FROM THEORY TO FACT
11, Apr 2019
Prelims level : Science and Technology Mains level : Achievements of Indians in science & technology; indigenization of technology and developing New technology
Why in News:
- Scientists have revealed the first image ever made of black hole after assembling data gathered by network of Event Horizon Telescope.
- The term black hole was coined in mid-1960 by American physicist John Archibald Wheeler.
- The matter is so compressed as to create a gravity field from which even light could not escape called black hole.
- The more the mass, bigger the hole
- They were theorised by Albert Einstein in 1915 to explain the laws of gravity.
- The first image of a black hole in a galaxy called Messier 87 in the constellation Virgo. It is about 6 million times the mass of our sun.
- A black hole is a region in space where gravity pulls to an extent that even light cannot escape. The gravity is so powerful because matter is compressed into a little space. This may occur when a star dies.
How Big Are Black Holes?
- Black holes may be either big or small. According to scientists, the smallest black holes are as small as an atom. These are very small but have the mass (amount of content in an object) of a mountain.
- A different type of black hole is stellar whose mass can be upto 20 times greater than mass of the sun. There can be many stellar black holes in Earth’s galaxy which is known by the name Milky Way. The biggest black hole is known as ‘supermassive’, and their masses can be 1 million suns together. According to Scientists, every large galaxy includes a supermassive black hole in the center.
- This supermassive black hole which exists in the middle of the Milky Way galaxy is known as Sagittarius. Its mass is same as about 4 million suns.
- It is one of the most violent place in the universe, and a point of no return beyond which anything such as stars, planets, gas, dusts, all types of electromagnetic radiation including lights gets sucked into it.
- The point within the black hole which nothing can escape from is called its event horizon.
Event Horizon Telescope:
- It is an international collaboration that aims to capture images of black hole areas by linking up various radio dishes from around the world that together create a virtual telescope roughly the size of planet Earth. The project began capturing data in 2006.
- the Event Horizon Telescope project aims to generate enough magnifying power to bring