Black Holes Options

[maryalien]

any one wanna talk black holes. i'm not a professional or anything. i vaguely remember hearing s. hawkin revising his opinion on it saying it wasnt a "worm hole" anymore and that it just destroys all matter and worth nothing else.

i only make my observations, childlike actually, to that of what happens on earth, and why shouldnt it happen in the rest of the universe. why should anything here (goverening law of physics, etc.) be different anywhere else?

just like a tornado, or water running down a drain (or that infamous lake that was drained by accident by some guys drilling and all the water drained into the salt mine, i cant remember the name now but a 6 inch hole sucked in a tanker), why wouldnt a black hole be that "event" that punched a hole into another "dimension/galaxy whatever" with less pressure.

and maybe all that "dark matter" is the "reminant" of what comes out of a black hole.

i dont know, just talking. my head is always "out there, out of earth..."

maryalien

[dvandorn]

First, though it's likely redundant for most of the people here, let's talk some basics about black holes.

Black holes are all about the relationship between mass, energy and gravity. Gravity is a function of mass -- the more mass you have, the greater gravitational influence it has on surrounding masses.

Gravity even affects photons and other energy "particles." A black hole comes into being when a body has so much mass that any particle of mass or energy that approaches it would have to accelerate faster than the speed of light in order to escape it.

That would be relatively easy to understand, if it weren't for the predicted effects of special relativity. Einstein's classic E=MC^2 equation states the relationship between mass and energy -- that a given amount of energy (E) is equal to the square of a given amount of mass (M) traveling at the speed of light ©. That's been taken to mean, rather simplistically, that mass cannot be accelerated all the way to the speed of light, and if it were, it would transform entirely into energy.

More importantly, special relativity also states that the passage of time is relative to how fast you are traveling compared to another point in space. The faster you go, relative to a given point in space, the slower time passes for you -- again, relative to that other given point in space.

When any mass passes the point near a black hole where it would have to accelerate to lightspeed or beyond in order to escape, the black hole's gravity would theoretically accelerate any such mass beyond the speed of light. But since that's both impossible *and* the required effect of such strong gravity, what happens beyond that point is called a singularity -- it's a region of space where physics cannot describe or predict conditions. That line itself, beyond which no mass can escape, is called the event horizon -- since no information, not even photons, can come out from within that boundary and tell us anything about any events happening within.

As a mass approaches the event horizon and is suddenly accelerated to just short of lightspeed, the passage of time for that mass would slow to a near-stop. For us, observing from outside, time would pass normally and we would see time pass normally for the accelerated mass as it comes close to being swallowed -- but once again, if the matter is accelerated to or beyond lightspeed, then time passage for it ought to stop entirely, and our physics can't describe what happens to mass that's frozen in time (at least, relative to the outside universe). So, once again, we have a singularity -- we just cannot describe what happens to the mass, how it might behave, or anything.

For a long time, it was thought that black holes sucked everything in, and nothing, not even the smallest amount of information about the black hole within or the mass falling onto it, would be able to escape. But we've found out that there are basically two kinds of information that *can* escape from a back hole: whether or not it's rotating, and whether or not it's electrically charged (and what the charge is).

You can tell if a black hole is rotating because its gravity field rotates with it, and the gravity field is the only really major thing that extends beyond the event horizon. You can observe this gravity field by looking at the effect it has on objects near the black hole. A spinning gravitational field accelerates mass both towards the black hole and along the rotation vector, so you can see and measure the rate of spin. (Again, an interesting thing, since we're observing a time-passage-dependent effect, rotation, outside of a system within which Einsteinian physics states that the passage of time should have stopped.)

Charge is also detectable based on how masses behave near a black hole. I'm not as knowledgable as to how we can determine the charge, but I know it can be done.

Spinning black holes also radiate mass and energy -- well, the disk around them does, anyway. The spinning gravitational field smashes infalling matter and energy into an equatorial disk. As matter swirls down towards the black hole, some of it follows a trajectory that accelerates it away from the black hole. The way it works (I dont have the math to explain the effect, I've just seen the results), the mass sprayed away from the black hole is shot out in jets from the rotational poles. And so, a spinning black hole can have the appearance of a child's top -- a spinning, spiraling disk rotating around the vertical "stick" of polar jets. The black hole within, of course, is invisible.

There has got to be some way in which quantum physics and multi-dimensional physics will eventually be able to describe the conditions that exist within the event horizon of a black hole. But, as of right now, no theories exist that account for all the known facts -- or that answer most of the outstanding questions.

Oh, and one other thing -- black holes aren't forever. They lose mass very slowly over the course of time (something else that I don't have the math to explain properly), and after many billions of years, they can simply evaporate. However, the theories as to what happens when a black hole falls back below the mass required to maintain the singularity are pretty raw right now. It's possible that massive amounts of energy are released, but it's also possible that the singularity doesn't collapse immediately at the point where the mass falls below that critical level.

I'm sure there are others out there who can fill in anything I've missed, and correct me if I've made any faux pas, here... but I think that's a pretty good starting point for any discussion.

-the other Doug