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 × 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 – 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 be a number of ways to reach them, for example they may cross paths and this may explain some mental illnesses such as schizophrenia. The split personality image may be just that, a version of them has somehow got in contact. But black holes and wormholes seem to be the best entrance into them. Because they are spinning the centrifugal points would keep it from collapsing so you wouldn’t be crushed, therefore being sucked into the wormhole and somewhere in our universe or another.
Time travel has also been controversial. But there are a few interesting findings. With the rotating black hole, due to conservation of angular momentum, it would rotate faster and faster as the radius decreases. Once the object's angular momentum increases beyond its mass, the event horizon of the hole would be moving in excess of the speed of light and at this point, the event horizon would simply vanish from the universe, exposing the singularity. Now we would be able to travel freely into the singularity which might hold the key to time travel, as it is something that totally disregards the laws of nature anything is possible.
Time dilation is a creation of Einstein. It tells us that the closer an object is travelling to light speed, the more time slows down. Now theoretically when travelling at light speed, time should stop, so travelling beyond light speed would technically be travelling backwards in time, thus allowing us to travel back in time.
CONCLUSION
This was an extremely short informative piece on black hole, white holes and parallel universes. Mastering black holes will give us endless opportunities for exploration, knowledge; it will totally change our lives and all belief up to now. We could even travel in time. We could even try to create artificial black holes that will enable us to travel to all parts of the universe in no time, or even to a different universe. The possibilities are endless.
REFERENCES
Barnett, A. (2002). Black holes and other space oddities. Dorling Kindersely, London.
Begelman, M. (1998). Gravity's fatal attraction: black holes in the universe. Scientific American Library, New York.
Couper, H. (1996). Black holes. DK Pub, New York.
Davies, P. (1994). The Edge of infinity: beyond the black hole. Penguin, London.
Gribbin, J. (1992). In search of the edge of time. Bantam, London.
Hawking, S. W. (1995). The nature of space and time. Princeton University Press, Princeton, N. J.
Oxlade, C. (1999). The mystery of black holes. Heinemann Library, Oxford.
Thorne, K. S. (1994). Black holes and time warps: Einstein's outrageous legacy. W. W. Norton, New York.
Wolfson, R. (2003). Simply Einstein: relativity demystified, 1st Ed. W.W. Norton, New York.