Produced by: Tarun Mishra Designed by: Manoj Kumar
On January 1, 2024, the Indian Space Research Organisation (ISRO) marked the New Year with the successful launch of PSLV-C58, which deployed XPoSat and 10 additional payloads into an eastward low-inclination orbit.
XPoSat is ISRO's first dedicated scientific satellite aimed at unraveling the mysteries of black holes by conducting detailed research on X-ray emissions and investigating the polarisation of intense X-ray sources in space.
In 1916, Albert Einstein first proposed the concept of black holes through his general theory of relativity, but he remained sceptical about their existence.
In 1939, Albert Einstein published a paper in the Annals of Mathematics, attempting to refute the idea of a "Schwarzschild singularity" – a term for black hole named after astronomer Karl Schwarzschild. The Schwarzschild singularity suggested a breakdown in space-time at the point of a gravitational singularity, creating a region from which even light could not escape.
Karl Schwarzschild was the first to discover the existence of black hole based on Albert Einstein general theory of relativity. Einstein, aiming to preserve the integrity of his theories, stated in his 1939 paper that Schwarzschild singularities "do not exist in physical reality.”
However, in 1965, a significant breakthrough occurred with the discovery of a peculiar astronomical object known as Cygnus X-1. This star system exhibited strong X-ray emissions, suggesting the presence of an unseen and incredibly dense object. Subsequent observations supported the hypothesis that Cygnus X-1 contained a black hole.
The term "black hole" was then coined in 1967 by American astronomer John Wheeler for these anomalies in deep space.
Albert Einstein's skepticism persisted until the 1970s when accumulating astronomical evidence, including observations of rapidly rotating stars and the behaviour of matter surrounding invisible objects, strongly indicated the existence of black holes.
By the mid-1970s, the scientific community widely accepted the reality of black holes, marking a shift from Einstein's initial skepticism to the acknowledgment of these enigmatic celestial entities. The indirect evidence and observational data supporting black holes' existence became increasingly compelling, aligning with predictions derived from Einstein's own theories.
Today, black holes are a well-established and crucial aspect of astrophysics, testament to the evolving understanding of the universe.