41. Black Holes - Science Background No Escape The Truth About black holes. Teacher Page Science Background. Index For details, consult any popular book on black holes. Back to Top . 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.

42. Black Holes Fuzzy Tangles Of Strings? CNN http://cnn.com/2004/TECH/space/03/03/shc.fuzzball.blackholes/index.html

43. Black Holes The Truth about black holes An Amazing Space activity designed to teach students about black holes. We are sorry, but The Truth 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

44. StarChild Dr. Stephen Hawking Tells about the physicist known for his study of black holes. http://starchild.gsfc.nasa.gov/docs/StarChild/whos_who_level2/hawking.html

45. Exploring Gravity From a student at the Curtin University of Technology in Australia, a tutorial with three levels introductory, intermediate, and advanced. Includes the history of gravity, orbits, air resistance, laws, escape velocity, and black holes. http://www.curtin.edu.au/curtin/dept/phys-sci/gravity/

46. Chandra Field Guide To X-ray Sources Black Holes An explanation of cosmic Xray sources, from black holes to galaxy clusters, as well as a review of the history of X-ray astronomy, what X-rays are and how http://chandra.harvard.edu/xray_sources/blackholes.html

47. Chandra Resources Q A Galaxies, Galaxy Clusters, AGN, And in content. Capable browsers will automatically be transported there in a few seconds. Thanks for visiting! black holes. CXC Home http://chandra.harvard.edu/xray_sources/black_holes.html

48. Two Super Black Holes On Collision Course CNN http://cnn.com/2002/TECH/space/11/19/blackhole.merger.ap/index.html

49. Suddenly, Universe Awash In Black Holes CNN http://cnn.com/2002/TECH/space/09/17/black.holes/index.html

50. Basic Topics Xray binaries and black holes. Models for the x-ray binaries. ergosphere; structure of black hole; spacetime around a black hole; X-ray binary black hole models; http://astrosun.tn.cornell.edu/courses/astro201/top_xrays.htm

51. 'X' Marks The Spot Where Black Holes Meet CNN http://cnn.com/2002/TECH/space/08/29/black.holes/index.html

52. Big Or Small, Black Holes Play Same Melody CNN http://cnn.com/2002/TECH/space/04/09/black.holes/index.html

53. CNN.com - Chandra Going Strong, Hunting Black Holes - August 30, 2001 CNN http://cnn.com/2001/TECH/space/08/30/chandra.anniversary/index.html

MAIN PAGE WORLD U.S. WEATHER ... ABOUT US CNN TV what's on show transcripts CNN Headline News CNN International ... askCNN EDITIONS CNN.com Asia CNN.com Europe set your edition Languages Time, Inc. Time.com People Fortune EW Chandra going strong, hunting black holes A drawing of the Chandra X-ray observatory By Richard Stenger CNN (CNN) The most powerful X-ray space telescope ever has astounded scientists with its haunting visions of strange black holes and mysterious dark matter ever since opening its eye to the heavens two years ago. Galaxies eating neighbors. A stream of matter eight times the length of the Milky Way. An X-ray shadow cast by one galaxy against another. The Chandra X-ray Observatory has seen them all and more in it brief tenure in space. The spacecraft, which took its first picture in August 1999, has given an unprecedented glimpse into hot spots in the universe, including those notorious monsters lurking in the heart of many galaxies. "Black holes, black holes, black holes. We're seeing them early in the universe, in huge sizes, in much greater quantities than some of us expected, and we've discovered new classes of black holes," said Chandra scientist Andrew Weisskopf, describing the returns from the $2.8 billion mission, one of NASA's most expensive. VIDEO Watch an animation of Chandra's orbit (Courtesy TRW) Play video (QuickTime, Real or Windows Media)

54. Frequently Asked Questions About Black Holes Frequently Asked Questions About black holes. Compiled by black hole? Or, why do some stars end up as black holes but others don t? http://www.phys.vt.edu/~jhs/faq/blackholes.html

55. Dozens Of Middleweight Black Holes Detected CNN http://cnn.com/2001/TECH/space/06/06/space.holes.reut/index.html

56. Stringy Black Holes Stringy black holes. Martijn Derix and Jan Pieter van der Schaar. Contents; Introduction; General Relativity; black holes Spherical symmetry; Schwarzschild solution; http://www-th.phys.rug.nl/~schaar/htmlreport/report.html

57. Black Holes HOW DO WE SEE black holes ? John Blondin Theoretical Astrophysics Department of Physics North Carolina State University. http://wonka.physics.ncsu.edu/~blondin/Blackhole/title.html

58. Matter 'seen' Disappearing Into Black Holes For First Time CNN http://cnn.com/2001/TECH/space/01/12/black.holes.ap/index.html

59. Black Holes What is a black hole? Where do black holes come from? How do we see black holes? http://wonka.physics.ncsu.edu/~blondin/Blackhole/intro.html

60. En.wikipedia.org/wiki/Black_hole s of the workings of these stellar phenomenons known as black holes....... black holes General Informationblack holes To learn the general ideas about black holes. http://en.wikipedia.org/wiki/Black_hole

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