Singularity- At the center of a black hole lies the singularity, where matter is crushed to infinite density, the pull of gravity is infinitely strong, and spacetime has infinite curvature.
Spacetime- the theory of relativity predicts that time, like space, is a dimension. In order to describe a four dimensional universe which has three spatial dimensions and one time dimension the word "spacetime" was coined.
Density- ratio of the mass of a body to its volume, usually expressed as its specific gravity.
Gravitational field- area surrounding an object, in which a gravitational or electromagnetic force is exerted on other objects.
Event horizon- the area in which things get sucked into (it is much greater than the black hole itself.) where we cannot see beyond.
Schwarzchild radius- the radius of the event horizon.
Hawking Radiation- The positive particle of a virtual particle pair released from the event horizon of a black hole after the negative one is absorbed.
Gravitational collapse- When a massive object collapses under its own weight.
Hubble space telescope- t he first general-purpose orbiting observatory. Named after American astronomer Edwin P. Hubble.
Hydrogen- chemical element that exists as a gas at room temperature. It is odorless, tasteless, colorless, and highly flammable.
Star- a burning object, like a planet but with fire, e.g. our sun.
Planet- any of the nine major celestial bodies that orbit the sun and shine by reflecting its light, or any similar celestial body orbiting a star other than the sun.
Singularity- the concentrated mass at the center of the black hole.
Vincity- surrounding area of the black hole.
Gravitational radiation- The energy that is emitted by strong sources of gravitational waves, for example, certain collapsing or colliding stars.