“The heavens declare the glory of God; the skies proclaim the work of his hands.” Psalm 19:1, the beauty of the night sky is nothing compared to the mysteries of space, the secrets it holds and the amazing creations that inhabit it. There are many mysteries for us to discover. One of these secrets are black holes, mass-less, unfathomable invisible stars, these giants of the universe, mercilessly drag everything into its grasp, black holes truly are the one of the supreme mysteries of our time. But what are they really?
A black hole is a region of space from which gravity prevents anything, including light, from escaping. The theory of general relativity predicts that a compact mass will usually deform space to form a black hole. Around a black hole, there is a defined surface called an event horizon that marks the point of no return. The hole is called "black" because it absorbs all the light that hits the horizon, reflecting nothing. Black holes of stellar mass are theorized to form when very massive stars collapse at the end of their life cycle. After a black hole has formed it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, super immense black holes of millions of solar masses may
form. Most studies of black holes agree that super massive black holes exist in the centers of most galaxies.
How are black holes formed? By the gravitational collapse, Gravitational collapse occurs when an object's internal pressure is not enough to resist the object's own gravity. For stars this usually occurs either because a star has too little "fuel" left to maintain its temperature, or because a star that would have been stable receives extra matter in a way that can cause it to become too cold. In either case the star's temperature is no longer high enough to prevent it from collapsing under its own weight. The result is one of the various types of compact star. The type of compact star formed depends on the mass of the remnant—the matter left over after the outer layers have been blown away, such from a supernova explosion or by pulsations leading to a planetary nebula. This mass can be considerably less than the original star—remnants exceeding 5 solar masses are produced by stars that were over 20 solar masses before the collapse. While most of the energy released during gravitational collapse is emitted very quickly, an outside observer does not actually see the end of this process. Even though the collapse takes a fixed amount of time from the reference frame of in falling matter, a distant observer sees the in falling material slow and halt just above the event horizon, due to gravitational time dilation. Light from the collapsing material takes longer and longer to reach the observer, with the light emitted just
before the event horizon forms delayed an infinite amount of time. Thus the external observer never sees the formation of the event horizon;...