# Definition:Probability Theory

## Definition

Probability theory is the branch of mathematics which studies probability spaces.

## Also see

• Results about probability theory can be found here.

## Historical Note

The discipline of probability theory is suggested by some sources to be a creation shared between Pierre de Fermat and Blaise Pascal.

Their intent was to describe certain games of chance and to calculate various probabilities.

They developed the fundamental principles in a series of letters in the year $1654$.

The field was developed significantly by Jacob Bernoulli, the results of his research appearing in his posthumous Ars Conjectandi of $1713$.

Modern probability theory is more than just calculating the chance of getting $m$ heads while tossing $n$ coins.

It is used to study problems in fields as diverse as economics, genetics, sociology, astronomy and physics.