C. V. Vishveshwara (Vishu) On The Black Hole Trek

With his seminal and pioneering work on the stability of the Schwarzschild black hole and its interaction with gravitational radiation, Vishu had opened a new window on black hole astrophysics. One of the interesting results that soon followed was that “a black hole has no hair”, it is entirely specified by the three parameters, mass, spin and charge, and nothing more. The discovery of gravitational waves in 2016 produced by merger of two black holes, and observed by the Ligo-Virgo collaboration, carried the definitive signature of quasi-normal modes, the phenomenon of black hole ringdown, exactly what Vishu had predicted in his 1970 Nature paper~(See Isaacson’s commentary) 46 years ago. This was the crowning glory.