Throughout history our clocks and watches have really been our best guess of what time it really ought to be. Throughout the ages, we’ve just been getting more accurate with our means of estimation. In China, around the year 960 to 1279 you could tell the time by following your nose.
They used incense, which is basically a slow burning scented match. If the manufacturer could reliably produce a stick that would, for example, take four hours to burn knowing the burn would be at a consistent pace means it could be used to tell time. By changing the chemicals used along the length of the stick they could change the smell once an hour, or change the colour of smoke. “Oh, (sniff) lavender… must be three o’ clock.”
If they had a series of weights strung up above the incense, the strings would burn as the fire passed by, the weights would drop and hit a gong to chime the hour.
Clocks are less smelly now, and pretty much all watches and wall clocks have a quartz movement since their invention around 1970. That means it’s using quartz to accurately measure time, because unlike burning incense, quartz is reliably consistent. We know that a quartz crystal, when given a small electric shock from a battery, will vibrate precisely 32,768 times per second. With a electronic device to count these vibrations, and then send out a pulse every 32,768 counts (every second), your watch stays true to the time all year long.
Our super-official clocks take it one step further, and rather than using the vibrations of a crystal which could get dirty, or have electrical problems, they count the movement in a single atom. Specifically they track the changes in energy levels in the atoms which is reliably consistent to a tiny degree… like, umm, clockwork! These clocks are immune to power outages, and keep better time than the solar system itself. So how much longer before daylight savings time means we actually shoot rockets to physically move the sun?
Side note: today’s the day to change your clocks back an hour, and/or temporarily extinguish your incense.
- Source: How does time work? – National Assoc. of Watch & Clock Collectors
