DURING THE early months of the pandemic lockdown , many people remarked on how strange their experience of time was . Weeks seemed to fly by — Is it Friday , again ?— and yet many moments dragged on slowly .
To researchers who study time , none of this is too surprising . Judgments about durations of time we remember are affected by almost every variable , including lack of salient stimuli , boredom , and our particular mood . Think of each event throughout your day as a tick of an internal clock . If you were lucky enough to not be affected directly by COVID-19 and your daily routine shifted to the virtual realm , one Zoom call likely blended into another and retrospectively the week zipped by because memory didn ’ t encode many ticks , but in the moment , the monotony made time crawl .
This common experience is just one example of the difference between what I call “ manifest time ” and “ physical time .” Manifest time is the model of time we use as we navigate through life — our common-sense picture of time drawn from experience . Physical time is the model of time that physics uses to understand the world . Whether the week flew by for you or not , the Earth still spun on its axis seven times .
As many such temporal illusions demonstrate , these two models can come apart perceptually . Have you ever noticed that when you look at the second hand of a clock , it seems to freeze just as you focus on it ? This is an example of the illusion known as chronostasis . The hand does not freeze , of course , but we experience it this way in order to save us from seeing the blur induced by quick eye movement .
The divide between manifest time and physical time gets very deep . Physics doesn ’ t characterize time as having a special present moment in it , yet this “ now ” is crucial to manifest time — it ’ s what seems to be really happening , after all , and what divides the world into a settled past and open future . Physics describes matter in motion , tracing particles through time ; its models don ’ t require a special , flowing “ You Are Here ” red dot , as found on a map . But all of human life is organized around these little red dots ! Our thought , language and behavior is arranged around this flowing-time structure .
Physicists and philosophers of science like me typically dismiss this difference as another illusion , the illusion of flowing time . But about 15 years ago I noticed something funny : no one explains this illusion , which I found both odd and unsatisfactory . If it is just an illusion , here we have one of the biggest and most important illusions around — affecting almost all human beings and arguably many animals — and no one really explains it . Chronostasis gets an explanation . Why shouldn ‘ t one of the most basic features of human life ?
Good philosophy can often take a hard question and transform it into a scientific one . Philosophical thought about intelligence and computability , for instance , led to advances in artificial intelligence and data science . Can we do something similar for manifest time ? Can we break it down , really understand it , and explain why critters like us would model time the way we do ?
That ’ s what my work does . Albert Einstein worried that the “ experience of the Now ” might not be explainable by science . That was because he was stuck using only physics . To explain an illusion , however , we also need the sciences that describe how human beings work , such as biology and cognitive science . Just as a boring week flying by turns out to be a natural by-product of our memory-based timing system , manifest time in my theory emerges as a natural reaction to the many cognitive and evolutionary challenges that we face . If I ’ m right , Einstein needn ’ t have worried .
So throughout the course of this pandemic , should you find yourself in a boring moment that drags on or at the end of another week that flew by , consider the factors that may have affected that experience . You might find it an appealing way to spend some of that time after all .
Craig Callender is a professor in the UC San Diego Department of Philosophy and co-director of the Institute for Practical Ethics , in the Division of Arts and Humanities . His 2017 book , What Makes Time Special ?, won the Lakatos Award , given annually for outstanding contributions to the philosophy of science .