A Journey to the centre of a Black Hole! The Universe can be an unbelievably violent and extreme place. Nowhere is this seen more clearly than with the many exotic objects that can be found scattered throughout the Cosmos – from transient stellar explosions to all consuming Black Holes. What is a Black Hole? A Black Hole is a compact/ localised region of space surrounding a collapsed mass within which gravity is so powerful that neither matter nor radiation can escape – in other words, the escape velocity (see page 3) exceeds the velocity of light. Formation of Black Holes A Black Hole is thought to have been formed when a star with a certain mass undergoes total gravitational collapse. For a star with mass greater than M, gravity squashes the star to such an extent that, in theory, its density becomes infinite and its volume is zero. This state of matter is called a “singularity” and is inaccessible to the laws of physics as we understand them, in other words it breaks the laws of physics. For a Black Hole to form the solar mass of the star has to be 3 times heavier than the Sun. The gravitational field surrounding a Black Hole is so high that no radiation (including light) can escape and as a result of this it appears black due to the absence of any observable emission. ( http://www.nasa.gov. What is a black hole? September 30, 2008) General Theory of Relativity The General Theory of Relativity is the geometric theory of gravitation. This theory generalises special relativity and Newton’s law of universal gravitation, providing a united description of gravity as a geometric property of space and time (spacetime). Spacetime is any mathematical model that combines space and time into a single continuum. Albert Einstein’s resear... ... middle of paper ... ...k Holes. November 27, 2013 (online website) available at: This website helped me to understand how x-ray sources are emitted due to two 2 Black Holes being very close to one another. McEvoy, Jordan. Stephen Hawking – A graphic guide. United Kingdom: Icon Books Ltd, 1999 (journal) available at: This book helped me cover the area of Hawking Radiation, a very difficult topic area to understand. Smolin, Lee. Three Roads to Quantum Gravity. Great Britain: Weidenfeld & Nicolson, 2000 (journal) available at: This journal provided me with all the quotes used throughout my report. Ridpath, Ian. Astronomy Dictionary. Great Britain: George Phillip Ltd, 1995 (journal) available at: This journal provided me with all the definitions used throughout my report.
Death by Black Hole: And Other Cosmic Quandaries is a biography that is divided into 5 chapters total and a total of 42 mini sections. Bringing together more than forty of Tyson's favorite essays explores a myriad of cosmic topics, from what it would be like to be inside a black hole to the movie industry's feeble
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)
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.
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:
In the 1970’s, Stephen Hawking made the argument that the quantum-mechanical effects of black holes made them emit radiation
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)
Quantum Mechanics This chapter compares the theory of general relativity and quantum mechanics. It shows that relativity mainly concerns that microscopic world, while quantum mechanics deals with the microscopic world.
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.
Gravity is defined as the force of attraction that causes objects to fall toward the center of the earth(“Gravity”). Without gravity, the world that we know would not exist. Gravity is the reason why objects are on earth and not floating in space. Although some discoveries have been made about gravity there are still numerous unanswered questions. There are several scientists who are well known for their contribution to science, these scientists include Aristotle, Galileo, Kepler, Newton, and Einstein. Over a course of several hundred years, scientists’ views about gravity has changed. No one really understands how gravity works, but people have learned about the effects of gravity. It started off with a philosophy point of view, and it then moved to a scientific methodology view, and then to scientific theory view.
Kirkpatrick, Larry, and Gerald F. Wheeler. Physics: A World View. 4th ed. Orlando: Harcourt College Publishers, 2001.
Fowler, Michael. “Modern Physics.” Lecture. Mass and Energy. 1 Mar. 2008. Web. 13 Oct. 2013.
Einstein, Albert. Relativity: The Special and General Theory. Three Rivers Press, New York, New York. 1961.
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.
Next to cosmology, Hawking is one of many physicists who are seeking out a flawless theory of Quantum Gravity. This topic is listed under the "Stephen Hawking" Wikipedia entry as one of Hawking's primary fields of research.
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.