New Delhi: “Unlike being portrayed in many science-fiction movies, black holes don’t move around sucking in objects like a vacuum cleaner,” said Somak Raychaudhury, Director of Inter-University Centre for Astronomy and Astrophysics, Pune, busting one of the most popular myths about black holes.

Raychaudhury, who was giving an online lecture at Nehru Science Centre, Mumbai began by addressing the myth that has been narrated in books and movies over and over again. He focused on explaining how the contribution of different scientists, starting from Isaac Newton till date, have evolved and resulted in a better understanding of black holes.

The lecture comes in the backdrop of three scientists who won the Nobel Prize in Physics for their contribution in understanding Black Holes. The scientists include 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, Raychaudhury 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 Hawking and Penrose in their paper, which was cited by the Nobel committee this year.” he said.

He further explained that black holes have two broad categories – the singularity and the event horizon. They are divided into three types, classified on the basis of their mass – Stellar-mass black holes, Mid-size black holes and SuperMassive black holes.

“Findings of Andrea Ghez and Reinhard Genzel have shown the supermassive black hole in the middle of our galaxy. One cannot see the black hole since no light comes from it. Hence the scientists thought of watching the stars very close to the black holes and observe their movement and believed that from their mass, the mass of the galaxy and the black holes can be measured. They have been observing the movement of stars in the galaxy for 30 years”, he noted.

Speaking on Laser Interferometer Gravitational-Wave Observatory – India and the role of the country in the findings and research of black holes, he said, “India is part of the biggest research in the world that is working in the field of black holes.”

The construction of the LIGO (Laser Interferometer Gravitational-Wave Observatory) is coming up in Hingoli district, Maharashtra. The land has been acquired for this purpose and work has already started, he pointed out.

Shri Somak Raychaudhury proudly claimed that all three of the eminent personalities who had contributed to the black holes were his teachers. “I learnt my General Relativity from Amalkumar Raychaudhuri, I took a mathematics course at Oxford University from Penrose and studied about black holes from Stephen Hawking.”

Notably, the LIGO-India project will be built by the Department of Atomic Energy and the Department of Science and Technology, Government of India, with a Memorandum of Understanding with the National Science Foundation (NSF), USA, along with several national and international research and academic institutions. The three institutes leading the project in India are Inter-University Centre for Astronomy and Astrophysics in Pune, Raja Ramanna Centre for Advanced Technology in Indore and the Institute of Plasma Research in Ahmedabad.