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!

Date coincidence

I gave a Maths talk on the 100 Prisoners Problem and prepared a Powerpoint for the talk. On the opening slide, instead of writing the date, I noticed that the next day would be 14th March, or Pi Day, and so I wrote "The Day Before Pi Day". A few months later in the same year I was asked to give the same talk. This was possibly only the second time I have given this talk formally to a large group. I decided to update the Powerpoint, and, naturally, this included the date. I would be delivering my second and last official talk on this topic on 27th June, the day before the 28th June, 2*Pi Day!! What are the chances of that?!

Finding links with someone. Twice.

I am from a small region in Northern Spain (Asturias). I lived there for most of my life and did my degree and PhD in Biology there (Universidad de Oviedo). In the department I used to work with a guy from Mexico DF. Then I moved to Oxford where I ended up living with a girl from Mexico DF and she is now one of my closest friends. After a few months of knowing her, we realise she had been close friends with the guy back to when they were both doing their degree in Mexico DF, more than 10 years ago. Furthermore, we also realised that she was friends with another guy from Barcelona (Spain) that I met briefly in Cambridge. My home town is 900 km from Barcelona.

Unexpected encounter

I live in Brazil with my wife and two kids - a girl and a boy. In june 2010 I travalled with my wife and my daughter (my son had not been born yet) to California. Upon arriving in Los Angeles, we took the shuttle from the rental car company in order to pick up the car we had booked. There was another couple in the shuttle and while we traveled from the terminal to the rental company site, me and my wife were chatting. By the time we arrived at the rental car company office the lady that was in the shuttle approached me and asked if we were from Brazil. I said yes and she followed asking if we were from the city of Curitiba, to which I said yes. She then told me that her brother lived in Curitiba as well, and that his name was Rick. Surprisingly her brother and I used to go to the same gym at that time and used to talk very often! She and her husband were living near the east coast of the U.S. and were travelling to L.A. on vacation. What a coincidence!

Good Cod, I don't believe it

This is not one to read before your lunch. In 1984 I was tucking into a school dinner of battered fish and chips, when I discovered to my horror that the fish contained a coiled up worm or other such parasite. As you might imagine, no more fish for me. About 6 or 7 years later I finally plucked up the courage to try some fish again, the first since the incident. And you’ve guessed it, again I find this particular fish has the same affliction. Somehow I found the whole coincidence so unlikely, that I laughed it off and did return to eating fish fairly regularly. In the 25 or so years since, I have never found another worm in a fish. I recall at the time being told that such fish infections were fairly common. Perhaps food inspection rules or the general health of cod has improved since the 80’s. I’m grading this as once in a lifetime, not because I think it is so unlikely to repeat, but because I sure hope it is.

answered phone in phonebox

It was a long time ago before mobiles. I was about 15 walking through town asked a phone rang in Lloyds avenue arches Ipswich and I walked over to answer I knew who it was and they asked for me. It was weeiirrdd. I will never forget it. I exclaimed my incredulity to them telling them I was at a public phone cubicle and I just happened to answer it. The details are hazy now it was 30 years ago but I remember it ringing and answering it and the shock of it. I seem to remember the friend on the phone didn't seem to understand what was happening, the coincidence of it. I am going to go and look at the phone number of the phone when in town next to see if it is similar our home phone at the time.

Gravestone

In 1975 I moved to the town of Hattiesburg MS to complete my degrees in Psychology and Nursing. I had brought my bike with me, and after moving into my apt, I decided to take a bike ride. I was riding along one of the main streets in town when I saw an old cemetery off to my left. I have always loved cemeteries--the quiet and peacefulness--and I liked to look at gravestones and see how old the person was at death and speculate on how he/she might have died. The cemetery appeared deserted, and I rode my bike along a little path for a ways. After a bit I decided to get off my bike and read some of the gravestones. The VERY FIRST one I looked at had my name on it. The lady was buried next to her husband Albert and she had died in 1958.

Same Birthdays

I graduated high school from the small town of Port Gibson MS in 1966. In our class of 42 students, five of us had the same birthday, Dec. 19. My name is Alice Carroll (maiden name--Sanders). I remember the names of the other 4 classmates with my birthday, but will not relate them here unless needed by the coincidence investigator.

Ex school classmate

While on a cruise to Norway I met an ex classmate who I had'nt seen for 63years.

Weird and geek like coincidence

I lived in Rhodesia in the 1960's and at the age of 14 (ie: 1970), I read a science fiction book that I found fascinating it was called "Earth Abides" by George R Stewart, written in 1949 and was a post-apocalyptic science fiction novel by American writer George R. Stewart. It tells the story of the fall of civilisation from deadly disease and its rebirth. The story was set in the United States in the 1940s, in Berkeley, California and the main character used a 2pound hammer to break lock to get into building for searching for food items and the like. Anyway I left Rhodesia returned to my home town in Scotland in 1973, damaged ny back in a motorcycle accident and had a lumbar disc removed in 1977 and changed career and ended up working as a computer programmer for the Scottish Health service in Edinburgh in 1986.

Even when you know the odds

A couple of years ago I decided to introduce my 8 year old son to probability theory (he loves maths), and sat down with a coin and pencil and paper. I explained that if we made 10 guesses for the toss of the coin, that about 5 of those guesses would be correct – whatever he chose. To prove the point, I chose HHHHHHHHHH, and he carefully guessed 10 well mixed sequences of H and T. We then tossed the coin 10 times, I scored 6 matches, he scored 4. Nice result. He was intrigued, so we played again. On this second run, to my astonishment, his prediction of the sequence of 10 was spot on. Ok, so there is a well-defined probability of 1 in 1024 for either of us to guess all 10 correctly, and we did play twice (approx 1 in 256). However, what coincidence that this happened so quickly, and whilst I was trying demonstrate how unlikely it was. Even mathematicians and their physic sons find such events worthy of note.

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