Welcome to the First ever article series of Curiosity. In this series we will try to answer all the question that makes us scratch our heads. So Let's get started.
What's really is black hole?
Black holes are one of the strangest things in existence. They don't seem to make any sense at all. Stars are mostly the massive collection of Hydrogen atoms that are made of enormous gas clouds. In the core of stars the nuclear fusion crushes hydrogen atoms to helium releasing a tremendous amount of energy. The energy is in the form of radiation. This radiation pushes against the gravity balancing each other. As long as there is nuclear fusion in the core the star is stable enough. But the story goes different with the massive stars. In the core of massive stars the fusion forms even heavier elements until they reach iron. Production of iron do not create any energy and hence starts accumulating at the center of the star and the balance between radiation and the gravity is suddenly broken. This imbalance causes collapsing of the core. Within the fraction of the second the star implodes. The star dies in the supernova explosion This produces either a neutron star or the star is converted into a massive black hole.
What's the black Part of the black hole?
If you looked at the black hole what you would really be seeing is the event horizon which is the black part of black hole. Anything that crosses the event horizon needs to be faster than speed of light to escape, so in other words that impossible. So we just see a black sphere reflecting nothing. So technically it isn't black, its just without color.
Now what is the Hole part of the black hole?
Well, the simple answer is "SINGULARITY". Nobody exactly knows what is it. A singularity may be infinitely dense which means all its mass is concentrated in the single point in space with no actual surface or volume or something completely different. Imagine if the Earth is crushed to the size of a football with the same mass as that of earth how much gravity would you feel around this football? You would be crushed and torn apart by the football. Same goes with the singularity.
What happens if you fall into a black hole?
Finally, Lets go inside the black hole. Its not going to be comfortable but its surely going to be fun. At first you see distorted light all around the black hole due to its gravity as the result we can even see beyond the black hole. Also when you get closer to the massive object, time slows down for you compared with a stationary observer. Every one would seem to be aging really fast. If a observer observed you reach the event horizon they would see you go slower and slower until you would freeze in the event horizon also the light coming from you would disappear as no light could get out.
Meanwhile from your perspective everything would start speed up outside the black hole. You can see your whole life your kids grand kids and 100s of generation rise and fall in just seconds for you. Billions of years will pass as you get closer. Well after you cross the event horizon there is no going back. Let's assume your legs are closer to the singularity. Even if your legs are only few inches away from your head the force of gravity will be way stronger on it. As you get closer to the center your whole body gets stretched out. The technical term is "spaghettified". And eventually you are just the stream of atoms before joining the singularity. If you still are lucky and didn't die you would see the border between the universe and black hole becoming a sphere. It will go smaller and smaller and all the light will be concentrated at one point. At this point you will surely die but if you go any further you will experience "Everlasting Darkness".