The first black hole known was Cygnus X-1, identified by several researchers independently in 1971. The discovery of neutron stars by Jocelyn Bell Burnell in 1967 sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality. Black holes were long considered a mathematical curiosity it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. David Finkelstein, in 1958, first published the interpretation of 'black hole' as a region of space from which nothing can escape. In 1916, Karl Schwarzschild found the first modern solution of general relativity that would characterize a black hole. Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. In many ways, a black hole acts like an ideal black body, as it reflects no light. Although it has a great effect on the fate and circumstances of an object crossing it, it has no locally detectable features according to general relativity. The boundary of no escape is called the event horizon. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. Around the time of alignment, extreme gravitational lensing of the galaxy is observed.Ī black hole is a region of spacetime where gravity is so strong that nothing – no particles or even electromagnetic radiation such as light – can escape from it. Animated simulation of a Schwarzschild black hole with a galaxy passing behind.

Falling into a black hole gif