This is my area about strange stuff, theories and general edge of science weird stuff.

This is a Schwarzschild black hole. It is very simple with a singularity at the centre, a Schwarzschild radius and an event horizon. This sort is almost impossible to exist as it has no spin. Black holes are thought to have come from dead stars, and as most stars are spinning then a non-spinning black hole is rare.

Thank you for listening to my knowledgable rant. If you would like to know more, please direct your attention to my report bellow...

If any of this is wrong, or you know some more then please get in contact with me.

I am hoping to create the biggest black hole data base on the net so all help is appreciated

Black Holes

Abstract:

This report is about one of the most mysterious phenomenon in the universe. It first analyses the physics involved with this interstellar body. It then moves on to explain in detail, the more debatable aspects of their existence and uses.

“Ultimately, we have to find one consistent

theory which will describe everything…

But you know, once we find it, it will rather

take the fun out of theoretical physics.”

Professor Stephen Hawking

Dark side of the force

Black holes are large centres of gravity, no more, no less. Yes the same force that causes a pen to drop to the floor, the planets to orbit the sun and the same force that holds the sun together.

To understand the physics of a black hole, you have to go back to the start.

When a star reaches its stable midpoint of its life, it has a very delicate balance. Gravity is trying to pull the whole thing in on itself, while the energy created by the nuclear fission reactions and its spin is trying to pull it apart.

The nuclear fission reactions force hydrogen to fuse to form Helium. In the intense heat other, heavier elements are formed. Eventual the core is fused into iron. A particularly large star uses it hydrogen fuel up within a few million years as opposed to a few billion years that our sun will last. When this energy output is reduced due to the lack of fuel the star becomes very unstable, it swells up into a Red giant as it uses up the last of its fuel. The reactions try to fuse the iron core, this causes a massive release of energy that blows away the outer layers in a spectacular Super Nova. The aftermath leaves a small, exposed core that slowly cools. This is a White Dwarf.

If the core contains less than 10 times the mass of our sun, it will pull itself in on itself until it can’t be compressed anymore and forms a neutron star. All the protons and electrons in the original core are compressed into neutrons. Sometimes the neutron stare is spinning and ejects powerful beams of radiation from its poles. Due to the density and mass, it is not uncommon to find gravitational pulls a trillion times than those on earth.

If a star is massive enough, it will form a white dwarf, but will collapse even further. The denser the object, the more gravitational pull it has. This keeps going to form a point of infinite density that takes up zero space… A black hole.

Gravity: Useful friend, deadly foe

Gravity is probably the strangest of all forces. It is relatively weak compared to the atomic force that holds atoms together. All bodies that have the property of mass have gravity. The more mass an object has, the more gravity it possesses, also the denser an object, the more gravity it possesses.

To escape a gravitational field, you need to go at some velocity. This is called the escape velocity and it increases with gravity strength. The escape velocity of earth is 11km/s. As already noted, gravity increases with density, as a stare collapses, its escape velocity increases by the square root of the decrease in size.

What makes a black hole so deadly is that the gravitational pull is so strong that the escape velocity becomes equal or more than light speed. It is debateable weather anything (or energy) can travel faster than the speed of light. If so, it would be impossible for anything to escape, not even a rocket with infinitely powerful engines!

What makes black holes so difficult to detect is not only that they drag in any detectable energy, but also bend energy around them and focusing it. This form of cosmic lens makes object appear brighter, therefore closer, than they actually are and can some times cause multiple images of object. This is because Einstein’s theory of general relativity says that huge bodies of mass bend space itself. Say space was a flat piece of rubber stretched out, if a ball is placed on it the rubber bends. Say you roll another, smaller ball towards the original ball, it will follow the well created and roll towards the other ball.

Seeing the invisible

One problem with studying the black hole phenomenon is that they have the tendency to bend any energy produced by them into orbit. This leaves no direct traces. Fortunately, they effect the surrounding environment leaving evidence of there presence.

If a partner of a star in a binary system collapsed into a black hole then the ‘living’ one will move in an orbit more biased towards the centre of gravity. This absurd movement can be detected and the gravitational centre determined.

As gas and debris move towards the hole, they form an accretion disk. This is where the gas is so compacted and becoming ever closer to light speed that they are superheated and emit X-rays. These can be detected and a distance calculated.

Bodies of large mass act as cosmic lenses; they bend energy and focus it. If an object seems closer than it should be then there is probably a massive object in the way, bending the detectable energy source.

Anatomy of a black hole

Black holes come in all sizes, from the super massive said to be at the centre of each galaxy, to atom sizes mini black holes that are as massive as a mountain!

Black holes are basically made up of a singularity, an event horizon and a Schwarzschild radius. A singularity is the clasped object, a point (or ring) of infinite density but which occupies zero volume. An event horizon is the edge of a black holes boundary, it is where if crossed, there is no return. Beyond it, the laws of physics break down. No information can be gained from this point as all energy signals get pulled in, there is no record of events beyond this, hence the name event horizon.

A Schwarzschild radius is the area between the event horizon and the singularity. It is a point where gravity is so strong that the laws of physics and time break down. As an object is drawn in, gravity becomes stronger and stronger towards the singularity; this causes the object to stretch. This is called spagetification.

As gravity gets stronger, the object speeds up, getting closer to the speed of light. It is theorised that as you approach light speed then time runs slower and slower. Also, the object would become redder, this is because as light struggles to escape, its wave length is stretched to the more red end of the spectrum.

From the outside, the object would look as if it was slowing down and is frozen in time just above the singularity. In side, time would appear to run as normal.

Three different types of black hole have been discovered so far.

They are as follows.

This type of black hole has a charge. This charge ‘fights’ the pull of gravity and creates a secondary event horizon. The outer event horizon is the point of no return. The inner event horizon is where matter can move freely and is not affected by the pull of gravity. As there is no other force acting on the matter, it will just carry on drifting towards the singularity.

This black hole has a spinning singularity. The rotational force as the star collapsed pulled it into a ring. It, like the Reissner Nordstrom hole has an opposing force, the spin, that creates an inner event horizon. It also has an ergosphere. This is an area between the static limit and the outer event horizon in which the spin of the black hole makes it imposable to be at rest. The static limit is the point where matter is not affected by the spin.

Oh, the possibilities…

Long since their discovery, black holes have inspired and captivated the minds of people. Perhaps it’s the name, which suggests an infinite area or the idea that falling into one is not the end. Whatever it is, there is allot of myth, but some is in debate.

Wormholes

Einstein and his colleague Nathan Rosen declared these would be possible for the ‘throat’ of a black hole to open up into a completely opposite throat and, possibly, universe. The passage, called the Einstein Rosen bridge could create a short cut through curved space.

Using one though is very hazardous as if it is small then the gravity will pull things apart. A spinning black hole should be used or hitting the singularity.

White holes

These are the opposite of a back hole, send out energy and matter. Some physicists theorise that this is not possible as the matter expelled would clump together, collapse, form a black hole and draw in the white hole. These are closely associated with wormholes and parallel universes.

I theorise that a white hole could be formed from opposing forces of charge or spin.

As the spin increases, the inner event horizon grows and the outer shrinks. If they merge, then the two forces cancel each other out. But there is a very little chance of the opposing force to exactly match the gravitational pull of the hole. If it is less (even by a micro fraction), there would still be a cloaking outer event horizon. If it is more, then either it explodes in a spectacular flash of energy, or it will link to a black hole and expel the victims of the black hole. It may also have the possibility of creating antimatter.

According to Einstein’s theory of relativity, gravity bends space like a ball on a rubber sheet, as mentioned above. Black holes generate such a pull that they bend space into an infinite hollow tube. I theorise that if there is a reverse force strong enough, it will pull space up into an infinite hollow tube. It may be possible for the two tubes to pull each other together and form a link, the Einstein Rosen bridge. But as the black and white singularities are at the end of the tubes, then they could meat each other and cancel each other out.

I would like to look into this further…

Bibliography:

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