VIRGINIA, July 27: More than 100 years ago, Albert Einstein predicted that light is deflected by extremely massive objects, but there is no way to test such powerful effects on Earth.

At the backdrop of the euphoria amongst scientific community about the recent first-ever photo of a black hole last month, one of my colleagues, who was not a science student in his high school, got intrigued by the concept of black hole and things thereof. He kind of posed a challenge to me to make him understand the concept. He felt more enlightened after I tried and simplified things for him. It was then I got an inspiration to write this article with somewhat layman approach to understanding black hole.

Christie's auctioneers said on Thursday that the so-called God Letter, written by Einstein in 1954, would be placed on public exhibit in San Francisco and New York ahead of the Dec. 4 auction.