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Topic: Naked singularity


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In the News (Mon 20 Nov 17)

  
  New York Times story on naked singularity bet
Singularities are believed to lurk at the hearts of fl holes, which conceal their existence from the outer world.
A naked singularity would be a singularity bereft of a concealing fl-hole shell, and therefore visible, in principle, to outside observers.
Singularities within fl holes are deduced from relativity theory as the result of the gravitational collapse of degenerate stars 1.6 times the mass of the sun or greater.
www.theory.caltech.edu /people/preskill/nyt_bet_story.html   (982 words)

  
 Naked singularity - Wikipedia, the free encyclopedia
In general relativity, a naked singularity is a gravitational singularity without an event horizon.
A naked singularity, by contrast, is a point in space where the density is infinite and which is observable from the outside.
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.
en.wikipedia.org /wiki/Naked_singularity   (567 words)

  
 2.1 Naked singularities and the hoop conjecture
Although a definitive identification of a naked singularity requires the event horizon (EH) to be proven to be absent, to identify an EH requires knowledge of the entire spacetime.
Wald believes, however, that it is likely that the ST slicing is such that their singularities are not naked - a trapped surface is present but has not yet appeared in their time slices [244].
Motivated by ST's results [230], Echeverria [96] numerically studied the properties of the naked singularity that is known to form in the collapse of an infinite, cylindrical dust shell [239].
relativity.livingreviews.org /Articles/lrr-2002-1/node3.html   (1520 words)

  
 Simplicity and Why the Universe Exists
A singularity is a place where the classical concepts of space and time break down as do all the known laws of physics because they are all formulated on a classical space-time background.
The lawlessness of the singularity entails that it 'would thus emit all [possible] configurations of particles with equal probability'[2].
Indeed, the singularity and the symmetry-breaking stages occurring shortly after the big bang, where the particles and forces acquired their specific masses and strengths, had an extremely low probability of occurring in a way that leads to an animate universe.
www.infidels.org /library/modern/quentin_smith/simplicity.html   (2868 words)

  
 singularity
Singularities may be points, one-dimensional lines, or even two-dimensional sheets.
The general theory of relativity predicts that singularities form inside fl holes but are concealed from the rest of the universe behind event horizons.
A proper formulation of quantum gravity may well avoid the infinities associated with classical singularities.
www.daviddarling.info /encyclopedia/S/singularity.html   (156 words)

  
 4.5 Critical phenomena and naked singularities   (Site not responding. Last check: 2007-10-04)
In summary, the critical spacetimes that arise asymptotically in the fine-tuning of gravitational collapse to the fl hole threshold have a curvature singularity that is visible at infinity with a finite redshift.
In any case, the singularity is naked and the critical solutions therefore provide counter-examples to any formulation of cosmic censorship which states only that naked singularities cannot arise from smooth initial data in reasonable matter models.
Therefore, the set of naked singularity data is at least codimension two in the space of data of bounded variation, and of codimension at least one in the space of absolutely continuous data.
www.univie.ac.at /EMIS/journals/LRG/Articles/lrr-1999-4/node17.html   (1704 words)

  
 cosmic.html
A singularity occurs when the quantities in a theory "blow up" or become infinite and therefore is a sign that the theory doesn't work.
But if the singularity is always hidden (rather than being "naked" and therefore observable), then what's going on at the singularity need not be accommodated by general relativity theory.
It is the challenge to that theory posed by the possibility of naked singularities that interests general relativity theorists such as Hawking and Christodoulou.
www.princeton.edu /pr/pwb/97/0414/0414-cosmic.html   (696 words)

  
 Betting on the Cosmos
First, Browne's definition of the terms: A singularity is a mathematical point at which space and time are infinitely distorted, where matter is infinitely dense, and where the rules of relativistic physics and quantum mechanics break down.
A naked singularity would be a singularity without a fl-hole shell, and therefore visible, in principle, to outside observers.
A naked singularity is such an object outside a fl hole, but Hawking believes it can exist only inside a fl hole.
www.sacred-texts.com /ufo/betcosmo.htm   (639 words)

  
 Cosmic censorship hypothesis - Wikipedia, the free encyclopedia
Singularities that arise in the solutions of Einstein's equations are typically hidden within event horizons, and therefore cannot be seen from the rest of spacetime.
The fundamental concern is that since the physical behavior of singularities is unknown, if singularities can be seen from the rest of spacetime, causality may break down, and physics may lose its predictive power.
Still, in the absence of naked singularities, the universe is deterministic — it's possible to predict the entire evolution of the universe, knowing only its condition at a certain moment of time (more precisely, everywhere on a spacelike 3-dimensional hypersurface, called the Cauchy surface).
en.wikipedia.org /wiki/Cosmic_censorship_hypothesis   (738 words)

  
 Google Answers: Kerr singularity calculations
But actually a Kerr singularity has two event horizons, an inner event horizon which can't be crossed without falling into the singularity and an outer event horizon encompassing a larger volume of spacetime.
It's my understanding that the inner event horizon of a Kerr singularity has more or less the characteristics of the inner event horizon of a nonspinning singularity, in that passing it is a one-way ticket into the singularity.
The geometries of the two may differ because the Kerr singularity has an inner event horizon that is toroidal, but I assume that when we are discussing the radius of the Kerr singularity's inner event horizon, we are talking about a measurement perpendicular to the axis of rotation.
google.com /answers/threadview?id=353813   (4082 words)

  
 Paradoxes Resolved, Origins Illuminated - A new possibility
The Einstein+Friedmann math and “M” Theory math clearly shows that a singularity should exist (and it does) and once you understand that the infinity is not the universe or infinite density, it un-constrains the possibilities for what a singularity might be, and you can look at other possible candidates.
The assumption that S=U…that the Friedmann naked singularity made the Whole universe…made the Dark Matter and the Dark Energy is the major reason that very little progress has been made in figuring them out.
About cosmic censorship and the event horizons when he said naked singularities could not be seen, plus gamma rays can’t be seen in visible light, so he has 2 outs If he wants to use them, but we doubt he will.
www.metaresearch.org /msgboard/topic.asp?TOPIC_ID=743   (3215 words)

  
 Spacetime Wrinkles Glossary
Because the singularity is "clothed" by the event horizon it cannot affect the exterior spacetime and we do not need to worry about the presence of the singularity.
The physical consequences of "naked" singularities are hotly debated among physicists.
Surely the presence of naked singularities arising occasionally in collapse under much more "controlled" circumstances would be the very reverse of a disaster.
archive.ncsa.uiuc.edu /Cyberia/NumRel/glossary.html   (3694 words)

  
 Schwarzschild singularity Comparison Table   (Site not responding. Last check: 2007-10-04)
This singularity is sometimes said to mark the beginning of time, but it is more realistic to recognize that an extrapolation to infinite density cannot be trusted.
According to Einstein's theory of general relativity, the entire mass of a fl hole is concentrated at a point at its center, the "singularity".
It is believed that quantum mechanical effects, not included in the theory, would cause the mass to spread out over a tiny but nonzero region, thus preventing an infinite density of matter and doing away with the singularity.
www.site.uottawa.ca:4321 /astronomy/Schwarzschildsingularity_table.html   (160 words)

  
 Cosmic Censorship   (Site not responding. Last check: 2007-10-04)
This possibility seems remote, however, and furthermore, no general theory of naked singularities exists at present, and no reliable ``fingerprints" of a naked singularity are known.
There is one seemingly naked singularity obvious to everyone, the initial singularity of the Big Bang.
This singularity is not really a counterexample to the conjectures, because it did not form from regular initial conditions --- and could not have done so according to the singularity theorems of general relativity theory.
www.itp.ucsb.edu /~doug/abs/cosmiccen.html   (547 words)

  
 Naked Singularity   (Site not responding. Last check: 2007-10-04)
Jack jogged to meet up with Sam as she slowed to a stop in the corridor outside her lab.
"Hey, is there such a thing as a naked singularity?" he asked with that boyish grin as if he couldn't believe such a term existed.
Her best defense was her ability to confuse him with word so she continued on "…a singularity is a mathematical point at which space and time are infinitely distorted, where matter is infinitely dense, and where the rules of relativistic physics and quantum mechanics break down…."
www.geocities.com /samcarterkicksass/naked.html   (357 words)

  
 1 Introduction   (Site not responding. Last check: 2007-10-04)
The extent to which this ``hidden'' singularity is generic and the types of singularities that appear in generic spacetimes remain major open questions in general relativity.
In the initial study, the critical (Choptuik) solution is a zero mass naked singularity (visible from null infinity).
It is a counterexample to the cosmic censorship conjecture [135
www.univie.ac.at /EMIS/journals/LRG/Articles/lrr-2002-1/node1.html   (1218 words)

  
 2.1 Naked Singularities and the Hoop Conjecture
The existence of a naked singularity is inferred from the absence of an apparent horizon (AH) which can be identified locally by following null geodesics.
Wald believes, however, that it is likely that the ST slicing is such that their singularities are not naked--the AH is present but has not yet appeared in their time slices [178].
Motivated by ST's results [169], Echeverria [70] numerically studied the properties of the naked singularity that is known to form in the collapse of an infinite, cylindrical dust shell [175].
relativity.livingreviews.org /Articles/lrr-1998-7/node3.html   (1041 words)

  
 Naked singularity
Einstein said when he was confronted with the notion of a singularity existing within a fl hole that, should a singularity exist it would twist all of spacetime up within itself and therefore it could'nt be true that singularities existed within fl holes.
Einstein was right, singularities don't "exist" within fl holes- instead a singularity is the consequence of a fl hole and is "reached" through the fl hole as part of the eventual collapse of the space-time structure of our universe.
The singularity will only "exist" at the end of time- in fact beyond time itself, as the singularity which generated the Big Bang existed before time began.
www.physicsforums.com /showthread.php?t=67789   (742 words)

  
 Physics News Update Number 308 - NAKED SINGULARITIES COULD EXIST   (Site not responding. Last check: 2007-10-04)
In cosmological terms, a singularity is a place of incalculably large---essentially infinite---mass density.
Singularities are supposed to reside inside fl holes but could never be observed because light is forever bottled up within the fl hole's event horizon.
Although he doubts whether a naked singularity could ever actually form, Hawking has now paid up on his bet.
www.aip.org /enews/physnews/1997/split/pnu308-4.htm   (110 words)

  
 New Page 2
Theoretical physicists believe the naked singularity is the solution of Einstein's relativity equation for gravity where a area of space time curvature is reached.
There is no event horizon to hide this singularity so it is there for naked.
A man named Steven Hawking believes that the naked singularity is not possible do to a supposed 'Cosmic Censorship' principle.
www.mrfizzix.com /blackhole/naked.htm   (67 words)

  
 Formation of a Black Hole   (Site not responding. Last check: 2007-10-04)
The space-time diagram at right shows matter in blue collapsing to form a singularity [the solid fl line], while the green curves are the future lightcones from events where light can escape to infinity, while the red curves are future lightcones from events where light cannot escape.
Before the creation of the singularity a simple analytic form is used instead of the exact solution for a collapsing sphere of pressureless matter.
In particular, the radius of a fl hole can not be defined as the distance from the central singularity to the event horizon, because observers trying to measure this would inevitably fall into the singularity.
www.astro.ucla.edu /~wright/bh-st.html   (319 words)

  
 Naked Singularity
A "naked singularity," as we all know, is an infinitely dense point mass around which no fl hole can develop.
Naked Singularity is an officially recognized organization of
If you would like to make a financial contribution to this young and fast growing publication, we at Naked Singularity would be truly Grateful.
www.bc.edu /bc_org/svp/st_org/nsing/default2.html   (93 words)

  
 Re: What is a naked singularity...
This mathematically singular point is surrounded by a region where light can't escape.
While physicists would normally be worried about equations becoming singular, in this case we know that the Einstein equations need to be extended to include quantum-mechanical effects when studying the small region near this singular point, and the fact that this singular point is effectively shielded from the rest of the universe by the horizon.
For a long time is was assumed that any singularity that would develop in general relativity would be covered by a horizon.
www.madsci.org /posts/archives/1997-03/858880930.As.r.html   (325 words)

  
 Unsolved Problems in Physics and   (Site not responding. Last check: 2007-10-04)
For fl holes, the singularity is contained inside a region in which any timelike or lightlike particle will eventually fall into the singularity.
A singularity not contained inside an event horizon is called a 'naked singularity'.
The weak cosmic censor hypothesis states that there are no naked singularities, therefore, no observer outside of the event horizon can observe the singularity.
www.personal.psu.edu /users/j/m/jmp456/problem13.htm   (288 words)

  
 Paradox Lost
Otherwise you might be zapped by a naked singularity or go back in time and kill your own grandmother.
This rings alarm bells, because lurking at the heart of a fl hole is a so-called singularity, a point with infinite density where space-time is infinitely curved.
It looks as if a space-time singularity might be momentarily exposed, a situation that Ford describes as "cosmic flashing".
members.fortunecity.com /templarser/paradox.html   (2845 words)

  
 Tom's Infinite Science Archive: Black Holes In Spacetime
At the singularity, at the center of a fl hole, it is no longer meaningful to speak of space and time, for at the singularity, space and time cease to exist as we know them.
But singularities are places of infinite density, where the laws of physics break down and anything is possible.
But he was so shocked by the idea of a naked singularity that he proposed a "cosmic censor" who would ensure that singularities are decently clothed with an event horizon.
www.angelfire.com /vt/VortexTom/Infinite.Black.Hole.html   (5354 words)

  
 Universal Theory - where is singularity   (Site not responding. Last check: 2007-10-04)
One can also argue that, singularity is a point, because we are not comparing it with anything of its kind, in its domain.
So the singularity would be benign for us because exposure to energy contained in it, is very brief.
By assuming the benign naked singularity as media accommodating core fabric of universe, many paradoxes in physics will obtain a deterministic explanation.
www.universaltheory.org /where_is_singularity.htm   (3228 words)

  
 Quantum gravity for real (February 2006) - News - PhysicsWeb   (Site not responding. Last check: 2007-10-04)
Naked singularities are one of the most exotic predictions of Einstein's theory of relativity.
The singularities are called naked because they could, in principle, be seen by astronomers.
By applying the techniques of loop quantum gravity -- a leading candidate for a quantum theory of gravity -- Joshi and co-workers calculated that a dying star does not form a naked singularity but has all its mass thrown away in a flash instead.
physicsweb.org /articles/news/10/2/2/1   (539 words)

  
 a naked singularity lies within the Sea of Dirac
As i was watching the anime Neon Genesis Evangelion, where one of the alien characters had the ability to capture its opponents in a Sea of Dirac, which was claimed to stretch over 800 meters in diameter, but had a thickness of only 3 nanometers, an idea sprung in my head.
This might be what you're looking for, might not, but there are no singularities in the theory (it's not even used anymore) and the sea of Dirac would be a lot bigger than they say it is.
Thank you but i fail to find anything in the link that refers to both Dirac and the naked singularity.
www.physicsforums.com /showthread.php?t=20993   (747 words)

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