User:Ancin maria devis/Sandbox

BLACK HOLE
How will it be if we fall into a hole? What about a black hole? Is there anything inside a black hole? What is a black hole?

A black hole is a place in space where gravity pulls so much that even light cannot get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.

In 1783 John Michelle wrote a paper in philosophical transactions of the royal society of London about dark stars .He said that these are massive and compact stars which have strong gravitational field that even light could not go out of it. Any light emitted from the surface of the star is dragged back by the star’s gravitational attraction before it could even reach far. He suggested that there could be many number of such stars. We cannot see them since no light is emitted from them but we can feel their gravitational field. These dark stars were later named as black holes.

''' Black hole: How big it is? '''

Black holes can be smaller or bigger based on the amount of stuff in it or matter present in it. There are black holes called stellar whose mass is about 20 times that of the sun. There are some other black holes whose mass is about the mass of 1 million suns combined together. Such black holes are called super massive black holes. Scientists found that there is a super massive black hole at the centre of every galaxy. The super massive black hole at the centre of our Milky Way galaxy is known as Sagittarius A*.

''' How a black hole is formed? '''

When a star burns out of fuel it will collapse and forms a black hole. This happens in case of stars whose mass is 20 times more than that of mass of sun. In case of a normal life of a star there is a constant tug of war between the gravitational pull and the pressure outside. It is the nuclear reaction in the star that provides enough energy and pressure to pull outside. This push and pull are balanced when a star is alive. Stars are not only transformed into black holes after its death. Transformation of star is depended upon its mass. If the mass of the star is low it will not have enough gravitational energy to begin the fusion again and this burnt out cinder will form a Brown dwarf. Those stars whose mass is near to the sun’s mass, its gravitational pull is balanced by the electronic repulsive force and thus it is transformed into White dwarf. Stars whose mass is greater than two and half the mass of the sun, it will collapse and this collapse is so violent that it will result in explosion known as supernovae explosion. If the core remaining after the supernovae is massive (about 2.5 mass greater than that of the sun), its repulsive force will not be sufficient enough to hold the collapsing and thus black holes are formed.

''' What will happen if we go inside a black hole? '''

The gravitational pull from the black hole is unimaginable. Even if you have the strongest shield or suit, you will be crushed into streams of atom even from thousands of miles away and this will be added to its mass.so a trip to black hole is a one way journey. Black hole has the boundary called the event horizon and it is where the gravity just strong enough to drag light back, and prevent it escaping. Because nothing can travel faster than light and so everything is dragged into it.

''' How can we observe a black hole? '''

When black holes occur in multiple star system we can observe their effect on visible companion stars.in fact the first black hole Cygnus x-1 was found out because of its strong X-ray emission and its gravitational effect on tightly orbiting massive star.

Mystery continues..

Black holes are always interesting to scientists as well a common man.it full of mysteries. There are lots of researches going on related to black holes. Recently scientists found that spin of black holes and galaxy formation has some connections.so there are lot of interesting information still unknown to us.It is still out there waiting for us. Black hole is not a hole,it is full of information!