Black Holes Briefly Revisited

BHs have finite mass. Even the universe has a finite amount of mass.

However, General Relativity predicts that a BH has infinite density as a singularity.

This is a bit troubling for mathematics and nobody likes that, so a new theory is percolating that the String Theory or M-Brane theory will provide a unification of gravity and quantum effects that might explain it and remove that "infinite" term in the equation.

From that there have been a few interesting postulates that "inside" a BH may lie another universe. I guess I am a little skeptical at this point because it is sounding too much like a Simpsons' episode to me. Maybe they have been watching one too many?

It gets very murky inside a BH. I guess when you have enormous amounts of mass in one spot that both space and time get warped, so the definition of a singularity gets tough to define since space is severely warped (if not twisted <== that's a pun).

Several theories suggest that inside a BH may be a one dimensional universe of infinite size. Another states that there may a worm hole link between two black holes, but where does all the mass actually go in this cosmic plumbing?

So, we are still guessing until we get a better understanding of gravity and quantum physics, which is a problem because things like String Theory are essentially unprovable at this stage of our technological understanding.

Hi AH,

You said "It gets very murky inside a BH."

I think that's why they call it a singularity. Maths & physics seem to break down as we get closer and closer to whatever exists inside a BH.

Maybe this year with the LHC coming on line, we're bound to have more answers(?). I suspect there will be more questions than answers though. At any rate we're bound to be more awed than we can now imagine.

-John

The matter of multiple infinities and orders of infinities was broached by Georg Cantor, the inventor of Set Theory, in the late 1800's. At the time it was an explosive idea, because it mingled mathematics and philosophy in ways that some people found offensive. It is still an explosive idea, for the same reason.

It is difficult for most of us to get our perceptions around even such a simple physical relationship as the vast scale of the known universe. The singularity presents a greater challenge, since it has no qualities, such as size or duration. It must be discussed using words that imperfectly represent it, because it is unique. There is nothing else that we could possibly experience that is even remotely like it.

There is an interesting short biography of Georg Cantor here: http://en.wikipedia.org/wiki/Georg_Cantor

Here's a similar sort of counterintuitive example from:-

http://mathworld.wolfram.com/Volume.html

Even simple surfaces can display surprisingly counterintuitive properties. For instance, the surface of revolution of around the x-axis for is called Gabriel's horn, and has finite volume, but infinite surface area.

Hi,

infinity is only a helpful mathematical tool that is used to describe the outer appearance if the total mass is supposed to be concentrated in one point.

So far the reality and results of astronomical observations is supporting the predictions of theory:

there is a radius (the event horizon) from where (or below) no information nor light waves or other electromagnetic radiation can escape.

What is happening inside this horizon: ??? Nobody knows. The models give no explanation and the outside appearance is the same regardless the mass distribution inside.

To decide if an unknown object is a neutron star or a black hole there is ample information in the spectrum as the energy of falling mass down to a neutron star (circling in increasingly smaller orbits until crash) is much different from the situation on a black hole: circling mass too but the red shift of the electromagnetic radiation (that is generated by the different processes at circling the center) at nearing the event horizon will be an indicator. This red shift is caused by the gravitational pull of the mass, so it is growing bigger and bigger until no longer any radiation can come out. This is smearing the spectrum (any line of a spectrum) into a broad band of wavelengths. Similar effects happening at the synchrotron radiation from circling charged particles, from the beams of high energy mass and radiation that come off the polar regions.

So "infinite" is likely not at all infinite.

But we human beings did not find an explanation nor theory what is really happening inside a black hole. But from the outside appearance we know that there are many.

Try hard to be better!

RHABE

Yes, it is definitely hyperbole. Which, by the way, is one of the few things in the entire universe that actually IS infinite. Almost everything else has limitations.

Stupidity not being one of them.