# World celebrates the ongoing mystery of pi

WARNING: The following Bushwhacked column contains actual science, mid-level algebra and may contain traces of facts.

In secondary school I did a mixed blend of humanities and sciences because I had no idea whatsoever what I wanted to do in life. Still don’t. The humanities subjects seem to have lodged in the deep recesses of the brain while the sciences didn’t make it to the end of year 12.

Oh, in the stupid small hours of the morning I can occasionally recite, parrot-fashion, that S=ut+1/2at squared, but the only time that came in handy was when I was dared to jump from a cliff into the sea, and by dropping a rock and timing its fall, I knew I was about 12 metres up.

The other thing which has stuck with me all these years is the fascination of pi (note: not pie. That’s an entirely different, but genuine fascination.) No, I’m talking π.

(Pause for explanation.) Pi is a truly weird phenomenon in the science world. At school, we learned it was 22 divided by seven. But over the years I’ve learned that’s not quite right. It’s the magical number which can allow you to do all sorts of things, such as calculate the surface area of a footy oval, the amount of fencing you need around the oval. Important stuff like that.

It is the ratio of a circle’s circumference to its diameter. One other remarkable thing it can do is help you find out how much beer is in a can.

Today, ladies and gentlemen is World Pi Day. Yep, it’s July 22. Clever, eh? It used to be on March 14 because one simple calculation of its value is 3.14. Not so clever.

In the US, this day is marked by pie eating and pie tossing. Which just goes to show that science geeks need to get out more.

Pi is interesting enough on its own without being dressed up with silly puns on its name. You’ve got to be careful about this because if you let geeks loose with this stuff, it can end in outbreaks of Morris-dancing.

We thought at school that we were oh so clever being able to quote equations which included π. 2πr. And π diameter.

Little did we know we were barely standing on the bottom rung of the scientific ladder. Indeed, those who had gone as much as two millennia before us were much smarter.

The mathematical constant π was known in at least Egypt and China before our year zero. It is thought to have been part of the process in calculating how to build the pyramids. In antiquity it’s known the Chinese calculated it to the seventh decimal point. The Indians calculated it to the fifth decimal.

The Babylonians first calculated it as 25 divided by eight. The Egyptians used 256 divided by 81. We now reckon 22 divided by seven is close enough.

But the actual, final value of π has never been pinned down. In Medieval times, it was calculated to the 11th decimal place both in England and India.

Last year, a computer took 23 days to calculate it to the two quadrillionth place.

That’s amazing. But it’s even more amazing that people in vastly different parts of the ancient world came up with the same value around the same time.

How did they arrive at this magical constant? Who was the first person to wake up with pi on his mind?

We think we’re so scientifically advanced in 2016, but can you imagine the metal discipline it must have taken someone in India or Babylon more than 2000 years ago to even arrive at the mathematical concept of π? Happy Pi Day, you saucy lot.

**WAYNE GREGSON**