Today - 26 September - is Susan's birthday!
It is also that of approximately 18.579436949424012813404792706216 million other persons - give or take a few. Assumptions behind this calculation:
- The world's population today is 6.786 billion
- Babies are as likely to be born on any one day as on any other
The world's population figure must be correct, because it is taken from that impeccable source: Wikipedia.
The assumption about the probabilities of birthdays is questionable, but are you going to be able to prove me wrong? I don't think so!
I point out the (approximate) number of other persons (I don't vouch for all the decimal places; that just comes out of Windows Vista's calculator, when dividing 6.786 billion by the number of days in a legal year = 365.2425 (think about it - remembering that years divisible by 100 but not by 400 are not leap years; I'm sure you'll work it out) - I point out, I say (a long parenthesis back), the number because today is also the birthdays of:
- Susan and my close friend Jenni Surrey
- Our daughter Helen's husband Robert's
And Susan thinks this amazing. I have offered the to calculate the probability, given a number of friends, that some two - or three, or whatever - have the same birthday, but she has declined. This is lucky for me as I am by no means certain I could make that calculation (correctly, that is).
The world has become a more boring place. I just wondered whether Wikipedia (again) could tell me that probability. It can. Sad when the mystery goes out of life. But looking at that page, the maths seems sufficiently opaque as to ensure I would get tired of trying to understand it before having finished.
Tuesday last, the 22nd of September, was my birthday - and also those of Bilbo and Frodo Baggins - so there! I did not blog last week-end, and I could tell you that the reason was because on the Sunday - the 20th - we went up to Eddie and Eveline's for what was the official John and Susan Birthday Lunch. It is true that we went - and had a lovely time with them all - but it would not be true. I could have blogged on the Saturday but did not - because I forgot.
Actually I just read the Birthday Problem page and it turns out to be pretty simple after all - ah, well!
Sue and I will leave shortly (this Saturday afternoon) to stand as Godparents for Gerard and Delia Farrell's new daughter (whose name, I am informed, is Magdalena); then off to Little Thai Restaurant for dinner. Little Thai is the only proper restaurant (as opposed to Burger Fuel, where we go for takeaways) that we go to. The reason: both cater to Susan's no-gluten needs.
And let me take this opportunity to wish a hearty 'Happy Birthday' to all 18.579436949424012813404792706216 million (minus one) of the rest of you whose birthday is today.