Letters to the Editor

摘要

Dear Suprakash, Very nice and comprehensive editorial published in the Nov-Dec, 2020 issue, with a fine collage of photos of AKR. Just wanted to mention that the process of harnessing energy from a black hole was actually discovered by Roger Penrose for particles scattering from a rotating black hole, and later generalized to waves scattering from a rotating black hole. The physics of the process is compelling, in that it ought to play a role in astrophysics. Alas, like Hawking radiation, this process is unobservable astrophysically. However, it is observable in analogue black holes in fluid systems in the lab. I have spoken about this at Presidency U, IITKGP and other places.