From UPSC perspective, the following things are important :
Prelims level : Black Holes
Mains level : Black holes and gravitation waves
Three scientists won this year’s Nobel Prize in Physics for advancing our understanding of black holes, the all-consuming monsters that lurk in the darkest parts of the universe.
Try this PYQ:
Q.Recently, scientists observed the merger of giant ‘blackholes’ billions of light-years away from the Earth. What is the significance of this observation?
(a) ‘Higgs boson particles’ were detected.
(b) ‘Gravitational waves’ were detected.
(c) Possibility of inter-galactic space travel through ‘wormhole’ was confirmed.
(d) It enabled the scientists to understand ‘singularity’.
Who are these laureates?
- Briton Roger Penrose received half of this year’s prize for the discovery that black hole formation is a robust prediction of the general theory of relativity.
- German Reinhard Genzel and American Andrea Ghez received the second half of the prize for the discovery of a supermassive compact object at the centre of our galaxy.
What are black holes?
- 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.
- Penrose has been awarded the prize for the discovery that black hole formation is a robust prediction of the general theory of relativity.
- Genzel and Ghez have been awarded the prize for the discovery of a supermassive compact object at the centre of our galaxy.
- 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 the gravity that shapes the universe “at the largest scale”.
- Penrose used Einstein’s general theory of relativity in order to prove that the process of formation of black holes is a stable one.
- 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.