Those virtual matter-antimatter particles can become real under certain circumstances. One of them is a tremendous gravitational pull of a black hole, "snatching" one particle and leaving another in real world. Another way to create them is if you have a very high energy photon, its energy can be channeled into the pair and the virtual pair becomes real.All matter in the Universe was created out of the radiation via pair production in the Big Bang. Dont even askwhere all the antimatter went

"Black holes are just points, right?" No, they are not -- It's best to think of them in terms of their event horizons which are very large spherical regions in space. Someone standing very far away from an event horizon will notice that spherical region in space that objects seem to fall into (very very slowly). "And they can have an arbitrarily small amount of gravity?" No, they have very large fravitational fields -- so large that right in the vicinity of the even horizon nothing can escape, except light, and just barely. "Would it be possible to arrange a constellation of arbitrarily small black holes, moving in such a way relative to one another, that they precisely balanced" If they are sufficiently far away from each other, they can form a stable system just like any set of massive objects -- I've actually read that astronomers know of a pair of black holes that rotate around each other. More than two? I have no idea. "ate space with antimatter, and radiated fields to keep from growing bigger - which fields then became new space elsewhere?" I don't think the above sentence makes sense. I don't think you have a clear mental picture of what fields are or do.MP, I very much appreciate your curiousity about these matters, and it's too bad you never had the chance to study physics formally. Or maybe if you did study what is called physics in a formal university course you would be put off so badly by the mind numbing curriculum and complete lack of interest on part of the lecturer and give up interest in the subject altogether.I wish I could find a book for you to read on these matters. Have you tried Brian Greene's "The Elegant Universe"? It's very inspiring, almost up-to-date, and Greene is a very good scientist.

>What I am curious about, is there a minimum size for these spherical event horizons?for a spherically (spherical symmetry) non-spinning black hole, we can use the Schwarzhild metric (the beautiful closed form solution to Einstein’s field equations) to find the event horizonDT^2=(1-2M/r)dt^2-dr^2/(1-2M/r)-r^2dp (timelike form)The Schwarzhild horizon (event horizon) we will have at the reduced circumference r=2M, where M is the mass measured in for example meters (for example the mass of the sun is about 1477 meters, the earth only 0.44 cm). However the even horizon is not a singularity (point), we only have a real singularity in r=0. For a spinning Black-Hole it is more difficult to calculate the event horizon.>I imagine people predict these things occur in collapsing stars, and so generally have a lot >of mass. Is there any other way one can form?The more massive a black hole is the smaller it’s density (?) if we had a black hole of billions of solar masses the density would be much less than for example water. It is even a small probability our universe is inside a gigantic black hole ? According to Kip Thorne at about a distance of 10 billion light years the amount off mass could be big to have gravity enough to stop light from escaping, that would be a black hole. However it looks like our universe is expanding which is against the predictions of a gigantic black hole. Inside a black-hole everything would crush to a singularity a zero point. However this could be the end of our universe, the universe likely started in a singularity (without time and space) and will possibly return to a singularity.Nothing that is inside the event horizon can ever escape (well never say never), so no signals from the inside of the black-hole can reach us, this is almost like LTCM, when the money first got inside the investment horizon the cash could never get out again.>Black holes are just points, right?Only if you have a naken singularity. But non-trivial naken singularities (without event horizon) is very very unlikely as I understand it.Stephen Hawking:"If there are non-trivial singularities which are naked, i.e., which can be seen from infinity, we may as well all give up. One cannot predict the future in the presence of a space-time singularity since the Einstein equations and all the known laws of physics break down there. This dose not matter so much if singularities are all safely hidden inside black holes but if they are not we could be in for a shock every time a star in the galaxy collapsed"

>And where does all that extra space come from between galaxies? And what happens to the entropy of a system when space between massive objects is eliminated?The spac-time will be gone. With the spac-time gone I would think also the entropy will be gone ?, well how much do we actually know about the singularity of a black hole. To predict what happens in the singularity we need to combine General relativity with quantum mechanics. The theory of quantum gravity is far from full developed. Omar please tell us where we stand in the theory of black holes singularity, we are very curious...??? MP if I assume your body weight is about 100kg (I assume you have gained some weight over christmas) then your event horizon is about 10^(-23) cm. Well as you still are comunicating to the outside world we must accept that you not have turned into a black hole (yet). The earths imaginary event horizon is about 1cm.Back to entropy, in a chapter "Quantum Black Holes" in the book"The Nature of Space and Time" Hawking are mentioning something about black-holes gives an entropy of 4*pi*M^2, I just got that book and have to get time to read more of it before I can get the intuition behind this, may be Omar or some other genius can explain why, how...??

Have you ever heard/read the phrase "From Black Holes to Black Scholes"? Do you know what they were talking about? They were talking about the @#$%&^% Wilmott Forum. That's what they were talking about A lot has happened on the Black Hole front over the past 10 years, particularly from the string theory point of view. I haven't kept up at all. Shame on me. I'll see what I can dig out and report to you.