Talk:Black star (semiclassical gravity)

Say what?!
The predicted interior of a black star will be composed of this strange state of spacetime, with each length in depth heading inward appear the same as a black star of equivalent mass and radius with the overlayment stripped off.

Could someone please expand that sentence in a way that makes sense? --TiagoTiago (talk) 00:29, 14 April 2010 (UTC)


 * I think it means every black star is an infinite onion of black stars. So the depths are only emitting Hawking radiation and similar upwards through the star by the same process as the surface emits radiation into space. I presume that provides the distributed pressure needed to make the concept work. 203.167.164.193 (talk) 13:01, 2 December 2012 (UTC)

Pressure as source of gravity
In general relativity, not only mass/energy is a source of gravity, but pressure is too (of the 10 components of the stress-energy tensor, 1 is mass/energy, 3 is momentum, and 6 is pressure). This means that if you try to counter gravity by increasing the internal pressure of a star, gravity increases, in order to counter it you have to raise pressure again, which again increases the gravity, and so on; the process can easily diverge. There seems to be a rather general phenonemon that once the radius of body goes below 9/8 of its Swarzschild radius, the central pressure goes to infinity, which means there will be a singularity there. Given this, I have hard to see how any source of internal pressure (even if it comes from Planck-scale physics, as opposed to the strong nuclear force as in the case of a neutron star) would be able to prevent a gravitational collapse, as it seems a black star is supposed to be more like (8+ε)/8. Presumably the theory does address this in some way however, and one topic of a full article ought to be how. 94.255.156.147 (talk) 17:04, 29 January 2011 (UTC)

Why no references
Why does this article have only a sources section and not a regular references section like in other wiki articles?

And why is a random website added at the bottom to the list of sources !? J mareeswaran (talk) 16:56, 13 October 2019 (UTC)

Incorrect statement
"matter compresses at a rate significantly less than the free fall velocity of a hypothetical particle falling to the center of its star" is incorrect. The speed of collapse is irrelevant. Under general relativity, not even light traveling at c can reach an event horizon from any point above the event horizon until after infinite time has passed at that point. The spacetime interval from any point above the event horizon down to the event horizon is infinite. Michael McGinnis (talk) 01:14, 3 July 2020 (UTC)