Pi

Pi (π), Mathematicians are engulfed by it and for good reason. It really is the definition of 'Eloquent Math'; an irrational number that is one of the most important constants used in Mathematics that can be so simply found and represented. Circumference of a circle/diameter of circle.

Pi is a number, which for a lack of better words is a number that is infinite and does not repeat its decimal representation at any stage; this alone makes it rather unique (barring Euler's constant and √2) and perhaps that is a reason behind it having such a huge popularity amongst Mathematicians and nerds alike.

At the current moment in time pi has been calculated to over one trillion decimal places, that my friends is how fixated Mathematicians are on pi! However this is really not necessary other than pure curiousity and looking for patterns in pi and to try and understand it some more. Pi calculated to 11 decimal places can accurately estimate the circumference of any circle that fits inside of the Earth to one millimetre; and if pi is represented to 39 decimal places you can estimate the circumference of any circle inside the observable universe to the radius of one hydrogen atom. To a trillion decimal places there would be nie on zero error whatsoever (about 3*10^-10 the radius of a hydrogen atom).

If you are beginning to be as fascinated with pi as I, and many others are, take a look around the internet and at the link to Yann Martel's "Life of Pi" that is a very compelling read.

Or if you'd prefer, the hardcover: