Matter can be defined as anything that occupies space. This would include all of the material that makes up our universe. On earth, matter is found naturally in three states, or structures, including solids, liquids and gases. In space, a fourth state of matter known as plasma is more typical.

Since the beginning of history, man has attempted to understand the changes that go on in the environment all the time. To this end, scientists and philosophers developed different theories to explain the nature of matter. The ancient Greeks were particularly prolific in this area. One of the first people to provide a theory of matter was the Greek philosopher Anaxagoras around 500 B.C. He suggested that each substance had its own "seeds" that came together to form substances. Later, Empedocles postulated that there were only four basic seeds or elements including earth, air...