A black hole is a region of space with an ultra high gravitational field that no matter can escape not even light, star or any planet. Still these days, many people only know that black holes exist but do not know how are black holes formed and what is the science behind it. Let’s dive deep into space science.
Black holes are invisible and people cannot see them. Few special types of space telescope with particular technology can help in finding black holes.
Sizes of Black Hole / Types of Black Holes:
A black hole can be very tiny or very large. The smallest black hole can be as small as an atom. Despite being very small, the mass of these black holes can be equivalent to a large mountain.
There is another kind of black hole called Stellar. Its mass is up to 20 times as that of the sun. There can be many stellar type black holes in our galaxy, Milky Way.
The largest black hole types are called Supermassive. The masses of these black holes can be 1 million times of sun. Scientists have proved that every galaxy has a supermassive black hole at its center. In our galaxy Milky Way, the supermassive black hole is named as Sagittarius A. Its mass is equivalent to 4 million suns.
How are black holes formed?
Stellar black holes are formed when a very big star collapses. Generally, the internal pressures produced by nuclear reactions in the centers of stars balances the gravitational field of the star. At the end of the star’s life, it cannot produce the internal power as nuclear fuel is exhausted. Hence, the mass of the star gets squeezed towards the center because of its own gravitational field.
The science behind black holes:
When a star collapses, the outer layer of the star is exploded into space. This phenomenon is called a supernova. The remaining part of the exploding star is called neutron star.
The nucleus containing protons and neutrons represent more than 99.9% of the matter, which has a size of around 1/100000 that of the electron clouds revolving around the nucleus. Electrons are very tiny, but the pattern of the electron cloud around the nucleus defines the size of an atom. So, when a star collapses/squeezes, the electron clouds are captured by the protons and are transformed into neutrons. So, in neutron stars, most of the matters are neutrons.
If a star with a mass of sun collapses, it becomes a white dwarf.
When a star with a mass of around 1.4 – 3 times of sun dies, it becomes a neutron star. As of now, the highest mass of neutron star discovered is 2.08x of the sun.
There is an unstable black hole, quark star (hypothetical) is created if the mass is slightly more than the neutron star.
If the mass of the star having more than at least 3 times the mass of sun collapses, it will form a black hole. The smallest mass black hole known to science is 3.8 solar mass having a diameter of 15 miles.
The boundary of the gravitational field from which no object can escape is called the event horizon.
After a black hole is formed, it keeps on growing by absorbing mass from its surrounding interstellar dust, gas. By absorbing large stars and merging with other black holes, a supermassive black hole can be formed.
What is inside a black hole?
A simple answer is “nobody knows”. Scientists basically understand what is outside of a black hole and how they behave. Inside the event horizon, an object must be having speed more than light in order to escape, which is impossible. There is one largest telescope called Event Horizon Telescope is being used by scientists to understand what is inside the event horizon. Nobody can predict when we will have a concrete idea on this.
If there are stars orbiting around the black hole, the orbital path can be used to determine the location and mass of the black hole. A black hole cannot be seen as it absorbs all the light, but from the behavior of its surroundings, scientists can find out the position of a black hole.
Who discovered black holes?
The black hole was first predicted by Albert Einstein in 1916 with his theory of relativity. American astronomer John Wheeler coined the term “black hole” in 1967.
Neutron stars were discovered in 1968 and the first Blackhole was discovered in 1971.
Can a Black Hole destroy Earth?
Earth will never fall into a black hole because there is no black hole close enough to our solar system. For example, if we replace the sun with a black hole with the same mass of the sun, Earth will not be pulled in. The black hole will be having the same gravity as that of the sun. Earth and the other planets will be still orbiting around the black hole as they are orbiting the sun now.
The sun will never turn into a black hole as it is not a large enough star to form a black hole.
I hope you understood all the details of the black hole. If you liked the post, please share with the ones who seek knowledge.