Talk:Magnetospheric eternally collapsing object

Was this article lifted?

This article is remarkably similiar to the recent NewScientistSpace.com news article at this address:

http://www.newscientistspace.com/article.ns?id=dn9620&feedId=online-news_rss20

It seems pretty clear that one is a copy of the other.

what this article must address

What is a highly redshifted rotating magnetic dipole? -- CannibalSmith 12:06 GMT 28 July 2006

Well it's not a monopole (only north or only south magnetic) just a plain magnet.

And gues it turns so fast it's starting to redshift (i'm not sure how fast an object can rotate, but i'll gues it's all a in single quantum state so altough it's huge it might interact as if it was one particle. (so how fast can a single particle spin?)

If it's not acting like a single particle, then i think the fastest rotation is the speed of light, redshift would then mean close to the speed of light. anonymous

Phrases in the article that are wrong

The article currently contains some phrases that are non-sense:

1. "An uncharged black hole cannot produce its own magnetic field,"

It is in principle possible for a black hole to generate a monopole magnetic field (if magnetic monopoles exist). I guess this phrases could be considered technically correct, if one reads "uncharged" as having no electric and no magnetic charge. However, then the sentence would be a rather misleading way of saying: "a Black hole does not generate a magnetic field if it does not generate a magnetic field", which is an obviously useless tautology. The thing that is true is that a black hole without electric charge cannot produce a magnetic dipole. (Which is what is meant).TR 13:39, 4 December 2014 (UTC)

I think it fair to assume that at this level the statement is ignoring the possibility of magnetic monopoles. In this case, the statement is effectively saying that there is no electrical charge to move and thereby create a magnetic field. One might clarify it as "electrically uncharged" or "electrically neutral". — Cheers, Steelpillow (Talk) 13:56, 4 December 2014 (UTC)

2. "Since it has not collapsed to a point, a MECO has a finite size, which in turn allows it to carry angular momentum and to rotate."

Black holes can rotate and carry angular momentum. See, rotating black hole.TR 13:39, 4 December 2014 (UTC)

AFAIK there is no difference in principle here between a MECO and a black hole. A rotating black hole does not collapse to a point either but extends finitely in at least one dimension and spins through two. A true point singularity cannot carry angular momentum. Or at least, that's what used to be believed. Has anything happened to change that? — Cheers, Steelpillow (Talk) 13:56, 4 December 2014 (UTC)

As far as I know, there is no relation between spacial extent and being able to carry angular momentum. For example, cosmic string defects can rotate and carry angular momentum. Or equivalently, in 2+1 dimensions you can have rotating point particles with angular momentum. (Both would produce closed timelike curves, and therefore considered unphysical, but that is a separate issue, since there are also CTCs around the singularity in Kerr black hole.)TR 15:46, 26 August 2015 (UTC)

As far as I know, there is no demonstration of a lack of relation between spatial extent and being able to carry angular momentum. The black hole case suffers a conceptual shift when considering momentum outside the Schwartzschild (which can be extracted via the Penrose mechanism) vs. angular momentum inside the Schwartzschild radius (which cannot be extracted save through Hawking radiation). In the one case the black hole patently has finite dimension. Solutions inside the event horizon are of course little more than metaphysics, but even they tend to postulate ring or rod singularites - specifically in order to carry the angular momentum. I have yet to meet a quantum physicist who claims that the spin of a particle such as an electron is in fact angular momentum carried in a point - they all hedge their words and say that the spin "has the same dimension" as angular momentum and/or that the size of the electron has not been determined but the Planck length sets a lower limit (or that it may be a one-dimensional compactified string in a Calabi-Yau space or whatever). I don't know about superstrings but they seem at least as mythical as singularities inside an event horizon. Nowhere have I seen rigorous argument attempted for angular momentum in a point. In fact quite the reverse: using dimensional analysis the origin of angular momentum is linear momentum times radius, which makes the dimension of angular momentum ML²T^-1. No matter how much one fiddles with relativity or goes quantum, that L dimension cannot be got rid of or it is not angular momentum any more. A point has no L dimension so it cannot carry the associated property. — Cheers, Steelpillow (Talk) 16:44, 26 August 2015 (UTC)

I gave you an example: A conical singularity in 2+1 dimensions (a point particle) has no physical extent but can carry angular momentum. Done.TR 10:42, 27 August 2015 (UTC)

Sorry, no. A spinning cosmic string; a) drags a non-zero extent of spacetime around with it, b) shows internal structure (which by definition is spatial) and c) like most solutions to General Relativity, probably doesn't exist in the physical world. Nor have you explained where the spatial dimension in the unit of angular momentum comes from in this case. You'll have to do a lot better than that. — Cheers, Steelpillow (Talk) 11:18, 27 August 2015 (UTC)

No, I don't. It is a fairly easy exercise to show that a spinning conical defect in 2+1 dimensions has an non-zero ADM angular momentum. That show conclusively that spacial extent is not a requirement for an object to be able to carry angular momentum. This is a completely separate issue of whether object with zero spacial extent can exist in the real world (probably not). Too see the flaw in your dimensional analysis argument, recall that people used the same argument to conclude that massless particle could not have momentum (because momentum is velocity times mass).TR 14:55, 27 August 2015 (UTC)

Two points. First, a strong motivation for the MECO theory is that it is a more realistic model than point singularities and suchlike metaphysics. There is no evidence that a point singularity - indeed any kind of singularity - is anything more than a physical absurdity signifying loss of reality in one's equations. I don't care if the Queen of Sheba is intrinsic to it. Second, recall that energy has the dimension ML²T^-2. We sometimes explain mass as "frozen energy" but I seldom meet the equivalent suggestion that we dimension mass according to a fundamental energy dimension E, as EL^-2T². When we do this, momentum has the dimension EL^-1T¹. This clearly applies to massless particles. If there is a similar redimensioning that we can make with L in point angular momentum, I have never seen it. — Cheers, Steelpillow (Talk) 16:00, 27 August 2015 (UTC)

Angular momentum has the same dimensions as action. That should fix your non-issue. The fact is there simply is no connection between spacial extent and angular momentum.TR 18:31, 27 August 2015 (UTC)

How silly of me. Comparable in its game-changing profundity to e=mc² is the principle that Action equals um, err.. now what was it again? Perhaps we should be talking about the action intrinsic to a singularity. I think it was the Bellman who remarked that "what I tell you three times is true," but as I have only said that once I could be wrong. Shall we agree to differ? — Cheers, Steelpillow (Talk) 18:54, 27 August 2015 (UTC)

Should this statement ""Since it has not collapsed to a point, a MECO has a finite size," not read ""Since it has not collapsed to a point, a MECO has a finite density,"? All theories of black holes and MECOs assert a finite size, but only vary in whether there is infinite density, not size. — Preceding unsigned comment added by 98.118.249.4 (talk) 15:53, 6 July 2015 (UTC)

"Finite size" is just another way of saying that it is not a point, the statement is not a deduction as you suggest but a tautology. Size provides a more meaningful hook to hang the ideas of angular momentum and rotation on than density or collapse provide. The statement is fine as it is. — Cheers, Steelpillow (Talk) 12:57, 28 July 2015 (UTC)

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