What is Black Hole?
A black hole is a part of universe wherein everything including light can be prevented from escaping. It is called “black” since it sucks up the entire light hitting on the horizon, without reflecting anything, reminiscent of a perfect black body in thermodynamics. As per the forecast of quantum mechanics, the black holes discharge black body-like radiation with a set temperature which is inversely proportional to the volume of the black hole, causing difficulties in observing this radiation for black holes of higher planetary mass. The special tools can show the closeness of stars to black holes and their actions which are different from other stars.
History of Black Hole
John Michell and Pierre-Simon Laplace, during the 18th century, considered the objects with strong gravity field for escape of light. Karl Schwarzschild found the solution for the common relativity during 1916 that is capable of characterizing a black hole, although its explanation as a section of space wherefrom nothing can escape was never completely praised for nearly four decades. It was during the ‘60s that conjectural work revealed black holes to be a generic forecast of common relativity. The innovation of neutron stars ignited interest in gravitationally warped solid objects as a potential planetary certainty.
The planetary mass black holes are expected to form when very gigantic stars collapse when their life cycle comes to an end. After formation of the black hole it can continue to grow by sucking mass from its neighborhoods. Super gigantic black holes of millions of solar masses are formed by sucking and amalgamating with other black holes. It is commonly agreed that most galaxies hold super gigantic black holes at their centers.
Characteristics of Black Hole
Despite its concealed center, the black hole’s existence can be concluded through its interaction with light and other electromagnetic radiation. Anything coming on a black hole can form a growth disk with heat caused by friction, shaping certain brightest objects in the world. Other stars tracking a black hole can be applied to settle on its volume and position. This data can be used to alienate possible options like neutron stars. In this way, Astronomers have thus recognized abundant gigantic black hole participants in binary systems, and established that the core of our milky way galaxy comprises a super gigantic black hole of approximately 4.3 million solar masses.
A black hole is invisible since strong magnitude pulls the entire light into the centre of the black hole. However, the scientists can establish the strength with which the strong magnitude affects the stars and gas surrounding the black hole. They can study the characteristics of stars to ascertain if they are flying around or tracking a black hole. When a black hole and a star are close to each other, high-energy light is generated which is invisible to human eyes. Scientists use satellites and telescopes to see the high-energy light in space.
Black holes do not wander in space to eat stars, moons or planets. Since no black hole is in close proximity to the solar system for Earth, it will not fall into a black hole. If a black hole of the same mass as of the sun was to occupy the sun’s place, the earth will still not fall in. The black hole will have the same gravity as of the sun. Earth and the other planets would track the black hole while tracking the sun. The sun is not a big star to make a black hole and will never turn into it.
How big is a Black Hole?
There are minimum two ways to describe the dimension of black hole. We can either express its mass or the space it occupies. Talking about the masses of black holes, there is hardly any limit in principle to assess the maximum or minimum can a black hole occupy. In principle, any quantum of mass can be made to form a black hole if it is compressed it to a very high density. We may doubt that most of the black holes present over there may have been produced due to demise of massive stars and hence we can expect those black holes to weigh almost equivalent to a massive star. A classic mass for such a gigantic black hole may be about 10 times the mass of the Sun. Astronomers may also imagine that many galaxies could anchor exceptionally massive black holes at their centers and could weigh about a million times equivalent to the Sun.
The mass of a black hole is directly proportional to the space it occupies. A black hole with a mass equivalent to the mass of the Sun would have a radius of 3 kilometers. Thus a typical 10-solar-mass black hole would have a radius of 30 kilometers, and a million solar mass black holes at the center of a galaxy would have a radius of 3 million kilometers. The Sun has a radius of about 700,000 kilometers, and hence the super gigantic black hole has a radius of only about four times bigger than the Sun.