In his last years, when he was sadly bewildered about many things, my father used to annoy his family by ceaseless sighing about his remembered past: “How has it all gone so quickly? It seems just like a dream”. We should have listened more intelligently because this implies the shrewd point that we have no subjective measure of time except what we infer from our memories of the events that we can recall. Einstein was brilliant at suave deepities1: “Time is what prevents everything from happening at once”. In my father’s elderly memory all the times of his life did happen almost at once because they were logged next to each other, equally accessible, so that he could flip as fast between decades as between days. His dream of an unnervingly accelerated history was a construct of the way his memory worked.
There are many ideas about why time seems to pass quicker as we grow old. I am notorious for having spent most of my working life dully puzzling why our decisions, of any kind, become slower as we age. Because of this, when a much loved teacher and friend reached his 80’s he began to ring me up to tell me that he had solved the problem of why time was passing so quickly in his old age: since he was 20 his reaction times had slowed by 15% and he deduced that this was why things now seemed to happen faster. If I would make the right experiments I might write a more useful paper than those I usually managed ? With experts in Time Perception, Alison and John Wearden I eventually did make some experiments asking volunteers to compare intervals as short as their reaction-times – a second or less,- and found that the older were , on average, just as accurate as the young but had become more variable.2 At least on the scale of a second or less unfilled moments do not seem to grow shorter in old age.
This was not the sharpest way to test my mentor’s hypothesis. In the 1880’s, at the very beginnings of human experimental psychology in Wilhelm Wundt’s laboratory in Leipzig, Muniz asked volunteers to estimate durations of brief intervals when they were empty of events or filled with strings of fast or slow and soft or loud clicks. He found that the faster (or louder) the click stream the longer young adults judged the intervals to be. It seems that we calibrate even very brief periods of time by the number or intensity of events that fill them. We can argue that this is because we cannot directly perceive time. We can only perceive events that occur in time and the order in which they happen. It may be that because older people process information more slowly they register fewer changes and so underestimate durations. Though Alison, John and I found no evidence that this works for very short empty intervals, during which there is little or nothing to perceive it seems plausible that when slightly longer intervals are filled with events age-slowing of our perceptions may cause us to miss some events and time will seem to pass more quickly than it did during the crammed moments of youth.
There are two different kinds of explanations for age-changes in time perception. As we have noticed one is based on changes in how much of what happens to us we can perceive and recall: explanations based on the content and organisation of memory. The other is that some physiological change slows an internal time-keeping system, a “biological clock”. A touching metaphorical illustration of the “failing clock” explanation is Ernst Junger’s 3 description of an antique hour glass that he kept on his writing desk as a memento of a lost friend. As years passed hourglass-time ran faster because the sand moving from the top to the bottom bulb wore and widened the funnel between.
We do seem to have a variety of biological clocks, some timing the cycles of night and day others the wheeling seasons and others brief intervals such as seconds or minutes. Many factors can affect their accuracy. For example brief intervals of seconds seems to pass more slowly when we are cold than when we are warmer 4 . So accuracy at estimating very short periods of time is possibly slowed as the number of events that we can notice declines, and time perception certainly varies with physiological changes. But these explanations do not account for my father’s feeling in his old age that his past and present were accelerating to vanishing point. I think that his feelings depended on how he remembered his past and compared it against his present.
The comparisons he might have made could be of several different kinds. An early 19th Century idea was that we gauge the speed of present time by comparing the numbers and durations of our recent experiences against our entire lifespan up to the present. So, for a child of 10, the past year would be 10% but for my father at 70 only 0.011% of total life experience. William James 5 dismissed this idea as “a description rather than an explanation” but, though I am intimidated that Claudia Hammond 6 agrees with him in her excellent book on time perception, I do not think that they are right. This is because comparing an immediately past interval against an entire lifespan is only one of many plausible comparisons, any and all of which we can make if we choose. James’ seems over-influenced by the fact that he had a rival explanation that he expressed in one of the most elegantly lush paragraphs in any textbook of psychology:
“[When we are young] ….apprehension is vivid, the retentiveness strong, and our recollections of that period , like those of a time spent in rapid and interesting travel, are of something intricate, multitudinous and long drawn-out. But as each passing year converts some of this experience into automatic routine which we hardly note at all, the days and weeks smooth themselves out in recollection to content-less units and the years grow hollow and collapse”.
It might seem that this could not possibly be said better (though I do not recognise, for myself, the “hollow collapse” of “content-less” years of my old age). It certainly could not be expressed more sonorously but I think that Thomas Mann’s novel, “The Magic Mountain”7, a staple of all discussions of the elastic properties of subjective time, says the same thing more clearly. At the top of Mann’s mountain is a tuberculosis asylum that his protagonist visits only to discover that he, himself, has the romantic malady and must become a patient. At the summit he compares the dragging passage of any current day with the speed-blur of remembered past weeks and months and time passes achingly slow because of this contrast, and because of his longing for something, anything at all, to happen. When remembered at the foot of the mountain, the same spell of summit time seems to have been remarkably brief because so few remembered events marked its passage.
Mann’s insights also show why the answers that we get from people will depend on the precise questions that we ask them: for example, how fast do you think that time is, currently, passing? How fast did it pass yesterday? How rapidly did it seem to pass in Warsaw or Shanghai ? During different periods of your life? etc. etc. It is hard to think of any experimental methodology that would give us sensible numbers with which to compare differences in subjective speed of time experienced by younger and older people in any and all life situations. Documenting peoples’ subjective judgements of the speed with which they feel that time passes can tell us whether and under what circumstances and in what times of life they feel that it is passing quicker or slower but gives us little idea by how much old age, or any other life circumstance, distorts their judgements. Perhaps it is only useful to try to put numbers to our experience when we are judging intervals that are so brief that whatever else we can experience and remember during them is irrelevant. When our time judgements depend on our memory of the number and quality and order of events that we have experienced the variety, the importance and the emotional impact of these events can make all the difference and it is dubious how trying to quantify changes in terms of speeding or slowing of clock or calendar time can help us.
It seems to me that when people become disgruntled at the remorseless passing of time they tend to comfort themselves with the idea that because we do not understand “what time is” our present experience of it may be wrong, or very limited. What time “is” in terms of the physics of the cosmos is one thing and how we experience it is quite another. Nevertheless mysteries can be comforting as well as threatening . T.S Eliot 8 echoes the mysticism of High Anglican Christianity :
“Time present and time past
Are both perhaps present in time future,
And time future contained in time past.
If all time is eternally present
All time is unredeemable.”
W.G. Sebald9 is just as satisfyingly mysterious, but without resonance of religious overtones:
……“It seems to me then as if all the moments of our life occupy the same space, as if future events already existed and were only waiting for us to find our way to them at last, just as when we have accepted an invitation we duly arrive in a certain house at a given time.”
Einstein, as usual, found just the aphorism to condense the incomprehensibility of physics when lay-persons’ understanding fails leaving them with a satisfying sense of numinous ignorance:
“Time is an Illusion”
It is precisely because all these and many other similar statements are both authoritative and incomprehensible that they bring old people like myself vague, bewildered comfort. Though we persist in consoling ourselves with this belief, things are not unreal just because we do not understand them. Others, like the eminent physicist Lee Smolen, who understand them better than most of us, derive robust common-sense counter arguments from equally impressive and impenetrable mathematics:
“Time is Real”10
It is obvious why most oldies would like to escape time but, of course, I have found no way to do this. The best dodge that I can offer is that while we cannot ignore its remorseless effects on our bodies and minds and on the world about us we are free to think about time in many different ways and some of these are more comfortable or more amusing than others. Our brains manage our realities by constructing models, or maps of the world in which we live. All of these different kinds of maps are, to some extent, arbitrary, though those that scientists try to draft are at least continually checked against new evidence and for internal consistency. Most of the maps that we build to interpret our everyday experience are much less rigorous than formal scientific theories and some depend on the limitations of the languages that we have to describe things to others and to ourselves. As a very young child learning to communicate in basic Hindi I became upset because the word for yesterday and for tomorrow is the same – kal. To feel that there might be no difference between these opposite directions from the present weakened my vague grasp of causes and effects. I still may not have worked this out. Other cultures, and the languages that they have developed to describe their world views have other quirks, quite different from everyday English. For instance the Navajo are said to have a circular, rather than a linear concept of time with passage marked in terms of the starts, progressions and ends of particular activities rather than by clocks or calendars 11.
Since most of what we know about time is derived by mental orderings of things that happen to us along an invisible dimension I think that we should try to expand our freedom and enlarge our maps of our subjective experiences by expanding the ways in which we think and talk about time. Why discuss time only as an ordering of markers on a dull linear track when we can invent constructions that include the relative probabilities of events along different time paths ? (e.g. for the implausible future “Far left of tomorrow”), or that signal their relative desirability (e.g. for the regrettable past “Way down below Yesterday”) or signal their distance from our present locations both in space and in time (“Miles away from last year”), or their distance and significance in space and time ( “But that was long ago, and in another country and, besides, the wench is dead” 12 ). This will not alter, or improve, our understanding of the reality of time, or help us to decide which physicists have more nearly got it right, but it might substitute amusement for numb awe whenever we catch ourselves, once again, futilely trying to eff the ineffable.
- Daniel Dennett in his 2009 speech to the American Atheists Institution conference, coined by the teenage daughter of one of his friends. The term refers to a statement that is apparently profound but actually asserts a triviality on one level and something meaningless on another. Generally, a deepity has (at least) two meanings: one that is true but trivial, and another that sounds profound, but is essentially false or meaningless and would be “earth-shattering” if true.(see Wikipaedia)
- Wearden, J. H., Wearden, A. J. and Rabbitt, P. M. (1997). Age and IQ effects on stimulus and response timing.Journal of Experimental Psychology: Human Perception and Performance, 23(4), 962–979.
- Junger, E. (1954). Das Sandhurbuch. Frankfurt am Main Springer Verlag
- Baddeley, A. D. (1966). Reduced body temperature and time estimation. American Journal of Psychology, 79, 475–479.
- James, W. (1890) Principles of Psychology. Available Digireads com. 2011.
- Hammond, C. (2013) Time Warped: Unlocking the Mysteries of Time Perception. Edinburgh, Canongate Books.
- Mann, T, (1924) The Magic Mountain English transl published 1927 by Albert Knopf NY.
- Eliot, T. S. (1936) First lines of “Burnt Norton” , in Collected Poems, Faber, London.
- Sebald, W.G. (2001). Austerlitz. C. Hanser (available on Amazon Kindle)
- Smolen, L. (2013). 0-0-0. Time Reborn. available from Amazon inc. digital books for Kindle.
- Charles, M., et al. (2011) Time Perception among Navajo American Indians and its relation to academic success. Paper at the 119th Annual convention of the American Psychological Association, Washington, D.C.
- With apologies to Christopher Marlow “The Jew of Malta”, circa 1590.