On 14 March 2015 the Winnipeg Skeptics held a Pi Day celebration, which featured games, trivia, and lots and lots of pie.

Since not everyone could make it out and people seem to like this sort of thing, here’s some pi- (and pie-) related trivia!

**Question One**

In the Star Trek episode “Wolf in the Fold”, the Enterprise’s computer (spoiler alert) becomes possessed by the spirit of Jack the Ripper. (God, Star Trek was dumb sometimes…) How does Spock foil the evil computer? (Answer)

**Question Two**

The digits of pi go on forever in a seemingly random sequence, meaning that it falls into which class of numbers? (Answer)

**Question Three**

Who said, “If you wish to make an Apple Pie from scratch, you must first invent the universe”? (Answer)

**Question Four**

While pi is popular, a minority of mathematicians argue that a constant equal to 2π would make for a better circle constant, for a host of (I think very convincing) reasons. What do they call their “2π” constant? (Answer)

**Question Five**

How long has the Greek letter “π” been used to represent the circle constant? (Answer)

**Question Six**

This successful World War II operation, which involved persuading the Germans that the Allies planned to invade Greece by planting fake war plans on a corpse in Spain, was named after a suet pie. (Answer)

**Question Seven**

Pi Day (14 March) is also the birthday of which famous physicist? (Answer)

**Question Eight**

According to a band member, a vision involving a man atop a flaming pie influenced a famous band’s name. Which band? (Answer)

**Question Nine**

Some of the earliest attempts to understand pi involved trying to do something that has now become a euphemism for a hopeless or impossible task. What is it? (Answer)

**Question Ten**

In 2005 the world record for memorizing the digits of pi was claimed by Chao Lu, a Chinese engineering student. How long did he spend reciting pi? (Answer)

I was going to have some questions about radians, but I couldn’t figure out how to formulate them in a way that was remotely entertaining. So… there aren’t any. You’re welcome.

**Answer One**

He instructs it to compute pi right down to the last digit, a task that it can never complete.

**Answer Two**

Irrational numbers

**Answer Three**

Carl Sagan

**Answer Four**

Tau. Pi is defined as the ratio of a circle’s circumference to its diameter; but it’s often written as the ratio of a circles circumference to double its radius (remember C = 2πr?). Tau is the ratio of a circle’s radius (rather than circumference) to its diameter, and it simplifies many common mathematical formulae.

**Answer Five**

About 300 years. It was William Jones who chose the Greek letter “π” to represent the circle constant in 1706. This choice was later popularized by Euler. Before the symbol’s introduction, mathematics was a lot wordier, involving things like, “let x be the quantity which, when the diameter is multiplied by it, yields the circumference”.

**Answer Six**

Operation Mincemeat, which was a British disinformation plan that persuaded Germany that they had accidentally intercepted “top secret” Allied documents. These plans were attached to a corpse deliberately left to wash up on a beach in Punta Umbría in Spain, and served to cover the actual Allied invasion of Italy from North Africa.

Mincemeat itself is a mixture of chopped dried fruit, distilled spirits and spices, and sometimes beef or suet. Originally, mincemeat always contained meat, but this is no longer the rule.

**Answer Seven**

Albert Einstein

**Answer Eight**

The Beatles. In a 1961 interview with Mersey Beat, John Lennon told the following story: “It came in a vision – a man appeared on a flaming pie and said unto them, ‘From this day on you are Beatles with an A.’ And so we were.”

**Answer Nine**

Squaring the circle. That is to say: constructing a square with the same area as a given circle using only a compass and straightedge.

**Answer Ten**

24 hours (and 4 minutes). So if you spent Pi Day eating pie, or doing anything at all other than reciting numbers, be grateful. In 2005, Chao Lu recited 67,890 digits of pi correctly, claiming the previous record from Hiroyuki Goto of Japan. Goto’s record was 42,195 digits. How useful is this? Well, for comparison, you could compute the circumference of a circle around the known universe with an error no greater than the radius of a hydrogen atom using only 39 decimal places.