Black hole

what is Black hole?

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

Because no light can get out, people can't see black holes. They are invisible. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars.

The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, no locally detectable features appear to be observed. In many ways, a black hole acts like an ideal black body, as it reflects no light.

    Types of black hole

Black holes are of four type:-

(1) stellar, (2) intermediate, (3) supermassive, and (4) miniature. The most commonly known way a black hole forms is by stellar death. As stars reach the ends of their lives, most will inflate, lose mass, and then cool to form White dwarf.

Supermassive black hole

The largest black holes are called "supermassive." These black holes have masses that are more than 1 million suns together. Scientists have found proof that every large galaxy contains a supermassive black hole at its center. The supermassive black hole at the center of the Milky Way galaxy is called Sagittarius A. It has a mass equal to about 4 million suns and would fit inside a very large ball that could hold a few million Earths. 
Small black holes populate the universe, but their cousins,supermassive black holes, dominate.
These enormous black holes are million or even billion of times as massive as the sun,but are about the same size in diameter. such black holes are thought to lie at the centre of pretty much every galaxy, including the Milky Way.
scientist aren't certain how such large black holes spawn .once these giants have formed, they gather mass from the dust and gas around them, material that is plentiful in the centre of galaxies, allowing them to grow to even more enoromous sizes.

                 

what if you fall in black hole?

So what happens if you accidentally fall into one of these cosmic aberrations? Let's start by asking your space companion — we'll call him samm — who watches in horror as you plunge toward the black hole, while he remains safely outside. From where he's floating, things are about to get weird.

As you accelerate toward the event horizon, samm sees you stretch and contort, as if he were viewing you through a giant magnifying glass. What's more, the closer you get to the horizon the more you appear to move in slow motion.

You can't shout to him, as there's no air in space, but you might try flashing him a Morse message with the light on your iPhone (there's an app for that). However, your words reach him ever more slowly, the light waves stretching to increasingly lower and redder frequencies: "Alright, a l r i g h t,   a   l    r     i…"

When you reach the horizon, samm sees you freeze, like someone has hit the pause button. You remain plastered there, motionless, stretched across the surface of the horizon as a growing heat begins to engulf you.

According to samm, you are slowly obliterated by the stretching of space, the stopping of time and the fires of Hawking radiation. Before you ever cross over into the black hole's darkness, you're reduced to ash.

But before we plan your funeral, let's forget about samm and view this gruesome scene from your point of view. Now, something even stranger happens: nothing.

You sail straight into nature's most ominous destination without so much as a bump or a jiggle – and certainly no stretching, slowing or scalding radiation. That's because you're in freefall, and therefore you feel no gravity: something Einstein called his "happiest thought".

After that you are where nobody knows and that's the end of your life journey.

so , make sure yourself before thinking  of going to black hole.