Related topics: galaxies , supermassive black hole , telescope , milky way , universe
Black hole
hideIn general relativity, a black hole is a region of space in which the gravitational field is so powerful that nothing, including light, can escape its pull. The black hole has a one-way surface, called an event horizon, into which objects can fall, but out of which nothing can come. It is called "black" because it absorbs all the light that hits it, reflecting nothing, just like a perfect blackbody in thermodynamics. Quantum analysis of black holes shows them to possess a temperature and Hawking radiation.
Despite its invisible interior, a black hole can reveal its presence through interaction with other matter. A black hole can be inferred by tracking the movement of a group of stars that orbit a region in space which looks empty. Alternatively, one can see gas falling into a relatively small black hole, from a companion star. This gas spirals inward, heating up to very high temperature and emitting large amounts of radiation that can be detected from earthbound and earth-orbiting telescopes. Such observations have resulted in the scientific consensus that, barring a breakdown in our understanding of nature, black holes do exist in our universe.
For more information about Black hole, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with black holes
Scientists Generate Black Hole Radiation in the Lab
Dec 07, 2009 |
4.2 / 5 (32) |
9
(PhysOrg.com) -- Due to their violent nature and long distance from Earth, black holes and their surroundings are very difficult to study. Currently, the main method to observe a black hole is to use an X-ray ...
Black Holes in Star Clusters stir up Time and Space (w/ Video)
Dec 16, 2009 |
4.8 / 5 (16) |
6
(PhysOrg.com) -- Within a decade scientists could be able to detect the merger of tens of pairs of black holes every year, according to a team of astronomers at the University of Bonn’s Argelander-Institut ...
Theorists propose a new way to shine -- and a new kind of star
Dec 14, 2009 |
4.5 / 5 (12) |
4
Dying, for stars, has just gotten more complicated. For some stellar objects, the final phase before or instead of collapsing into a black hole may be what a group of physicists is calling an electroweak star.
Silicon technology offers extended X-ray vision of high-energy cosmos
Space & Earth / Space Exploration
Dec 21, 2009 |
5 / 5 (3) |
2
(PhysOrg.com) -- As elements of the integrated circuits running our computers, phones and electronics, silicon wafers are everywhere. An ESA-led effort is establishing an out-of-this-world use for these ...
Suzaku catches retreat of a black hole's disk
Dec 10, 2009 |
4.5 / 5 (16) |
2
(PhysOrg.com) -- Studies of one of the galaxy's most active black-hole binaries reveal a dramatic change that will help scientists better understand how these systems expel fast-moving particle jets.
Stars Fueled by Dark Matter Could Hold Secrets to the Universe
Nov 03, 2009 |
4.4 / 5 (58) |
44
(PhysOrg.com) -- The first stars in the universe may have been very different from the stars we see today, yet they may hold clues to understanding some of the mysterious features of the universe. These "dark ...
First black holes may have incubated in giant, starlike cocoons
Nov 24, 2009 |
4.2 / 5 (20) |
22
(PhysOrg.com) -- The first large black holes in the universe likely formed and grew deep inside gigantic, starlike cocoons that smothered their powerful x-ray radiation and prevented surrounding gases from ...
The Energy Sources of Ultraluminous Galaxies
Nov 27, 2009 |
4.7 / 5 (20) |
3
(PhysOrg.com) -- Ultraluminous infrared galaxies ((ULIRGs) are galaxies whose luminosity exceeds that of a trillion suns; for comparison, the Milky Way galaxy has a typical (and much more modest) luminosity ...
Fermi Telescope Peers Deep into Microquasar (w/ Video)
Nov 27, 2009 |
4.8 / 5 (17) |
0
(PhysOrg.com) -- NASA's Fermi Gamma-ray Space Telescope has made the first unambiguous detection of high-energy gamma-rays from an enigmatic binary system known as Cygnus X-3. The system pairs a hot, massive ...
Black hole caught zapping galaxy into existence?
Nov 30, 2009 |
4.8 / 5 (27) |
9
(PhysOrg.com) -- Which come first, the supermassive black holes that frantically devour matter or the enormous galaxies where they reside? A brand new scenario has emerged from a recent set of outstanding ...
Is Everything Made of Mini Black Holes?
May 18, 2009 |
4.6 / 5 (56) |
56
(PhysOrg.com) -- In trying to understand how gravity behaves on the quantum scale, physicists have developed a model that has an interesting implication: mini black holes could be everywhere, and all particles ...
Chinese scientists create metamaterial black hole
Oct 16, 2009 |
4 / 5 (56) |
20
(PhysOrg.com) -- Two physicists in China have used metamaterials to create the first artificial electromagnetic black hole. The scientists, Qiang Cheng and Tie Jun Cui from the Southeast University in Nanjing, ...
Scientists observe super-massive black holes using Keck Observatory in Hawaii
Dec 10, 2009 |
5 / 5 (8) |
3
An international team of scientists has observed four super-massive black holes at the center of galaxies, which may provide new information on how these central black hole systems operate. Their findings ...
The Edge of a Black Hole
Aug 18, 2009 |
4 / 5 (27) |
14
The existence of black holes is one of the most amazing and bizarre predictions of Einstein's theory of gravity. Despite his original misgivings about their reality, massive black hole holes are today believed ...
Studying how black holes grow
Space & Earth / Space Exploration
Dec 17, 2009 |
5 / 5 (2) |
1
Black holes are some of the most exotic objects in the universe. They are the final evolutionary stage of giant stars much larger than the sun. When these stars explode, their cores collapse down to the size ...
