An elementary question for the black hole experts

On Jun 11, 7:12 pm, Tom Roberts wrote:
On 6/11/12 6/11/12 2:30 AM, AB wrote:

When a massive star exhausts the nuclear fuel whose burning keeps it hot, the
star’s internal pressure plunges. Gravity overwhelms the pressure and pulls
the star inward upon itself. The star implodes, shrinking smaller and
smaller, ultimately its gravity grows so enormous that nothing, not even
light, can escape its grip. The star creates a black hole around itself..

Yes, pretty much. For normal matter, as dlzc pointed out, this only occurs if
the star's mass is larger than the Chandrasekhar limit.

This is not correct. Chandrasekhar limit is a theoretical equilibrium
where the electron degeneracy of outgoing pressure (maximum at the
limit) equates that of gravitation (no theoretical limit).
Asymptotically above that limit, the star will implode. In doing so,
the renewed pressure in the core will fuse any forms of helium
isotopes together to form heavier elements (in terms of atomic number)
in plasma state. Eventually, it is believe that it will trigger an
explosion called type-Ia supernova. This is regarded as the standard
galactic candle to measure absolute luminosity in which it allowed the
Perlmutter-led team to win the most recent Nobel Prize in physics by
denouncing the conservation of energy --- first law of
thermodynamics. Thus, to form a black hole, the initial mass has to
be much higher than the Chandrasekhar limit where the gravity would
overcome the exploding pressure from fusing helium to heavier
elements. shrug

Note that the black hole
is not "created around itself", but rather the horizon first appears as a point
that expands with the local speed of light to an appropriate radius (determined
by how much mass is inside it).

The predicted creation of black holes comes from the Schwarzschild
metric which is just one of the infinite numbers of solutions to the
field equations that are static, spherically symmetric, and
asymptotically flat:

** ds^2 = c^2 (1 – 2 U) dt^2 – dr^2 / (1 – 2 U) – r^2 dO^2

Where

** U = G M / c^2 / r
** dO^2 = cos^2(Latitude) dLongitude^2 + dLatitude^2

Schwarzschild’s original solution which is not to be confused with the
Schwarzschild metric does not manifest black holes. Besides the
Schwarzschild metric and Schwarzschild’s original solution, the
following simple spacetime solution also does not manifest black
holes.

** ds^2 = c^2 dt^2 / (1 + 2 U) – (1 + 2 U) dr^2 – r^2 (1 + 2 U)^2
dO^2

Since all of these satisfy Newtonian law of gravity at weak curvature
in spacetime, what is your justification to support the Schwarzschild
metric but not the others? We will take silence as your lack of
understanding in why which means you are doing science with gut
feeling, voodoo science, or just random picking (Las Vegas style).
None of these are remotely close to the confines of scientific
methods. shrug

--- But then what really happens to the "matter" of the star? - what is meant
by "star itself is destroyed" -- from the perspective of mass-energy
equivalence?

We have no knowledge about such things in the world we inhabit, but we do have a
model, General Relativity, which is applicable outside the singularity that it
predicts.

There are infinite such solutions. The founding fathers of GR found
several and just cherry-picked one (the Schwarzschild metric) without
any justifications. shrug

That model implies that conservation of energy holds at every point of
the manifold (but the singularity is omitted from the manifold).

Gee, Tom, aren’t you forgetting something? The equation describing
the spacetime of the Schwarzschild metric certainly does indicate a
conservation of energy. However, according to Nathan Rosen’s fudged
mathematics, even the Schwarzschild metric where the mass of the
gravitational object is null compared with its gravitating mass, it
even emits gravitational waves and falsifies the first law of
thermodynamics. Yeah, you cannot tell the violation of the
conservation of energy in the Schwarzschild metric. What a
contradiction it represents. shrug

Since the star
collapses to higher densities than either a nucleus or a neutron star, it's
clear that something new must happen there, such as a new form of matter
arising, or perhaps an escape to some other dimension or hitherto hidden region
of the manifold, but we simply do not know what happens there.

Among the solutions to the field equations that are static,
spherically symmetric, and asymptotically flat, the ones manifesting
no black holes outnumber the ones that do, the statics is heavily
against you and the self-styled physicists. Although science is not a
discipline that favors certain statics, the self-styled physicists are
incapable of offering any justifications to decide on the
Schwarzschild metric. Since you have no idea the Schwarzschild metric
is merely one of the infinite solutions, you are totally clueless.
Why are talking as if you know something about GR? You are the one
who actually needs to study and learn about GR instead of
regurgitating what your peers are bull****ting you. Tom, it is
obviously that you know not much about GR. Why are you not taking
your own advice advocating others to study GR? shrug

interesting, since the speed of light (not
its velocity as a "rock") depends only
upon the density of the refracting medium,
in the opposite sense of Newton's "theory" (or
Snell's law .-)

Note that the black hole
is not "created around itself", but rather the horizon first appears as a point
that expands with the local speed of light to an appropriate radius (determined
by how much mass is inside it).