Black hole angular momentum

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by EBTX</i>
<br />What happens to the angular momentum of a star (in the Standard Model) when it collapses? If it is conserved, to get to even the size of a proton at the "singularity", either the mass of the star must increase many, many times over ... or ... the velocity of matter going round the "core" must be many times greater than light ... or ... do we just scrap MVR (if so, for what?).<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">You might be interested to know that Einstein himself made a very similar argument against the possibility of black holes. The following is the reference and enough of a quote to give you the flavor of his argument. -|Tom|-

A. Einstein, "Annals of Mathematics", vol. 40, #4, pp. 922-936 (October 1939, written late in his career while he was at Princeton) – shows a respect for physical principles over mathematical reasoning:

"If one considers Schwarzschild's solution of the static gravitational field of spherical symmetry ..., [g_44] vanishes for r = m/2. This means that a clock kept at this place would go at rate zero. Further it is easy to show that both light rays and material particles take an infinitely long time (measured in 'coordinate time') in order to reach the point r = m/2 when originating from a point r &gt; m/2. In this sense the sphere r = m/2 constitutes a place where the field is singular.

"There arises the question whether it is possible to build up a field containing such singularities with the help of actual gravitating masses, or whether such regions with vanishing g_44 do not exist in cases which have physical reality. ... [brief discussion of uncompressible liquids omitted]

"One is thus led to ask whether matter cannot be introduced in such a way that questionable assumptions are excluded from the very beginning. In fact this can be done by choosing, as the field-producing mass, a great number of small gravitating particles which move freely under the influence of the field produced by all of them together. This is a system resembling a spherical star cluster. ... The result of the following consideration will be that it is impossible to make g_44 zero anywhere, and that the total gravitating mass which may be produced by distributing particles within a given radius, always remains below a certain bound. [core of analysis omitted; skipping to conclusions]

"The essential result of this investigation is a clear understanding as to why the 'Schwarzschild singularities' do not exist in physical reality. ... The 'Schwarzschild singularity' does not appear for the reason that matter cannot be concentrated arbitrarily. And this is due to the fact that otherwise the constituting particles would reach the velocity of light.

"This investigation arose out of discussions [with Robertson and Bargmann] on the mathematical and physical significance of the Schwarzschild singularity. The problem quite naturally leads to the question, answered by this paper in the negative, as to whether physical models are capable of exhibiting such a singularity." [End of Einstein quote]

I think that the singularity cannot exist even at the mathematical level ... unless ... one ignores some "other" mathematics related to physical principles other than gravity.

Still, I see no reason why a black cannot form ... it simply cannot have an interior arrangement wherein everything is confined to a singularity at the center of the hole. My personal preference is for the matter within the Swarzchild radius to take up the form of a rotating equatorial "belt" just under that radius with not much in the deep interior. This might lend itself to some observational possibilities since a belt mass would form a body with a weak field a the poles (at small multiples of the radius).

EBTX, If you feel that blackholes can form I ask you why you feel there is a need for them? And do you feel they do in fact exist at all?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by EBTX</i>
<br />I see no reason why a black cannot form ... it simply cannot have an interior arrangement wherein everything is confined to a singularity at the center of the hole.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">What you describe is not a "black hole", which necessarily has a singularity and the interchange of space with time. You are instead describing an ordinary object that has an escape velocity greater than the speed of light. Such objects were first proposed in the 19th century, and are called "Mitchell stars". -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">And do you feel they do in fact exist at all?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Yes, I think that such objects can exist (though not with the singularity in the middle). I see no reason why matter cannot continue to "pile up" in the same place. If the total gravitational attraction is greater than any nuclear energy that would tend to blow them apart ... then ... there you are ... "something" must happen ;o)

There is a reason why matter does not continue to pile up in one place even if it has not yet been discovered. The way matter forms into shapes is governed by laws of nature that set limits on how much matter can be piled on in one place.