Introduction Black holes are one of the more interesting topics in astrophysics. Even though they are commonly accepted as being real, their actual existence has yet to have been proven2. Black holes are objects that have such a concentration of mass that nothing can escape their gravitational pull once it crosses the black hole's event horizon or Schwarzschild radius. The Schwarzschild radius is the radius where, for anything inside, the escape velocity is greater than the speed of light. Since the speed of light is the maximum possible velocity, nothing escapes from a black hole. They are given their name from the fact that they do not emit any light, since light is also pulled into them. History The term "black hole" was first introduced in 1971 by John Archibald Wheeler1. The actual phenomena the term describes was theorized to exist back in 1916 by Karl Schwarzschild. Then, it was just a curiosity as a possible solution to Einstein's general theory of relativity which described gravity as a curvature of space-time2. It wasn't until 1939 that Oppenheimer and Snyder seriously considered the possibility that massive stars could collapse and become what is now called black holes at the end of their lives. Today, black holes are a commonly accepted theory that even the average person has some idea of what they are. There was even a recent Associated Press story about two black holes in the NGC6240 galaxy that scientists predict will someday merge. Properties Black holes have many interesting properties. The most obvious from their name is the fact that they can't be seen since no light is emitted from them. One of the ways they can be detected is by the x-rays given off by the matter being pulled into them before it crosses the Schwarzschild radius. As the matter is pulled in, it gains kinetic energy, heats up, ionizes, and when it reaches a few million Kelvin, emits x-rays3. Black holes can also be detected by the way nearby objects are affected by their immense gravity. As you get nearer to a black hole, light begins to be bent toward it. Black holes have a radius around them that forms what is called the photonsphere. At this point, photons of light can actually orbit the black hole4.
Starting with black holes, Khalili describes the creation of one. I found that a black hole is what remains when a massive star dies. Because stars are so massive and made out of gas, there is an intense gravitational field that is always trying to collapse the star. As the star dies, the nuclear fusion reactions stop because the fuel for these reactions gets burned up. At the same time, the star's gravity pulls material inward and compresses the core. As the core compresses, it heats up and eventually creates a supernova explosion in which the material and radiation blasts out into space. What remains is the highly compressed and extremely massive core. The core's gravity is so strong that even light cannot escape. This object is now a black hole and literally cannot be seen because of the absence of light. Because the core's gravity is so strong, the core sinks through the fabric of space-time, creating a hole in space-time. The core becomes the central part of the black hole called the singularity. The opening of the hole is called the event horizon. Khalili describes that there are two different kinds of black holes:
Death by Black Hole: And Other Cosmic Quandaries explains about his ability to blend content, accessibility, and humor, Tyson is a natural teacher who simplifies some of the most complex concepts in astrophysics
The whole idea of time and black holes has been questioning scientist and many common people for decades. Whether or not the theories provided make it physically possible to allow us to ever use any type of a black hole to an advantage? Technology over these past years has allowed us to learn more and more about what black holes are and what they can do. While also allowing ourselves to discover new possibilities that they might bring forth to greater innovations in our near future. But we can only imagine, through our knowledge and technology, what a black hole could do for us, due to all the dangers they bring forth.
The origins of the super-massive black holes which concludes how they were formed and what caused them to form is an unsolved problem which is yet a mystery of astrophysics. ( Millis 2014)
...f gas, which collapsed and broke up into individual stars. The stars are packed together most tightly in the center, or nucleus. Scientists believe it is possible that at the very center there was too much matter to form an ordinary star, or that the stars which did form were so close to each other that they coalesced to form a black hole. It is argued that really massive black holes, equivalent to a hundred million stars like the Sun, could exist at the center of some galaxies
The idea of Black Holes was first proposed in the 1700s by scientists John Michell and Pierre-Simon Laplace, who argued, independant of each other, that there might be objects in the universe with such a large gravitational force, that even light could be trapped. Published in 1916 Einstein’s theory of general relativity which included how gravity does affect light’s motion, gave way to scientific discoveries involving black holes. In Einstein’s own theory, he was only able to approximate the solutions to some of his own equations, however Karl Schwarzschild was able to provide the solutions. These solutions described objects like black holes that had such massive density that nothing could escape them. Schwarzschild theorized that if an object had such a small radius, that the escape velocity will be greater than the speed of light. Because as previously mentioned, nothing is faster than the speed of light, the object would be sucked into itself by it’s own gravitational pull, which would cause the object to disappear. What r...
In truth, English geologist John Michell was the first to suggest the existence of black holes. He referred to them "dark stars" and based his calculations on Newt...
Although Dr. Hawking impacts many areas of science and cosmology, his work with black holes has revolutionized modern physics. He works in all areas of black holes, including how they work, singularities, and most importantly, Hawking radiation. Black holes are very simpl...
For centuries, physicists and philosophers alike have wondered what makes up our universe. Aristotle thought that all matter came in one of four forms: Earth, Air, Fire, and Water. Since then we have come a long way, with the discovery of the atoms and the subatomic particles they are made of. We can even guess at what makes up protons and neutrons. We have since then discovered and predicted the existence of particles other than the atom, such as the photon, neutrino, axion, and many others.
Before I begin to speak about black holes, I will have to explain what the white glowing specks in the sky are. Without a star a black hole could not be formed. In the beginning of a star life a hydrogen is a major part of its development. Stars form from the condensation of clouds of gas that contain hydrogen. Then atoms of the cloud are pulled together by gravity. The energy produced from the cloud is so great when it first collides, that a nuclear reaction occurs. The gasses within the star starts to burn continuously. The hydrogen gas is usually the first type of gas consumed in a star and then other gas elements such as carbon, oxygen, and helium are consumed. This chain reaction of explosions fuels the star for millions or billions of years depending on the amount of gases there are.
Geologist John Mitchell is credited with first devising the idea of a black hole. He said that if some force could compress the sun down to an small enough size, it would have a gravitational field so strong, that one would need to be going faster than the speed of light to escape it (UTFC). All objects in the universe have what is called a schwarzschild radius. An object’s schwarzschild radius is the radius that an object would have to be compressed into in order to have an escape velocity greater than that of the speed of light, or a black hole. (VSBH).
Einstein himself, working at Princeton with Nathan Rosen had discovered that the equations of relativity actually represent a black hole as a bridge between two regions of flat space-time, a phenomenon known as the “Einstein-Rosen Bridge”. Later on, in 1963, the New Zealand mathematician Roy Kerr found that if a black hole is rotating, a singularity still forms, but in the form of a ring, not a point. It was believed that in principle, a particle may be able to fall towards the singularity, but if at some point moved through the hole instead of the ring, the particle may not be lost forever. Therefore, with these theories in mind, a particle falling into a black hole will fall through the ring that the singularity has become, then going through the Einstein-Rosen Bridge, eventually being spewed out of the white hole into another space-time continuum.
The Effects of Gravity There are some people who worry when they're outside, if they don't keep a good grip on the ground, they'll just go flinging off into space. They needn't really worry. about this, because gravity generally keeps that sort of thing from happening. The thing is, no one is really sure what causes gravity, but the effects have been studied by many. physicists and astronomers of the world.
Black holes are the result of the death of a massive star, leaving behind a dense remnant core that eventually collapses to create a gravitational force so strong that nothing, including light, can escape the force. The theory that black holes existed started back in the early 1900s and since then astronomers and scientists have been trying to get a better understanding of them. This phenomenon has been a working progress for astronomers and scientists for many years and as we develop a better understanding of our solar system, the more likely it is to make a significant discovery that can answer some of the most difficult questions about our incredible galaxy and solar system. The more information we are able to acquire about our universe, the more questions we might be able to answer about our existence. With advancements in technology we may be able to see some significant discoveries and insights into the world of black holes.
Two galaxies which are believed to revolve around our own are the Small and Large Magellanic Clouds. Only visible from the Southern Hemisphere, Magellan, the famous European explorer, was the first to describe these galaxies. Even though we know a great amount more than the astronomers in the past, there is still an even larger amount we do not know about the universe to this day. Even our own solar system contains many questions yet to be answered. Some of these include the possibility of a planet beyond Pluto (Planet X), the means by which the system was created, and even the possibility of a sister star to the Sun named Nemesis.