Talk:White hole

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Contents 1 white hole violate thermodynamics 2 Strange edit 3 more content 4 Reason for removing the 'Hitchhiker's Guide to the Galaxy' edit 5 Big Bang 6 energy conservation problem of black holes? 7 Bubble universe 8 Edits of User:Whiteholes 9 Get this clear 10 Recollapse? 11 Revisions to the article 12 Do you..... 13 Disputed tag 14 Law violation

[edit] white hole violate thermodynamics

Would a white hole violate thermodynamics any more than a black hole would? Who said anything would have to actually be falling out of it? - Leperous

[edit] Strange edit

For a second time User:Noz92 did a complete replacement [1] of the article, I reverted again for these reason:

• old content, includeing referencesm was deleted
• new content not very layman-friendly
• it's Schwarzschild, not Swartzchild. If you don't know this, there a some doubts about your qualifications to edit this article

Pjacobi 15:49, 2005 Jan 22 (UTC)

---

Can somebody who speaks Japanese check the edit by 166.121.37.7. The old link was an actual article while the current one looks like the notice of no article yet. --Laura Scudder | Talk 00:09, 19 Apr 2005 (UTC)

[edit] more content

Added some more to justify why people believe in white holes in the first place. I think maintaining energy conservation for the whole universe (thought of as a closed system) is the main reason. The Big Bang theory essentially proposes that the universe was created from a white hole , but that doesn't mean that there must still exist other smaller white holes in our universe. Penrose (Emperor's New Mind) discusses the controversies of white holes in some depth. Might have to read that again ! Mpatel 08:30, 22 May 2005 (UTC)

I appreciate the work various people have done to motivate belief in the existence of white holes, but overall the article seems to suggest that there's *not* much reason to think they exist, so it would be nice if someone could make the original motivation clearer. Who first postulated their existence? What motivated the original suggestion? Mathematical fallout from accepted theory? Explanation of some phenomenon? Simple symmetry with black holes? Also, has the idea's fortunes waxed and waned over time? Is it a divisive topic, or merely an off-hand suggestion? Thanks. — B.Bryant 00:11, 30 May 2005 (UTC)

[edit] Reason for removing the 'Hitchhiker's Guide to the Galaxy' edit

I've noticed a few times on WP that people mention things along the following lines: 'in the science fiction series blah blah blah, ... one character falls into a wormhole and blah blah blah'. It might be OK to mention stuff like that in non-scientific articles, but in the middle of scientific ones is a little out of place. Perhaps a little section on science fiction is appropriate in the scientific article (especially for controversial ideas like wormholes) - something like the article Alcubierre drive (if I remember correctly). Mpatel 08:26, 8 Jun 2005 (UTC)

[edit] Big Bang

The article had suggested that the Big Bang was simply a white hole, as they both share the characteristic that they 'spew out matter'. This assertion is a bit silly, as the Big Bang did a lot more than spew out stuff. I created time, space, matter and energy.

Realised by anyone who knows roughly what the Big Bang theory is; the assertion that the Big Bang 'was' a white hole (or very similar to one) is better than saying that 'some have suggested that the Big Bang was created by a white hole', which is even sillier than the previous version, as you're saying that space, time, matter and energy were created by an object that supposedly resides in our universe - circularity (all this without giving any references). Give a reference (or an authority on the subject who made this claim) and you can keep what you wrote. ---Mpatel 16:43, 14 Jun 2005 (UTC)

"keep what you wrote"

I am tired now, so please don't take this the wrong way, but I do not appreciate your tone. I am not trying to do anything 'my way' as it were, I just feel that the old wording was wrong. The current wording is hardly ideal either. "The dubious nature of white holes takes on a new twist when it is realised .. " is not encyclopedic wording. -- Ec5618 01:43, Jun 15, 2005 (UTC)

Whether you appreciate my tone or not is irrelevant - my only gripe is that if you say, 'some people believe/think etc. ...' then you must give a reference, according to WP. The current wording is not ideal, I agree with you on that point, but I think it's better than what was written. Like I said, you can keep what you wrote provided you give an authoritative reference. ---Mpatel 09:43, 15 Jun 2005 (UTC)

I still don't appreciate your tone, and I'll ask you, directly this time, to do something about it. Now, dubious is a value statement, as is new twist in which both 'twist' and arguably 'new' are POV. When it is realised suggests that any logically thinking person will eventually realise this, which is not a message you'll want to be sending. If a reader does not 'realise' this, he'll disagree with or doubt the validity of the intire article.

'Some scientists have realised'. -- Ec5618 10:30, Jun 15, 2005 (UTC)

Well, your 'tone' isn't much better either (if you think it's possible to define a 'tone' online). I'll say it again, according to WP, you have to give a reference if you're making a claim, for example, that some scientist said something (you have to say which scientist(s)). The words 'twist' and 'new' are POV individually, but if you put them together in the context of the present article, there's nothing POV about the combination. It is a new twist because that's exactly what it is. I think it's clear we're not getting anywhere with this, so how about we come to an agreement and not include either of our suggestions (at least until we can clear up the argument) ? ---Mpatel 11:07, 15 Jun 2005 (UTC)

I'll apologise for my tone then.

Most of the sources I have found accent the idea that a White hole is currently no more than a mathmatical anomaly, and that this anomaly is found in mathmatical calculations using normal space/time as a starting point. While a layman might conclude that the similarities between a white hole and the Big Bang are uncanny, these similarities seem to be only skin deep.

[2] | [3] -- Ec5618 12:56, Jun 15, 2005 (UTC)

This was primarily taken from a video interview with Dr. Michio Kaku, who also referenced Stephen Hawkings ideas with baby universes. The idea that a white hole "is" the big bang seems to be incorrect. The white hole definition is better defined as the product of the big bang occuring, which some think is just a colliding of membranes, one of which had a black hole on it at the center of the collision.

Lots of ideas have been revised as well as the general understanding of some of the laws of thermodynamics... especially when you now have to think 11 dimensionally. Not saying that the laws have changed, but there can be new interpretations and clarifications that can arise due to the addition of extra dimensions.

Given the fact that "no matter" and "no universe" existed on the membrane our universe exists on, the idea that a white hole created time space and everything else here is plausible. Time, as viewed from someone that "existed" here before the existence of this universe, is due to the movement initially given to and instilled into this universe, is it not? The white hole is the "sticky" new end of the transfer of matter from one membrane to the next.

A few references... http://www.space.com/scienceastronomy/white_hole_030917.html http://education.guardian.co.uk/academicexperts/story/0,,1419424,00.html

I think this is the video where he touches on it. http://vids.myspace.com/index.cfm?fuseaction=vids.individual&n=2&videoid=641879988

--Outcomer 17:48, 4 September 2006 (UTC)

[edit] energy conservation problem of black holes?

Somehow an energy conservation problem of black holes has emerged in this article. Can the author of this sentence please provide references? Otherwise I'll delete it. --Pjacobi 18:00, 2005 Jun 26 (UTC)

Done. --Pjacobi July 9, 2005 13:41 (UTC)

It was in the article that I linked when I made that revision. In fact everything stems from that article. Whoever erased everything that was added, please follow up with some of the latest information from Steven Hawkingm, Michio Kaku and possibly Brian Greene. The theory goes that our universe is actually a white hole. Two membranes collide which cause matter on one of the membranes (which has centralized itself in a small section of the membrane due to a black hole forming) to be transfered to the next... creating a "wormhole" which is sort of like what we witness when we place our fingers together when we have glue on one of them. When we pull them apart, the glue is transfered but there is also a strand which gets stretched between the two fingers. The white hole of the worm hole is then really just the product of the membrane collision, its the after math of the collision. The instant of the collision is the big bang. The white hole is the universe being formed on the other membrane.

Part of my original energy conservation rant I was going to erase. The first part. The second part, was accurate however, and is how it is viewed now. It completely justifies the law. From reading the original article, the first authors stated that some argue the white hole theory goes against the second law. However, it does not. Some theorize now that this universe will die with lots of black holes. All matter eventually ends up being involved in a reduction of entropy, or the organizing of itself in a black hole, instead of being spread out through space. This goes against the second law. White holes and the collision of membranes solves that and says that the matter is then spread out even more, not only in this universe but also on an external membrane.

Actually the energy conservation problem was brought up in the article before I clarified it. My clarification was removed as well...

--Outcomer 17:22, 4 September 2006 (UTC)

[edit] Bubble universe

the universe should not be called as UNIverse but instead be called MULTIverse. There is NOT only 1 big bang that happen. It is possible that there is a parrallel universe somewhere! another universe made up mostly of anti-matter. Do you know the granfather paradox? Although going back in time does not affect the future, it affects the parrellel universe. So in parallel universe or in other bubble universe, it is possible that whiteholes exist there, instead of blackholes.

if any one got other doubts please post here.

[edit] Edits of User:Whiteholes

I've reverted (again) a change of User:Whiteholes [4]. Our current knowledge implies that collapsing antimatter will form black holes, not white holes. Please give your sources. --Pjacobi 08:14, 13 September 2005 (UTC)

[edit] Get this clear

a star that collaspe in our part of the universe is purely made up of hydrogen and helium carbon etc. and if this star collaspe, it will form a black hole for example "cygnus-x". And NOT a white hole. but in other bubble universe, the star itself is made up of anti-hydrogen, anti-helium, anti-carbon etc. and NOT neccessrily be matter. It will be anti-matter. Anti-matter is the opposite of matter. White holes is the opposite of black holes. So it is only logical to say that an anti-matter star collaspe into a white hole and a star made up of matter will collaspe into a black hole. If you don't even know this, i suggest you do up more reading before posting here again.

You're wrong. A hypothetical antimatter universe is not a world in which everything is opposite. People in such a world would not come to life if they were shot. Things would not fall up. Black is not white.

Yes, a black hole is the theoretical opposite of a white hole. That doesn't mean they are made up of something else. It doesn't mean they can only exist in other 'bubble' universes. Where are you getting your information? -- Ec5618 15:26, 13 September 2005 (UTC)

Related question: the article states a white hole is the time reversal of a black hole. Isn't the time reversal of a black hole also a black hole? In classical physics, the time reversal of a gravitating object is also a gravitating object, not an anti-gravitating. In general relativity, the Schwarzschild metric and the like are time-symmetric. Am I out to lunch? -Dan 20:39, 18 November 2005 (UTC)

You're close. As none of the metric coefficients depend on t, the Schwarzschild metric is clearly invariant under both translation and reversal in t. But t is not timelike everywhere; it becomes spacelike within the event horizon, and r becomes timelike. The metric is not invariant with respect to reversal of r, and so the behaviour within the event horizon depends on which direction we choose as 'future.' If we choose the direction of decreasing r as 'future,' we have a black hole, where we can no more avoid travelling towards the singularity at r=0 than we can avoid moving forwards in time in everyday life. Make the opposite choice, and we have a white hole. Does that clear things up? ~ Tsumetai 20:32, 14 December 2005 (UTC)

[edit] Recollapse?

It strikes me as unlikely that a white hole could collapse -- a white hole is a gravitational mirror, a perfect reflector (but not retroreflector) for all incoming material and light, as its boundary is a barrier of infinite potential energy. Neglecting anything emitted from the hole (which would very likely be moving at escape speed relative to anything already present), a large amount of matter collected around a white hole would congregate into a sphere, not growing because of its own gravity and not shrinking because of the (negative) gravity of the hole. There might conceivably be a way to pack enough matter onto it that the matter collapsed into a black hole outside the white hole, but this is distinct from the white hole somehow collapsing. Of course, on that note, how does a white hole react to normal gravity? Would a black hole near to a white hole suck it in, or be repelled itself, or simply annihilate (possibly leaving a weaker hole of one variety or the other)? --Tardis 19:34, 15 December 2005 (UTC)

If I understand correctly, a white hole acts gravitationally like a concentration of negative mass, suggesting that the hole would repel and be repelled by normal matter, but doublecheck with the lurking physicists before taking that statement as being correct. Surrounding it with a shell of normal matter such that the net mass present is greater than zero would give you something that could collapse, but models of situations involving negative mass tend to do strange things, so again, ask a physicist. --Christopher Thomas 08:09, 22 March 2006 (UTC)

[edit] Revisions to the article

I've made substantial revisions to the article in an attempt to clean it up. One point bothers me - most discussions of white holes state that they emit matter, but if they're a vacuum solution, this isn't necessarily true (any more than a black hole is required to be consuming matter as a part of its existence).

It would also be handy to have clarification on whether or not they act like they have negative mass (preferably with references cited, so this information can be added to the article). The article presently gives the impression that a white hole has positive mass. --Christopher Thomas 09:01, 22 March 2006 (UTC)

[edit] Do you.....

Do you even think that whiteholes even exist? I don't think they exist. They can't as entropy can only increase not decrease!!!!!!!!!!!!!!!!!!!!! —This unsigned comment was added by 219.74.160.43 (talk • contribs) on 04:27, 26 March 2006.

• It would violate the law of thermodynamics, but it could theoretically exist mathematically if you ignore thermodynamics. Since a white hole has not been observed, I'd say they don't exists, but I'm not a scientist. --Frenchman113 00:53, 30 March 2006 (UTC)
  • When I first read this subject, I considered the Big Bang might be a form of White Hole. Maybe I am right, maybe not.

[edit] Disputed tag

This whole section talking about entropy seems to fundamentally misunderstand entropy and give too much weight to the "greater entropy is greater disorder" metaphor. High entropy in systems dominated by electrochemical interactions corresponds to states with uniform distributions of particles, but enropy in systems dominated by gravitational interactions operates very differently. In systems dominated by the both attractive and repulsive electromagnetic force, these forces cancel out over long ranges, and there are a large number of equivalent states with uniform distributions of particles. Because gravity is always attractive, forces add up over long ranges, and there are a large number of equivalent states with clumps of particles (and relatively few equivalent states with uniform distributions of particles). "Disorder" is only useful as an intuitive measure of how likely a particular state is. Disordered states are numerous and more complicated to distinguish from each other; ordered states are more rare and uniquely identifiable.

Anyways, my point is that independant of the existence of white holes or their thermodynamic properties, the statements "If anything, black holes by themselves without an exit point violate the second law. Black holes are points at which entropy is reversed. The entropy that exists in our solar system is greater than that of which is in a black hole, which continues to lower entropy by engulfing and trapping everything within its grasp." are false. In particular I imagine you'd be hard pressed to find a physicist who thought that black holes lower entropy.

In fact the consensus is that black holes are objects of maximal entropy. I quote Entropy#Entropy_and_cosmology: If the universe can be considered to have generally increasing entropy, then - as Roger Penrose has pointed out - an important role in the increase is played by gravity, which causes dispersed matter to accumulate into stars, which collapse eventually into black holes. Jacob Bekenstein and Stephen Hawking have shown that black holes have the maximum possible entropy of any object of equal size. This makes them likely end points of all entropy-increasing processes, if they are totally effective matter and energy traps. Hawking has, however, recently changed his stance on this aspect. I'm not sure what precisely Hawking changed his stance regarding, but regardless it seems clear to me that black holes are regarded as having quite high entropy.

Disclaimer: my knowledge of these subjects comes almost solely from pop-sci books such as The Fabric of the Cosmos and A Brief History of Time, and from Wikipedia itself. I am not educated in the finer mathematics of these theories. Bradkittenbrink 06:43, 29 August 2006 (UTC)

A large amount of dubious material was added to this article over the past few months. I haven't gotten around to vetting it myself yet. If you want this to be done more quickly, maybe ping a few of the GR types over at Wikipedia:WikiProject Physics. --Christopher Thomas 06:53, 29 August 2006 (UTC)

Although the shock-wave metric business isn't complete crap, it still gets relatively too much coverage for something quite on the speculative side (even for an already speculative topic such as white holes), and the 2nd law discussion wanders way of course. I'm going to just toss the latter discussion for a start, but the bottom line is probably that the article needs expansion. 192.75.48.150 14:00, 29 August 2006 (UTC)

My understanding was that black holes are now thought to be objects of maximal entropy, only given the fact that they perhaps lead to another universe where the matter could be transfered and therefore spread out. "To an observer" in the "immediate sense", they "seem" as if they are in fact lowering entropy. That was all my contribution was trying to say.

Not only that, but isnt also true to say that gravity, since it is now thought to come from another membrane, or at the very least from somewhere outside of our universe, is therefore an outside force, which when accumulating around our own matter and eventually causing black holes to form, is in fact a reverse of entropy in our universe, since it is the product of an outside force?

--Outcomer 17:29, 4 September 2006 (UTC)

The reason the entropy of a black hole was originally postulated was thermodynamic considerations, and the mechanism of Hawking radiation lent it credibility. It is not dependant upon the existence of D-branes or other universes, which are still speculative theories (more so than Hawking radiation, that is). 192.75.48.150 18:51, 5 September 2006 (UTC)

Although I am not an expert on thermodynamics (6 years of biology/chemistry, and now pharmacy school), my understanding is that if black holes are releasing thermal radiation, then you can assume there is an increase of entropy? What I was trying to point out, was that although to the observer they appear to reverse entropy as far as dispersal goes, they are in fact sending their matter elsewhere... which could show itself here as a release of energy... going from being ordered in the singularity to disordered in the extra dimension / baby universe?

--Outcomer 04:34, 7 September 2006 (UTC)

[edit] Law violation

I'm not a physicist but it says that the existence of white holes that are not part of a wormhole is doubtful as they appear to violate the second law of thermodynamics (entropy etc.) is this right or should it be the first law of thermodynamics (energy conservation and that)? —The preceding unsigned comment was added by WikiSlasher (talk • contribs) 06:36, 4 December 2006 (UTC).

Wow that was quick. —The preceding unsigned comment was added by WikiSlasher (talk • contribs) 06:37, 4 December 2006 (UTC).

Ah it was HagermanBot that added the unsigned template so fast. --WikiSlasher 06:40, 4 December 2006 (UTC)