What is a long time?

4 min readNov 20, 2021


I wrote this article several years ago, but didn’t publish it until today (Nov, 2021).

Our personal experiences impact what “feels” to us like a long or short time. If we are anticipating some much-desired event, time usually seems to move much more slowly while we are waiting for that event to begin than it does between the start and end of that event. That said, and setting aside the Theory of General Relativity, time actually passes at a uniform rate in our day to day lives.

We measure time in days, the amount of time it takes planet Earth to rotate on its axis, years, the time it takes planet Earth to circumnavigate the sun, other physical phenomena, and fractions and multiples of those units. Another unit that influences our comprehension of time, but one we seldom use to measure time is our own lifespan. The average modern human lifespan is about 80 years. Any span of time that is much more than a lifetime is difficult for us to fully comprehend because it is beyond the context of our personal experiences.

The following are some historical milestones presented graphically in order to compare them to a single Human Lifespan (HLS). Each bar shows an ever longer timespan with the preceding timespan(s) sown to scale.

Average Contemporary Human Lifespan 80 years (1.0 HLS)
About 300 years since the beginning of the Industrial Revolution (3.75 HLS)
The Birth of Christ was about 2000 years ago (25 HLS)
First Agriculture was about 9,500 BC at the beginning of the Holocene Era (144 HLS)
The emergence of the species Homo Sapiens 200,000 years ago (2,500 HLS)

Notice that a single human life span is no longer a large enough portion of the Homo Sapiens diagram to be visible at this scale over the span of time since the first humans emerged. It took a very long time before the descendants of those first humans began farming, about 10,000 generations.

Here’s some more…

Hominids, first non-human ancestors, about 6 million years ago (75,000 HLS)
Mammals get their chance when non-avian dinosaurs go extinct 66 million years ago (825,000 HLS)
Dinosaurs emerge about 230 million years ago (2,875,000 HLS)
Multi-cellular Life begins about 600 million years ago (7,500,000 HLS)

Okay… That’s enough… I’m sure you get the idea… We humans have been around as a species for only a very brief period of time compared to the history of life on planet Earth, and individually for an even tinier fraction of that time.

Multi-cellular life - 600,000,000 years = 7,500,000 Human Lifespans
Human Species - 200,000 years = 2,500 Human Lifespans
Industrial Revolution - 300 years = 3.75 Human Lifespans

Looking again at the time span from the beginning of the industrial revolution until now.

The last 300 Years

You can see things are changing much more rapidly these days than they have in the past.

Humans are very creative. Among other things, we create tools. Tools that give us advantages. They bring us comfort and security… that improves our individual survivability, and subsequently the survivability of our species. The earliest tools were simple, but they may have made the difference between survival and extinction. Those tools gave us the means to make other more sophisticated and more helpful tools. Each generation of tools improved our situation a little more than the previous generation and sets us on a course to create even better things. Eventually, our situation improved enough so we could devote time to things other than basic survival. Our curiosity led us to use that time for investigation and exploration. The knowledge gained thereby helped us produce more and better tools… and so on and so on.

We call this progression of tool development “technology.” Technology improves our individual survivability, and subsequently the survivability of our species. That certainly was true for many millennia, but today the rate and extent of change is so great, and comes with initially unforeseen problems, that now these technological changes are actually threatening the survivability of our species… and all the other species with whom we share this incredibly rare planet.




On the internet they can’t tell that you’re actually a dog…