Physics of Black Holes :: physics science space

What are Black Holes? A black hole is theorized to be a collection of collapsed matter of whose gravitational pull is so strong that not even light can escape its force. The matter is is forced in a very, very tiny area and therefore the matter is very dense. Since light cannot escape, they are considered to be truly black. This, obviously, makes it hard to detect an actual black hole, and therefore, have only been theorizd to exist. These theories are slowly turning into "conclusive evidence." This evidence includes the particle dust given off from matter entering the black hole, as well as observations of orbits of bodies near the black hole. Black holes are usually formed after supernova explosions, in which the remnants of this explosion implodes within itself. It will continue to condense to a volume of zero and infinite density. This is known as a singularity. How do we know? History Karl Swarzschild first came up with the concept of black holes in 1916. This was based upon Einstein's theory of relativity. The Swarzschild radius is the radius where the escape velocity equals the speed of light. The Swarzschild radius can be calculated using the escape velocity equation: vesc = (2GM/R)^1/2 Substituting the speed of light for the v: R = 2GM/c^2 If you notice, the Swarzschild radius is only dependent upon the mass of the body. Anything that enters this radius will not exit, due to the tremendous amount of gravitational pull. So, How do we know? Again, as mentioned earlier, we can't directly observe a black hole. We can, however, make observations to the surroundings around the black hole. It used to be that theorists were the only scientific persons who acknowledged an existence of black holes, however, today, the story is quite different. The popular idea today is that black holes do exist and are common in all the galaxies so far investigated. One reason is Einstein's theory of General Relativity. This theory accounts for the existence of black holes, and if they do not exist, then the General Relativity theories by Einstein would be wrong. Considering all the tests and experiements done to date to try and disprove this theory have all been rejected, this seems unlikely. Also, scientists today look for high concentration of mass in a small area. Calculations and technology allow this to happen. Another factor in proving the existence of black holes is the Hubble Space Telescope. The Hubble Space Telescope has accumulated a large amount of data and information supporting the existence of black holes.