Your number is in π.*
We looked. All 100 billion digits. Twice, for luck.
Homework
(optional, but fun)Every one of these runs on the same digits. None of them will help your career.
Q1Pi-dle
One hidden word a day, eight guesses to find where it lives.Wordle's nerdier cousin.
Q2Couples counselling
Two names, one π, an exact distance.Arithmetic instead of feelings. 30 million digits is 0.03 seconds. Romantic.
Q3Dial a digit
Any position up to one hundred trillion.The world's longest phone directory. The 100-trillionth digit is 0. We were also disappointed.
Q4Trial by mathematics
Two names enter. The one π mentions first wins.Settle it like adults.
Q5Digit Roulette
One mystery decimal a day. One guess.A one-in-ten chance, every single day. The house is π.
Q6Higher or Lower
Two famous things. Which turns up first?Pizza or pasta. Finally, a scientific answer.
Q7Love Hunt
Hide a secret message in π, one word per clue.Passing notes in class, with extra steps.
Q8Memory Trainer
Ten new digits a day. How far can you go?Revision, but for a number that never ends.
Q9Hall of Finds
Everyday words visitors found, and how deep they hide.A trophy cabinet with no trophies. Just depth.
Q10The Pi League
Clubs, countries and cities, ranked by who turns up first.The only table where being early beats being good.
How deep does your number go?
Short numbers turn up immediately. Phone numbers need billions of digits. Bring snacks.
- Feynman point: π stutters on 9 (around 762 digits in)
- your PIN, probably (around 6,900 digits in)
- your birthday (DDMMYY) (around 690,000 digits in)
- an 8-digit number (around 69 million digits in)
- your phone number. bring snacks. (around 6.9 billion digits in)
- 99% of phones by here (around 46 billion digits in)
Questions from the back row
Do you store my number
No. We're forgetful by design. Your number goes in, a position comes out, and we immediately lose interest.
Is every number really in π
Probably. Mathematicians have suspected it for centuries and proved it for none of them. They remain polite about it.
Why 100 billion digits
Because 99.995% of phone numbers fit. The other 0.005% have been informed.
Who's hiding behind the π
Famous people, a pie and ten digits. None of them were asked. All of them would have said yes.
Isn't this just Life of Pi
Fewer tigers, more digits. But the boy in that book did chalk π on a blackboard to claim his own name, which makes him the patron saint of this lecture hall. Read the Life of Pi note.
This whole idea started with a conversation on The Rest Is Science. Read the thank-you note.