Why black hole is black?

Why black hole is black?

PROF WAQAR HUSSAIN

           

                              

                              A black hole is a regions of space having extremely high density (around 10¹⁸ kg/m³; one can imagine its density by supposing that if earth is squeezed to a volume of a peanut, it will become a black hole) of a matter that result in enormous gravitational attraction, so no matter, radiation and even light cannot escape from its grasp if it comes to its range. That is why it appears black. Such regions are believed to form when a massive star collapses. So, for understanding of a common man, you can say: “It is a dead body of a star”.

           Black hole usually lies at the centre of a galaxy. A supermassive black hole Sagittarius A is lying at the centre of our Milky Way galaxy. It has a mass equal to about 4 million suns and has a size equal to the sun.