Black holes not only bend space, time, and light, but they hold an unparalleled grip on the imagination of scientists, artists, and the general public. They fascinate audiences as the muse of science fiction, but black holes are real objects that provide deep insights into the nature of our universe.
However, the nearest known black hole is more than 26,000 light-years away (more than 150 quadrillion miles) and emits no light of its own. How could something so inherently hidden be discovered, much less understood?
A large part of that discovery is thanks to Andrea Ghez, Nobel Laureate and professor of physics and astronomy at the University of California, Los Angeles (UCLA). Ghez will be speaking at WashU as part of the McDonnell Distinguished Lecture Series, titled “From the Possibility to the Certainty of a Supermassive Black Hole”.
Ghez shared the 2020 Nobel Prize in Physics for her discovery of our galaxy’s central black hole — not by directly observing it, but by tracking many other stars nearby. By 2020, Ghez’s research group demonstrated that a missing “compact object” must be in the center of all these stars, which today has been confirmed to be a black hole. She is the fourth woman to ever receive the Nobel Prize in Physics and continues to push the frontier of black hole research today.
“The universe offers a much more extreme laboratory than you can find anywhere on Earth,” Ghez said.
As she explained during the colloquium portion of her lecture series, Ghez’s research journey has seen rejection, resilience, competition, and technological leaps from within and beyond astrophysics.
It took decades for Ghez and her colleagues to overcome the technical challenges posed by our Earth’s atmosphere, closely track the motions of stars near the center of our galaxy, and put the missing pieces together. In the end, however, they proved the existence of a dark, massive central object, four million times the mass of our Sun but compressed to a size smaller than our solar system.
For an audience of physicists and planetary scientists, as well as other curious professionals and students, the groundbreaking discoveries and questions of black hole dynamics, galactic evolution, and optical imaging are exciting enough. But looking to speak to a broader audience for the public lecture, Ghez aims to appeal to a more intrinsic connection between people and astronomy.
“It speaks to our deep humanity — the fact that we are a small, small speck in a very big universe. I think that’s one of the fundamental appeals of astronomy,” Ghez said.
All members of the WashU and St. Louis community are encouraged to attend Ghez’s public lecture as part of the 2026 McDonnell Distinguished Lecture Series, which will begin at 7:00 p.m. in Whitaker Hall on March 26.