Have you looked at life displayed on a postcard?
How many methods are there to measure time? Let us count the ways.
Time it takes for the Earth to rotate once around its axis. A day.
Time it takes for the moon to go around the Earth. A month.
Time it takes for the Earth to go around the sun. A year.
Or if one wants to get esoteric, and precise, then the span over which 9,192,631,770 transitions between two hyperfine levels of the ground state of the Cesium-133 atom occurs is the standard for a second. Go figure, whatever that means. Understanding that will take too many hours of my time!
Somewhere along the trajectory of human civilization a day got divided into twenty-four hours, an hour into 60 minutes, a minute into 60 seconds. These numbers seem arbitrary as they are not related to (periodic) movement of celestial bodies which are a natural way to measure time.
A little help from Bing tells that the origin of 24 hours in a day, or 60 seconds in an hour came from Babylonians and Egyptians.
The Babylonians, around 2,000 BCE, used a base-60 numbering system known as the sexagesimal system, which probably is the origin of dividing an hour into 60 minutes.
The ancient Egyptians are credited to the division of the day into 24 hours. They used sundials and water clocks (clepsydra) to track the passage of time. The day was divided into ten hours of daylight and ten hours of night, with two twilight hours added at the beginning and end of the day.
Slowly, the 24-hour day became more standardized and widely adopted in the Roman period and has persisted and remains the standard for measuring time in many cultures around the world.
Then there are various notions of time that depend on disciplines of knowledge — Geological time (eons, eras, periods, epochs); Biological time (lifespans of organisms, growth rates, heart beat per second, circadian rhythms, evolutionary time); Economic measures of time (financial years, quarters) Climate measures of time (solar cycle, oscillations in climate data on years, decades, centuries, or even millennia).
Among all the ways to either measure or conceptualize time, time also has the weirdness of being a subjective experience and varies from person-to-person and also varies within one’s life. Our perception of the passage of time, and how we process and remember events, is truly a mind warping experience.
Time can drag on when bored or anxious; it flies when engaged in enjoyable activities. One can also get into the flow and lose the notion of time altogether.
This subjective time dilation or contraction can make it seem as though time does not always flow at a consistent rate. Sometimes it goes bananas!
There is also a feeling that time seems to pass more quickly and goes through “time compression” as we get older. When we’re young, a year might represent a larger portion of life we had, making it seem longer. As we get older, each year becomes a smaller percentage of our total life, leading to the perception that time is passing more quickly.
Exponential changes in technology and cultural shifts have also contributed to a perception of time passing quickly. The increasing flow of information and the increasing pace of modern life may also create the impression that time is moving faster.
All these examples point to an often distorted perception of time. One weird distortion is that month seems to fly by (and before you know, it is time to pay bills again) while a year seems quite long.
At other times, a year seems to go in a hurry, and yet, years of childhood seem to be eons away. Trying to imagine ourselves 50-years agomight as well be trying to peek before the Big Bang.
One of the most bizarre aspects of time is that if one counts life in number of years vs. number of days, and two create a different impressions for how long we are going to live. Living 80 years feels like an adequate life span but living for 29,200 days, ummm, not so much.
I guess measuring life in the number of days is a weird concept. We do not go around saying that an acquaintance is 32,850 days old now.
For that matter, looking at the lifespan in the number of weeks all laid out on a page just feels creepy. An entire life laid out on a half sheet of paper; that is all we have to live?
Now that I am older, there is also a tendency to begin to look at life based on different measures. Being in the middle of my sixties, a thought comes that I would perhaps see our son 20–30 more times and that becomes an awfully small measure of time and also a depressing and disconcerting thought.
On the same lines, perhaps I will see my sister in India five more times or less. The measure of life becomes even smaller.
Measuring time in how few instances you have left to repeat something makes the heart skip a few beats.
It also makes you realize how short our remaining existence could be.
So yes, there are many objective and subjective ways to measure time and within those options certain ways of perceiving time make us look at our existence through a different set of glasses.
Some of those glasses have a way of magnifying mortality.