According to dictionary.com, a black hole is "a theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape." Since space is the next great human frontier, it's best that scientists and everybody else become more familiar with what's out there. Black holes are the sinkholes of space, but one million times more dangerous. As of now, black holes are still a big mystery, but there are some interesting facts about them.
The Point Of No Return
It's no secret that black holes are dangerous. They have an extremely strong gravitational pull. Every hole has what you call an event horizon, something you don't want to be in. Once something enters the gravitational pull, its reached the point of no return.
To put in simpler terms, there is a boundary with black holes. If you are outside the boundary, you don't have to worry about anything. The moment something crosses over, that's all folks! Any object will have no choice but to fall into the black hole.
Why So Dense?
If you were on Jeopardy! and the question was: "the densest object in the universe," would you guess correctly? Some might think it's some type of metal, but that isn't the case at all.
Black holes are the densest objects in the universe! That's pretty hard to imagine, but it certainly is the truth. Scientists haven't discovered anything out there that could dethrone the dense king. For better understanding, the density is similar to squeezing Earth inside a sphere with a nine-millimeter diameter.
Just How Big Can They Get?
Scientists haven't uncovered all of the secrets about black holes, but they have found out some vital information about them. Something rather interesting that these holes do is pull objects into their event horizon. Once something enters that boundary, they are apart of the darkness.
Due to this astonishing feature, how large do you think black holes can become? Since there is no limit to what can get dragged in (liquid, gas, solid matter), black holes can grow infinitely large!
Hawking Theorized This About Black Holes
Yes, it's true that black holes have that special trick that provides them with the gravitational pull. It brings in any object that crosses over their boundary, allowing them to grow as large as they want. But Stephen Hawking had a theory on how they disappear.
According to Hawking, black holes emit radiation. The mass of the hole causes the radiation to seep out thus causing the black holes to lose their mass in the form of radiation. Eventually, they evaporate!
Black Holes Are Versatile In Size
Black holes don't always grow infinitely large. The opposite tends to happen as well. Eventually, some start to shrink in size and become smaller than an electron. Once it reaches this point, it's called Planck Length.
Planck Length is the quantum size limit and theoretically, nothing can get any smaller than that and there is no instrument available that can measure that length. They say the value of Planck is 1.61619926 x 10-35 meters. Solving that would be a tough math problem.
The Center Of Darkness
We've covered some crucial facts about these mysterious space masses and we're just getting started. Once something enters the boundaries, it enters the event horizon and gets pulled inside. While inside the black hole, loads of chaos takes place from the outsides all the way to the core.
What do you call the core? The center of these holes is called The Singularity. This is the ultimate destruction point. There is nothing that can survive this point.
Is It Possible To Escape?
After everything you've read so far, do you think it would be possible for something to escape the clutches of a black hole? You'd be wise to say no because technically, there is no known way of achieving a way out.
Theoretically, you would have to travel faster than the speed of light to escape the event horizon of a black hole. Good luck with that, as it's pretty much impossible unless you're some type of fictional character.
A Way To Measure The Size Of A Black Hole
Did you know the size and mass of a black hole are directly proportional? Unfortunately, you can't really measure the size, but there is an alternate way of finding that information out. Scientists call it the Schwarzschild Radius.
This radius is of the event horizon, that deadly boundary no object wants to cross. The larger the radius, the bigger the black hole, which also translates to increased density as well. How anyone sat down and took the time to figure all of this out is sensational.
Our Galaxy's Relation With Black Holes
Is there a black hole located in the Milky Way galaxy that Earth sits in? If there is, isn't that unsafe for the kind people that inhabit the planet? To answer both questions, yes there is a black hole in the center of the galaxy by name of the Sagittarius A*.
Sagittarius A* has a mass of four million solar masses. One solar mass is equivalent to the size of our Sun. Thankfully, Sagittarius A* is 30,000 light years away.
Humans Vs. Black Holes
Dying an ugly death varies, but some are more terrifying than others. Getting devoured by a shark would be pretty bad, falling off Mount Everest sounds horrible too, but what about getting dropped into a black hole? That's one thing you don't want to happen and probably won't happen to anyone anytime soon.
Getting dropped into a black hole means you die, plain and simple. You will get stretched to death too. Whichever part of the body enters the event horizon first will become victim to the gravitational pull and accelerate the speed of that body part falling compared to the others.
The Universe Equation
Luckily for us, the black hole in our Milky Way galaxy is thousands of light years away so we won't get sucked into the event horizon. According to some scientific equations, every black hole has one universe in it.
That could be bad news for loads of other planets that end up the deadly boundaries of the hole. This equation hasn't had approval yet, but if it is true then we are living in a black hole right now! We being the universe.
Sagittarius A* is the black hole located at the center of the Milky Way, but it wasn't always there. Over two million years ago, the event called Seyfert Flare happened to bring that hole into our universe.
Seyfert Flare is when a star exploded and created the hole. It's safe to say that we are a pretty good distance away if nothing has happened to us after millions of years. Who knows what it'll be like in another few million years.
Stephen Hawkins taught us that radiation emits from black holes, but more also comes out of these dark abysses. Studies reveal not only do black holes suck in objects, but they also release material, which happens at the speed of light.
The materials are energetic particles that get shot into space along the axis of the hole which then makes an impression of a straight beam right through the middle of the black hole.
Once you enter the event horizon, unless you can travel at the speed of light, you're a goner. It isn't that simple, however. Scientists do this thing where they have to name everything that happens, so what do you call something that enters the event horizon?
Any type of matter that goes into that boundary gets broken into sub-atomic particles. This process gives the black hole the ability to make carbon and iron which are vital life-supporting elements.
The Father Of Black Holes
Many might believe that the genius Albert Einstein discovered black holes, but that is far from the truth. Einstein merely brought the theory back to life in 1916, but there was someone else who had already developed the theory.
In 1738, a man by the name of John Michell brought black holes into the world of science with his findings. It all stemmed from him wondering if there was a gravitational force that could prevent even light from escaping the pull.
If There's Black, Then What About White?
What goes up must come down, right? There is a universal law of polarity which means the state of having two opposite contradictory tendencies. If there are black holes that pull in matter, some scientists speculate that there is an exact opposite of this.
Rather than sucking things in, a white hole would relentlessly spew out matter. Up until 2006, this was just a myth, but then scientists saw some obscure bursts of gamma rays out in our universe which could indicate white holes.
Beware Of Your Car Keys
The general idea is that only stars are capable of becoming black holes after they explode. That is a fact, but that's not the only way black holes come into existence. Pretty much anything that's capable of shrinking can take on this role.
When an object is able to and gets infinitesimally small, it generates a gravitational pull that becomes insanely high, thus making one of these holes. That means that even your car keys have the power to take this form.
Black holes are very powerful creations. Thanks to their ability to suck in matter including gas, scientist believe they play a role in limiting stars in the universe. Did you know that gas was a vital part of forming stars?
All of that gravitational pull power will cease any formation of stars because they need gas. Liken this to humans going under water and trying to live without oxygen. Now that just can't happen at all.
The First Black Hole Image
"We have seen what we thought was unseeable," said Sheperd Doeleman, director of the Event Horizon Telescope Collaboration. "We have seen and taken a picture of a black hole." In April of 2019, the world finally got the opportunity to see what a black hole looks like.
The image you see here is the hole. The dot in the middle is the black hole while the outside "ring" is matter and light getting sucked into the event horizon as it is closer to the center. The brighter light on the outside is light trying to come towards us.
Noisy Black Holes!
In order to capture the first image of the black hole, scientists used radio telescopes. These telescopes are only able to "see" radio frequencies on the electromagnetic spectrum. If there was no sound there, we'd only see a big blob.
Black holes make a static sound. While this sound cannot be heard in the vacuum of space, the device used to see the hole captured the loud static created by the distortion of the event horizon.