This Saturday is **International Pi Day. **

In fact every March 14th is International Pi Day (it’s 3/14, at least if you’re an American), but this year is particularly special. On 3/14/15 at 9.26 and 53 seconds, we’ll be able to celebrate the magical number’s first 10 digits.

‘We’, of course, meaning ‘men’ – throughout history it has tended to be the male half of the species that gets excited about pi. Maybe chasing what we know will be an endless stream of digits is just another example of us loving pointless pursuits, like trainspotting or supporting the England cricket team.

Either way, here for your delectation are several slices of pi:

**3. **The Greek mathematician Archimedes was obsessed with calculating pi. When the Romans invaded he was so engrossed in a mathematical drawing that he yelled at an enemy soldier: ‘Do not touch my circles!’ The soldier’s response? He cut Archimedes's head off.

**. **The Persian scholar Al-Khwarizmi (c.780-c.850) calculated pi to four places (3.1416). His term al-Jabr (adding the same number to both sides of an equation) gives us our word ‘algebra’.

**1. **Dutchman Ludolph van Ceulen extended the run to 35 places. When he died in 1610, '3.14159265358979323846264338327950288' was engraved on his tombstone.

**4. **Supercomputers have now worked pi out to over 13 trillion places – and still there are no patterns or repetitions.

**1. **In the Star Trek episode ‘Wolf in the Fold’, Spock defeats an evil computer by ordering it to 'compute to the last digit the value of pi'.

**5.** During the OJ Simpson trial, one of OJ's lawyers argued with an FBI agent about the value of pi – it was his way of questioning the agent's intelligence.

**9.** Pi is the secret code in Hitchcock's Torn Curtain, as well as The Net starring Sandra Bullock.

**2. **In the first million digits, the sequence '12345' occurs eight times.

**6.** The most frequent digit in the first million places of pi is 5, with 100,359 appearances. The least frequent is 6, showing up a mere 99,548 times.

**5.** Did the ancient Egyptians know about pi when they built the Great Pyramid at Giza? The ratio of its height to the perimeter of its base is the same as that of a circle’s radius to its circumference.

**3.** Coincidentally, International Pi Day is also Albert Einstein’s birthday.

**5. **Beginning at the 762nd decimal place there are six consecutive 9s. This is known as the Feynman Point, after legendary American scientist Richard Feynman. He joked that he wanted to memorise pi up to that point so he could recite the 9s then say ‘and so on’, thereby pretending that they recur forever after that point. (This is a scientist’s idea of a joke.)

**8.** The amateur British mathematician William Shanks spent 15 years of the 19th century calculating the first 707 digits of pi. Unfortunately he made a mistake after the 527th, meaning the rest were all wrong.

**9. **Another blunderer was Kate Bush. Her 2005 Kate Bush song Pi concerns a man with ‘a complete infatuation with the calculation of pi … he must, he must, he must put a number to it’. As part of the lyrics Bush recites pi to 116 decimal places. But she gets them wrong: the first mistake comes after 53 digits, and later she misses 22 digits out completely.

**7. **Want to remember the first 7 numbers, including the 3 before the decimal point? Simply count the letters of each word in the sentence 'How I wish I could calculate pi'.

**9.** A slightly longer ‘piem’ is ‘How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics.’

**3.** As recently as 1973, the official world record for memorising pi was a mere 930 digits (Nigel Hodges, Great Britain).

**2. **By 1975, however, the impressively-named Simon Plouffe of Canada had raised the bar to 4096.

**3. **In 1978 American David Sanker went through the five-figure barrier, clocking up 10,000 digits.

**8. **Since 2005, the record has stood at 67,890 digits, a feat achieved by 24 year-old Chinese graduate Lu Chao. It took him 24 hours and 4 minutes to recite the numbers.

**4. **That’s the official record, mind you. Guinness World Records won’t recognise the efforts of retired Japanese engineer Akira Haraguchi, despite his 2006 recitation of the first 100,000 digits being filmed. (Even his toilet breaks were filmed, to show he wasn’t cheating.)

Haraguchi – who has been known to forget his wife’s birthday – says that memorising pi is ‘the religion of the universe’, and an expression of his search for eternal truth. He even chants it quietly at funerals, ‘as if I were chanting a Buddhist sutra’. But then he is a man.