The Nobel Prize in Physics this year has been awarded to Sir Roger Penrose, Reinhard Genzel and Andrea Ghez. Read on to find out why they were presented with this award. All their work is related to one of the most intriguing and mysterious objects in the Universe- black holes. Black holes are regions of spacetime that have an extremely strong gravity. They form when a massive star collapses on itself. Half the prize was awarded to Sir Roger Penrose for proving the existence of black holes theoretically and the other half, shared between Andrea Ghez and Reinhard Genzel, for granting experimental evidence. Interestingly, Andrea Ghez is the fourth woman to win a Nobel prize!
Sir Roger Penrose is a British mathematical physicist. He received his share of the prize for his work in 1965 to show that ‘under very general conditions, collapsing matter would trigger the formation of a black hole’(1). He invented several mathematical techniques and concepts like trapped surfaces while developing his proof. Before Dr Penrose’s proof, black holes weren’t considered real as they were thought to be formed only due to perfectly spherical stars. Later, Penrose along with Stephen Hawking provided us with new insights on singularities.
Andrea Ghez works as an American astronomer at the University of California, Los Angeles while Reinhard Genzel works as an astrophysicist at the Max Planck Institute for Extraterrestrial Physics.
Andrea Ghez and Reinhard Genzel have been honoured with the prize for discovering the black hole at the center of our galaxy, the Sagittarius A*, using some of the world’s largest telescopes at that time. Ghez and Genzel both led separate teams that confirmed the existence of the black hole. Genzel’s group first used the New Technology telescope in Chile but later moved to the VLT or the Very Large Telescope. Ghez’s team used the Keck observatory in Hawaii. Andrea Ghez and her team have monitored the motions of a few stars present in that region from 1995 to 2007.Some object present there was causing stars around it to revolve at high speeds. One star’s orbital period was observed to be just 16 years! Using this data, they found out that the mass of the black hole the stars were orbiting was 4 billion times the mass of the Sun!(2)
These discoveries have helped us know that black holes aren’t just fiction, but are really out there!
“Roger Penrose, Reinhard Genzel and Andrea Ghez Bag the Nobel Prize for Physics – Physics World.” Accessed November 10, 2020. https://physicsworld.com/a/roger-penrose-reinhard-genzel-and-andrea-ghez-bag-the-nobel-prize-for-physics/.
Khanna, Gaurav. “The Trailblazing Discoveries That Won the 2020 Nobel Prize in Physics.” The Wire Science (blog), October 8, 2020. https://science.thewire.in/the-sciences/nobel-prize-in-physics-2020-penrose-genzel-andrea-ghez-black-hole-general-relativity-studies/.
the Guardian. “Three Scientists Share Nobel Prize in Physics for Work on Black Holes,” October 6, 2020. http://www.theguardian.com/science/2020/oct/06/nobel-prize-in-physics-awarded-to-trio-for-work-on-blackhole-formation.