The 2020 Nobel Prize in physics was awarded Oct. 6 to Caltech Alum and professor of Astrophysics at UCLA, Andrea Ghez for the discovery of a supermassive compact object at the center of our galaxy.
Einstein’s theory of relativity ignited curiosity and mass research into the true nature of supermassive compact objects deforming into black holes. Research that decades later would eventually prove the presence of a black hole residing at the center of the Milky Way Galaxy.
“This is incredibly well-deserved recognition for Andrea’s exceptionally careful work carried out over many decades,” Fiona Harrison of Caltech said. Caltech is a world-renowned research and engineering institute marshaling innovative tools and minds to address fundamental scientific questions.
Ghez shares half of the award with Reinhard Genzel of UC Berkeley and the Max Planck Institute for Extraterrestrial Physics. The other half of the Nobel Prize goes to Roger Penrose of Oxford for the proof that black holes are a direct consequence of Einstein’s theory of relativity.
The journey began with Ghez and Genzel closely studying Sagittarius A* and the reason behind it being a mysterious source of radio waves. It has been theorized by both Nobel laureates that a supermassive black hole was behind Sagittarius A*’s strange properties, but at the time their existence was unconfirmed.
“At the beginning the question was, ‘Is there a supermassive black hole at the center of our galaxy, and by extension, can you prove they really exist?” Ghez told the LA Times.
Observing the orbit of 100 stars around Sagittarius A*, Ghez and her team studied their movement under the effects of its gravity. Compared to the average star in a galaxy which takes millions of years to complete an orbit, these particular masses of plasma manage to do so within the time range of a single human’s lifetime. This was a powerful indicator of the presence of a supermassive black hole.
“We were seeing velocities at several percent the speed of light,” UCLA colleague and collaborator of Ghez, Mark Morris said. “I have to say we were fairly blown away.”
Ghez and her team utilized infrared laser technology and the Keck telescope to accurately measure the movement and size of these stars revolving around the object. Those measurements coupled with a technique called speckled imaging, a technique Ghez developed herself, provided sharper and crisper images of the supermassive object that finalized the proof of the presence of a black hole.
“I’m thrilled and incredibly honored to receive a Nobel Prize in Physics,” Ghez said. “We have cutting-edge tools and a world-class research team, and that combination makes discovery tremendous fun. Our understanding of how the universe works is still so incomplete. The Nobel Prize is fabulous, but we still have a lot to learn.”
Confirming the existence of the black hole at the center of the Milky Way Galaxy would confirm the object responsible for governing the orbit of the stars at the center of the galaxy. The pioneering work will pave the way toward long-term research on the inner structure of compact supermassive objects and motivate even further research on testing the theory of gravity under extreme conditions produced by a black hole.
“There’s so much that we don’t understand, and from a scientist’s point of view it’s really … it’s most interesting to be working in the area that we … that frontier of our knowledge,” Ghez told the Nobel Foundation.
Ghez has nurtured a roaring passion and curiosity for the universe ever since childhood when she aspired to become an astronaut. Years later she became the fourth female Nobel laureate in Physics following Donna Strickland, Maria Goeppert Mayer and Marie Curie. Ghez encourages all to delve into the questions about the universe, about its scope, about the relativity of all it, and about sciences in general.
“To me it’s always been very important to encourage young women into the sciences,” Ghez said. “So to me it means an opportunity and a responsibility to encourage the next generation of scientists who are passionate about this kind of work into the field.”
Ghez continues her research on the roles supermassive compact objects play in the universe. Questions like ‘are there black holes residing at the center of other galaxies similar to the Milky Way’ and ‘are they similar in function or design’ are the forces propelling Ghez’s drive to continue her work with such vigor as an astronomer.
“It’s a passion for the universe,” Ghez said. “It amazes me every time I go to the telescope,”
Ghez’s enthusiasm is fed every time the laws and physics of extraterrestrial space are crispened, bolstering her own understanding of the universe.