1980 was 20 years ago, prove me wrong – perception of time

We’ve all likely seen this meme in one form or another: 1980 was 20 years ago. When I first saw it, I could not stop myself from laughing because it spoke the truth. This statement felt universal and just about everyone I knew could relate to it. However, I wondered why. What made this something fixed in reality? Did it have to do with the fact that too many people forgot Y2K and still for no good reason use 2-digit years, allowing the roll-over of the century to confuse them, or are other forces at play?

As a person who lived through Y2K in the IT sector (the end of days for those who don’t remember them) I use a 4-digit years almost exclusively (and in ISO format to boot). So that didn’t seem like the most likely reason my perception had distortion. It must be aliens. What other explanation could exist for such a universal shared delusion?

Okay, aliens is a big stretch (though the movie is only 20 years old).

If not aliens, what?

So what has messed with everyone’s perception of time? I am fond of saying “Reality and its perception seldom converge, and perception always beats reality.” Objectively, 1980 (excluding the 20,000 years that was 2020) is just over 40 years ago—apologies to the old people, my own sense of self struggled to read what I have just typed—but factually the earth has flown 41 orbits around the sun in that time. Strangely, it feels better saying it in that fashion. Perhaps I should only describe my age as rotations around the big nuclear fusion reactor in the sky. I can see your eye rolls, but that won’t stop me.

It’s math, you need calculus

Anyway, the reality of our perception of the world is governed by math and a slight change in a small quantity of something generates a greater change in our perception than that same change in a larger quantity of the same thing. This observation is called Weber’s Law, or Weber-Fechner’s Law, started with the observation of differentiating between weights and then expanded to other perceptions.

Weber's Law

This ratio means that as time passes and more and more years —revolutions around the sun—build up between our birth and the current day, the perception of a single day, or year, becomes smaller and less noticeable. The relative speed the earth moves has not changed appreciably, but our ability to perceive the change has. This impact to our perception applies to many things in the physical world as well as concepts such as finance and time. The law has gaps and fails to accurately model extreme conditions, but it generally reflects the logarithmic function of our  human perception. Any time you try to apply math to human psychology, the best you get is an approximation. However, the human behaviors described by the law show up in many places one might not expect.

More information

Ernst Heinrich Weber lived from 1795 to 1878, and his student Gustav Theodor Fechner lived from 1801 to 1887. 

Watch the 2018 video below to learn more (because Numberphile).