Singularity Shapes

[frobozz]

Ok, so my question is simple, would it be possible to have a singularity whose shape is a sphere (hollow inside) if so, how might it come about, and if not why not?

 

[vogon13]

Are you imaging something like a shell of neutronium around the universe?<br /><br />We be ok here, but would experience the usual (sorry for wording) singularity effects if we traveled to 'edge' of our universe, and a hypothetical individual outside our universe looking at it would see a presumably normal (but very large) singularity?<br /><br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[le3119]

You should research the Kerr-Newman black hole: the spinning variety of black holes. Its singularity is theoretically ring-shaped.

 

[cuddlyrocket]

Its event horizon is ring-shaped. Any singularity is a point.

 

[frobozz]

Hmm, where is it shown that every singularity must be a single point? Do you have a reference?

 

[cuddlyrocket]

Reference.<br /><br />The singularities at the centre of black holes, and the singularity at the Big Bang are points where the physical equations are undefined (and for which some parameters - eg density - increase without limit when approaching that point).

 

[frobozz]

That's not a reference, that's a statement which infact does not prove your theorem. As space Relativistically is a 4 dimensional manifold there is no reason mathematically why one can't construct an array of points arranged in a sphere where the physical equations are undefined. <br />

 

[pluto_vic]

Actually, the equations have been 'solved' and indeed say that the singularity of a spinning black hole would indeed be ring shaped. I could provide references confirming this, but don't have anything with me at the moment.

 

[frobozz]

Hmm, I only know of two particular solutions to the equations (Schwartzchild and Kerr)I hadn't heard that these were the only possible solutions. I should like to see a proof of the uniqueness of those solutions (wrt to the physics of course) and would be interested in the reference.