Seminarium Teorii Względności i Grawitacji

The collapse of massive matter clouds under their own gravity was studied by Oppenheimer and Snyder, and Datt, in the late 1930s within the framework of Einstein gravity. As a result of this gravitational collapse, a region developed in space-time from which no particles or even light could escape, which came to be known later as a `Blackhole'. Subsequently, such blackholes came in intense focus again in the 1960s, further to observations of highly energetic phenomena in the universe such as Quasars. Then, assuming that all massive stars must end up as blackholes only when they undergo gravitational collapse at the end of their lives, much development took place in blackhole physics. Further investigation of gravitational collapse phenomena however revealed that under physically realistic conditions, the collapse could result in the delay of event horizons which define a blackhole. Then the singularity developing as the collapse endstate would be visible to faraway observers. We discuss these intriguing perspectives and emerging trends in this very active arena of research today. Various findings such as quantum effects near visible or naked singularities, observational effects that may distinguish blackholes from naked singularities, the recent possibilities on regular blackholes, and others are pointed out. We also allude to the likely insights that mayemerge on quantum gravity, and implications for observational astrophysics, from these developments.