Editorial A Second Look
The smallest common unit of time is also one of the most fascinating.
This year feels longer than usual. Anyone else feel that way too? Looking back on our marginally younger selves, on December 31 2019, 11:59:59 PM, anticipating what the new year would bring — who wants to go back to that time? Well, we can’t. We can’t move about in time the same way we move about in a physical space, this is what some physicists theorise is the limitation of being three-dimensional creatures. If we were four-dimensional (time being the fourth dimension), presumably we could go back to yesterday, or last week, or last year. Just like going back upstairs to your apartment when you realise you’ve forgotten your sunglasses (or hand sanitiser).
So we are not masters of time, despite the existence of some watch companies who have taken on this grandiose appellation. We can’t go about in time as we wish, not even by a single second. All we can do — as we have always done to phenomena that we don’t control — is study it. What do we really understand about these units that govern our lives and impel us inexorably forwards?
Let’s examine the smallest common unit of time, the second. It’s called the second, because it was the second division of an hour into 60 parts. (The first division of an hour into 60 parts is known as the minute.) Why did I use the past tense in that sentence? Isn’t that still the definition of a second?
Not anymore. Not since 53 years ago.
In 1967, the 13th General Conference on Weights and Measures was held in Paris, attended by delegates from member nations of the Convention du Mètre, organised under the collective International Bureau of Weights and Measures (BIPM, Bureau international des poids et mesures). Together, they decided that a second would be defined by an unchangeable physical constant, the vibrations of a caesium atom in a state of rest at 0 degrees Kelvin. This was in contrast with the ancient, and variable, definition of a second, which was derived from a series of mathematical reductions based on the orbit of the Earth around the Sun.
It was an age of science and precision, when knowledge came from the study and analysis of facts. Two years later, Seiko debuted the Astron, the world’s first mass-produced wristwatch utilising a quartz oscillator, precipitating the period we now know as the Quartz Crisis and decimating the mechanical watch industry. Time-jump (metaphorically, because we can’t do so literally) 50 years ahead, and here we are, in a strange reversal of causation, facing global economic and climate instability because science has ceased to be a guiding principle for some among those enacting national economic and fiscal policy.
One of the greater ironies of doing what we do is the realisation that we know so much about watches and so little about time. But every day we learn a little more. About everything.