Nobel Prize of Physics
Recently, the Royal Swedish Academy of Sciences decided to award one half of the 2020 Nobel Prize in physics to Roger Penrose and the other half jointly to Reinhard Genzel and Andrea Ghez for furthering the understanding of black holes, the most “enigmatic” objects in the universe.
- Recently, three biologists shared the Nobel Prize in medicine for the discovery of the vaccine for the hepatitis C virus.
What is a ‘black hole’?
- A black hole is formed when stars collapse and can be defined as a space in the universe with an escape velocity so strong that even light cannot escape it.
- Escape velocity is the speed at which an object must travel to override a planet or an object’s gravitational force. For instance, for a spacecraft to leave the surface of the Earth, it needs to be travelling at a speed of about 40,000 km per hour.
- Since light cannot get out, black holes are invisible and can only be tracked with the help of a space telescope or other special tools. And the reason light cannot escape is mainly that the gravity inside a black hole is very strong as a result of a lot of matter being squeezed into a small space.
Contribution of Penrose
- Penrose’s work has shown that black holes are a direct consequence of Albert Einstein’s general theory of relativity. Einstein himself did not believe that black holes exist and presented his theory in November 1915, providing a new way to look at and understand gravity that shapes the universe “at the largest scale”. Gravity also shapes space and influences the passage of time. It is this gravity, which is so great inside a black hole that is able to bend space and slow down time.
- Penrose used Einstein’s general theory of relativity in order to prove that the process of formation of black holes is a stable one. He proved that black holes exist and described them in detail back in 1965, ten years after Einstein died.
Contributions of Genzel and Ghez
- Genzel and Ghez, on the other hand, have discovered that an invisible and an extremely heavy object governs the stars’ orbit at the centre of the Milky Way. This extremely heavy object has the mass equivalent to 4 million solar masses and is packed into an area about the size of our solar system.
- Essentially, their work tells us that at the centre of our galaxy the Milky Way lies an invisible supermassive object, of which a black hole provides a reasonable explanation. Physicists have been suspecting the existence of a black hole at the centre of our galaxy for over 50 years now.