Talk:Naked singularity

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Question: Did Hawking really loose 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)

Contents

[edit] 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)

[edit] 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)

[edit] Oh my god...

All of the article makes sense, but the last part is just stupid. Maybe an expert should improve it. Hello? Anyone? 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)


[edit] 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)

[edit] 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.

[edit] 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".

[edit] 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)

[edit] 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.