Talk:Naked singularity/Archive 1

Archive 1

By Hawking's chair...

Question: Did Hawking really lose a bet on so-called "naked-singularities" or rather on the question whether or not information that went into the singularity, that is beyond event horizon of the black-hole, eventually does come out again?

Both; see John Preskill's page on the topic. Piquan 23:04, 10 October 2005 (UTC)

Electrical currents and naked singularities

The article currently states:

It has been suggested that by passing a considerable amount of electrical current through the singularity in a black hole will cause the event horizons to overlap, and thus cease to exist, forming a naked singularity. (This amount of current would entail something in the order of every atom in the Solar System having its electrons harnessed. This is, of course, totally impractical.)

However no references are presented to support this suggestion, and with no further explanation as to the mechanism I find this statement dubious at best.

As such, I'm removing the statement from the article. If an appropriate reference can be found, then I'm happy for it to be re-inserted.

--PJF ^(talk) 11:38, 5 May 2005 (UTC)

D.B.Esq?

Who is this D.B.Esq fellow, and why do I care what he thinks? Does his opinion have a reason to be in an encyclopedia? It looks like the sort of thing that should go here in talk (or on sci.physics), not in the article text. Piquan 23:04, 10 October 2005 (UTC)

Oh my god...

All of the article makes sense, but the last part is just stupid. Maybe an expert should improve it. Hello? Anyone? lol Freddie 02:26, 22 February 2006 (UTC)

Well, if it's true (and sourced, perhaps), I don't mind it. If things like that could REALLY happen, then by all means it can be included. However, I don't see how a proton could turn into an orange - as far as I know, all that proton can do is continue falling into the singularity, or something like that. Although conventional physics falls apart, wouldn't that mean oranges wouldn't be able to exist anyway, as they rely on conventional physics to, say, be orange-coloured and roundish, and have tasty juices? Meh, I dunno. -JC 06:00, 23 February 2006 (UTC)

The bit about an atom turning into an orange was added by Darth Xana. This is Xana's only edit to Wikipedia (and it took three tries to get it right). I suspect it's just nonsense. I'm not an expert, but it sounds like something out of bad sci-fi. Besides that, it appears to refer to singularities in general, and should therefore go under Gravitational singularity, not here. I'm going to remove it in accordance with Wikipedia:Verifiability. --Piquan 08:06, 24 February 2006 (UTC)

The last part is ridiculous. There are no set laws. There are only models which suit what happens in nature and we express these concepts through words and thought the occurrence of a naked singularity wouldn't "break" these models and cause the whole universe to go into chaos. That is absurd. 203.208.71.49 07:02, 14 November 2006 (UTC)

Bet/Merge

Am I missing something? The Thorne-Hawking-Preskill bet looks rather unrelated. Is is another bet.

Anyway, merging into the better article Cosmic censorship hypothesis seems to be the way to go.

Pjacobi 15:52, 4 November 2006 (UTC)

The Cosmic censorship hypothesis concerns naked singularities, but does not define them. The strong cosmic consorship hypothesis says that naked singularities could form, but does not and should not describe the result of such a formation, a job that should be reserved for this article on the narrower topic. Consequently, I think this article should maintain its individuality. I'll try to give this article some attention, possibly rig up my old astronomy books that I used to read, and strip this article of a stub rating. C3PO the Dragon Slayer 23:53, 4 November 2006 (UTC)

The merged article could also be under the title "Naked singularity". --Pjacobi 00:30, 5 November 2006 (UTC)

The cosmic censorship hypothesis is a related article, but is not exactly the same topic. The current state of the formerly mentioned article is of fair coverage of all aspects of the cosmic censorship hypothesis, including those facets that are more or less related to naked singularities. This article should pay more attention to the formation of such hypothetical objects, just to give an idea of what should be done. C3PO the Dragon Slayer 19:42, 5 November 2006 (UTC)

Factual accuracy

How exactly can a gravitational singularity exist without an event horizon? The statements under "effects" sound somewhat dubious. X [Mac Davis] (DESK|How's my driving?) 21:16, 14 November 2006 (UTC)

That's what naked singularities are all about. The problem is that there isn't a working theory of quantum gravity to amend this anomaly. Naked singularities, from what I understand from Wikipedia and other (more credible) sources, are the singularities of rotating black holes that are spinning so fast that the two event horizons merge and shrink inward all the way. I'm no astrophysicist, so I may be completely wrong, but then again, the leading scientists who make these calculations could be equally wrong. C3PO the Dragon Slayer 20:49, 18 November 2006 (UTC)

as far as I understand from kerr metric, the inner|outer horizon always surrounds singularity, the fact that outer|inner horizon touches inner|outer under some condition does not yet mean that two horizon will "merge and shrink" after that? 195.137.203.137

that's still me, 195.137.203.137; I've found naked singularity metric elsewhere on wikipedia but without anything explained about it; maybe someone will look into that? 91.124.55.187

___Note: The Wikipedia article dealing with the existence of an electrical "Cauchy" horizon as well as a gravitational "event" horizon, is that for a Reissner-Nordström black hole. The shrinkage of the radii is discussed there (and is related to the Cosmic censorship hypothesis which the above discussion assumes). The metric involved is not the Kerr metric, for that is restricted to a black hole with no charge. Rather, the metric is the Reissner-Nordström metric, for which the Kerr metric is a degenerate case.

Hawking radiation?

I'm no expert by any stretch of the imagination, but wouldn't Hawking radiation prevent the existence of a naked singularity? If, like the article suggests, a naked singularity could do such things as emit light and information, then what would prevent it from evaporating far faster than a conventional black hole?204.155.226.2 19:24, 30 November 2006 (UTC)

___ Note: The Wikipedia article on an Extremal black hole observes that "Such black holes are stable and emit no Hawking radiation".

the importance of the accuracy

In my opinion it doesn't really matter if it isn't true, the accuracy of the theory is being disputed by physicists. We should not be discussing the accuracy of the theory unless we are physicists, and if you are you need to do it some where else —The preceding unsigned comment was added by 71.163.61.119 (talk) 21:38, 5 May 2007 (UTC).

As long as we have a good source.--204.155.226.2 19:40, 29 May 2007 (UTC)

Since I added the metrics section with a reference, I'm removing the factual accuracy banner. I see no reason to keep it on the page for this theoretical model. I'm also removing the line where it says "many scientists..." with no reference Seanfife (talk) 18:07, 30 April 2010 (UTC)

Accuracy impossible in this case

Although this theory may seem like utter nonsense, there ARE some underlying mathematical equations that MIGHT conceivably produce a naked singularity. I'm no expert and I can't quote them, thus I won't be editing the article - but the accuracy arguments are hard to solidify either way. This is a fringe topic in a very poorly understood framework. It needs to be mentioned, but there's just no proof either way. Ladytetsu 17:53, 18 August 2007 (UTC)

___Note: See the above notes for reasonably accessible Wikipedia articles dealing with the supersymmetry and string theory implications of the singularities in question. This is not a fringe topic in at least one sense: the underlying theories are testable by observation.

However, it is true that the conditions around a naked singularity might exceed the region of validity of the metric which has been tested experimentally. For an example, the Earth is a rotating charged massive body, and an orbiting satellite can be shown to follow the corresponding relativistic mechanics (see Reissner-Nordström metric). The experimental test was first done for cesium clocks on a jet aircraft flying at approximately one Earth radius, in 1971 (Hafele & Keating); but the Earth's charge is so small, the rate of rotation so low, and the orbital radius so large, that the Reissner-Nordström metric becomes doubly degenerate and reduces to the familiar Schwarzschild metric.

This Wiki entry is nonsense

I'm happy to be identified. Hawking and Penrose proved to the satisfaction of anyone who can go through their math, which involves manifolds that not many have a good grip on, such as the new D-branes, that naked singularities cannot exist in General Relativity, that they are hidden by a membrane, now called the 'event horizon', no matter their M, J, or Q, the only possible parameters.

Confusion arises when one mixes up, as do almost all astrophysicists, what is seen at the 'frozen star' (the superior Russian name for black hole) and what can be seen by us. In 1975 when he could still talk I had a go-round with Hawking on his Hawking radiation. I maintained that as the passage of time asymptotically slows to zero as seen by us as the event horizon is forming, that we could never see Hawking radiation, and that no black holes could therefore evaporate as seen by us.

We had an interesting side conversation, disturbed by Jane, who didn't want him to be disturbed too much, on what a person falling into through the event horizon of a very massive black hole would see. I thought that the person would be destroyed by it, as it would be all the future of the Universe compressed to an instant burst of very high-frequency radiation. He averred that he had not thought about that. I don't know the answers to all these things, but left the party with a much reduced opinion of Mr. Hawking, but with my respect for what he had done intact.

He and I both rejected the idea of primordial black holes, as General Relativity was not valid at the time the so-called Big Bang occurred.

About his later personal life the less said the better. I can just say that Jane sits atop my pile of women that I respect. —Preceding unsigned comment added by Antivenin (talk • contribs) 09:11, 22 October 2008 (UTC)

Scientific American article on Naked Singularties Feb 09

FYI, the February 2009 issue of Scientific American has a cover story by Pankaj S. Joshi on page 36 devoted specifically to the possible existence of naked singularties. Some of the information from that article might be appropriate for inclusion here, as it explains the concept in more general, layman terms and offers examples of computer simulations and such of how such a singularity might come about. I'd recommend that someone more familiar with this article than myself take a look at the SciAm article and use it as a reference to include interesting bits or to help make the article a little more approachable to the general public. 63.95.36.13 (talk) 19:58, 30 January 2009 (UTC)

link to SciAm article --83.233.210.252 (talk) 01:03, 7 March 2009 (UTC)

Quantum Star

I've redirected "quantum star" to this page. Nan Yang (talk) 01:29, 10 February 2009 (UTC)

Singularity Thunderbolts

There is no discussion of unstable naked singularities. Casadio/Harms in 2002 'Can black holes and naked singularities be detected in particle colliders?' claims that unstable naked singuarities could be possible results of lhc collision. Despite serious possibility being granted to singularity thunderbolts from among the 77 or so papers on the subject, possible safety concerns of this seem not to be considered by any other than myself - a non physicists. It seems to me the symmetry thought to be required for naked singularities could well be not naturally occuring. However lhc proton proton collisions seem to me to satisfy the same basic criteria of symmetry. Far fetched equal radial spherical dust cloud collapse is not required to be homogenous. Lhc collisions aren't homogenous either.

Would the argument that relevant single particle collision occur naturally - so that we wouldn't be here if singularity thunderbolts are possible - necessarily hold up? Is this argument dissmissable simply on grounds of it seeming too far fetched?

The chances of proton proton or electron electron collision of the same sort as of lhc and at sufficient energy >1TeV seem not to be necessarrily likely. Inflationary Big bang models allow for such proton proton collision but models of evolution of the universe are open to continued debate. Inflationary models do not address the extent that there is anisotropy in the cosmic microwave background radiation, and involve expansion of the universe at faster than the speed of light. —Preceding unsigned comment added by 82.69.31.176 (talk) 14:04, 11 April 2009 (UTC)

Newton's gravitational equations and naked singularities

Any first year physics student learns the equation F=GMm/R^2 which states that the force of gravity is inversely proportional to the square of the radius from the source of gravitation. A singularity has a radius of 0 so its gravitational force is infinate in the immediate proximity of the singularity. This is the resulting cause of the event horizon. The only way I can see for a singularity to be naked is if GMm=0. You would then have 0/0 so F would be undefined thus negating the event horizon but it seems to me that it would also negate the singularity ~~Jeremy Redd~~ —Preceding unsigned comment added by Akai ma (talk • contribs) 08:27, 5 March 2009 (UTC)

I would rather hope that first year physics students know Newton's universal law of gravitation before they become university students! But since Newtonian physics breaks down long before the you develop singularities Its not really relevant.

It would make the article more clear if it explained how a singularity can theoretically be observable. If a singularity is an object with infinite density, then the spacetime around it has to be curved, right? What happens to all that gravity and spacetime curvature? How does light suddenly start escaping from the gravity well? The math may make this self-evident for graduate physicists, but not at all for lay readers. 209.162.56.112 (talk) 21:39, 23 February 2014 (UTC)

another part for the fiction section of this page

I didn't want to add it directly because I don't have all the information for it. But there is a book that I used to own; rather a collection of short stories by one author over many years, called The Complete McAndrew. It also talked about naked singularities, swartzchild(sp?) black holes, and Kerr-Newman black holes. Anyway, if anyone knows more about it, it would be a good add to the page I think. —Preceding unsigned comment added by 71.237.162.90 (talk) 16:29, 12 June 2009 (UTC)

That book would be The McAndrew Chronicles, by Charles Sheffield, a collection of (science fiction) short stories. An expanded version was published in 2001 under the title The Compleat McAndrew. Not sure if it's really on topic, since there isn't a fiction section here, but if a fiction section were added, this might be appropriate to put in it (or at least, the story "Killing Vector" from that book).Geoffrey.landis (talk) 04:27, 12 March 2011 (UTC)

Numbers?

Why do so many experts hate numbers? Is a naked singularity more probable for a one kilogram black hole, a 4 solar mass black hole or a 40 million solar mass black hole? Surely the mass has some effect on the probability of a real naked singularity?. Does it need to rotate at one rpm or one trillion rpm? Surely we have some idea? If the singularity is a million times smaller than a quark how can it absorb a quark. It is like expecting one virus to eat an elephant whole.66.177.105.109 (talk) 23:25, 20 July 2010 (UTC)

inextricable link to Black holes in fiction

I would like to add either a Main Page template link, or some other sort of reference, in the "In Fiction" section, to Black holes in fiction. Often black hole fiction also involves naked singularities; and by its very nature involves singularities in general. Additionally, is it not the case that some theories of naked singularities would suggest that removing the rotation component, would allow them to become black holes, or vice-versa?

Before I do anything along these lines, I wanted to see if there were any comments. Tacticus (talk) 05:32, 18 December 2013 (UTC)

added some metrics

I put in two of the metrics, Kerr and Reissner-Nordstrom, that predict naked singularities and a link to a third, Kerr-Newman.

Sean

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