The Physics Nobel Prize is awarded to the person who made the most important discovery or invention in the field of physics each year. This year, The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics to Roger Penrose for his discovery that black hole formation is a robust prediction of the general theory of relativity.

Andrea Ghez and Reinhard Genzel shared the Nobel Prize with him for their discovery of a supermassive compact object at the center of our galaxy. The Nobel Prize money in Physics 2020 was divided, one half awarded to Roger Penrose and the other half jointly to Reinhard Genzel and Andrea Ghez. In the statutes of the Nobel Foundation it says: “A prize amount may be equally divided between two works, each of which is considered to merit a prize. If a work that is being rewarded has been produced by two or three persons, the prize shall be awarded to them jointly.

Black holes are massive objects. This term refers to a region of space-time where gravity is extremely strong. Their gravitational field is so strong that no particles, even electromagnetic radiation such as light can escape from it. At its center, the black hole harbors a puzzling zone called a singularity. 

A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole. However, scientists can see how the strong gravity affects the stars and gas around the black hole in order to identify when a black hole is present. They can also study stars to find out if they are flying around or orbiting a black hole. NASA is also using satellites and telescopes that travel in space to learn more about black holes. These spacecraft help scientists to explore the universe better. 

Ghez’s team used the 10-meter Keck Telescope in Hawaii, and Genzel’s group used the 8-meter aperture telescopes at the European Southern Observatory in Chile. Building these large telescopes was a big technological challenge for them. It involved mechanical design, civil engineering, electrical and electronics expertise. For over thirty years, they had to work on the resolvability and sensitivity of their telescopes. This led to the discovery of a supermassive compact object at the center of our galaxy.

Einstein’s general theory of relativity suggests that black holes are theoretically possible, and Roger Penrose thus used mathematical methods to demonstrate that the general theory of relativity leads to the formation of black holes. Reinhard Genzel and Andrea Ghez discovered that an extremely heavy object which is invisible governs the orbits of stars at the center of our galaxy. A supermassive black hole is the only currently known explanation.

Andrea Ghez is the fourth woman to win the Physics Nobel Prize. Marie Curie was the first, in 1903. After her, Maria Goeppert Mayer won the prize in 1963 and Donna Strickland won the prize in 2018.