5 GREAT IRRATIONAL NUMBERS

  1. π
    Pi - The ratio of a circle's circumference to its diameter. 3.14159...
  2. e
    Euler's Number - The base at which a population's exponential growth rate equals its size. 2.71828...
  3. ψ
    The Golden Ratio - the proportion by which a square can be cut from a rectangle, leaving behind a rectangle of the same proportion. Also the limit of the ratios of the Fibonacci numbers. 1.61803...
  4. √2
    The length of the diagonal of a unit square. The first number proven to be irrational. 1.41421...
  5. γ
    Euler Mascheroni Constant - the difference between the sum of the first n terms of the harmonic series and the natural logarithm for large n. Closely related to the distribution of prime numbers. 0.57721...