News tagged with black holes

Repulsive gravity as an alternative to dark energy (Part 2: In the quantum vacuum)

(PhysOrg.com) -- During the past few years, CERN physicist Dragan Hajdukovic has been investigating what he thinks may be a widely overlooked part of the cosmos: the quantum vacuum. He suggests that the quantum vacuum has ...

Physics / General Physics

created Feb 01, 2012 | popularity 4.7 / 5 (77) | comments 143 | with audio podcast report

Physicists propose test for loop quantum gravity

(PhysOrg.com) -- As a quantum theory of gravity, loop quantum gravity could potentially solve one of the biggest problems in physics: reconciling general relativity and quantum mechanics. But like all tentative ...

Physics / Quantum Physics

created Jan 03, 2012 | popularity 4.3 / 5 (34) | comments 106 | with audio podcast feature

NASA satellite could reveal if primordial black holes are dark matter

(PhysOrg.com) -- The primary objective of NASA’s Kepler satellite, which was launched in March 2009 to orbit the Sun, is to search for Earth-like planets in a portion of the Milky Way galaxy. But now ...

Physics / General Physics

created Dec 09, 2011 | popularity 5 / 5 (18) | comments 46 | with audio podcast feature

Could primordial black holes be dark matter?

(PhysOrg.com) -- “We know that about 25% of the matter in the universe is dark matter, but we don’t know what it is,” Michael Kesden tells PhysOrg.com. “There are a number of different theories about what da ...

Physics / General Physics

created Sep 21, 2011 | popularity 4.1 / 5 (27) | comments 48 | with audio podcast feature

Physicists create sonic black hole in the lab

(PhysOrg.com) -- Black holes get their name because they absorb all incoming light, and are so dense that none of that light can escape their event horizon. In a new study, scientists have created a sonic ...

Physics / General Physics

created Jan 10, 2011 | popularity 4.5 / 5 (38) | comments 9 | with audio podcast feature

Ghostly gamma-ray beams blast from Milky Way's center

(Phys.org) -- As galaxies go, our Milky Way is pretty quiet. Active galaxies have cores that glow brightly, powered by supermassive black holes swallowing material, and often spit twin jets in opposite directions. ...

Space & Earth / Astronomy

created 4 hours ago | popularity 4.7 / 5 (3) | comments 10 | with audio podcast

How black holes grow: New study indicates they eat binary star partners

A study led by a University of Utah astrophysicist found a new explanation for the growth of supermassive black holes in the center of most galaxies: they repeatedly capture and swallow single stars from pairs ...

Space & Earth / Astronomy

created Apr 02, 2012 | popularity 3.9 / 5 (7) | comments 4 | with audio podcast

'Ordinary' black hole discovered 12 million light years away

(PhysOrg.com) -- An international team of scientists have discovered an ‘ordinary’ black hole in the 12 million light year-distant galaxy Centaurus A. This is the first time that a normal-size black ...

Space & Earth / Astronomy

created Mar 27, 2012 | popularity 4.5 / 5 (18) | comments 31 | with audio podcast

Researchers create computer simulations of primordial black holes striking the Earth

(PhysOrg.com) -- Black holes have captured the imagination of scientists and amateur enthusiasts for years. The idea of some dark entity out there in the far reaches of space sucking up anything and everything ...

Physics / General Physics

created Mar 23, 2012 | popularity 3.9 / 5 (14) | comments 37 | with audio podcast report

Ultra-fast outflows help monster black holes shape their galaxies

(PhysOrg.com) -- A curious correlation between the mass of a galaxy's central black hole and the velocity of stars in a vast, roughly spherical structure known as its bulge has puzzled astronomers for years. ...

Space & Earth / Astronomy

created Feb 27, 2012 | popularity 5 / 5 (3) | comments 10 | with audio podcast

Chandra finds fastest wind from stellar-mass black hole

Astronomers using NASA's Chandra X-ray Observatory have clocked the fastest wind yet discovered blowing off a disk around a stellar-mass black hole. This result has important implications for understanding ...

Space & Earth / Astronomy

created Feb 21, 2012 | popularity 4.1 / 5 (7) | comments 10 | with audio podcast

Black hole came from a shredded galaxy

(PhysOrg.com) -- Astronomers using NASA's Hubble Space Telescope have found a cluster of young, blue stars encircling the first intermediate-mass black hole ever discovered. The presence of the star cluster ...

Space & Earth / Astronomy

created Feb 15, 2012 | popularity 4.6 / 5 (13) | comments 13 | with audio podcast

NASA's RXTE detect 'heartbeat' of smallest black hole candidate (w/ video)

(PhysOrg.com) -- An international team of astronomers has identified a candidate for the smallest-known black hole using data from NASA's Rossi X-ray Timing Explorer (RXTE). The evidence comes from a specific ...

Space & Earth / Astronomy

created Dec 15, 2011 | popularity 4.5 / 5 (11) | comments 27 | with audio podcast

Disaster looms for gas cloud falling into Milky Way's central black hole

The normally quiet neighborhood around the massive black hole at the center of our Milky Way Galaxy is being invaded by a gas cloud that is destined in just a few years to be ripped, shredded and largely eaten.

Space & Earth / Astronomy

created Dec 14, 2011 | popularity 4.9 / 5 (11) | comments 55 | with audio podcast

How supermassive black holes came into existence shortly after the Big Bang

(PhysOrg.com) -- Researchers at Carnegie Mellon University's Bruce and Astrid McWilliams Center for Cosmology have discovered what caused the rapid growth of early supermassive black holes — a steady ...

Space & Earth / Astronomy

created Dec 12, 2011 | popularity 4.8 / 5 (18) | comments 30 | with audio podcast

Black hole

In 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.
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