Beast of Barclay's Bank
Many years ago a strange organism appeared outside a branch of Barclays Bank north of London. The first member of the public to encounter it in the wild was an actor from a TV series. We know how old it is from documentary evidence, but if we didn't we could still carbon date it. Carbon dating uses a weakly radioactive isotope of carbon, carbon-14. If we know the proportion of C-14 in the organism when it was born, we could use the known rate of decay of C-14 to determine the organism's age.
The organism in question apparently had a strong survival advantage and has since proliferated to an unimagined degree. It has now colonized every continent and in some areas can be found almost everywhere, especially densely populated urban areas. It is usually known by an acronym, ATM, but its full name (non-Linneaen) is Automated Teller Machine. It has evolved considerably since its first appearance on earth and now carbon dating is no longer possible. Since ATM's are made out of inanimate materials, you may wonder how it was ever possible. To explain that we have to go back to its birth, 40 years ago. The ATM's father was inventor John Shepherd-Barron, now 82 years old. Like Archimedes, his eureka moment occurred in the bath:
"It struck me there must be a way I could get my own money, anywhere in the world or the UK. I hit upon the idea of a chocolate bar dispenser, but replacing chocolate with cash."
Barclays was convinced immediately. Over a pink gin, the then chief executive signed a hurried contract with Mr Shepherd-Barron, who at the time worked for the printing firm De La Rue.
Plastic cards had not been invented, so Mr Shepherd-Barron's machine used cheques that were impregnated with carbon 14, a mildly radioactive substance.
The machine detected it, then matched the cheque against a PIN number. (BBC)
C-14 emits very weak beta particles, so Shepherd-Barron wasn't concerned about the radiation exposure. It wasn't the only thing that wasn't very powerful. The machine only dispensed £10 at a time. Of course £10 went a bit further then. One consequence of the ATM that went beyond the cash availability is very much with us today: the PIN number.
Mr Shepherd-Barron came up with the idea when he realised that he could remember his six-figure army number. But he decided to check that with his wife, Caroline.
"Over the kitchen table, she said she could only remember four figures, so because of her, four figures became the world standard," he laughs.
Of course now we have much longer PINs and my security codes are so complex -- ten digits, upper case and lower case and at least one number and one special character -- the only way I can remember them is to write them on the blackboard in my office.
That's the price of good security, I guess.
Cross-posted at Effect Measure