanced Study from Harvard.

The talk, titled “Gravitational Waves: A New Window to the Universe,” was part of Radcliffe’s annual Kim and Judy Davis Dean lecture series in the Science series.

Radcliffe Dean Tomiko Brown-Nagin kicked off the conference with his own take on the breakthrough discovery, which took place in 2015.

Gravitational waves are ripples in space-time caused by high-energy cosmic events like the fusion of black holes. Even if scientists like Albert Einstein theorized about gravitational waves as early as 1916, they rejected them as very weak and therefore undetectable.

“Indeed, our desire for a new and deeper understanding has led to groundbreaking discoveries throughout history,” Brown-Nagin said. “Few subjects have captured our curiosity as much as the cosmos itself. “

Mavalvala explained at the start of her lecture that before the discovery of gravitational waves, astrophysicists relied on light, which she called a “natural messenger,” to study the universe.

However, while working with the Laser Interferometer Gravitational-Wave Observatory, which has locations in Livingston, Louisiana and Hanford, Washington, Mavalvala and his colleagues first detected gravitational waves.

At Tuesday’s talk, which took place on Zoom, Mavalvala described his methodology and that of his colleagues.

“The L in LIGO stands for laser. It was the light source that made this possible, ”she said. “When you’re trying to take a very precise measurement, you need a very, very good ruler.”

The detectors consisted of four-kilometer-long tunnels with extremely precise lasers and mirrors that were constantly looking for a signal from a gravitational wave rippling through space, she said.

“If you had a really accurate clock, you measure the travel time of light, and if a gravitational wave passes, that light travel time would change as the gravitational wave narrows and expands the space between the laser and the laser. mirror, ”Mavalvala explained.

Seeing the signal for the first time in September 2015, Mavalvala and his colleagues were in disbelief. According to Mavalvala, they shook their heads and said, “No, that can’t be real. Their historical observation, she said, was “as beautiful as astrophysical history because it brought us face to face with the smallest and most fundamental forces of nature at the quantum level.”

Despite the groundbreaking success achieved by Mavalvala and his team, they faced challenges, Mavalvala said in an interview after the conference.

“When you’re trying to do something with such precision that’s never been done before, there’s almost nothing you can just buy off the shelf,” she said. “We had to invent solutions for just about every technology we were using. “

Mavalvala stressed that scientific achievements should not end conversations but should actually start new ones.

“We have activated this whole new way of feeling the universe, but this moment in history will not be remembered for these particular discoveries, but for the paradigm shift where we can now use gravity alone or gravity with light as a new tool for unimaginable discovery, ”she told the conference.

Currently, Mavalvala and his team are trying to improve the way astrophysicists detect gravitational waves by using a quantum light source instead of a regular laser.

—Editor-in-Chief Jorge O. Guerra can be contacted at [email protected]. Follow him on twitter @jorgeoguerra_.

– Editor Christie K. Choi can be contacted at [email protected].