tagged w/ Black Holes
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The closest look at the gaping maw of the giant black hole that sits at the heart of our own galaxy has been taken by astronomers.
Because this remarkable object is so distant - it takes light from around the hole 25,000 years to reach Earth - they had to make among the highest resolution measurement ever achieved to reveal what, in cosmic terms, is a very small structure.
By combining telescopes in Hawaii, Arizona, and California, astronomers could make out the tiny angular scale of 37 micro-arcseconds - the equivalent of a baseball seen on the surface of the moon, that is, 240,000 miles away - to probe how the laws of physics behave in these extraordinary conditions.
The cores of most large galaxies are thought to harbour supermassive black holes - formed from the coalescence of smaller black holes, or by the accretion of stars and gas. That includes our own galaxy, the Milky Way.
**CONTINUES**The closest look at the gaping maw of the giant black hole that sits at the heart of... more
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An experiment to find out the secrets of the big bang could create a blackhole and destroy the Earth, claim sciencists.
By smashing sub-atomic particles together at speeds close to the speed of light, the LHC aims to recreate the conditions that existed a fraction of a second after the Big Bang.
But critics claim that the 'time machine' could instead spawn a shower of mini-black holes, which could grow exponentialy and swallow the Earth.An experiment to find out the secrets of the big bang could create a blackhole and... more
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Astronomers have shed light on how stars can form around a massive black hole, defying conventional wisdom.
Scientists have long wondered how stars develop in such extreme conditions.
Molecular clouds - the normal birth places of stars - would be ripped apart by the immense gravity, a team explains in Science magazine.
But the researchers say stars can form from elliptical discs - the relics of giant gas clouds torn apart by encounters with black holes.
They made the discovery after developing computer simulations of giant gas clouds being sucked into black holes like water spiralling down a plughole.
"These simulations show that young stars can form in the neighbourhood of supermassive black holes as long as there is a reasonable supply of massive clouds of gas from further out in the galaxy," said co-author Ian Bonnell from St Andrews University, UK.
More Information : http://sciencenow.sciencemag.org/cgi/content/full/2008/822/2
http://www.stfc.ac.uk/PMC/PRel/STFC/YoungStars.aspx
Astronomers have shed light on how stars can form around a massive black hole, defying... more
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From the report: Black holes, with their overwhelming gravitational pulls, generally aren't considered good neighbors for the types of dusty gas clouds where new stars are born.
But sometimes stellar nurseries can escape the maws of supermassive black holes and spawn abnormally large stars on eccentric orbits, a new model suggests.
The stars would be so massive that they'd die relatively young, burning out before the black hole had time to crush them with its gravity.
The finding could help explain why two unexpected groups of young stars, called disk stars, exist near the supermassive black hole at the center of our Milky Way galaxy.
One population contains stars that are just six million years old, and the other has stars that are even younger. (See an updated map of the Milky Way released in June.)
"The high tidal shear from the black hole should tear apart the molecular clouds that form stars," wrote the Scotland-based study authors Ian Bonnell from the University of St. Andrews in Fife and Ken Rice from the University of Edinburgh.
The computer simulations show that when a starmaking cloud approaches a large black hole like the one at our galaxy's heart, the tidal shear can cause the type of celestial commotion that's needed to make new stars. The oversize newborns then circle the black hole on the same bizarre, oblong orbit as their parent gas cloud.
The findings, reported in today's issue of the journal Science, could yield insight into the life cycles of black holes.
"Hopefully, by studying these things, we'll get a better insight into how black holes grow and form," Bonnell said. From the report: Black holes, with their overwhelming gravitational pulls, generally... more
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"For black holes, there appears to be very little room for mediocrity, astronomers have found.
A study suggests they come in either small or large sizes, but medium-sized ones are very rare or non-existent.
A team of astronomers has examined one of the best hiding places for a middleweight black hole, and found that it cannot possibly host one.
Details of the research are to be published in the latest issue of the Astrophysical Journal.
If a medium black hole existed in a cluster, it would either swallow little black holes or kick them out of the cluster
Daniel Stern, JPL
Black holes are incredibly dense points of matter, whose gravity prevents even light from escaping.
The least massive black holes known are about 10 times the mass of our Sun and form when colossal stars explode as supernovas.
The heftiest black holes are billions of times the mass of the Sun and lie deep in the bellies of almost all galaxies.
That leaves black holes of intermediate mass, which were thought to be buried at the cores of globular clusters.
Globular clusters are dense collections of millions of stars, which reside within galaxies containing hundreds of billions of stars.
Theorists argue that these clusters should have a scaled-down version of a galactic black hole. Such objects would be about 1,000 to 10,000 times the mass of the Sun - medium-sized as far as black holes are concerned.
Now, a team of astronomers led by Stephen Zepf of Michigan State University, East Lansing, has carried out a detailed examination of a globular cluster called RZ2109.
The researchers' work led them to the conclusion that it could not possess a medium-sized black hole.
"Some theories say that small black holes in globular clusters should sink down to the centre and form a medium-sized one, but our discovery suggests this isn't true," said co-author Daniel Stern of Nasa's Jet Propulsion Laboratory in Pasadena, California."
More at link!"For black holes, there appears to be very little room for mediocrity,... more
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Should we avoid terms which use 'black' and 'white' as descriptions? Or does behaviour like this just give political correctness a bad name?Should we avoid terms which use 'black' and 'white' as... more
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I have no idea if this is about as scientifically accurate as, say, an anatomy model of a bird based on Donald Duck.
The creator of this video has allegedly claimed it was in fact designed to illustrate what happens when scientists try to crack a joke, but again I cannot verify the accuracy of this.I have no idea if this is about as scientifically accurate as, say, an anatomy model... more
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Well, if we're all going to die, at least we'll be killed by something INSANELY COOL! Look at this thing. It's every Sci-Fi fiction writer's wet dream.Well, if we're all going to die, at least we'll be killed by something... more
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The GRID and the largest and most expensive particle accelerator ever:
"The Times online reported recently that a data communications grid built to transfer data from the world's largest particle accelerator may be able to function as an alternate Internet, with speeds about 10,000 times faster than an average broadband connection. This network - referred to in the article simply as “the grid” - was built with modern fiber optic technology and currently has 55,000 servers connecting the CERN laboratory in Geneva, Switzerland with eleven locations internationally. The grid was built to house the data coming from CERN's newest project: the world's largest particle accelerator. The Large Hadron Collider (LHC) is designed to study the inner workings of matter and perhaps even discover the elusive Higgs Boson particle. Internet history buffs may recall that Sir Tim Berners-Lee invented the World Wide Web in 1989 while researching at CERN."
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Concerning adverse reactions:
"One of their concerns is that the mini-black holes generated by this machine could eventually coalesce into a larger black hole that would then begin absorbing matter. Another possibility is that new combinations of quarks could come into existence, creating a stable, negatively-charged strangelet which could turn everything it touches into strangelets as well – plunging us into a parallel universe of stable, negatively-charged strangelets. Yet another theory is that high-energy collisions in the LHC could result in massive particles that only have one magnetic pole, rather than the typical north-south pole magnetism with which we are familiar. Critics worry that such particles could start a huge chain reaction, converting atoms into different forms of matter."
The GRID and the largest and most expensive particle accelerator ever:
"The... more
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Scientists say they have unlocked some of the secrets behind black holes, the gravitational fields known for sucking up light and stars from the Universe. In a report in the journal Nature, US researchers say they have worked out how black holes emit jet streams of particles at close to light speed. The University of Boston team say the streams originate in the magnetic field near the edge of the black hole. They say it is within this region that the jets are accelerated and focused.
Despite the fact that it is probable that a black hole lurks at the centre of our Milky Way galaxy, astronomers still know very little about these celestial monsters which vacuum up almost everything in their path, even light. Professor Alan Marscher of the University of Boston and his colleagues claim they have delved deeper than ever into their heart.
Using almost every type of telescope known to humankind, Prof Marscher believes he has worked out where and how the jets - or blazars - are formed. Using an array of 10 powerful radio telescopes, aimed at the galaxy BL Lacertae, the researchers studied a black hole just as it was sending forth a blazar jet.Scientists say they have unlocked some of the secrets behind black holes, the... more
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Apparently researchers have discovered what they are dubbing internet black holes. Areas of the internet where data disappears not attributed to server issues or problems with the end user. They have yet to discover where the data goes or what causes this new phenomenon.
My take. Bosses and teachers will be hearing a lot of this. "I swear I sent you that report, but the black hole ate it". Apparently researchers have discovered what they are dubbing internet black holes.... more
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Scientists say they've found the smallest black hole so far, which is less than four times the mass of our sun and about the size of a large city. But the mini-black hole, dubbed J1650, could still stretch a person into a 'strand of spaghetti' with its pull, the researchers told a meeting in Los Angeles.Scientists say they've found the smallest black hole so far, which is less than... more
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An artificial black hole has been simulated in a laboratory by scientists using lasers at St Andrews University.
Intense light pulses were used to create an artificial event horizon - the defining feature of a black hole known as the "point of no return".An artificial black hole has been simulated in a laboratory by scientists using lasers... more
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Antimatter, which annihilates matter upon contact, seems to be rare in the universe. Still, for decades, scientists had clues that a vast cloud of antimatter lurked in space, but they did not know where it came from.
The mysterious source of this antimatter has now been discovered ? stars getting ripped apart by neutron stars and black holes.
While antimatter propulsion systems are so far the stuff of science fiction, antimatter is very real.Antimatter, which annihilates matter upon contact, seems to be rare in the universe.... more
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"The monster celestial object is 18 billion times more massive than our own Sun, says a team from Finland - six times larger than the previous record.
"The object, called OJ287, is orbited by a smaller black hole, which allowed its mass to be measured very accurately.
"The finding also enabled the researchers to test Einstein's theory of gravity for the first time in a strong gravitational field."
More at link."The monster celestial object is 18 billion times more massive than our own Sun,... more
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It seems a black hole is pummeling a small, nearby star cluster with a jet of highly charged radiation.It seems a black hole is pummeling a small, nearby star cluster with a jet of highly... more
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"We've seen many jets produced by black holes, but this is the first time we've seen one punch into another galaxy like we're seeing here."
Upon finding a galaxy that was victim of bullying, the nerds instantly invited it to sit at their lunch table and offered it some pretzels. "We've seen many jets produced by black holes, but this is the first time... more
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So there's this galaxy, about a billion and a half light-years away from us.
And at its center is a black hole. And that black hole is spewing out a beam of energy a million light-years long.
Which is hitting another galaxy like an intergalactic punch to the face!
Holy jeez I am glad we live in a quiet corner of space.So there's this galaxy, about a billion and a half light-years away from us.... more
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sloan
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added this
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4 years ago
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Apparently, every galaxy has a black hole in its center. The largest black holes emit powerful jets of gamma rays and X-rays from their center, so powerful that they can wreak havoc in a hapless smaller galaxy that wander into them. Apparently, every galaxy has a black hole in its center. The largest black holes emit... more
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There is a dichotomy in that article - if nothing, not even light, can escape from a black hole, then no Cosmic Rays could emanate from them either, but they do. Which brings me to ask if those cosmic rays are the hyper-subliminated material of all that the black hole ingests which is spewed out in the form of cosmic ray? There is a dichotomy in that article - if nothing, not even light, can escape from a... more
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