JOIN USBlack holes don't move around sucking objects: IUCAA chief
Black holes don’t move around sucking in objects, said Somak Raychaudhury, director of Pune-based Inter-University Centre for Astronomy and Astrophysics, as he sought to bust myths about black holes.
“Unlike being portrayed in many science-fiction movies, black holes don't move around sucking in objects like a vacuum cleaner. If the Sun turns into a black hole today, it won't suck the other planets; the earth will still be revolving around the sun as if nothing happened, except that there won't be any light and that the earth will turn very cold…but still, we will be revolving,” he said.
A veteran astrophysicist, Raychaudhury focussed on how the contribution of different scientists over different periods of time, right from Isaac Newton till date, have resulted in a better understanding of the black holes.
He was delivering an online lecture on 'The Nobel Prize 2020: Physics' – Unravelling the Mythical Black Holes’ organised by Nehru Science Centre, Mumbai.
This year, three scientists have won the 2020 Nobel Prize in Physics for their contribution in understanding Black Holes: Roger Penrose (for the discovery that black hole formation is a robust prediction of the general theory of relativity), Andrea Ghez and Reinhard Genzel (for the discovery of a supermassive black hole at the centre of our galaxy).
While talking about the relevance of the lecture being organised, Raychawdury also pointed out the ‘Calcutta connection’ of Nobel Prize for black holes.
He mentioned that in their study about black holes, both Stephen Hawking and Roger Penrose used the formalism laid down in 1955 by Amalkumar Raychaudhuri, a famous professor of physics at Ashutosh College under the University of Calcutta. His paper ‘Relativistic Cosmology Paper 1’ is about Einstein’s theory of general relativity.
“The paper says nothing about black holes, instead it is a concept of ‘differential geometry’. Hawking used this concept to define how a spinning star with angular momentum collapses and distorts the space-time to finally end up in a singularity, and showed how singularity is quite natural and that it is not an unusual happening in the universe. This was explained by both Hawkins and Penrose in their paper, which was cited by the Nobel committee this year,” said Chaudhury.
"A black hole has two basic parts: the singularity and the event horizon. The singularity is at the centre and is where the mass resides. It was Stephen Hawking and R Penrose who wrote the first paper on Singularities,” he added.
Black holes are of three types, classified on the basis of their mass - Stellar-mass black holes, Mid-size black holes and Super-massive black holes.