# Interesting things about PI(2)

March 30, 2012 | In: Science facts

In 1882 Lindeman proved that Pi was transcendental, that is, that Pi is not the root of any algebraic equation with rational coefficients. This discovery proved that you can’t “square a circle”, which was a problem that occupied many mathematicians up to that time.

Although it is a very hard question, PI can be measured, but on a very small scale, meaning you can calculate it on you own circle. Let’s take a jar cap, for instance. We can measure the circle’s circumference with a simple cord and the diameter as well. The value of PI is *Circomference divided by diameter*.

This is a nice trick, but you’ll find that your answer will be aproximately 3,1. It’s actually 3,14.

Even today, PI continues to be a fascination of many people around the world. If you are interested in learning more, there are many web sites devoted to the number Pi. There are sites that offer thousands, millions, or billions of digits, pi clubs, pi music, people who calculate digits, people who memorize digits, Pi experiments and more. Many thinkers, including philosophers tried to give PI an ultimate response, but, as you know, even the best computers in the world are trying harder. Here’s a bunch of formulas:

** Leibnitz’s Formula**

PI/4 = 1/1 – 1/3 + 1/5 – 1/7 + …

**Wallis Product**

PI/2 = 2/1 * 2/3 * 4/3 * 4/5 * 6/5 * 6/7 * …

2/PI = (1 – 1/2^{2})(1 – 1/4^{2})(1 – 1/6^{2})…

**Euler’s Formula**

(PI^{2})/6 = (n = 1..) 1/n^{2} = 1/1^{2} + 1/2^{2} + 1/3^{2} + …

And here’s one for you: did you know that you would only need to know pi to 47 digits to work out the circumference of the universe and be only one proton off?

**Link to this page**