Cambridge Coincidences Collection

As of the 23rd May 2022 this website is archived and will receive no further updates.

understandinguncertainty.org was produced by the Winton programme for the public understanding of risk based in the Statistical Laboratory in the University of Cambridge. The aim was to help improve the way that uncertainty and risk are discussed in society, and show how probability and statistics can be both useful and entertaining.

Many of the animations were produced using Flash and will no longer work.

Well I Never!

Professor David Spiegelhalter of Cambridge University wants to know about your coincidences!

The Clarks of Ashford

In 1987 two people got married; one from Holland one from England. Mr Clark's birthday is on 21 December and his grandfather's birthday was on 22 December. His wife, Mrs Clark, has her birthday on 24 December and her grandfather's birthday was on 23 December. This was not discovered until some time after they had met. Although Mr & Mrs Clark have birthdays that are only just over a year apart, the grandfathers had some years between them. Also, Mr Clark's mother shares a birthday with a sister of Mrs Clark's mother. Mrs Clark's mother shared a birthday with Mr Clark's grandmother. The son of Mrs Clark's sister was born on the 25 September and Mr Clark's brother was born on 24 September. What is the chance of this?

The world's most boring book

I have been spending today at home rewriting a set of notes on discrete event simulation for a group of business students. It's a topic I dropped for a while, but had just decided to reinstate it in a slightly different form. I was working my way through the final lecture on random numbers, trying to shorten it, and wondering if all the stuff on external number generation was worth keeping.

Crossword answer on TV

Since I took early retirement I have become somewhat addicted to prize crossword puzzles and competitions. Last Monday I started completing a Crossword puzzle in Chat magazine (Issue 43, p7). My daughter, meanwhile, was watching an old episode of Frasier on TV. As Niles Crane offered a guest some pâté, at that very exact moment I read the clue for 4 down (Meaty spread, 4 letters).

BIRTHDAYS ON SAME DAY TIMES 2

There are 12 people in our office. Two of them share a birthday. Therefore the odds of this are 16.7% (1- 364/365 * 363/365*362/365*...354/365). Hope this maths is correct. BUT my problem is that another pair of people share a birthday (on a different day). What are the odds of this happening? Thanks

Hymn writers age at death

Recently at a local Methodist service I noticed that of the five hymns chosen by the preacher, the writers in the case of three of them all died at the age of 61. The translater of the fourth also died at the age of 61. The hymn book has the dates of the writers etc. printed after each hymn and I always look whilst enjoying singing!

Peter and the Wolf

When my children were little, they were listening to Peter and the Wolf on an audio cassette while we drove in the car. As we were approaching a tricky junction I wanted to concentrate on the traffic so I hit the stop button on the player. The music continued uninterrupted and I thought the tape had got caught up in the works (as they used to). I pushed the eject button, the tape shot into my hand and the music continued uninterrupted! The radio was set to Radio 3 and the tape was perfectly sychronised with a performance of Peter and the Wolf, in the exact same bar, note, chord and same pitch...well A440 concert pitch. Clearly not impossible but...? Can I submit more than one?

Mr Andrew Eaton

Hi David, from a mathematics teacher - so with a keen interest in your work. In 2007 in my new Year 9 class here at Notre Dame High in Norwich I met a student called Isobel Wood. To help me learn names I used to do the '23 people in the room' needed for a 50% chance of a repeated birthday. Isobel shared the same birthday as me (9th June). In 2010, again in Year 9, another different Isobel Wood appeared on the register. I wish I had PREDICTED her birthday but didn't - how cool would it have looked! Her birthday too was 9th June. What are the chances please? (as Harry Hull might say). Keep up the good work - a former student now studying Actuarial Science at the UEa is a big fan! Kind regards A Eaton - off to buy Ed Smith's book.

telephone coincidence

My sister and I only ring each other once in a blue moon. One day I thought to give her a call and I picked up the phone and I was just about to dial when I heard a voice on the line. I said to the person on the line that we must have a crossed line. Anyway the voice said " Don't be stupid, It's your sister ! " The phone hadn't even rung before I picked it up so we had totally coincidentally telephoned each other at the same moment.

Precisely calculable 1 in a million chance

I bought a 3 digit combination lock for my bicycle at halfords. By chance(?) I got number '835' the first 3 digits of my 6 digit telephone number (after the area code). I lost the lock. My closest friend gave me his old combination lock - number '016' the last three digits of my 6 digit telephone number.

home coincidence

Having moved from Cornwall to Troon in South Ayrshire last year,I was keen to make new friends: I joined a T'ai Chi class in Prestwick and quickly made friends with Jennie. She gave me a lift home on one occasion and asked where I lived;when I gave her the address,she asked for the number of my flat;it turns out that I now live in the flat formerly occupied by her late mother-in-law.This flat was sold to my -(then)-lanfdlord. Furthermore,it then transpired that Jennie's husband and I had both been working at London Heathrow as Immigration Officers in the 1970s. He was the first and only person I have met who did the same rather specialised job at the very same time as me.

Pages