Geometry.Net - Basic_B: Black Holes

Physics Central
A page on modern physics, such as quantum mechanics and black holes, and some mathematics.
http://www.geocities.com/mik_malm/
Your Gateway To Entire Knowledge About The Universe
Provides information about the beginning of universe and solar system. About the planets, quasars, the Milky Way, black holes. Life of a star. Travel in space and extra terrestrial beings.
http://www.geocities.com/beyondearth2001/
Suite101.com
A review of the theory and history of black holes.
http://www.suite101.com/article.cfm/advanced_physics/28145

Extractions: Member Central Join Our Community! Login Member Update What's New ... TravelSuite Suite University About Suite University Visit the University Course Listing New Courses ... Featured Courses New Topics Basketball Teaching Creative Writing to Children Maine People Organic Vegetable Gardening ... More... Suite Events My Favorite Place War and Peace Spring Into Health! Earth Day 2003 More about Suite101 About Suite101.com Topic Not Found The page you were looking for is in a topic that is not available in Suite101.com. The reason that the link is erroneous may be because it is to a topic that no longer exists. Click here to go to the topics directory License Info Submit Comments http://www.suite101.com/topicnotfound.cfm
Introduction To Black Holes
Cambridge Relativity black holes. Introduction to black holes. Thereforewe are quite confident that there should also be some black holes.
http://www.damtp.cam.ac.uk/user/gr/public/bh_intro.html

Extractions: Introduction to Black Holes A black hole is a region of spacetime from which nothing can escape, even light. To see why this happens, imagine throwing a tennis ball into the air. The harder you throw the tennis ball, the faster it is travelling when it leaves your hand and the higher the ball will go before turning back. If you throw it hard enough it will never return, the gravitational attraction will not be able to pull it back down. The velocity the ball must have to escape is known as the escape velocity and for the earth is about 7 miles a second. As a body is crushed into a smaller and smaller volume, the gravitational attraction increases, and hence the escape velocity gets bigger. Things have to be thrown harder and harder to escape. Eventually a point is reached when even light, which travels at 186 thousand miles a second, is not travelling fast enough to escape. At this point, nothing can get out as nothing can travel faster than light. This is a black hole. Do they really exist?
Howstuffworks "How Time Travel Will Work"
Special relativity, understanding, space phenomena, black holes, wormholes, cosmic strings and problems.
http://www.howstuffworks.com/time-travel.htm

Extractions: There may be no other concept that captures the imagination more than the idea of time travel the ability to travel to any point in the past or future. What could be cooler? You could jump into your time machine to go back and see major events in history and talk to the people who were there! Who would you travel back to see? Julius Caesar? Leonardo da Vinci? Elvis? You could go back and meet yourself at an earlier age, go forward and see how you look in the future... It's these possibilities that have made time travel the subject of so many science fiction books and movies. It turns out that, in some sense, we are all time travelers. As you sit at your desk, doing nothing more than clicking your mouse , time is traveling around you. The future is constantly being transformed into the past with the present only lasting for a fleeting moment. Everything that you are doing right now is quickly moving into the past, which means we continue to move through time.
Black Holes: General Information
sof the workings of these stellar phenomenons known as black holes.Description Learn about the amazing phenomenon that is a black hole.Category Science Physics Relativity black holes Educationblack holes To learn the general ideas about black holes.
http://www.geocities.com/blackholeinfo/
Black Holes
black holes. There are many popular myths concerning black holes, manyof them perpetuated by Hollywood. black holes What Are They?
http://imagine.gsfc.nasa.gov/docs/science/know_l2/black_holes.html

Extractions: For Educators Black Holes Booklet The Life Cycle of Stars Booklet Show me related lesson plans Black Holes There are many popular myths concerning black holes , many of them perpetuated by Hollywood. Television and movies have portrayed them as time-traveling tunnels to another dimension, cosmic vacuum cleaners sucking up everything in sight, and so on. It can be said that black holes are really just the evolutionary end point of massive stars . But somehow, this simple explanation makes them no easier to understand or less mysterious. NOTE: This section is about what are called "stellar-mass black holes". For information about black holes with the mass of billions of Suns, see Black holes are the evolutionary endpoints of stars at least 10 to 15 times as massive as the Sun. If a star that massive or larger undergoes a
Black Holes
A service of the HighEnergy Astrophysics Learning Center. A nice introduction to black holes. Intended Category Science Physics Relativity black holes Education black holes. Standards Button. Level 1 topics include Introduction toblack holes; Journey into a Black Hole! Level 2 topics include
http://imagine.gsfc.nasa.gov/docs/introduction/black_holes.html

Extractions: All material on this site has been created and updated between 1997-2002. Useful plugins NASA's privacy statement Do you have a question, problem or comment about this web site? Please let us know External links contain material that we found to be relevant. However they're not maintained by us and the content may have changed. If you find any external links that contain inappropriate material, please let us know!
BLACK HOLES By Ted Bunn
black holes FAQ. Near a black hole, this distortion of space is extremelysevere and causes black holes to have some very strange properties.
http://cosmology.berkeley.edu/Education/BHfaq.html

Extractions: Loosely speaking, a black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull. Since our best theory of gravity at the moment is Einstein's general theory of relativity, we have to delve into some results of this theory to understand black holes in detail, but let's start of slow, by thinking about gravity under fairly simple circumstances. Now imagine an object with such an enormous concentration of mass in such a small radius that its escape velocity was greater than the velocity of light. Then, since nothing can go faster than light, nothing can escape the object's gravitational field. Even a beam of light would be pulled back by gravity and would be unable to escape. The idea of a mass concentration so dense that even light would be trapped goes all the way back to Laplace in the 18th century. Almost immediately after Einstein developed general relativity, Karl Schwarzschild discovered a mathematical solution to the equations of the theory that described such an object. It was only much later, with the work of such people as Oppenheimer, Volkoff, and Snyder in the 1930's, that people thought seriously about the possibility that such objects might actually exist in the Universe. (Yes, this is the same Oppenheimer who ran the Manhattan Project.) These researchers showed that when a sufficiently massive star runs out of fuel, it is unable to support itself against its own gravitational pull, and it should collapse into a black hole.
The Astronomy Page
Links to sites covering several spacerelated topics, from general interest, telescopes and photography to black holes, quasars and comets.
http://www.theschoolpage.com/astro.htm

Extractions: Jonathan Tate , is a member of the Board of Directors of the international Spaceguard Foundation, a consultant to the International Astronomical Union Working Group on Near Earth Objects, an associate of COSPAR and a Fellow of the Royal Astronomical Society. Tate is the Director of the newly established Spaceguard Centre at the former Powys County Observatory in mid-Wales and leads the International Spaceguard Information Centre. The Spaceguard Centre will become a leading centre for public outreach and education in all matters astronomical. He will be glad to answer questions. Click here to ask a question. Be sure to include your name, age and E-Mail address. Black Holes, Quasars, etc.:
Splash Page
Thoughts on physics, aliens, exotic propulsion, and philosophy.
http://www.stardrive.org/
Welcome To Foundation Physics
This work is based on an elementary particle, the PParticle, and includes amongst other topics, discussions of relativity, origin of background radiation, nature of black holes and the nature of light.
http://www.foundationphysics.com/

Extractions: Foundation Physics: Preface: This work is based on an elementary particle, termed the 'P-Particle', which is first postulated to be the fundamental constituent of all matter present in the universe. The particle is defined by several axioms and can be regarded as being the quantum of matter. Just as energy is quantised, and energy and mass are interchangeable, then on this basis the idea of mass being quantised is first assumed and subsequently verified. It is subsequently shown that this particle can be identified with the neutrino. From this model, a large number of results are derived which potentially shed a new light on aspects of physics ranging from classical Newtonian mechanics and relativity to quantum mechanics and particle physics. Amongst the topics included are:
Black Holes And Neutron Stars
black holes and Neutron Stars offers a nontechnical discussion aboutblack holes and neutron stars. Topics include what they are
http://www.eclipse.net/~cmmiller/BH/
Space And Time
Course based on Stephen Hawking's best selling book, A Brief History of Time . The course deals with topics in modern physics such as Einstein's Special Theory of Relativity, Quantum Theory, black holes and the Creation of the Universe.
http://www.hartwick.edu/physics/spacetime.html

Extractions: Welcome to the homepage for Physics 127: Space and Time. This course is based on Stephen Hawking's best selling book, "A Brief History of Time". The course deals with exciting topics in modern physics such as Einstein's Special Theory of Relativity, Quantum Theory, Black Holes and the Creation of the Universe. Paul Hewitt's text "Conceptual Physics" is also used to fill in details about basic physics concepts such as energy, momentum, wave motion, atomic and nuclear physics that are necessary in order to understand the ideas in Hawking's book. You can read the syllabus by clicking here. Here are some links to other web pages that may help you to learn about some of the ideas discussed in this course: Stonehenge This page contains several photos of the Stonehenge monument taken by Dr. Hickey in the Fall of 1999. Views of the Universe . This page and the dozen or so pages that follow it contain lots of background about the geocentric and heliocentric models of the universe. There is also a wealth of information about Kepler, Galileo, Newton, etc.
Falling Into A Black Hole
This is a website that describes the geometry of a black hole and what would happen if one were to Category Science Physics Relativity black holes EducationFalling Into a Black Hole. In which we fall into a black hole on a realfree fall orbit. All address. Falling Into a Black Hole Index.
http://casa.colorado.edu/~ajsh/schw.shtml

Extractions: In which we fall into a black hole on a real free fall orbit. All distortions of images are real, both general relativistic from the gravitational bending of light, and special relativistic from the near light speed orbit. The black hole belongs to a quadruple stellar system, a binary binary. The system is fictional, but plausible. After you are done dying at the central singularity of the black hole, feel free to explore more about the Schwarzschild geometry, about wormholes, about the collapse of a black hole, and about Hawking radiation. . These pages last modified 19 Apr 2001. The URL of this site is http://casa.colorado.edu/~ajsh/schw.shtml Here's the Movie Index . For what's see site history Movie preview Approaching the black hole (89K GIF movie) Firing a probe while orbiting the black hole (95K GIF movie) Falling to the singularity (217K GIF movie) Clicking on the text link gives you the movie in normal size. Clicking on the image gives you a double-size version of the same movie (same resolution, same number of K, just twice as big on the screen). For explanations of these movies, and more, advance
Relativity And Black Hole Links
HEASARC's Imagine the Universe educational resource includes information aboutblack holes. Michael Cramer Andersen's Geometry around black holes.
http://casa.colorado.edu/~ajsh/relativity.html

Extractions: Andrew Hamilton's Homepage Falling into a Black Hole A tour of Special Relativity Cosmology links ASTR 3740 Homepage (Spring 2000) Relativity and Black Hole links: Chris Hillman's Relativity on the World Wide Web is a superb place to start. Spacetime Wrinkles , a relativity exhibit. Space Telescope Science Institute for pics from Hubble Space Telescope Astronomy Picture of the Day , such as LMC X-1 Here or here for art from HEASARC (High Energy Astrophysics Science Archive Research Center). HEASARC's Imagine the Universe educational resource includes information about black holes. Exosat x-ray images Alan Bridle's radio images of Radio Galaxies and Quasars Gravitational Lensing Homepage. Max-Planck-Institut fur Astrophysik Gravitational Lensing Page. Pete Newbury's gravitational lensing demos Movies from the NCSA (National Center for Supercomputing Applications). Michael Owen's High Mass X-Ray Binary Page. NCSA-Potsdam-Washington University Relativity Page. Cambridge Relativity Homepage. Ben Bromley's images of an accretion disk around an extreme Kerr black hole and of a turbulent accretion disk around a black hole Menu of art courtesy of the people running the Integral gamma-ray satellite.
Black Holes
black holes. black holes are fundamentally simple nature. Here is a linkto some Frequently Asked Questions (and answers!) about black holes.
http://csep10.phys.utk.edu/guidry/violence/blackholes.html

Extractions: Black holes are peculiar objects with many strange properties, but most books and articles have emphasised their exotic aspects, and obscured their fundamentally simple nature. Here is a link to some Frequently Asked Questions (and answers!) about black holes. The description given below was first worked out by the French mathematician Pierre Laplace in 1796, so they are not even a modern invention! Before discussing black holes themselves we should think briefly about gravity.
Supermassive Black Holes
Supermassive black holes. The active galaxies appear to require a compactenergy source of enormous strength. Origin of Supermassive black holes.
http://csep10.phys.utk.edu/astr162/lect/active/smblack.html

Extractions: Black Holes The active galaxies appear to require a compact energy source of enormous strength. The most plausible candidate is a rotating, supermassive black hole of order a billion solar masses at their center. Until recently there has been strong circumstantial evidence to support such a mechanism. In the past few years evidence of much more direct nature has emerged. The left portion of the following Hubble Space Telescope photograph shows the center of the giant elliptical galaxy , which is the 87th entry in the famous Messier Catalog This galaxy is believed to contain a supermassive black hole of several billion solar masses at its center. The observations indicate that approximately 3 billion solar masses are concentrated in a region at the galactic core that is only about the size of the Solar System. The diagonal line across the right image is a jet of high-speed electrons approximately 6500 light years long that is probably being ejected from the galactic nucleus by the black hole located there. The right side of the figure illustrates schematically Doppler shift measurements made on the central region of M87 that suggest rapid rotation of the matter near the center. The measurement was made by studying how the light from the disk is red shifted and blue shifted by the Doppler effect, using the Faint Object Spectrograph aboard the Hubble Space Telescope. Part of the swirling disk spins in Earth's direction and the other side spins away from Earth, thus causing opposite Doppler shifts. The gas on one side of the disk is moving away from Earth at a speed of about 550 kilometers per second (red shift). The gas on the other side of the disk is approaching the Earth at the same speed (blue shift).
The Search For Black Holes
A brief overview of black holes, information about the discovery of Cygnus X1, and a short list of Category Science Physics Relativity black holes ObservationsThe Search for black holes. Steven Degennaro's SPAC250 final project black holes, if they truly exist, are very strange objects indeed.
http://www.owlnet.rice.edu/~spac250/steve/

Extractions: Black holes, if they truly exist, are very strange objects indeed. Imagine, if you will, an object resting in the vast emptiness of space, totally undetectable except for its gavitational pull. Imagine an object so massive, and so densely packed, that not even light can escape its immense gravity. Now imagine flying towards one of these objects, as light from the stars behind it becomes bent by its strong gravitational field, and circling around it at some distance. Now imagine approaching and orbiting at the photonsphere, the radius at which light rays become so bent, they actually curve all the way around, and you can see the back of your head! Think of falling deeper and deeper towards the black hole, as tidal forces stretch your body into spaghetti. Imagine spiralling inward toward a singularity in spacetime, an infinitely dense geometric point where all the laws of physics, in fact the very fabric of space and time, break down and cease to exist. Picture watching someone take the plummet towards the event horizon, the point past which no information can be transmitted, seeming never to quite reach it, though he himself feels he has already crossed it - in a finite amount of time! These are just a few of the strange phenomena that accompany the compact stellar remnants coined 'Black Holes' by physicist John Wheeler. These are strange and fascinating objects, truly, but as of yet, they are still considered theoretical. That is why astronomers and astrophysicists of all disciplines have turned their attentions towards the search for actual black holes in the vastness of space. The search is a difficult one, because black holes cannot actually be seen, and must be detected indirectly. However, it is a very important one, as the discovery of actual black holes would provide further proof of Einstein's General Theory of Relativity, which first predicted their existence over fifty years ago.
Submitting To The Black Hole
Tables summarizing input from authors on respose time for SF markets. Updated constantly.
http://www.critique.org/critters/blackholes

Extractions: While many Science Fiction/Fantasy/Horror magazine and book publishers respond to submissions in a timely manner, many don't; and sometimes their response times are at odds with those stated in their guidelines. Which is to say, when writers submit a manuscript to an editor, they often feel like they've launched it toward a black hole. These pages are an attempt to locate verifiable response time data as well as "horror stories" for markets that have kept (or are keeping) manuscripts far longer than one might consider reasonable. (Credit the idea to Sharon Lee , former Executive Director and current President of SFWA Authors are encouraged to drop by to get a handle on how long to expect a manuscript will be at a given market (and, perhaps, get a sense of when to query ). There is also some hope that this public knowledge will encourage editors to speed up their responsiveness, or at least alter their guidelines to match their reality. Authors are also asked nay, begged to report their own response times. This helps everyone. (Note that only paying markets are tracked.)

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