What happens if you measure your fingernail for 30 years?
Nail growth: 30 years of observation
A doctor measured how fast his own fingernail grew, faithfully, for three decades (and kept going).
Ig Nobel 2025
Dr William Bean started tracking the growth of one of his own fingernails as a young man and simply never stopped. This paper reports 30 years of his careful measurements; he went on to publish an update at 35 years too.
Over the decades his nail grew a little more slowly as he got older. It is a lovely example of curiosity plus patience, carried out with nothing fancier than a nail and a notebook.
Some people keep diaries. Dr Bean kept a fingernail.