Black Holes
...uld have to throw the rock at a velocity of 11.2 km/s in order for it not to come back down, i.e. it would escape the gravitational pull and go into space. The moon on the other hand is much smaller and if you were to throw a rock up at the same speed it would travel further up because there is less of a gravitational pull on the moon. The escape velocity on the moon is about 2.4 km/s. Now imagine the sun, it has a huge mass and enough of a gravitational field to keep the planets of our solar system orbiting around it without drifting away. So the larger the object, the more gravity it has and the greater the escape velocity. Black holes are the result of some stars at the end of their life, provided they are at least three times the mass of our sun. In the centre of the massive star hydrogen is being fused under intense pressures and temperatures to form helium. The pressure from these reactions stops the sun from collapsing under the huge forces of gravity. When the reactions stop, there will be enormous pressure, the star will be crushed down further until the surface of the star reaches its event horizon at which point the star will become a black hole (smaller stars will have different outcomes, some will explode, some will become white dwarfs, but the huge ones have too much pressure pushing on them and cannot explode so become a black hole). The event horizon, or Schwarzchild radius, is the point at which, when passed, there is no return. The definition is if an object of a mass M is compressed into a radius rs then its gravity would become so strong that not even light can escape. The formula goes: rs = 2GM/c2 Where rs is the Schwarzchild radius, G is Newton¡¦s gravitational constant (6.673 „e 10-11 m3 kg-1 s-2), M is mass, and c is speed of light. For a black hole that is 30 times the mass of our sun, the Schwarzchild radius is 100 km. So anything within this distance will be devoured, and has no possibility of escape. Or has it? WHITE HOLES AND WORMHOLES To try to explain this topic properly a lot of maths and physics is required which is time consuming and very complicated, so this is simplified. A white hole is the opposite of a black hole, working backwards in time. Just as a black hole sucks everything in, the white hole on the other end spits it out. As before, textbook physics is useless and will tell you this is not possible but who¡¦s to say that is correct. Wormholes, or the Einstein ¡V Rosen Bridge, as with white holes, are controversial but no one actually knows for sure so lets say they exist. These are a kind of bridge between the black hole and white hole. Enter the black through the tunnel and out the white. Simple as that. But it¡¦s not. They would probably be unstable so something would be needed to hold them open, radiation from stars might be dangerous and the bigger problem is where they would lead. They are the absolute basics to that subject, so now a little bit more. Where would this lead us? Could this be a way of travelling to distant places of the universe, or to a parallel universe, or maybe a different time? Before beginning there we must first expand a little more on the whole black/white/wormhole package. Up to now, it has been about stationary black holes, but this cannot be as they are products of stars that spin, so black holes are most likely spinning around in space. This is good because the wormhole would not be created. This spinning effect would produce a vortex, giving rise to a wormhole so you could go through it. PARALLEL UNIVERSES AND TIME TRAVEL A parallel universe is one where things might be similar but not the same. For example in one parallel universe you might be president, in another the dinosaurs survived and live with us, and so on. There may be an infinite amount of them. There may b...