Popular Science: They "see" Black Holes-Interpretation of the 2020 Nobel Prize in Physics
Xinhua News Agency, Beijing, October 6 (Reporter Luo Guofang) The 2020 Nobel Prize in Physics was awarded to three winners because "they discovered one of the most bizarre phenomena in the universe-black holes."
British physicist Roger Penrose proved that black holes are a direct product of general relativity.
German scientist Reinhard Genzel and American scientist Andrea Gates discovered that in the center of our galaxy, an invisible and extremely massive celestial body controls the orbits of surrounding stars. The only explanation for the celestial body is a supermassive black hole.
Einstein's general theory of relativity overturned the traditional concept of space and time.
His equation predicts the existence of black holes: massive celestial bodies will bend space and slow down time, and a super-massive celestial body can even swallow light to form an "absolutely dark" space. This is a black hole.
It is worth mentioning that Einstein himself did not believe that black holes can really exist.
However, 10 years after Einstein's death, Penrose used clever mathematical methods to demonstrate that black holes can be formed, and described them in detail: a singularity hidden in the core of the black hole, its space-time curvature is infinite, and its density is also Tends to be infinite.
Once matter begins to collapse, nothing can stop the collapse from continuing, and all matter can only move towards the singularity in one direction.
This is a "one-way street" leading to the end of time.
Penrose’s seminal paper was published in January 1965 and is still considered to be the most important contribution to general relativity since Einstein.
Now, the existence of a singularity in the center of a black hole has become a common understanding in the scientific community.
The gravitational force of a black hole is so powerful that even light cannot escape. The boundary where no light exits is called the "event horizon".
It is impossible to peep into the black hole directly—all the secrets of the black hole are hidden in its event horizon.
However, the stars point out the direction for assiduous scientists.
Using the orbit of the star as a guide, Genzel and Gates presented the most convincing evidence so far that an invisible supermassive object is hidden in the center of the Milky Way.
100 years ago, American astronomer Harlow Shapley first determined the center of the Milky Way, the direction of Sagittarius (also known as Sagittarius).
But it was not until the 1990s, with the advent of larger and more advanced astronomical observation equipment, that scientists were able to conduct a more systematic study of the center of the Milky Way.
Genzel and Gates each lead a research team that has been trying to observe a region called "Sagittarius A*" in the center of the Milky Way through dust clouds since the early 1990s.
The Genzel team initially used the New Technology Telescope (NTT) in Chile, and then the Very Large Telescope (VLT) on the Chilean Paranal Mountain.
The Gates team used the Keck Observatory on Mauna Kea Mountain in Hawaii, USA.
Over the past 30 years, Genzel and Gates’ team has continued to improve their observation techniques, tracking the movement of the brightest stars among the many stars in the observation area.
One of the stars completed a complete orbit around the center of the galaxy in less than 16 years, and scientists were able to map its complete orbit.
After decades of observations, the two research teams came to the unanimous conclusion: there is a very massive and invisible celestial body in the center of the Milky Way. There is a mass of about 4 million suns in the space not exceeding the solar system. The stars spin rapidly.
The only reasonable explanation for this invisible celestial body is that it is a black hole.
On April 10, 2019, the "Event Horizon Telescope" project composed of 8 radio telescopes around the world took the first black hole photo in human history.
The black hole photographed is located in the center of a galaxy called M87, and its mass is 6.5 billion times that of the sun.
In the near future, the "true content" of the black hole in the center of the Milky Way may also be revealed.
David Haviland, chairman of the Nobel Prize in Physics Jury, said at the award ceremony that the discoveries of this year's winners have opened up new horizons for the study of dense and supermassive celestial bodies.
But these peculiar objects still raise many questions that need to be answered further, and stimulate future research.
He said: "There are not only questions about their internal structure, but also questions about how to test our theory of gravity under extreme conditions next to black holes."