Pi

Normally I am not a numbers nerd but this is where I cross over into the world of numbers. 

This strange number has of course solved equations both simple and complex.  It is however the less interesting portion of its history from my prospective.  All irrational numbers regardless of their identity are continuous,and as far as we know they are infinite, never repeating (starting over).  This led to some serious difficulties in history.  You see numbers were the way man made sense of the world, trigonometry and geometry were especially revered for making the universe make sense.  Yet here we have the ratio of a circle's circumference to its diameter, a seemingly innocuous value somewhere between three and four.  I say somewhere because we really don't know.  How is this you say? Oh know you've just fallen into the rabbit hole, you have asked the nerd a question! See we have tried to determine exactly where pi is on the number line and failed.  Not that we haven't made progress, we have!  We have in fact calculated out to 5 trillion digits of this number, but we will never hit the end of it.  It is as if God is laughing at the human need to solve everything.  The most complex part of this for some to comprehend is that this number is not even remotely unique; in fact it is true that all numbers share this irritating nature.  There is in fact an infinity between any two numbers. If I say I am 99% sure of something that means that I am not 99.9 % sure, if I am 99.999999999999999999% sure than I am still not 100% sure!  As a matter of fact no matter how many nines I put on the end I will never reach a hundred percent! Thus Zeno's paradox Achilles and the tortoise (seehttp://en.wikipedia.org/wiki/Zeno's_paradoxes).  This number pi is different because it was one of the first we cared about.  The different ways we have found to calculate it is why it is interesting to me.  See for a circle the size of the known universe with accuracy in the sub atomic range, we need....wait for it.... around 40 digits!  So why 5 trillion and counting?  Mathematicians are nuts!  A professor at my college put it this way when talking about science "all biologists are in essence chemists, all chemists are essentially physicists, all physicists are mathematicians and of course all mathematicians are crazy!".  So, once you've caught the science bug, you can expect people to use very logical and rational techniques to do the most irrational things!  (Pun intentional).