Introduction
Definition: Black holes are rapidly spinning stellar bodies of incredible mass. A typical black hole has a mass many times that of our own sun , but the size approaches point density. For all intents and purposes, black holes are singularities, a fact that many physicists find contradictory, since in general the universe abhors a singularity. They are formed when a large sun exhausts its fuel and collapses to a very small volume. Of course, conservation of angular momentum and mass hold true, so as the star shrinks, it rotates faster and faster, and its density becomes greater and greater. Eventually, the star becomes so dense that space-time curves so much in its vicinity that not even light can escape. For more on space-time, click on curved space time at the bottom of the page.
Black holes are fascinating phenomena. Only recently have physicists begun to even find proof of their existence, and yet their unique physical properties have extraordinary and galaxies-wide effects. The physics to truly understand the underpinnings of black holes have only been around since 1915 when Einstein conceived and presented his General Theory of Relativity, in which gravity is considered in terms of curved space-time. However, in Exposition of the System of the World, written over a hundred years earlier in 1798, Laplace predicted that masses of sufficient size would have a gravitational attraction so large that light itself could not escape. Stephen Hawking, the author of A Brief History of Time-- perhaps the most successful cogent popular science book ever written-- and an extraordinary physicist, wrote one of the definitive papers on the physics behind black holes. (and then interestingly enough, recanted his once firm belief that black holes even existed--at which time he married his nurse. Physicists are eccentrics in a long and noble tradition.
Black Holes Collide
"In a looming collision of giants, two super massive black holes are drifting towards a violent merger and an eruption of energy that will warp the fabric of space"
Sound like science fiction?
It isn't. The words above were written in an article entitled "Telescope Sees Black Holes Merging", by Paul Recer, writer for the online Yahoo Science AP. The article was posted November 19. 2002.
The Harvard-sponsored Chandra Observatory has captured for the first time two black holes in orbit around each other in the extraordinarily bright galaxy NGC6240, a mere 400 million light years away. This is no stable orbit.
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
A black hole is what’s left after a star has collapsed and died of old age, its gravitational force was so strong, the star could no longer withstand. This makes the dead star exert very strong forces of gravity, making escape once entering the event horizon of a black hole impossible. This event horizon is most commonly simplified as, “the point of no return,” because it’s most likely impossible for anything to escape its horrendous force. Somebody that whiteness’s this would seem as if the object that entered the event horizon will become slower and slower as if it will never pass through. The object will become redshiftted as time passes, no light is emitted from the hole to someone witnessing, but to whatever is passing through then it will pass as if time remains normal. Some do believe that black holes will eventually die by evaporating, it will leave behind lots of radiation.
The responsibility of super massive black holes is to hold the galaxies together. (Millis 2014) Super massive black holes are very dense and its believed that their density can reach infinity in a way that even light can't pass through their gravitational force. (NRAO 2014)
A Black Hole is defined as an object in space that is so compact, that has a gravitational pull so powerful, not even light can escape its pull. In most cases Black Holes are formed when a massive star (much larger than our own) undergoes a supernova explosion. When this happens, the star may collapse on its own gravitational pull, thus resulting in a an object with infinitely large density and zero volume. As a result, the escape velocity (the speed required to escape the gravitational pull) becomes even greater than the speed of light, and because nothing can travel faster than the speed of light, nothing can escape a black hole.
Black holes - the strange scientific phenomenon that has astounded physicists and astronomers alike for decades. Popular subjects in science fiction novels, black holes are one of the greatest enigmas of the scientific world. Even today, the concept of a super-dense ball of matter that not even light can escape from is somewhat farfetched, and many scientists disagree with each other about nearly every aspect of a black hole. This project will attempt to shed some light on these mysterious formations, and will inform you the reader of the most popular and widely accepted theories surrounding them.
Hawking, Stephen. “Our Picture of the Universe.” Fields of Reading. 6th ed. Ed. Nancy R. Comely et al. New York: St. Martin’s, 2001. (565-574)
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.
Black holes were originally thought to have only mere mathematical concepts. There was seemingly no possible way to compress any object into a space small enough to equal to its schwarzschild radius. Later however, astronomer Subrahmanyan Chandrasekhar calculated that stars much larger than our own sun should theoretically be able to collapse into a black hole (UTFC). A star is like a blown up balloon with the force of gravity trying to compress the balloon inwards and the air trying to push the balloon outwards. Likewise, stars are held in balance by gravity trying to collapse the star inwards going against the outwards pressure of the internal reactions of the star called nuclear fusion.
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.
Waller, William H. The Milky Way: An Insider's Guide. Princeton, N.J: Princeton UP, 2013. 42+. Print.
Hawking, G, 1973, Astronomical Alignments in Britain, Egypt and Peru, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, Vol. 276, No. 1257, pp. 157-167
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.
Astronomers believe that most galaxies consist of a supermassive black hole at the center, which attracts all constituents of galaxies such as, dust, gases (mainly Hydrogen and Helium), atoms, stars, interstellar clouds and planets to the center by force of gravity, but are not sure whether all galaxies contain a black hole in the center. Galaxies keep moving in relative motion to one another and intermittently can come so close that the force of gravitational attraction between the galaxies may become strong enough to cause a change in the shape of the galaxies, while in exceptional cases, the galaxies may collide. If two galaxies collide, they may pass right through without any effect or may merge, forming strands of stars, extending beyond 100,000 light years in space (World Book Online Reference Centre, 2005). Hence, neighboring and often other colliding galaxies induce the sha...
Although I was not doing an article on black holes, I decided to watch the following documentary, merely because it was related to the cosmos.