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]

Mind? Of course not! That's what we do here.

By the way, I did a bit of research and got an explanation for the evaporation of black holes. It seems that there is a phenomenon known to exist in the cosmos called "vacuum fluctuations." Basically, what happens is that a pair of particles -- basically, a particle and an anti-particle, or in other words, matter and anti-matter -- can appear spontaneously in a vacuum. They immediately annihilate each other, so conservation of mass and energy is maintained. But for that instant, it is not. And it is that violation of the second law of thermodynamics that allows a black hole to evaporate.

You see, over the course of billions of billions of years, such a pair of particles will appear billions of times next to the event horizon of a black hole. One of the pair will be swallowed by the black hole, and the other will radiate away from the black hole. The effect is such that the mass of the particle that escapes is actually reduced from the mass of the black hole. Over billions of billions of years, this process will reduce the mass of a black hole down to zero.

But, as Richard says, that process takes many, many times longer than the cosmos has already existed. So, a vast majority of black holes haven't lost all that much mass, and it will take many billions of times longer than the Universe has already existed for most black holes to evaporate in this fashion. And since there is little data to constrain the upper or lower limits of the spontaneous particle creation/annihilation, it's hard to set an exact date by which all the black holes in the Universe will evaporate.

So -- in the final analysis, it's something that happens. But it happens so slowly, relatively speaking, that we don't have to worry too much about it.

-the other Doug

[Marcel]

But, as Richard says, that process takes many, many times longer than the cosmos has already existed.  So, a vast majority of black holes haven't lost all that much mass, and it will take many billions of times longer than the Universe has already existed for most black holes to evaporate in this fashion.  And since there is little data to constrain the upper or lower limits of the spontaneous particle creation/annihilation, it's hard to set an exact date by which all the black holes in the Universe will evaporate.

So -- in the final analysis, it's something that happens.  But it happens so slowly, relatively speaking, that we don't have to worry too much about it.

-the other Doug

As far as i know, singularities can exist in a variety of "sizes" and the time it takes for a black hole to evaporate by means of "Hawkins radiation (particles, antiparticles and gamma radiation) depends on it's mass. The lighter a black hole is, the faster it evaporates. Black holes that reside in galaxies (the 1 billion solar mass ones) theoretically take 10 to the 73 years to evaporate. However, there's theoretical evidence that smaller black holes (even as tiny as the Planck length) exist as well and they evaporate in very short times (instantly that is).

A question that keeps me curious about this theory is: if there's radiation coming from a black hole in the form of particles, antiparticles and gamma radiation (which has a speed of 300000 kms/hour), there must be other forms of radiation (the long searched gravity waves that is thought to escape from neutronstar-pairs ?) that can make its way from the event horizon. Why should gamma radiation make it, while other wavelengths cannot ?

Great explanation "other Doug' !