Space has always been a fascinating subject for us. While with the progress of science we have learned a lot about our mysterious galaxy and it’s matters, but most of the cosmos is still unknown to us. Among many, one thing that has become a fascinating subject for most of us is the Black Holes. In 1916, Albert Einstein predicted black holes in his general theory of relativity. In 1967, American astronomer John Wheeler used the term Black Hole. In 1971, the first Black Hole was discovered. Black Holes are three types- stellar black holes, supermassive black holes, and intermediate black holes.
A black hole is a region of spacetime that has such a strong gravitational effect that nothing can escape its pull, not even light. The black holes are extremely dense and reflect no light and after something has hit its defined boundary known as the “event horizon” there is no return from there for that matter. Also, because of the massive gravitational influence, black holes distorts space and time. As an example, if your friend falls into a black hole and you’re watching from outside, your friend’s time clock would be running slower and slower. But from your falling friend’s perspective, his clock is running normally and your clock is running fast.
Black Holes Aren’t Visible
We can not really see a black hole because it is as its name suggest, black. Black holes don’t cast radiation on their own. And since light can’t escape from a black hole, it is actually impossible for us to see a black hole directly even with instruments. The way we can sense a black hole is by looking at the hole’s effects on its environment. If a star gets too close to the accretion disk of a black hole, it gives off radiation as it heats up. Or if a star gets pulled by a black hole, it gets rips into shreds. When it begins to flow toward the black hole, it gets faster, gets hotter and glows brightly in X-rays.
2. The Formation Of Black Holes
Black holes of stellar mass forms when very massive stars collapse at the end of their life cycle. After these large stars run out of fuel and begin to collapse under its own gravity it forms a black hole. This event also causes a supernova or an exploding star. Part of the star gets thrown into space. But not all stars become a black hole, such as if our sun dies, it will become a red giant star. Because the sun doesn’t have enough mass to collapse into a black hole. After the black hole is formed it will continue to grow by absorbing mass from its surroundings or absorbing other stars and merging with other black holes and this way the supermassive black holes of millions of solar masses forms. Primordial black holes are said to have formed right after the Big Bang. In the early universe, when the conditions were highly dense and inhomogeneous, sufficiently dense regions formed black holes by undergoing gravitational collapse.
3. They Don’t Suck
This is a misconception that many of us held at one point or another that black holes are like the vacuum of our cosmos. In reality, black holes don’t go swallowing world around the universe. In fact, they follow the rules of gravity like any other objects in the space. Black holes are only dangerous if you get too close to its disc. When companion stars shed some of their mass in the form of stellar wind, and the material in that wind then falls into the grip of a black hole or if a star gets too close to the accretion disk of a black hole it falls into the black hole because of the hole’s extreme gravitational force. As an example, if our sun is replaced by a black hole of the same mass, it would have the same gravity as the sun. Earth would not fall in the hole, it would just keep rotating as now.
4. They Also Emit Materials
Black holes not only suck materials from space but they also emit materials into space. The speed that the black hole emits those is nearly the same as the speed of the light. There are many black holes that emit materials into space and this event thought to happen every 10,000 to 1 million years. Some scientist has found a black hole by using an array of advanced radio telescopes. It is located at a distance of 1.5 billion light-years from our Eart in a different galaxy. The emission force is so powerful that material emitted by the Black Hole is blown right out of the galaxy. Sagittarius A* also fling out planet-sized spitballs. These matters are actually made of matter that slips from the accretion disk before passing the point of no return and settles into planet-sized fragments. The Sgr A* emits these extremely hot objects at a speed up to 20 million miles per hour. The shot out energetic particles creates an impression of a straight beam right through the center of the Black Hole.
5. Sagittarius A*
There are some scientific theories that suggest that every Black Hole contains one universe. Though it is not proven yet if this is true everything that we have learned about black holes till now, will change. If this theory is somehow proven that will mean that we are right now living inside a Black Hole. It is said that almost every galaxy has a supermassive Black Hole at the center of it. As galaxies have a habit of colliding with other galaxies occasionally and black holes also do the same. When two Black Holes bump into one another they collide and one of those two gets out of its galaxy. Our Milky Way galaxy also has a supermassive Black Hole at its center, known as Sagittarius A. It is said to be approximately 30,000 light years away from us. According to the scientists, Sagittarius A came to life after a star exploded 2 million years ago. Termed as Seyfert Flare, the massive explosion was so big that it was actually visible from Earth. The radiation formed from the Seyfert Flare 2 million years ago was 100 million times more powerful than the remaining radiation we experience today.
6.What Will Happen If You Fell Into A Black Hole
The theory has long suggested that if you fell into a black hole that is the size of the Earth, gravity would stretch you out like spaghetti, it is called Spaghettification. you would become a stream of subatomic particles that would whirl into the black hole. Though your death would come before you reached the singularity which is the core of a black hole. According to a study, quantum effects would cause the event horizon to act much like a wall of fire, instantly burning anyone to death. But theories also suggest if you dive in a massive black hole that is the size of our solar system. Your body may be able to hold its structural integrity. And if you somehow manage to survive, you’ll be able to see the curvature of space-time, and everything that fell into the black hole before you and will fall after you. You might be able to see the history of our universe.
7. Supermassive Black Holes Also Give Birth To Stars
A recent discovery shows that the way those planet-sized fragments are ejected from the accretion disk of black holes. In the same way, supermassive black holes often unloose enough material to form whole new stars. And some of those newly formed stars land in deep space, far beyond their galaxy of origin. Supermassive black holes also control the number of stars a galaxy gets. This depends on how quickly the process of star formation turns off. In galaxies with smaller black holes, star formation comparatively stops more quickly. Any matter that is broken down into subatomic particles by the event horizon of a black hole has the ability to create life-supporting elements like carbon and iron. Also, black holes are very much like spheres and not funnels as illustrated in many textbooks. They don’t have any tunnels in the middle instead all that exists at the center of a black hole is a massive amount of matter compressed infinitely.
According to some scientists, there are other regions of spacetime which cannot be entered from the outside, although matter and light can escape from it. Known as the white holes, according to many, white holes simply doesn’t exist. White holes hypothetically endlessly spew or spurt out matter into this universe exactly opposite of a black hole. Though scientist might have found the first evidence of a real white hole. In 2006, somewhere in our universe scientists observed unusual bursts of gamma rays from an object. If this is proved then we might learn about something that is even more complex and fascinating that a black hole.
9.Theoretically, Any Matter Can Be A Black Hole
Theoretically speaking, stars are not necessarily the only things that can become black holes. According to scientists, even your car keys can have a gravitation effect as strong as a black hole. If the car keys or any other object shrunk down to an infinitesimally small point and still retained all of their mass, their density would reach astronomical levels. And eventually, it will get a gravitational pull that is ridiculously high as a black hole. Also, black holes are extremely noisy. Though as we all know sound waves cannot travel through space vacuum. By the use of special instruments, scientists have claimed that the event horizon makes a staticky sound. This apparently happens when the immense gravitational pull increases the speed of the particles nearly to the speed of light.
10. Energy Source
Black Holes can be a massive energy source since it holds the ability to generate more efficiently than our Sun. It is because of the accretion disc that spins around the black hole. The disc contains matters such as gas, dust and other stellar debris. The material that is on the inner edge of the disc close to the event horizon orbits way more quickly than the very outer edge of the disk. Because the event horizon has a much stronger gravitational pull. Because of moving so rapidly, the material hits up to billions of degrees Fahrenheit. It can transform the mass from the material into energy in a form called blackbody radiation. If we compare it to nuclear fusion, while nuclear fusion converts about 0.7 percentage of mass into energy, a black hole converts 10% of mass into energy. Also, with time black holes evaporate. This phenomenon is called Hawking radiation or black hole evaporation. It was first predicted by Stephen Hawking in 1974. Hawking radiation separates a black hole’s mass into space and over time, and will actually do this until there is nothing left, essentially killing the black hole.