By Adam Bakewell, Co-host of Generic Drift
The passage of time can be a curious thing. Though the clock ticks away marking second after uniform second, organising into uniform hours and 24-hour days, time (or at least how we perceive the passage of time) can seem anything but steady. One of the more common observations among humans on the passage of time is that it seems to speed up the older we get.
Time doesn’t go faster as we get older, rather we notice more slowly that time is passing.
My nan assured me of this as a child, and though I have a shorter frame of reference than her, the older I get the more apparent it becomes. My five years in high school seemed to last much longer than the nine that I’ve been at university (I know, only one to go!). The six-weeks summer holiday from school seemed to last forever as children, yet those same six-weeks fly by for their teachers. Why?
The answer, according to a theory published by Adrian Bejan in European Review, is to do with the physics-rooted basis of how humans perceive the passage of time.
Physical time, that represented by clocks, is not the same as “mind time”. Time is the domain where changes in the physical world are perceived to happen. Our minds sense (or perhaps, construct a version of) reality as images funnelled into the cortex of our brains; and when those images change we experience it as the passage of time.
While the clock ticks on steadily, the way that we record mental images changes over time: younger minds receive more images during a day than older minds. Since each period of clock time stays constant, but we have more images reconstructing that period when younger, this leads to the illusion that time itself speeds up. Time doesn’t go faster as we get older, rather we notice more slowly that time is passing.
Several physical features of ageing cause the rate at which we accumulate and process mental images to slow. The tangled webs of nerves and neurons grow in size and complexity as we age, meaning each signal has a longer path to tread. These networks degrade as they age, meaning that there is more resistance slowing the flow of electrical signals. Children even move their eyes more than adults (they have a higher saccade frequency to give it the fancy scientific term), acquiring and integrating more information in a shorter time.
But this is only scratching the surface. Why, even as adults, do some days feel so much slower than others? How can an hour long meeting seem to drag on forever, but an hour long lunch break zip by without a trace?
Bejan suggests that ‘slow’ days are full of memories of what happened, events and productivity. These slow, productive, days happen when the body and mind are rested after periods of regular sleep. According to Bejan athletes know this well (and being a former member of the Romanian national basketball team he might know); lack of sleep makes anticipating and reacting to a game much harder. Students, staying up all night to cram before an exam, might be giving themselves less time (that is, less perceived time) compared to those who got an early night instead. The rested mind is better at processing information, and so has ‘more time’ to work on the problems, spot mistakes, or scratch out the whole page and start again. Our behaviours now, and in the past, can distort our experience of time in the future.
Some scientists believe that social media is one of the primary causes of time distortion in young people. It can be easy to “waste” minutes or even hours scrolling through pictures on Facebook, watching videos on YouTube, or lurking on Reddit. We’re only just starting to appreciate in a formal scientific sense the effects that this can have on how we perceive the world offline.
More studies are needed to properly quantify this phenomena, to see if gen-Zs and millennials really are altering their experience of time itself – because time distortion can have serious consequences: from sleep deprivation and mood changes to mental disorders.
Bejan, A., 2019. Why the days seem shorter as we get older. European Review 27 1-8.
Turel, O., D. Brevers, & A. Bechara, 2018. Time distortion when users at-risk for social media addiction engage in non-social media tasks. Journal of Psychiatric Research 97 84-88