Think back to your early school days. Sitting in the Math class learning about that mystical, irrational number which is the ratio of a circle’s circumference to its diameter or “pi r squared”.
Yes that pi.
And today, Saturday March 14th 2015 is (unofficially) Pi Day, mostly celebrated in countries that use the month/date format.
Not only that, it’s a very special pi day that occurs only once each century because for a brief moment in time, at 9.26.53 am to be precise, in numerical format it will be the first ten consecutive digits of pi – 3 14 15 9 26 53.
HISTORY OF Pi
Pi is a very old number.
In 1706, an English mathematician, William Jones, was the first person to use the Greek letter Pi for the number. In the Greek alphabet, Pi (π) stands for ‘perimeter’.
From history books, we know that ancient Egyptians, Greeks, Hebrews, and Babylonians knew about its existence and their mathematicians had worked out that it was approximately 3. The Bible sets it at exactly 3.
Curiously, scientists investigating the construction of the Great Pyramid of Giza discovered that its perimeter ratio is approximately twice pi, demonstrating that the builders knew of and used this formula.
It’s an infinite decimal – in other words, you’ll never get to the end of it. In 2013 computer scientists worked it out to 3 plus more than 13 trillion digits.
Even Einstein got in on the act.
His General Theory of Relativity states that pi can’t be created precisely by simply measuring a circle, because we live in a curved universe. And circles can never factor out to pi on a curved surface. However, pi is always the same number, no matter which circle you use to compute it.
Pi FUN FACTS
- Some people celebrate by waking up at exactly 9.26.53 am
- Lots of pies are eaten in honour of Pi, some decorated with the π symbol
- Daniel Tammet, an amazing autistic savant, set a European record after reciting from memory, 22,514 consecutive pi digits in 5 hrs 9 mins – with no mistakes
- This quirky website lets you find your birthday using the first 200 million digits
- A couple of Artists, Martin Krzywinski and Cristian Ilies Vasile created a fabulous Archimedean spiral by giving each pi digit a colour and used the first 13,689 to create the spiral
- Google search ‘digits of Pi’ to find endless lists of computer calculations for pi. Really?
- On the World Science Festival website you can test your knowledge with their Pi Day quiz
- It has even featured in an episode of Star Trek. Spock tells an evil computer to compute pi to the last digit (which is highly illogical – Spock’s favourite phrase) thereby destroying the nasty computer.
If, like me, you decided pi was one of those necessary evils you needed to know about to pass your school exams, but couldn’t ever imagine using, then you’d be wrong. Pi is actually used in everyday situations.
- In navigation: planes flying long distances actually follow the arc of a circle and need to calculate fuel, distance, weather accurately
- GPS uses Pi to help you find your location
- It’s used in geometry to calculate areas or arc lengths
- It’s used to calculate signals ie radar, television, radio
- Engineers use it to represent unknown factors in testing and simulation projects
If you want to type the pi symbol on your PC, hold down the Alt key and type 227.
On a Mac hold down the Alt/Option key and type P.
If you’re a lover of coincidences and quirky facts, you might like to know that today, 3/14, is also Albert Einstein’s birthday and 2015 marks the 100th anniversary of his General Theory of Relativity.