21. What Is A Black Hole? What Is a Black Hole If a ball is thrown upwards from the surface of the Earth it reaches a certain height and then falls back. http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

22. Black Holes black holes are peculiar objects with many strange properties, but most books about black holes. The description given below was first worked out by the http://csep10.phys.utk.edu/guidry/violence/blackholes.html

Black Holes 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. What Is Gravity? What Is a Black Hole? Light and Gravity Gravitational Lensing ... How Could We See a Black Hole? Home Mike Guidry: guidry@utk.edu http://csep1.phy.ornl.gov/guidry/mwg-root.html

23. Big Bertha Thing White Dwarfs, Neutron Stars, And Black Holes Alltext page on the various stages in the discovery and development of theories of white dwarfs, neutron stars and black holes. http://www.geocities.com/tonylance/dwarf.html

White Dwarfs, Neutron Stars, And Black Holes While stars seem unchanging in comparison with a person's lifetime, they are in fact evolving objects that are born, mature, age, and die. After death, they leave behind stellar "fossils" as gravestones of their existence. The most evident of these fossils, the small stars known as white dwarfs, have been known for over a century. In recent decades, however, research has shown that such fossils can be more remarkable objects, known as neutron stars, or possibly can even be "singularities", collapsing forever and folding space around themselves to form "black holes". This document provides a survey of white dwarfs, neutron stars, and black holes. Contents List THE DISCOVERY OF WHITE DWARFS WHITE DWARFS AND ELECTRON DEGENERACY THE STRUCTURE AND EVOLUTION OF WHITE DWARFS WHITE DWARFS AND THE AGE OF THE GALAXY ... COMMENTS, SOURCES, AND REVISION HISTORY 1. THE DISCOVERY OF WHITE DWARFS Between the years 1834 and 1844, the German astronomer Friedrich W. Bessel performed a series of careful observations of Sirius, the brightest star in our sky. Sirius, sometimes called the Dog Star, is about twice as massive as our own Sun, 25 times brighter, and is about nine light years away in the constellation Canis Major. Bessel's careful observations revealed a wobble in the motion of Sirius across the sky, indicating the presence of a hidden companion. However, nobody was able to locate the hidden companion until 1862, when the telescope maker Alvan Graham Clark spotted it while he was testing out a new large refracting telescope. The companion became known as Sirius B, or just the Pup, while the Dog Star itself became technically known as Sirius A.

24. Hewitt To Act Over GP 'black Holes' Action to end GP 'black holes' was announced by Health Secretary Patricia Hewitt. http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

25. Supermassive Black Holes The most plausible candidate is a rotating, supermassive black hole of order a This galaxy is believed to contain a supermassive black hole of several http://csep10.phys.utk.edu/astr162/lect/active/smblack.html

Supermassive 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. Evidence for a Supermassive Black Hole in M87 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).

26. 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

TCDA("cc=oth; dt"); Auto Stuff Science Stuff Health Stuff Entertainment Stuff ... Shop for Stuff Top Subjects Car Engines Lock Picking Nuclear Bombs Tattoos ... Gas Turbine Engines Sponsored By: Subjects Earth Science Engineering Life Science Military ... Browse the Science Library Explore Stuff Lidrock.com Stuffo.com Big List of Articles Get the Newsletter ... Physical Science How Time Travel Will Work by Kevin Bonsor Table of Contents Introduction to How Time Travel Will Work Understanding Time Space Phenomena Black Holes Wormholes Cosmic Strings Problems with Time Travel Lots More Information Shop or Compare Prices 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.

27. Black Holes General Information Provides information on black holes. http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

28. Splash Page Thoughts on physics, aliens, exotic propulsion, and philosophy. http://www.stardrive.org/

Sorry, your browser doesn't support Java(tm). Sorry, your browser doesn't support Java(tm). Enter Here!

29. Black Holes Portal linking to sites about very high density objects black holes, neutron stars. http://www.galacticsurf.com/trounoirGB.htm

BLACK HOLES French Sites English Sites French Sites http://pages.infinit.net/mycroft/suppleme... 9 photos of black holes with associated explanations. http://pages.infinit.net/gafen/ Introduction to the black hole physics: the best way to be in ! http://tpe.trousnoirs.free.fr/ A web site dedicated to black holes: their birth, relativity, index etc... A web site easy to understand for all. http://www.trous-noirs.fr.st/ From the end of the life of a star to the formation of a black hole. very nice site. http://www.iquebec.com/trounoir/ Black hole formation (a web site entirely dedicated to this subject). http://www.cybersciences.com/Cyber/3.0... An article of cyber science: How to make a black hole without danger ! http://www.geocities.com/CapeCanavera... Black hole and singularity: very fine web page. http://pages.infinit.net/mycroft/trousnoirs... 5 chapiters describing the different types of black holes. http://perso.wanadoo.fr/astro.flashespac... News: Mysterious bubbles  http://www.geocities.com/CapeCanaveral/...

30. Beyond Einstein NASA's Structure Evolution of the Universe Theme Web Site, supporting Beyond Einstein From the Big Bang to black holes. http://universe.nasa.gov/

Bypass navigation links and go to page content The discoveries of Albert Einstein sparked the scientific revolution of the 20th century and rank among the greatest achievements of humanity. Recent developments show that we can now complete Einstein's legacy and, in the first decades of the 21st century, unravel the mysteries of the Universe that await us . . . The Science The Program Great Observatories Probes ... Home A service of the Exploration of the Universe Division at NASA Goddard Space Flight Center Web site design and maintenance by Pat Tyler, Responsible NASA Official: Phil Newman Privacy, Security, Notices

31. The Chandra X-ray Observatory Center Gateway To The Universe Of CHRONICLES XRay Fluorescence Reveals the Hidden Secrets of black holes and Ancient Manuscripts More (13 Jun 05) http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

32. Relativity And Black Hole Links Robert Nemiroff s Virtual Trips to black holes Neutrons Stars, one of which provided Gary Felder and Charles Stebbins Thermodynamics of black holes. http://casa.colorado.edu/~ajsh/relativity.html

Andrew Hamilton's Homepage Falling into a Black Hole A tour of Special Relativity Cosmology links ASTR 3740 Homepage (Spring 2004) Relativity and Black Hole links: Chris Hillman's Relativity on the World Wide Web is a superb place to start. Greg Egan's Foundations offers an accessible introduction to relativity. 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.

33. Foundationphysics 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/

Part I Home Part III Part II ... Part IV Foundation Physics This site presents a detailed theory based on an elementary particle, the P-Particle, postulated to be the fundamental constituent of all matter in the universe, and subsequently shown to be identifiable with the neutrino. The particle is defined by several axioms and can be thought of as the quantum of matter. Just as energy is quantised, and mass and energy are interchangeable, then on this basis the idea of mass being quantised is first assumed and subsequently verified. The implications of the model are far-reaching, with new light shed on facets of physics ranging from classical Newtonian mechanics, to quantum theory and particle physics, to black holes. A selection of contents is provided under each section of the site. The individual parts themselves are obtainable in pdf format. I hope you enjoy the site and welcome any comments or questions. Bijan Yavari London 2005 Introduction P-Particle Theory: a neutrino-based TOE www.foundationphysics.com bijanyavari@yahoo.com Pdf version of website

34. Spacetime Wrinkles Major advances in computation are only now enabling scientists to simulate how black holes form, evolve, and interact. Learn about relativity and its predictions through text and video files at this site. http://archive.ncsa.uiuc.edu/Cyberia/NumRel/NumRelHome.html

SPACETIME WRINKLES In 1905, Albert Einstein published his famous Special Theory of Relativity and overthrew commonsense assumptions about space and time. Relative to the observer, both are altered near the speed of light: distances appear to stretch; clocks tick more slowly. A decade and a year later, Einstein further challenged conventional wisdom by describing gravity as the warping of spacetime, not a force acting at a distance. Since then, Einstein's revolutionary insights have largely stood the test of time. One by one, his predictions have been borne out by experiment and observation. But it wasn't until much later that scientists accepted one of the most dramatic ramifications of Einstein's theory of gravitation: the existence of black holes from whose extreme gravity nothing, not even light, can escape. Major advances in computation are only now enabling scientists to simulate how black holes form, evolve, and interact. They're betting on powerful instruments now under construction to confirm that these exotic objects actually exist. You might like to take a two-minute video tour of this exhibit's contents. However, the Quicktime movie is rather large (12.3 MB!), so be patient when downloading. It could take several minutes. (Further information on downloading movies can be obtained from the

35. Slashdot | Hidden Black Holes Discovered Hidden black holes Discovered article related to Space and Science. http://science.slashdot.org/article.pl?sid=05/08/07/0524238&from=rss

36. Howstuffworks "How Black Holes Work" Astronomers announced this week that they have solid evidence of a black hole swallowing up a star. Yep i swallowing a star /i . http://science.howstuffworks.com/black-hole.htm

TCDA("cc=oth; dt"); Auto Stuff Science Stuff Health Stuff Entertainment Stuff ... Shop for Stuff Top Subjects Car Engines Lock Picking Nuclear Bombs Tattoos ... Gas Turbine Engines Sponsored By: Subjects Earth Science Engineering Life Science Military ... Browse the Science Library Explore Stuff Lidrock.com Stuffo.com Big List of Articles Get the Newsletter ... Space How Black Holes Work by Craig C. Freudenrich, Ph.D. Table of Contents Introduction to How Black Holes Work What is a Black Hole? Types of Black Holes How We Detect Black Holes Lots More Information Shop or Compare Prices You may have heard someone say, "My desk has become a black hole!" You may have seen an astronomy program on television or read a magazine article on black holes. These exotic objects have captured our imagination ever since they were predicted by Einstein's Theory of General Relativity in 1915. Photo courtesy NASA/Space Telescope Science Institute (J. Gitlin, artist) Artist concept of the near vicinity of the black hole at the core of galaxy NGC 4261 What are black holes? Do they really exist? How can we find them? In this edition of

37. Astronomy For Kids - KidsAstronomy.com Stars, planets, black holes, Junior Astronomers Club. http://www.kidsastronomy.com/

Outer Space Solar System Deep Space Space Exploration ... How Big Is The Universe Resources News Astronomy Dictionary Teacher's ... Free eCard Send your friends a free astronomy eCard Free Wallpaper Give your screen an astronomy make-over Math For Kids A Math Resource For Children. For Information About KidsAstronomy.com Click Here Links UniverseToday.com NationWideShelving

38. Black Holes The Truth about black holes An Amazing Space activity designed to teach students about black holes. http://amazing-space.stsci.edu/resources/explorations/blackholes/

We are sorry, but The Truth about Black Holes requires that you have Javascript enabled in your web browser. Currently your browser either does not have support for javascript, or else you have the support disabled. You can find more information on the requirements for this lesson and how to meet them on the teacher pages

39. Madasafish A layman's exploration of the purpose of life. http://members.madasafish.com/~mysticarts/

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40. Black Holes - Science Background What evidence do we have for the existence of black holes? 10. How does the Hubble Space Telescope search for black holes? http://amazing-space.stsci.edu/resources/explorations/blackholes/teacher/science

No Escape: The Truth About Black Holes Teacher Page: Science Background Index: Science background 1. What is a black hole? 2. How is a stellar black hole created? 3. How can light be trapped by the gravitational pull of a black hole if light has no mass? ... Selected references Science background: The following information is provided to give the teacher some additional knowledge about the effect of gravity and black holes. This material can be used to inspire research topics for students or to encourage class discussion. Back to Top 1. What is a black hole? Back to Top 2. How is a stellar black hole created? To create a massive core a progenitor (ancestral) star would need to be at least 20 times more massive than our Sun. If the core is very massive (approximately 2.5 times more massive than the Sun), no known repulsive force inside a star can push back hard enough to prevent gravity from completely collapsing the core into a black hole. Then the core compacts into a mathematical point with virtually zero volume, where it is said to have infinite density. This is referred to as a singularity. When this happens, escape would require a velocity greater than the speed of light. No object can reach the speed of light. The distance from the black hole at which the escape velocity is just equal to the speed of light is called the event horizon. Anything, including light, that passes across the event horizon toward the black hole is forever trapped.

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