Fire is an example of the fourth state of matter, which is called plasma. A plasma is similar to a gas in that it's particles are spread far apart and have no attraction towards each other. They are different in that the atoms that make the particles up have been stripped of their electrons, producing positively charged nuclei and negatively charged electrons, all independent of each other. Plasmas occur in space in stars, like our sun. Plasmas also occur on Earth, as fire, lightning, fluorescent light bulbs, and in electronics, such as plasma television sets. Plasmas are also produced as an interaction between charged ion streams from the sun when they reach our ionosphere, called the aurora borealis and aurora australis. The borealis is the northern lights, while the australis is the southern lights. The other three states of matter are solids, liquids, and gases.