Black Holes

This is about how black holes form. There are three theories. So if you want to know how a black hole forms, then you’re in the right place. Let’s jump right in! The Forming of Black Holes Fascinating to us, black holes are the focus of countless sci-fi flicks, novels, and more.  But, how are black holes formed?  Actually, there are multiple answers to this question.  First, let’s quickly review what black holes actually are. What Is a Black Hole? Black holes are points in space where gravity and pressure are so strong that nothing can escape, not even light.  In fact, since not even light can escape the tremendous power, black holes remain invisible in space, giving black holes their name.  So, how are black holes formed? 3 Theories How Black Holes Are Formed There are three primary types of black holes. And, because of this, there are three main ways in which black holes form: #1 Primordial Black Holes Primordial black holes formed purely from extremely dense matter, present during the early universe.  Currently, primordial black holes are merely hypothetical. However, several modern theories believe primordial black holes are responsible for dark matter. Shortly after the big bang, the universe was an extremely dense cosmic soup. Matter (mainly hydrogen) tightly packs small spaces. This tightly-packed environment that would have caused primordial black holes. One hundred times the power of Hubble, James Webb Space Telescope will see far into the past, when the universe was a mere infant. Launching in 2018, JWST may allow us to detect these hypothetical objects. #2 Stellar Black Holes Stellar black holes form when the cores of massive stars collapse inward on themselves. As massive stars run out of nuclear fuel, they can no longer fight their own gravity.  Now, the star’s core crashes in, causing a blinding supernova explosion.  Finally, a black hole remains where the star once sat in space. Ultimately, our Sun will never turn into a black hole because of its “small” size. Rather, stars must be at least 20 times the mass of our Sun to form a stellar black hole. Naturally, we have not directly seen a stellar black hole. However, we can monitor their effect on surrounding objects.  Astronomers can observe stars swirling rapidly around the black hole’s perimeter.  Finally, as the star draws nearer, we can observe the light emitted as the black hole devours it, releasing tremendous energy and radiation. #3 Supermassive Black Holes Supermassive black holes sit ominously at the center of most galaxies.  Actually, our own Milky Way has a supermassive black hole at its heart, called Sagittarius A* (pronounced Sagittarius A Star).  Currently, we know very little about how these objects form. But, it is widely thought that they form at the same time as their host galaxy. As galaxies form, unfathomable amounts of gas and debris swirl around.  Similar to a large star’s collapse, the gas cloud’s mass, gravity, and density come crashing down. The result is believed to be a supermassive black hole.

Black holes are objects in space with gravity and density so strong that even light cannot escape their grasp. Hence, the fitting name, black hole.  Naturally, you might be asking yourself, “how do we know black holes exist?”  After all, how do you “see” something that emits no light? Without any visible light, our human eyes cannot see black holes.  However, we can zero in on a black hole by watching how their powerful gravity affects things––stars, gases––around them. For instance, a black hole’s powerful gravity would suck in gases from a nearby star.  As the gases get sucked in faster and faster, it heats up tremendously, emitting radiation, like X-rays. So we humans do have the ability to “see” X-rays by way of modern technology. Plus, when large objects, like stars, approach the black hole, their orbiting speed changes.  Scientists can observe and measure these speeds, helping them creating “chalk outlines” of where the black hole should be. Currently, our hard evidence remains technically inconclusive. So how do we know black holes exist?  By observing their impact on surrounding matter and advanced technology, humans are getting closer to confirming that black holes really exist.

This is about black holes. Black holes are leftovers from massive dying stars. So if you want to know what a black hole is in detail, then this article is for you. Let’s jump right in! Black Holes Are Dying Stars A black hole is formed from a dying star. But, not just any star. It has to be massive. At least 20 times the mass of our Sun, which is already enormous.  As the star goes through the process of its violent death, all of its material is crushed down so tightly that processes and physics, as we know them, break down and no longer make sense.  The density, mass, and gravity in this space are now so devastatingly strong that nothing can escape, not even light itself. Hence, the name, black hole. As complex and mysterious as this process is, it’s relatively simple to understand at a very high overall view.  Let’s check it out! Nuclear Fusion During a star’s long life, it lives off of fuel that it creates by itself. Very green, right?!  Stars create this fuel through a process called Nuclear Fusion.  The environment inside of a star is hot and extreme, and its internal molecules move around recklessly at rapid speeds.  As the molecules bounce around, they smash into each other.  Normally, molecules have tremendously strong protective forces to prevent themselves from combining with one another, known in science as the strong nuclear force.  However, under the extreme conditions in a star, the molecule’s forces are overcome, and molecules begin to collide and join together to create heavier elements.  Hydrogen combines to form Helium, Helium eventually combines to create Oxygen, and so on. This is the process of nuclear fusion (the NUCLEUS of the atoms is FUSING … get it?). When these atoms fuse together, they are now carrying extra energy and become very unstable, and do not know what to do with it.  So, they shed this newfound energy by emitting it as powerful radiation. Because of this emitted radiation, we have to be cautious of the dangerous light coming from our Sun on a bright summer day. This is the leftover energy coming from our Sun, a star, as it burns its fuel. A Dying Star As the star creates and burns its nuclear fuel, it creates constant, powerful energy flowing outward.  But, since stars are also extremely large and massive, they also cause extremely strong gravity pushing inward on themselves.  So, a star constantly keeps its structure and stays alive by fighting its own inward gravity with its own outward energy. Eventually, the star runs out of molecules to turn into nuclear fuel, and the trouble begins.  The fuel is now all gone, and gravity still remains the same and begins to win.  The tremendous weight of the star collapses inward on itself at near-light speeds and creates a devastating explosion called a Super Nova.  The star’s shell is blown off, and all of its remaining mass crushes down on the star’s core.  The leftover star material is all crammed into a remarkably small space that is densely compacted beyond what our human brains can comprehend. This is a black hole. The Anatomy of a Black Hole Event Horizon The event horizon is where the black hole begins. This is the front door of the black hole if you will.  Our picture shows a cone-like structure, which is made up to simply help you understand this concept.  Astronomers actually believe that a black hole has no actual structure and the event horizon happens in all directions, like a sphere. Beyond the event horizon, the mass, pressure, density, gravity, and everything else are so strong that nothing can ever escape again, including light itself. This is why we call it a black hole.  So, as the black hole sucks in the nearby matter, it is pulled across its event horizon and never to be seen again.  Of course, with its immense gravity, entire stars and even galaxies can be sucked in and destroyed! Singularity The singularity of a black hole is where all of its material eventually comes to a single point.  Remember earlier when we said all of the dying star’s matter was crushed into a tiny space? Well, that was extreme.  But, now, all of the matter inside of the black hole eventually gets smashed down into a microscopic pin point. That’s even more extreme.  So extreme that, as humans, we can’t actually comprehend this. All of our astronomy and physics that we have learned for hundreds of years completely fall apart now, and nothing we know makes any sense.  Since, for obvious reasons, astronauts can’t go inside of a black hole to explore and learn, we know very little about the singularity. This has, and will continue to be, one of the most sought-after answers in astronomy and science. How Do We Find Black Holes? You might be naturally wondering if light can’t escape, then how do we know a black hole is there? And, this is a great question!  Astronomers are able to spot these invisible objects in several ways. First, we can observe how matter and objects behave around the black hole to pinpoint its existence and location.  Due to its strong forces, stars, gases, and other objects around the black hole begin moving very fast and chaotically.  Astronomers observe single locations where they believe a black hole lies and monitor the surroundings for years, observing the changes. Black holes periodically feed on surrounding materials. While they are eating, massive amounts of energy shoot out as they digest their food.  Scientists can use these cosmic dinner times to detect and study the energy given off from the food. It most commonly emits x-rays that we can detect using special telescopes on Earth. Teams of scientists have constantly observing a black hole named Sagittarius A* (pronounced Sagittarius A Star) right in the middle of our own Milky Way Galaxy.  In fact, it’s now widely believed that there are massive black holes in the centers of nearly all galaxies. There’s no need to worry. …

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