The Formation of Black Holes
Created | Updated Oct 19, 2005
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Black Holes are formed by very violent, and often unseen, processes. Stars are kept alive by fusing the atoms in their cores to produce energy, light, and heat to fuse the next pair. In the early stages of a stars existance, the star is fusing hydrogen. As the star ages, eventually all the hydrogen has been fused into helium. The star will shrink slightly, as the energy needed to fuse helium is slightly greater than that needed to fuse hydrogen, then expand to a larger size than it's original. This expansion is caused by the more violent reactions caused by fusing helium. The fusion process continues; after helium comes carbon, then oxygen, then silicon, then iron. When the star has a core of Iron, it is doomed.
Iron is at the bottom of what physisists like to call the "energy curve". Elements on the left branch of the curve take less energy to fission than fuse, and elements on the right take less energy to fuse than fission. Iron is at the bottom of this curve, meaning that it takes more energy to fuse or fission than you could possibly get out of that reaction.
At this point in the stars life, its next form will be decided. For a small star (less than one solar mass), it will be a dwarf star (white or brown), to dim to see. For a star like ours (one solar mass) it will form a white dwarf star. For a star that is relativly large (about ten solar masses) it will most likely form a neutron star, which is very dim and extremely dense (as well as being the only known source of the theoretical substance Nutronium which would be approximatly ten thousand times denser than the densest substance on Earth.) For a star that is very large (greater than 15 solar masses) its fate is to die a horrible death.
When a massive star dies, it does so in a big way: It supernovas. Some of you may be wondering what a "super" nova is that a regular "nova" isn't. When a fairly small star runs out of fuel and dies, it ejects the outer shell of materiel, and then performs a series of small collapses and even smaller ejections, before becoming what it will be for a very long time. This is a Nova. When a star goes supernova, it literally explodes, from the core out. This is extraordinarily violent and very bright. Some photos of supernovas are included here.1
As the star itself explodes the core simultaneously implodes. If the mass of the core was sufficiently large, the core will keep collapsing, growing denser and denser, until it is so dense that it cannot support its own weight and density. At this point, we say that the star has fallen inside its own event horizon. As the gravity pulls at the remains of the stars core, the core continues to shrink, still growing denser and denser, until the force of gravity has compressed the entire volume of the stellar core into one infinitesimally small point. This is the point, the exact point, where the core achieves infinite density, and infinitly curves the surrounding spacetime. Even light, as it rushes to spread from the supernova, is caught in the new gravity well. See diagram to right.2
This might be the point to explain a new term. Space-Time curvature is the "curve" of space-time, which is the universe, the physical world, the passage of time, all of creation, everything. The more dense something is, the more it curves spacetime, so that the gravity well is an actual dip or curvature in the fabric of spacetime. A diagram is included here.3
Because the singularity is a part of spacetime, it curves it accordingly. Unfortunatly, because the singularity is infinitly dense, it curves spacetime infinitly. Not even light can escape that curvature, and the Black Hole is truly born. The "Event Horizon" is the exact point in space where it is physically impossible to escape the pull of gravity: you would have to be going faster than light, and that is (for all intents and purposes) impossible.
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The Structure and Mechanics of Black Holes
Black Holes are formed by very violent, and often unseen, processes. Stars are kept alive by fusing the atoms in their cores to produce energy, light, and heat to fuse the next pair. In the early stages of a stars existance, the star is fusing hydrogen. As the star ages, eventually all the hydrogen has been fused into helium. The star will shrink slightly, as the energy needed to fuse helium is slightly greater than that needed to fuse hydrogen, then expand to a larger size than it's original. This expansion is caused by the more violent reactions caused by fusing helium. The fusion process continues; after helium comes carbon, then oxygen, then silicon, then iron. When the star has a core of Iron, it is doomed.
Iron is at the bottom of what physisists like to call the "energy curve". Elements on the left branch of the curve take less energy to fission than fuse, and elements on the right take less energy to fuse than fission. Iron is at the bottom of this curve, meaning that it takes more energy to fuse or fission than you could possibly get out of that reaction.
At this point in the stars life, its next form will be decided. For a small star (less than one solar mass), it will be a dwarf star (white or brown), to dim to see. For a star like ours (one solar mass) it will form a white dwarf star. For a star that is relativly large (about ten solar masses) it will most likely form a neutron star, which is very dim and extremely dense (as well as being the only known source of the theoretical substance Nutronium which would be approximatly ten thousand times denser than the densest substance on Earth.) For a star that is very large (greater than 15 solar masses) its fate is to die a horrible death.
When a massive star dies, it does so in a big way: It supernovas. Some of you may be wondering what a "super" nova is that a regular "nova" isn't. When a fairly small star runs out of fuel and dies, it ejects the outer shell of materiel, and then performs a series of small collapses and even smaller ejections, before becoming what it will be for a very long time. This is a Nova. When a star goes supernova, it literally explodes, from the core out. This is extraordinarily violent and very bright. Some photos of supernovas are included here.1
As the star itself explodes the core simultaneously implodes. If the mass of the core was sufficiently large, the core will keep collapsing, growing denser and denser, until it is so dense that it cannot support its own weight and density. At this point, we say that the star has fallen inside its own event horizon. As the gravity pulls at the remains of the stars core, the core continues to shrink, still growing denser and denser, until the force of gravity has compressed the entire volume of the stellar core into one infinitesimally small point. This is the point, the exact point, where the core achieves infinite density, and infinitly curves the surrounding spacetime. Even light, as it rushes to spread from the supernova, is caught in the new gravity well. See diagram to right.2
This might be the point to explain a new term. Space-Time curvature is the "curve" of space-time, which is the universe, the physical world, the passage of time, all of creation, everything. The more dense something is, the more it curves spacetime, so that the gravity well is an actual dip or curvature in the fabric of spacetime. A diagram is included here.3
Because the singularity is a part of spacetime, it curves it accordingly. Unfortunatly, because the singularity is infinitly dense, it curves spacetime infinitly. Not even light can escape that curvature, and the Black Hole is truly born. The "Event Horizon" is the exact point in space where it is physically impossible to escape the pull of gravity: you would have to be going faster than light, and that is (for all intents and purposes) impossible.
Return to Index page
The Structure and Mechanics of Black Holes
1The astute reader will most likely notice a distinct and pronounced LACK of any such photos, and immediately pronounce me a raving liar. I should like for this not to happen. The publishing company that owns the rights to the photos and diagrams that I Had wished to include here informed me kindly that should I so much as show said photos to another sapient life-form, my personal belongings and entire existance would be forefit. Not wishing to draw the Guide into any litigatious idiocy, no diagrams will be included here2See no such diagram, because of the publishing company mentioned in footnote #1.3I'm sure you know the drill by now.
