Chaos theory is a mathematical theory basically says that small differences in calculations that do not effect a small sample, may have gigantic effect on a large sample. Think of it like if you were counting the grains of sand on a beach and you missed a few. That would not matter and your answer would be basically right for a single calculation. However, if you did that over and over million times, your answer would be way off and you might not know why. You can find more information here: http://en.wikipedia.org/wiki/Chaos_theor...

Chaos theory refers to the sensitivity and unpredictability in complex systems. Someone who studies chaos theory is called a chaotician. You can find more information here: http://www.wisegeek.com/what-is-chaos-th...