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Cosmic Reflections. Black Holes Re-visited
Dick Bain
Well actually, you probably wouldn't want to visit a black hole in the first place, considering the conditions that exist in their vicinity. I wrote about black holes before but at that time I doubted their existence, but I was in good company. Albert Einstein once wrote a paper explaining why black holes couldn't exist. (1) It is especially ironic that he rejected the idea of black holes, since it was his theoretical work that suggested to other physicists the possible existence of black holes. But recently I have parted company with Albert regarding black holes, based on the evidence that astronomers have discovered in the past few years.
A black hole is a body so dense with a gravitational field so intense that at a particular distance from it nothing, not even light, can escape from its grasp when it passes this close to the black hole. During the life of a star, energies created by the process of fusion of hydrogen to helium generate enough outward pressure to overcome the force of gravity and prevent the star from collapsing. (460, 465) When the star has burned most of its fuel and can no longer maintain the balancing pressure, the star collapses. The remnant may be one of three things. If the collapse is gradual, the star may end up as a very dense, small star known as a white dwarf. Since some internal fusion continues the white dwarf does not collapse. This star is thought to end its active life as a black dwarf, a dead star after its fuel is totally expended. This is what some of the dark islands of space are according to The Urantia Book. (170)
Chandrasekhar calculated that a white dwarf star cannot exceed the Chandrasekhar limit of 1.4 solar masses. Stars larger than this apparently blow off a great deal of matter in a supernova when they no longer have enough internal pressure to avoid collapse. The remnant of this process is thought to be what is known as a neutron star. As the name suggests, the star consists entirely of neutrons, and is as much as 100 million times denser than a white dwarf. The total collapse of a neutron star is prevented by a phenomenon known as degeneracy pressure. A neutron star emits very little visible light, so they are generally detected by the pulses of radio energy they emit or their gravitational effects on a companion star in a binary system. This type of star is known as a pulsar. The third possibility for the end of life of a star is a black hole.
If a star is above about three solar masses, when it reaches the end of its life and collapses, the supernova remnant may be too massive to be stabilized by degeneracy pressure, and may collapse past the neutron star stage.(2) When the collapsing star reaches a certain diameter, its gravitational field becomes so intense that whatever is closer to the star than a certain distance-known as the Schwartzchild radius (1) or event horizon-can never escape from the star's gravitational grasp. A logical question, and one that has bothered many theorists is: Does the star continue to contract to an infinitesimal point, known as a singularity? This would mean that the star would be squeezed to such an extent that even basic particles like electrons couldn't exist. Under these conditions, the black hole would consist of the simplest particles possible, identified by the Urantia Book as ultimatons. However, the book tells us that ultimatons are unaffected by gravitational fields (465), and therefore they could leak out of the black hole, thus reducing its mass before it had contracted to a singularity. Physicist Stephen Hawking proposed a different mechanism whereby particles could escape from a black hole, thus eventually evaporating it. Physicists early proposed that the black hole would not contract to a singularity, at least in our time frame of reference. Since time and space are severely warped in the volume close to the surface of the black hole, all events occurring there, including the star's contraction, would appear to take a very long time, much longer than the present age of the universe to occur. In fact, black holes were referred to as "frozen stars" before they were called black holes.
Astronomers also have seen evidence of black holes at the center of many galaxies. (3) The centers of these suspect galaxies show one or more large jets of gas emitted from the center of the galaxy at right angles to the galactic plane. The astronomers feel that the gas jets are effects caused by the black hole. Another indication of black holes is a rapidly whirling ring of material surrounding whatever is at the center of these galaxies. This whirling ring of gas and dust is also seen around the dark companion of some dual stars. The intense gravity of the black hole strips material from its visible companion, or companions in the case of a black hole in the center of a galaxy. As the material moves closer to the black hole, it is compressed and heated and gives off X-rays. These X-rays have been detected by several X-ray telescope satellites in the past few decades. The speed of the gas spiraling in toward the black hole can be determined by measuring its Doppler shift on either side of the black hole. The Doppler shift is the change in the frequency of the light given off by the spiraling ring material due to its motion towards us or away from us. The speed of this material and the apparent size of what it is orbiting gives us an idea of the mass and the volume it occupies. Though the size of some of the objects at the center of the galaxies is astronomically small, the calculated masses are as high as several million suns. (3) An object this dense could hardly be nything but a black hole.
I have been asked before if black holes are mentioned in The Urantia Book. Specifically, are the dark bodies around Havona or the dark islands mentioned in the book, black holes? We can decide quite easily about the dark bodies. On page 153 the authors tell us that these bodies "...neither reflect nor absorb light..." Black holes don't reflect light, but they certainly do absorb it. In the book, the dark islands of space are defined as: "..the dead suns and other large aggregations of matter devoid of heat and light." They go on to mention: "The
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