BLACK HOLE (Syllabus: GS Paper 3 – Sci & Tech)

Black Hole:

• Meaning: It is a cosmic body of extremely intense gravityfrom which nothing, not even light, can escape.

oA black hole can be formed by the death of a massive star.

oWhen such a star has exhausted the internal thermonuclear fuels in its core at the end of its life, the core becomes unstable and gravitationally collapses inward upon itself, and the star’s outer layers are blown away.

• Background:

o1st predicted by: Albert Einstein in 1916, with his general theory of relativity.

oFirst interpretation of "black hole": By David Finkelstein in 1958, as a region of space from which nothing can escape.

oThe term "black hole" was coined: In 1967 by American astronomer John Wheeler.

oCygnus X-1: The first black hole identified by several researchers independently in 1971.

• Detection: Because light cannot get out, black holes are invisible and can only be tracked with the help of spatial telescopes and special tools.

oThe first image of a black hole was captured in 2019 by the Event Horizon Telescope (EHT) collaboration.

• Types: According to their mass with respect to the mass of our sun. There are four types of black holes: stellar, intermediate, supermassive, and miniature.
• Causes of different sizes of black holes: Black holes come in many sizes and their size depends on how much material is in them (their mass).