Douglas Reid Skinner
The first precision atomic clock
was built in 1955
by Louis Essen and Jack Parry.
It was accurate measuring down
to a millionth of a billionth of a second
and worked by counting the number of times
an atom of caesium-133
flipped from one state to another.
Defined this way, a second’s the time it takes
for nine thousand, one hundred and ninety-two million,
six hundred and thirty-one thousand,
seven hundred and seventy spin flips
to have happened in your atom,
which on any one day is much the same time
as an Amethyst Woodstar hummingbird
requires for the eighty wingbeats that keep
it hovering in place and sipping nectar
from a delicate floral trombone.
Featured at The Red Wheelbarrow on 25 August 2022