Now and then, admittedly out of uncertain motivation, I like to take a journey into the frivolous.
I once read a "Ripley's Believe It or Not" claiming that fingernails grow at twice the rate at which toenails grow. Why that might be so I have no idea, but it got me curious about just what kind of growth rates were being addressed. I decided to find out by enacting the cliché of watching one's nails grow. (I still don't have the patience to watch paint dry.)
Using a rigid box to position my camera at exactly the same height each time, I photographed my hand on a flat table top over and over again through a period of thirty-seven days until I felt I had a before and after pair of pictures which I could compare.
The collected pictures looked like this:
Taking the first and the last pictures, I photographed a ruler that I placed on the table on top of two pads of 8½x11 paper to bring the ruler to the same elevation as one fingernail.
I then made measurements from those three photographs with the following result:
The 1.4 mm of growth doesn't sound like much, but do you remember that old cigarette ad about that "silly little millimeter"?
My next move was to go find a nail scissors.