Astrophysicist Jeremy Darling of University of Colorado Boulder is taking a completely different tack to hunt for gravitational waves. These subtle cosmic tremors, that stretch and squeeze space and time itself, provide important clues about the universe’s most fundamental workings. Darling’s innovative method involves utilizing quasars—extremely luminous objects located millions of light-years away—to measure the universe’s gravitational wave background.
In 2023, a team of scientists successfully measured the gravitational wave background, an achievement that highlights the growing interest in understanding these phenomena. Darling wants to expand on this foundation to explore how gravitational waves affect the development of baby galaxies into mature galaxies. They will be testing fundamental principles of gravity itself.
Quasars and Gravitational Waves
Gravitational waves are an inevitable tsunami-like tide of energy that sweeps through the entire universe, affecting all in their wake. Darling describes that these phenomena forcefully stretch and squeeze spacetime across our line of sight. They produce the effect of things zooming in and out of the sky. The tiniest of movements can be undetectable by the eye but provides rich data for astrophysicists.
For astrophysicist Jeremy Darling, the appeal of studying quasars is their great distance from Earth. These weird objects dispense unfathomable amounts of energy and present a one-of-a-kind vantage point from which to study gravitational waves. Quasars are billions of light-years away from us. That distance allows scientists to pick up miniscule perturbations as gravitational waves pass through the fabric of space itself.
Darling explained, “If you were able to live for millions of years, you would be able to see some really small movements in the universe. You’d see those quasars moving side to side! This unassuming viewpoint is critical in isolating the minute influence gravitational waves have on far-off targets such as stars and galaxies.
Utilizing Gaia Satellite Data
To continue his research, Darling has drawn on data from the European Space Agency’s Gaia satellite. So far over nearly three years of data, Gaia has taken new observations on about a million quasars. This massive dataset presents deep analysis opportunities. It enables us to investigate the gravitational wave background and look for other faint signals that might be lurking behind the noise.
If we are able to identify millions of these quasars, we will be able to find these signals nestled within that enormous dataset. Darling was unapologetic in her declaration. His strategy is based on the ability to sense the influence of gravitational waves in 3D. It emphasizes mapping how these waves interact with the locations of quasars relative to Earth.
Darling’s approach is aimed at detecting slowly-moving gravitational waves that sweep across large areas over long timescales on the order of years to decades. He uses the latest technology to keep a close eye on these shifts. His mission is to discover new truths about gravitational waves and their bigger picture meaning for cosmic evolution.
Future Discoveries on the Horizon
The Gaia collaboration plans to make an additional five-and-a-half years of quasar observations publicly available in 2026. These new data have the potential to unlock even more secrets from the universe’s gravitational wave background. This anticipated dataset will enhance Darling’s research capabilities and potentially lead to groundbreaking discoveries about how galaxies evolve over time.
There is much more we can learn from directly obtaining these precise measurements of gravitational waves,” Darling stated. His efforts truly represent the next big step in explaining how these great cosmic collisions were weaving the very fabric of our universe.