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Worm Holes are the hypothetical theoretical connection between a black hole and a white hole.
Specifically defined, a black hole is a region in space where the velocity of escape exceeds the speed of light in that medium. When a star dies and begins to shrink a name is given to the size below which it must shrink in order to become a black hole. The name for this size is the star's "Schwarzchild Radius" and the primary factor which determines whether or not a star will shrink below it's Schwarzchild Radius is its initial mass.
Schwarzschild Radius also called gravitational radius, distance that defines the size at which a spherical astronomical object such as a star becomes a black hole. A black hole is an object so dense that not even light can escape the pull of its gravitational force. If an object collapses to within its Schwarzschild radius, it becomes a black hole. The radius is named after German Astronomer Karl Schwarzschild, who derived the first model of a black hole in 1916. Nothing, not even a particle moving at the speed of light, can escape the gravitational pull of a black hole.
Therefore, the Schwarzschild radius is the largest radius that a body with a specific mass can have and still keep light from escaping. The formula for the Schwarzschild radius of a body is the Schwarzschild radius of the body, G is a constant known as the universal constant of gravitation, M is the mass of the object, and c is the speed of light.
The Schwarzschild radius of a black hole marks its event horizon, or the boundary past which light can enter but not escape. Astronomers believe that once an object collapses to within its Schwarzschild radius, it continues collapsing until it becomes a singularity, or a point with infinite density and a radius of zero.
The Sun has a mass of 2x1030 kg (4x1030 lb) and a radius of about 700,000 km (about 400,000 mi). Its Schwarzschild radius is about 3 km (about 2 mi). If the sun were to collapse into a sphere with a radius of less than 3 km, light from the sun would be trapped and the Sun would become a black hole. The sun, however, is not massive enough for it to collapse to this size and become a black hole.
An object with a mass equal to that of the Earth would have a Schwarzschild radius of about 3 mm (about 0.1 in). For an object with Mount Everestıs mass, the Schwarzschild radius is only about 1x10-11 mm (4x10-13 in). Some astronomers believe that any black hole smaller than this would be relatively unstable and would evaporate quickly, releasing gamma rays (seeX Ray). Astronomers have speculated that the mysterious sources of celestial gamma ray bursts may be evaporating primordial black holes.
Only stars that expire with around 3 times a much mass as the Sun can hope to attain black hole status. In order for a star to have much of a chance of having a mass this high after it's inner nuclear fire is extinguished it must have begun its life with more than 50 times the mass of the sun. The name for this lower mass limit which a star must have after death to become a black hole is "Oppenheimer's Limit."
A star much smaller than this will not have enough mass to collapse into a black hole and will have a very different death in store for it that is not within the scope of our discussion here. If a star does shrink below it's Schwarzchild Radius there is a name assigned to the imaginary sphere at the Schwarzchild Radius, the "Event Horizon." At twice the distance of the Event horizon is the "Photon Sphere," or the distance at which a photon may be caught in orbit around a black hole.
This discussion of escape speeds and trapped photons should prove somewhat startling and/or disturbing. It leads to the simple question, "if not even light can escape, and no particle with mass can go faster than light, then what happens to anything caught in the pull of a black hole?" The simple answer is that it never escapes, it is drawn into the black hole with an unescapable gravitational force. However there are other possibilities, and it is here that we look to relativity for an explanation. From a relativistic viewpoint, a black hole is a location of extreme distortion in the space time continuum.
Looking at things this way, every object of mass in the universe creates a distortion in space time, the more massive the object, the larger the distortion. A black hole is different in its definition however, because it is a distortion so extreme that it has infinite curvature, it is actually a tear in space time. Under this definition at the center of every black hole is a spacetime singularity. What this singularity leads to or could be used for are completely theorized, but will be discussed in more depth later.
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