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| {{Expert-subject|Science|date=October 2008}}
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| In [[general relativity]], a '''naked singularity''' is a [[gravitational singularity]] without an [[event horizon]]. In a [[black hole]], the singularity is completely enclosed by a boundary known as the [[event horizon]], inside which the gravitational force of the singularity is strong enough so that light cannot escape. Hence, objects inside the event horizon—including the singularity itself—cannot be directly observed. A naked singularity, by contrast, is observable from the outside.
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| The theoretical existence of naked singularities is important because their existence would mean that it would be possible to observe the collapse of an object to ''infinite density''. It would also cause foundational problems for general relativity, because general relativity cannot make predictions about the future evolution of [[space-time]] near a singularity. In generic black holes, this is not a problem, as an outside viewer cannot observe the space-time within the event horizon.
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| Some research has suggested that if [[loop quantum gravity]] is correct, then naked singularities could exist in nature,<ref>M. Bojowald, Living Rev. Rel. 8, (2005), 11 (http://relativity.livingreviews.org/Articles/lrr-2008-4/)</ref><ref>R. Goswami & P. Joshi, Phys. Rev. D, (2008) (http://arxiv.org/abs/gr-qc/0608136)</ref><ref>R. Goswami, P. Joshi, & P. Singh, Phys. Rev. Letters, (2006), 96 (http://arxiv.org/abs/gr-qc/0506129)</ref> implying that the [[cosmic censorship hypothesis]] does not hold. Numerical calculations<ref>D. Eardley & L. Smarr, Phys. Rev. D., (1979), 19, (http://prola.aps.org/abstract/PRD/v19/i8/p2239_1)</ref> and some other arguments<ref>A. Krolak, Prog. Theor. Phys. Supp., (1999) 136, 45, (http://ptp.ipap.jp/link?PTPS/136/45/)</ref> have also hinted at this possibility.
| | Marketing locally for smaller businesses is the best approach to help others while developing your own online business. I first did this in 2006 each time a relative was having problem getting his handyman business up and running. I'd merely been online for about six months at the time, and I observe for about two months as he invested hundreds of dollars for a little ad inside the local paper, and went doortodoor in the heat of the summer, leaving his homemade flyers on people's doorsteps.<br><br>Sporting a great deal of make-up and fitted in the most beautiful clothes and jewelry, 1000s of teen-age Gypsy women in Roma were associated with their parents to arrive at an open-air bride marketplace to be able to search for Mr. Right who is prepared to spend a lot of money for his future spouse. As the purchase of items, a young bride's worth up-to thousands of pounds.<br><br>If you are at a computer and need to discover some exciting issues on the Internet to entertain you, the list of many engaging sites may oftimes be helpful to you. Web sites keep you not just in a couple of minutes but perhaps hours and all-day.<br><br><br><br>The methods are very similar as [http://hmccap.com/wp-content/uploads/team/managing/juan-pablo-schiappacasse_esp.html jaun pablo schiappacasse canepa]. Nevertheless, there are some variations that you have to know to be successful. This program provided below will coach you on making the required changes from on-line to mobile marketing in the desired markets of the decision. Market strategies for cellular areas are not hard, but minus the right knowledge, you might waste some funds understanding them.<br><br>Set up an everyday option, a thing that are certain to get visitors to buy without thinking. Everyone loves a deal and most of the time they are willing to take on others to have it. Why you think ebay does so effectively, people are being helped by them to prove their value infront of others. People enjoy profitable specials.<br><br>When someone buys a product from your own link then you'll obtain a part of the price tag. If the affiliate program pays out a 50% commission and the item sells for $100.00 your slice is likely to be $50.00 The lovely thing about affiliate marketing is that it's all performed online consequently you do not have to do any one on one selling or usually no selling at all. All you need to do, usually, is just add interested individuals to the item. And it-all happens online. It's an ideal place to start, Because you can advertise online usually for free or very inexpensively. You'll be able to begin slowly, in your spare-time and as you figure out how to earn online your company may increase to other online tasks. It might become a way to obtain passive income.<br><br>Search Engine Optimization (SEO) has become a critical part of internet marketing. If customers want to find something on the web, bulk use Google, Bing, or Yahoo to find it. Therefore, you need to ensure you're among the top sites on the search results. SEO can help develop higher website rankings through social networking, report submission, link constructing, etc. If this isn't a location where you're feeling particularly comfortable, this can also be a good activity to outsource. |
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| To this date, no naked singularities (and no event horizons) have been observed.
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| ==Predicted formation==
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| From concepts drawn of [[rotating black hole]]s, it is shown that a singularity, spinning rapidly, can become a ring-shaped object. This results in two event horizons, as well as an [[ergosphere]], which draw closer together as the spin of the singularity increases. When the outer and inner event horizons merge, they shrink toward the rotating singularity and eventually expose it to the rest of the universe.
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| A singularity rotating fast enough might be created by the collapse of dust or by a supernova of a fast-spinning star. Studies of [[pulsar]]s{{Citation needed|date=April 2007}} and some computer simulations (Choptuik, 1997) have been performed.
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| This is an example of a mathematical difficulty (divergence to infinity of the density) which reveals a more profound problem in our understanding of the relevant physics involved in the process. A workable theory of [[quantum gravity]] should be able to solve problems such as these.
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| This model also ignores the relativistic aspects of singularity formation. Such a process involves relativistic effects that cause an asymptotic slowing of time compared to the universe at large. To ''see'' a singularity or event horizon ''form'' a collapsing mass would have to be observed for far longer than the longest conceivable life-span for a universe like ours. Spinning the collapsing mass in an attempt to create a ''naked singularity'' does nothing to get around the relativistic time-dilation observed by the universe that we inhabit. Simply put, while mathematically possible, {{According to whom|there are not now, and never can be, actual event horizons or singularities in any part of the observable universe|date=January 2014}}.
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| ==Metrics==
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| Disappearing event horizons exist in the [[Kerr metric]], which is a spinning black hole in a vacuum. Specifically, if the [[angular momentum]] is high enough the event horizons will disappear. Transforming the Kerr metric to [[Boyer-Lindquist coordinates]], it can be shown<ref>Hobson, et. al, General Relativity an Introduction for Physicists, Cambridge University Press 2007, p. 300-305</ref> that the <math>r</math> coordinate (which is not the radius) of the event horizon is
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| <math>r_{\pm}= \mu \pm (\mu^{2}-a^{2})^{1/2}</math>,
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| where <math>\mu = G M / c^{2}</math>, and <math>a=J/M c</math>. In this case, "event horizons disappear" means when the solutions are complex for <math>r_{\pm}</math>, or <math>\mu^{2} < a^{2}</math>.
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| Disappearing event horizons can also be seen with the [[Reissner–Nordström metric|Reissner-Nordström]] geometry of a charged black hole. In this metric it can be shown<ref>Hobson, et. al, General Relativity an Introduction for Physicists, Cambridge University Press 2007, p. 320-325</ref> that the singularities occur at
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| <math>r_{\pm}= \mu \pm (\mu^{2}-q^{2})^{1/2}</math>,
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| where <math>\mu = G M / c^{2}</math>, and <math>q = G Q^{2}/(4 \pi \epsilon_{0} c^{4})</math>. Of the three possible cases for the relative values of <math>\mu</math> and <math>q</math>, the case where <math>\mu^{2} < q^{2}</math> causes both <math>r_{\pm}</math> to be complex. This means the metric is regular for all positive values of <math>r</math>, or in other words the singularity has no event horizon.
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| See [[Kerr-Newman metric]] for a spinning, charged ring singularity.
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| ==Effects==
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| A naked singularity could allow scientists to observe an infinitely dense material, which would under normal circumstances be impossible by the cosmic censorship hypothesis. Without an event horizon of any kind, some speculate that naked singularities could actually emit light.<ref>{{cite news |url=http://space.newscientist.com/article/dn12707-is-a-naked-singularity-lurking-in-our-galaxy.html |author=Stephen Battersby |title=Is a 'naked singularity' lurking in our galaxy? |date=1 October 2007 |accessdate=2008-03-06 |publisher=[[New Scientist]]}}</ref>
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| ==Cosmic censorship hypothesis==
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| The [[cosmic censorship hypothesis]] says that a naked singularity cannot arise in our universe from realistic initial conditions.
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| ==In fiction==
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| *[[M. John Harrison]]'s [[Kefahuchi Tract]] trilogy of [[science fiction]] novels ([[Light (novel)|Light]], [[Nova Swing]] and [[Empty Space]]) centre upon humanity's exploration of a naked singularity.
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| *"Dark Peril" by [[James C. Glass]] (published in [[Analog Science Fiction and Fact|Analog]] March, 2005), is a story about space travelers on an exploratory mission. While they investigate a strange cosmological phenomenon, their two small space crafts begin to shake, and they are unable to leave the area. One crew member realizes that they are trapped in the [[Ergosphere]] of a [[black hole]] or [[naked singularity]]. The story describes a cluster of multiple black holes or singularities, and what the crew does to try to survive this seemingly inescapable situation.
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| ==See also==
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| *[[Black hole electron]]
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| *[[List of astronomical topics]]
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| *[[List of physics topics]]
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| ==References==
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| {{Reflist}}
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| ==External links==
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| *[http://xstructure.inr.ac.ru/x-bin/theme3.py?level=1&index1=203038 Naked singularity] on [[arXiv]]
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| *M. C. Werner and A. O. Peters, [http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRVDAQ000076000006064024000001&idtype=cvips&gifs=yes "Magnification relations for Kerr lensing and testing cosmic censorship"], ''Physical Review D'', Vol. 76, Issue 6 (2007).
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| *Pankaj S. Joshi, [http://www.sciam.com/article.cfm?id=naked-singularities "Do Naked Singularities Break the Rules of Physics?"], ''Scientific American'', January 2009.
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| *Marcus Chown, [http://www.newscientist.com/article/mg20327204.700-fastspinning-black-holes-might-reveal-all.html "Fast-spinning black holes might reveal all"] ''New Scientist'', August 2009.
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| {{Black holes}}
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| {{DEFAULTSORT:Naked Singularity}}
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| [[Category:Black holes]]
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Marketing locally for smaller businesses is the best approach to help others while developing your own online business. I first did this in 2006 each time a relative was having problem getting his handyman business up and running. I'd merely been online for about six months at the time, and I observe for about two months as he invested hundreds of dollars for a little ad inside the local paper, and went doortodoor in the heat of the summer, leaving his homemade flyers on people's doorsteps.
Sporting a great deal of make-up and fitted in the most beautiful clothes and jewelry, 1000s of teen-age Gypsy women in Roma were associated with their parents to arrive at an open-air bride marketplace to be able to search for Mr. Right who is prepared to spend a lot of money for his future spouse. As the purchase of items, a young bride's worth up-to thousands of pounds.
If you are at a computer and need to discover some exciting issues on the Internet to entertain you, the list of many engaging sites may oftimes be helpful to you. Web sites keep you not just in a couple of minutes but perhaps hours and all-day.
The methods are very similar as jaun pablo schiappacasse canepa. Nevertheless, there are some variations that you have to know to be successful. This program provided below will coach you on making the required changes from on-line to mobile marketing in the desired markets of the decision. Market strategies for cellular areas are not hard, but minus the right knowledge, you might waste some funds understanding them.
Set up an everyday option, a thing that are certain to get visitors to buy without thinking. Everyone loves a deal and most of the time they are willing to take on others to have it. Why you think ebay does so effectively, people are being helped by them to prove their value infront of others. People enjoy profitable specials.
When someone buys a product from your own link then you'll obtain a part of the price tag. If the affiliate program pays out a 50% commission and the item sells for $100.00 your slice is likely to be $50.00 The lovely thing about affiliate marketing is that it's all performed online consequently you do not have to do any one on one selling or usually no selling at all. All you need to do, usually, is just add interested individuals to the item. And it-all happens online. It's an ideal place to start, Because you can advertise online usually for free or very inexpensively. You'll be able to begin slowly, in your spare-time and as you figure out how to earn online your company may increase to other online tasks. It might become a way to obtain passive income.
Search Engine Optimization (SEO) has become a critical part of internet marketing. If customers want to find something on the web, bulk use Google, Bing, or Yahoo to find it. Therefore, you need to ensure you're among the top sites on the search results. SEO can help develop higher website rankings through social networking, report submission, link constructing, etc. If this isn't a location where you're feeling particularly comfortable, this can also be a good activity to outsource.